Rolling-contact bearing type clutch

Abstract: A one-way clutch comprises rollers (3) inclined to the axis of rotation (6) in line contact with both inner and outer contact surfaces (1a)(2a) at least one of which is a mono-hyperkoloid, there being axial biasing means (7). The rollers may be cylindrical (Fig.1), conical (Fig.6), hourglass-shaped (Fig.7) or barrel shaped (Fig. 8).

Description: The present invention relates to a one-way roller clutch. In one-way clutches according to the prior art, for example as shown in Fig. 14 of the accompanying drawings, cylindrical rollers 3 are arranged in the raceway between outer and inner rings 1 and 2; the inner raceway surface of the outer ring 2 is formed into saw-like cams to bring the inner and outer rings 1 and 2 into clutch condition by the cylindrical rollers 3 engaged with the cam surface 2c on the outer ring 2. Other one-way clutches are known, wherein both raceway surfaces of the inner and outer rings are cylindrical, and cam-like sprags are arranged between the inner and outer rings in place of the cylindrical rollers of the above example, to have each sprag engaged with the raceway surfaces in reverse rotation by spring force. With the above described clutches according to the prior art, in the torque transmitting condition of the clutch the rollers 3 are fixedly engaged with cam-like inner surface portions 2c of the outer ring 2 which are not circular or uneven in the radial direction, while in the free rotation condition the rollers 3 are freely sliding. However, since the thrust angle must be smaller than the friction angle, formation of a cam within the pitch P of the sprag rollers 3 would restrict the cam height, thus causing a possibility of rollers 3 overriding cam portions 2c and damaging the clutch. To solve these problems, a one-way clutch is known (JP-A2-1983-52092), wherein rollers or sprags are disposed slantly to the raceway path between the inner and outer rings having a shape of conical roller bearing, and both the rings can be freely rotated in one direction while they are positively connected in the other direction of rotation. Because the inner and outer rings of the known one-way clutch both have conical surfaces, the rollers may be brought into line contact with either the inner raceway surface or the outer raceway surface, but not with both at the same time, thus causing unstable rotation of the rollers, resulting in an extremely high surface pressure of the contact portions which fail to be in line contact. Furthermore, there are known other one-way clutches of similar type (DE-A-1 915 516, EP-A-0 190 017, EP-A-0 312 656), which are engaged only by axial forces of rotating intermediate rollers moving the inner or outer ring to narrow their raceway space. With these clutches immediate clutching action is not attained when the clutch rotation is reversed from free running condition to clutch engaging condition. Moreover, clutches of this kind have an annular member which prevents an axial movement of the rollers when the clutch is going to its engaging condition. This annular member limits the moving force which acts on the inner or outer ring to narrow the raceway width. It is therefore an object of the invention to provide one-way roller type clutches of the kind described, which not only have smooth free rotation taking advantage of rolling-contact bearing, but will be fast operating when the rotation of the driving clutch part is reversed from free running into coupling condition of the clutch. This object is achieved by the features of claim 1. Owing to these features, the forcing means are always acting to narrow the width of the raceway. To attain the free running condition of the clutch the movement of the intermediate rotating bodies leads to widening the raceway against said narrowing action of the forcing means thereby assuring the free rotation of the clutch parts. When the rotation is reversed to change the clutch operation from free running into engaged condition, said widening effect of the intermediate rotating bodies does not exist and the width of the raceway is narrowed under the action of the forcing means, whereby zero clearance is immediately attained. The width of the raceway is furthermore narrowed owing to the engaging condition, which results in achieving a reliable operation of the clutch. When the direction of rotation is reversed to attain the free running condition of the clutch, the relative axial movement between the intermediate rotating bodies and the inner or outer rotating clutch part is limited by the annular member which then prevents the rollers from being disengaged from the raceway. Further features of the invention are claimed in the dependent claims. The one-way roller type clutches according to the invention have a simple configuration, an enhanced performance in the free running position, and are easy for application to input/output systems, especially to such systems where axial displacement of the parts is not allowed. The line contact of the intermediate rotating bodies with the inner and outer raceway surfaces will provide a uniform load distribution and an excellent rolling in the free running position of the clutch while a sufficient coupling force is achieved due to the jamming effect of the intermediate rotating bodies in the coupled position of the clutch. An automatic alignment force applied to the intermediate rotating bodies can ensure a uniform load distribution in various conditions of the clutch such as deformation, wear and variations of dimensional accuracy. As a result, the clutches according to the invention can tolerate a large rated load, have a long service life and ensure a stable operation with smooth free rotation. Further, the clutches function as bearings, thus eliminating the need for additional bearings on the shaft. The driving shaft or the mechanical element, such as a gear member, can be used as the inner or outer rotating clutch part. Thereby the configuration of a system including the one-way roller clutch can be simplified, thus achieving low cost and a wide application. Each of the intermediate rotating bodies may be divided into two or more body parts in the center axis direction. With this feature, an excellent jamming of the intermediate rotating bodies in the fixed raceway is obtained and the rolling resistance is reduced, thus enhancing the performance in the free running condition. If an input/output rotating body is provided to transmit a torque, said body may be located at one face of the outer rotating body and at the same face of the inner rotating body mounted at a predetermined position axially spaced from the inner rotating body so as to freely rotate relatively to the inner rotating body via a bearing. Said input/output body is connected to the outer rotating body through torque transmission means for transmitting the torque to the outer rotating body, and the forcing means is provided between the input/output rotating body and the outer rotating body to force the outer rotating body in axial direction and to narrow the distance between the raceway surfaces. The reverse configuration may be chosen, i. e. the input/output rotating body is located at one face of the inner rotating body and mounted at a predetermined axial position axially spaced from the outer rotating body so as to freely rotate relatively to the outer rotating body via the bearing, and is connected to the inner rotating body through the torque transmission means for transmitting the torque to the inner rotating body. The forcing means is then provided between the input/output rotating body and the inner rotating body to force the inner rotating body in axial direction and to narrow the distance between the raceway surfaces. With these arrangements, the input side and the output side of the input/output rotating body can be connected without displacement in the axial direction. As a result, even if an axial displacement of the input/output sides is not allowed, these rolling-contact bearing type clutches can be used, thus enhancing their versatility. In the accompanying drawings, there are shown illustrative embodiments of the invention from which these and other of its objectives, novel features and advantages will be readily apparent. In the drawings: Fig. 1 is a perspective view showing a rolling-contact bearing type clutch according to the present invention; Fig. 2 is a perspective view showing the rollers and internal parts of the embodiment in Fig. 1; Figs. 3 to 5 are explanatory drawings to determine the raceway surface shapes; Figs. 6 to 8 are perspective views showing other embodiments; Figs. 9 and 10 are explanatory drawings to determine the raceway surface shapes; Figs. 11 to 13 are sectional views showing other embodiments; and Fig. 14 is a perspective view showing a one-way clutch according to the prior art. Fig. 1 is a view showing a rolling-contact bearing type clutch according to the present invention, and Fig. 2 is a perspective view showing the rollers and internal parts of the embodiment in Fig. 1: An inner ring 1 corresponding to the inner rotation body in the previous description is mounted on a shaft 4 movably by a key engagement 5. An outer ring 2 corresponding to the other rotation body is disposed facing the inner ring 1 to form a combination of raceways 9. A plurality of rollers 3 corresponding to the intermediate rotation body are, as shown in Fig. 2, disposed between the raceways 9 slanting to a plane including a center shaft 6 (axis line) of the inner ring 1 at angle of β (e.g., 15 degree). The inner ring 1 is pushed by the outer ring 2 via a combination of a plate spring 7 and a spring retainer ring 8 corresponding to the energizing means, to a direction to narrow the space of the raceways 9 (from right to left in the drawing). A flange 10 corresponding to the ring member which brings the movement of the rollers 3 in the axial direction to widen the distance of the raceways 9 to a stop is formed on the inner ring 1 at the end thereof. As configured above, in the free rotation condition (clockwise or right rotation of the shaft 4 and the inner ring 1 viewing from the right end side in the drawing), the rollers 3 will rotate to the left to advance the inner ring 1 to the right direction against an energizing force of the plate spring 7 while guided by the outer ring raceway surface 2a to enlarge the space of the raceways 9. In other words, an action of tapered screw will be produced between the inner and outer rings 1 and 2 via the rollers 3. The action will cause a right direction advancement of the inner ring 1 relative to the outer ring 2 based on the principle of the screw advancement to enlarge the space of the raceways 9. As a result, the inner ring 1 can be freely rotated without causing a wedge action of the rollers 3 between the raceways 9. It should be noted that the flange 10 is disposed at the end of the inner ring 1 to prevent the rollers 3 from advancing the inner ring 1 too far in the right direction and from disengaging from the inner ring 1 in the left direction. On the other hand, in the reverse rotation condition (the shaft 4 rotates counterclockwise viewing from right) the movement of the components will be contrary to the above description: the rollers 3 will rotate to the right not to advance but to retreat the inner ring 1 to the left direction. The compression force of the plate spring 7 will move the inner ring 1 to the left relative to the outer ring 2 to narrow the space of the raceways 9. The action will cause the rollers 3 to be locked between the raceways 9 to produce a wedge effect. As a result, the inner ring 1 and the outer ring 2 can be clutched as soon as the shaft 1 starts the reversal rotation. In this condition, the pushing portion 2b at the right end side of the outer ring 2 may be connected to the outer ring 2 itself, and further two pieces of the rolling-contact bearing type clutches may be arranged facing each other to make two or more rows. In the embodiment in Fig. 1, the inner ring 1 is movable in the axial direction, but not the inner ring 1 but the outer ring 2 may be movable. Further, a thrust bearing mounted in place of the spring retainer ring 8 portion can have a further enhanced free rotation. In Fig. 2, rollers 3 are arranged on the inner ring 1 slanting to a section including the axis 6 thereof by an angle of β, and the rollers 3 is retained in place by a retainer 11 to keep off each another. This configuration can prevent adjacent rollers 3 rotating in a same direction from running against each other with a relative tangential speed in an opposite direction, resulting in a smooth rotation of the rollers 3 and a smooth revolution thereof around the inner ring 1. Now, the shapes of the inner and outer raceway surfaces 1a and 2a required for a line contact of the rollers 3 with the inner and outer rings 1 and 2 will be described: Figs. 3 to 5 are explanatory drawings to determine the raceway surface shapes in a case of cylindrical rollers 3; Fig. 3 is a perspective view of X-Y-Z coordinates, in which a roller 3 is so placed that the axis 3a passes through the Y axis a distance F away from the origin 0, parallel to the X-Z plane, slanting to the X-Y plane at an angle β. The X axis represents the common axis 6 of the inner and outer rings 1 and 2. The section 3b of the roller 3 shows a section of the roller 3 cut by a parallel plane to the X-Z plane passing the X axis at an arbitrary position x. Points Uc and U′c are respectively intersections with the X axis and the X-Z plane of the perpendiculars from the center Pc of the cross section to the X axis and the X-Z plane. The line 3a′ passing the origin 0 and the point U′c is a projected line of the roller axis 3a to the X-Z plane, forming an angle β with the X axis. Apparently referring to Fig.3, U c U′ c = x tan β P c U′ c = F Therefore, designating a distance from the rotation axis 6 of the rings (i.e., X axis) to the center Pc of the roller 3 as PcUc = yc , y c² = F² + (x tan β)² Accordingly, y c² / F² - x² / (F/tan β)² = 1 Since the equation (1) shows a hyperbola, the axis line of the roller 3, that is, the center line of the raceway formed with the inner and outer rings 1 and 2 is hyperbolic with respect to the rotation axis 6 of the rings. Fig. 4 is a drawing explaining how the rings 1 and 2 come into contact with the roller 3 arranged as above. Designate as Q an intersection of the X axis with a plane which passes the center Pc of the roller 3 at right angle with the axis 3a of the roller 3. Considering spheres Si and So (So in Fig. 4) having the same center of Q which are respectively inscribed and circumscribed to the roller 3, contact points Pi and Po of the roller 3 with the spheres Si and So would be on a perpendicular QPc , respectively the radius r of the roller 3 apart from point Pc. Therefore, designating QPc as R, the radii of the spheres Si and So are respectively (R-r) and (R+r). Designating as Ui and Uo the intersections of planes passing the points Pi and Po and parallel to the Y-Z planes with the X axis (see Fig. 5), PiUi and PoUo are respectively distances from the points Pi and Po to the X axis, and distances OUi and OUo from the origin point 0 are respectively the X axis coordinates of the points Pi and Po. Therefore, designating OUi , OUo , PiUi and PoUo as xi, xo, yi and yo, functions F (xi, yi) and F (xo, yo) represent the curved surface shape of the raceways 1a and 2a of the inner and outer rings. Fig. 5 is an enlarged view showing related portions to determine these relation. Since QPc (equal to R) is at right angle with the center axis 3a of the roller 3, and the point U′c is an intersection of a perpendicular from the point Pc to the X-Z plane therewith, U′cQ is at right angle with the axis 3a′. Therefore, O Q = (x / cos β ) / cos β = x / cos² β R² = F² + {(x / cos² β ) sin β}² = F² + x² tan² β / cos² β Then, designating an angle < QPcUc as  , since ΔQPcUc is a right triangle, On the other hand, PcPi and PcPo equal r, and ΔQPiUi and ΔQPoUo are similar to ΔQPcUc, And, from the above equations, F (xi, yi) and F (xo, yo) are introduced as follows: These equations express only that the inner and outer ring raceways 1a and 2a has shapes of quadratic curved surface. Obtaining ratios of xi-x/yi-yc and xo-x/yo-yc, from equations (2) to (5), Since the relation of x and yc is hyperbolic from the equation (1), and tan²β in the above equation is constant, the relation of xi and yi, and xo and yo is hyperbolic. As a result, the inner and outer raceways 1a and 2a are mono-hyperboloids of revolution about the common center axis 6. For example, assuming yi² / ai² - xi² / bi² = 1 yo² / ao² - xo² / bo² = 1 and F = 9, r = 1.5, β = 15 degree, ai, bi, ao and bo are respectively calculated to be approximately 7.5, 30.7, 10.5 and 36.2, thus giving inner and outer raceway surfaces numerically as mono-hyperboloids. Fig. 6 shows an embodiment wherein the cylindrical shape of the roller 3 in Fig. 1 is replaced with a conical shape. Since the generating line of a conical roller is a straight line, the inner and outer raceway surfaces become mono-hyperboloids of revolution similar to those of cylindrical roller. Conical roller-contact bearing type clutches may have similar constructions and functions to those of the cylindrical ones, but the conical one can have a further enhanced rolling. The conical type embodiment shown in Fig. 6 has a flange 10 at the end of the inner ring 1 to prevent the inner ring 1 from moving out of the inner ring 1 in the axial direction. But, since the conical shape of the roller 3 can generate a wedge action only by a slight movement of the roller 3, the flange 10 may be eliminated when the inner ring 1 is fixed on the shaft in the axial direction. Such conical rolling-contact bearing type clutches may be used in two or more rows. Figs. 7 to 8 are perspective views showing other embodiments having a cylindrical inner or outer ring raceway surface: The basic construction and functions of these embodiment are similar to those of the embodiment shown in Fig. 1, thus omitting description of the common features. Since the embodiments shown in Figs. 7 and 8 have rollers 3 of hourglass or convex drum shape with sectional areas extended from one end to the other end, even if the inner ring 1 (in Fig. 7, the shaft 4 also serves as the inner ring) and the outer ring 2 do not move in the axial direction, the rollers 3 will advance to right (when the rollers 3 rotate clockwise viewing from the right in the drawing) or retreat to the lfet due to the rotation of the inner and outer rings 1 and 2, thus providing a free rotation, or clutch action due to the wedge action generated by the rollers 3. In this case, since the convexed surface of the roller 3 comes into contact with the convexed surface of the inner ring raceway 13, and with the concaved inner surface of the outer ring raceway 2a, the surface pressure on the inner ring 1 is higher than the outer ring 2, which produces a larger frictional force, thus causing the roller 3 to be rolled with the inner ring 1 and slided on the raceway 2a of the outer ring 2 to the axial direction. As a result, when the inner ring 1 rotates clockwise viewing from the right, the roller 3 is rotated to the left (retreat), while slipping with respect to the outer ring 2 in the axial direction along the inner ring raceway surface 1a (4a). At the same time, the roller 3 is pressed by the force of the plate spring 7, thus causing the roller 3 to be wedged between the inner and outer raceway surfaces 1a and 2a, thereby placing the inner and outer rings 1 and 2 into clutch condition by the wedge action of the roller 3. Therefore, this embodiment can eliminate the need for a member (flange 10 in Fig.1) which brings the axial movement of the roller 3 in this direction to a halt. On the other hand, in the reverse rotation (when the inner ring 1 or the shaft 4 rotates counterclockwise viewing from the right side), the rollers 3 can freely advance without causing wedge action, thus providing a free rotation of the inner and outer rings. In this case to bring the advancement of the roller 3 to a stop, a guide ring 12 is provided to guide the rolling. Such a rolling-contact bearing type clutch as having a cylindrical inner or outer ring raceway surface can directly use the inner ring for the shaft, or the outer ring for a mechanical element such as gear, pulley and flywheel which needs clutch function and whose inner surface can be used, or a hollow shaft, thus achieving a simplified construction and a low cost as well as an easy installation and a wider application as a clutch. The inner and outer rings of the type of clutch does not move in their axial direction, thus making the design of a driving system easier. It should be noted that the type of clutch may also be designed to have a similar configuration to the one of the embodiment shown in Fig. 1 in which the inner and outer rings can be moved. In this case, in the free rotation or the clutch condition, the function of the inner and outer rings as tapered screw via the rollers can be also used. Further, such roller-contact bearing type clutches as described above may be used in two or more rows. Now, the shapes of the roller 3 and the outer raceway surface for the cylindrical inner ring raceway surface 1a will be described: Fig. 9 is an explanatory drawing to determine the outer ring raceway surface shape, and (A) is a front view, (B) a plan view, (C) a side view and (D) is a side view viewing from oblique direction ; To have a roller 3 slanted at an angle of β in line contact with the inner ring raceway surface, the line of contact must be an intersecting line on the outer surface of the inner ring 1 when the inner ring 1 is cut by a plane slanted at the angle of β from the plane including the axis 6 of the inner ring 1, and the shape of the line is a part of an ellipse. Therefore, the surface shape of the roller 3 becomes like a hourglass which is formed by a rotation of a partial ellipse directing the outside. Designating the radius of the inner ring as R, the minor axis length of the ellipse is R and the major is R / sin β . When the ellipse is drawn in the front view (A), the major axis length becomes (R / sin β ) · cos β = R / tan β Therefore, the equation of the ellipse is expressed as follows, placing the center to the origin point; v²/ R² + x² tan² β/ R² = 1 But, the x and y do not directly express the points on the outer ring raceway surface 2a, but the slant angle β of the roller 3 must be considered (compensated) as in the case with the cylindrical roller. Designating the distance between the center line of the ellipse Q drawn at the upper surface of the roller 3 and the shaft line 6 as F, and a compensated value of the center line of the ellipse Q for the slant angle β as u, from Fig. 9 (C), the following equation (7) is introduced; u² = F² + (x tan β)² In short, the relation of u and x is hyperbolic. The equation (7) with respect of u corresponds to the equation (1) for the cylindrical roller. Therefore, as in the case with the cylindrical roller, a compensation must be made. When an equation which is compensated for u is designated as u′, the equation u′ is also hyperbolic as described for the cylindrical roller. Therefore, the shape of the outer ring raceway surface 2a becomes the following, when expressed by a distance yo from the axis line 6; yo = u′ - v The equation (6) expresses an equation for an ellipse Q, same as the ellipse P on the axis line 6. Therefore, from the equation (8), the shape of the outer ring raceway surface 2a becomes a rotation surface about the center axis 6 of a combined curve of hyperbolic y coordinate u′ and ellipsoidal y coordinate v, that is, a combined surface of a mono-hyperboloid of revolution and an ellipsoid of revolution. Fig. 10 is an explanatory drawing to determine the inner ring raceway surface shape; In this case, the inner ring raceway (1a) shape can be determined also in the similar manner to the above described. Thus, the surface shape of the roller 3 becomes a convex drum formed by a revolution of a partial ellipse. The shape of the inner ring raceway surface 1a can be expressed by the following equations: v²/R² + x² tan² β / R² = 1 u² = F² + (x tan β)² The equation u′ is introduced by compensating the equation u as described above, as follows: yi = u′ - v The inner ring raceway surface 1a is a revolution of a combined curve of hyperboloid and ellipse. The embodiments shown in Fig. 1 and Figs. 6 to 8 all has a one-piece roller (3) assembly, which may be divided into two or more subassemblies in the axial direction. This arrangement can enhance the performance in the free rotation. More specifically, this type of clutch can reduce rolling resistance, has an enhanced skewness, and increase the adaptability for alignment and machining accuracy. Figs. 11 and 12 are sectional views showing other embodiments: Rolling-contact bearing type clutches which use cylindrical rollers, and can be used with an input/output side fixed in the axial direction. A space between the inner and outer rings 1 and 2 forms a raceway 9 for the cylindrical rollers 3 retained therein by a retainer 11. On the same one-end side of the inner and outer rings 1 and 2, an input/output rotation body such as a housing 14 which transmits input torque is disposed via a thrust bearing 13 which functions as the bearing of the clutch. The housing 14 is mounted fixedly to the inner ring 1 in the axial direction and rotatably by the thrust bearing 13 built therein. Further, the housing 14 is so connected to the outer ring 2 as to rotate integrally therewith through a torque transmission pin 15 (Fig. 11), or an involute spline 16 (Fig. 12) or a ball spline (not shown). A pre-compressed spring such as a coil spring 7′ or a plate spring 7 is provided between the housing 14 and the outer ring 2 as energizing means, to apply a pre-force to the outer ring 2. In using this inner ring 1 or housing 14 as the input side or output side, these embodiments can be generally used as a rolling-contact bearing type clutch when no axial displacement of an input side and output side is allowed. The embodiments shown in Figs. 11 and 12 shows examples in which the housing is disposed to the outer ring side, but the housing may be connected to the inner ring (1) side through involution spline 16 so that the torque is transmitted to the inner ring 1 as shown in Fig. 13. As described above, in the rolling-contact bearing type clutch according to the present invention, the rollers are intentionally slanted to the plane including the same axis line 6 of the inner and outer rings, so that, in the relative free rotation between the inner and outer rings, the rollers 3 can rotate maintaining a stable line contact with the inner and outer ring raceway surfaces while maintaining a stable revolution about the same axis of the inner and outer rings, thereby obtaining an excellent load distribution. In this case, even if there should be a dimensional error in rollers 3, or variations in a force previously applied by the plate spring 7 in the start operation, the rollers 3 can change their attitude, so that all the rollers 3 would participate in the carriage of the load, thus achieving an automatically unified load distribution. Therefore, the clutch with a general machining accuracy can realize a calculated load distribution, thus obtaining an even clutch operation. Further, the rollers 3 functions as a rolling member of a bearing by their rotation and revolution in the free rotation, while as a sprag member of the clutch operation by the action of the energizing means and their automatic aligning action in the reverse rotation (clutch). Therefore, if there should occur a deformation of the inner and outer raceway surfaces or a wear of rollers / raceway surfaces, the inner ring 1 or outer ring 2 or roller 3 may have an axial displacement, but pose no challenge to the clutch operation, thus eliminating the need for addition of the wall thickness of the inner and outer rings to ensure the rigidity for the inner and outer forces or for paying a special preventive consideration for wear, thereby realizing a light weight compact clutch assembly. Furthermore, the rolling-contact bearing type clutch according to the invention has a circular radial section of the rollers as seen in the general roller bearings, facilitating the calculation of the allowable surface pressure by using the same equation and factors as in the general bearings. It will be obvious to these skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is shown in the drawings and described in the specification but only as indicated in the appended claims.

Claims: One-way roller clutch comprising an inner rotating part (1), an outer rotating ring-shaped part (2), a plurality of intermediate rotating bodies (3), said inner and outer rotating clutch parts (1; 2) being provided with an inner and an outer raceway surface (1a; 2a) respectively, facing each other to form a combination of raceways (9); said inner and outer raceway surfaces (1a; 2a) being of similar shape, e.g. monohyperbolic, or being of different shapes, e.g. one being cylindrical and the other one being combined of a monohyperboloid and an ellipsoid of revolution about the axis (6) of said inner and outer rotating parts (1; 2); said intermediate rotating bodies (3) being disposed in the circumferential direction of said raceway (9) with their center axes slanting at a predetermined angle (β) to a section including the same axis (6) for said inner and outer rotating parts (1; 2), wherein forcing means (7) are provided to force either said inner rotating part (1), said outer rotating ring (2) or said intermediate rotating bodies (3) in the axial direction to assist to lock said intermediate rotating bodies (3) between said raceway surfaces (1a; 2a), the surface of each intermediate rotating body being in line contact with said inner and outer raceway surfaces (1a and 2a), and wherein said inner or outer rotating part (1 or 2) is provided with an annular member (10) limiting the relative axial movement of said intermediate rotating bodies (3) with respect to said inner or outer rotating part (1 or 2) when said inner rotating part (1) or said outer rotating ring (2) is rotated in a direction to attain the free running condition of the clutch. A clutch as claimed in claim 1 wherein said inner and outer raceway surfaces (1a and 2a) are mono-hyperboloid of revolution about one axis line (6), and said intermediate rotating bodies (3) have cylindrical rolling surfaces, and said forcing means (7) forcing either said inner rotating part (1) or said outer rotating ring (2) in axial direction to narrow the space of said raceway (9), and said annular member (10) being arranged to limit the relative axial movement of said intermediate rotating bodies (3) with respect to said inner or outer rotating part (1 or 2) when the space of said raceway (9) is widened. A clutch as claimed in claim 1 wherein said inner and outer raceway surfaces (1a and 2a) are mono-hyperboloid of revolution about one axis line (6), and said intermediate rotating bodies (3) have conical rolling surfaces, and said forcing means (7) pushing said intermediate rotating bodies (3) in the direction from their large diameter end to their small diameter end, and said annular member (10) being arranged to limit the axial movement of said intermediate rotating bodies (3) and to guide rolling them near their large diameter end. A clutch as claimed in claim 1 wherein said inner raceway surface (1a) is cylindrical about one axis line (6), and said outer raceway surface (2a) is a combined curved surface of a mono-hyperboloid of revolution and an ellipsoid of revolution about said axis line (6), and said intermediate rotating bodies (3) have hourglass-shaped rolling surfaces formed partially like an ellipsoid of revolution and with the cross section gradually increased from one end to the other end, and said forcing means (7) pushing said intermediate rotating bodies (3) in the direction from their large diameter end to their other end, and said annular member (12) being arranged to limit the axial movement of said intermediate rotating bodies (3) and to guide rolling of them near their large diameter end. A clutch as claimed in claim 1 wherein said outer raceway surface (2a) is cylindrical about one axis line (6), and said inner raceway surface (1a) is a combined curved surface of a mono-hyperboloid of revolution and an ellipsoid of revolution about said axis line (6), and said intermediate rotating bodies (3) have convex drum-shaped rolling surfaces formed partially like an ellipsoid of revolution and with the cross section gradually increased from one end to the other end, and said forcing means (7) pushing said intermediate rotating bodies (3) in the direction from their large diameter end to their other end, and said annular member (12) being arranged to limit the axial movement of said intermediate rotating bodies (3) and to guide rolling of them near their large diameter end. A clutch as claimed in claim 4 wherein said inner rotating part is the driving shaft. A clutch as claimed in claim 5 wherein said outer rotating ring is a mechanical element, such as a gear member. A clutch as claimed in anyone of claims 1 to 7 wherein said intermediate rotating bodies are divided into two or more subassemblies in the central axis direction. A clutch as claimed in anyone of claims 1 to 8 wherein a torque transmitting input/output rotating body (14) is provided which is mounted at a fixed position axially spaced from said inner rotating clutch part (1) via a bearing (13) whereby said inner and outer rotating parts (1 and 2) can rotate relatively to each other, said torque transmitting rotating body (14) being connected to said outer rotating clutch part (2) by torque transmission means (15), and said forcing means (7') is provided between said input/output rotating body (14) and said outer rotating body (2) to force said outer rotating body (2) in axial direction so as to narrow the space of said raceway (9). A clutch as claimed in anyone of claims 1 to 8 wherein a torque transmitting input/output rotating body (14) is provided and is mounted at a fixed position axially spaced from said outer rotating clutch part (2) via a bearing (13), whereby said inner and outer rotating parts (1 and 2) can rotate relatively to each other, said torque transmitting rotating body (14) being connected to said inner rotating clutch part (1) by torque transmission means (16), and said forcing means (7) is provided between said input/output rotating body (14) and said inner rotating clutch part (1) to force said inner rotating part (1) in axial direction so as to narrow the space of said raceway (9).

Inventors: TAKATA NOBUO, TAKATA, NOBUO
Applicants: THK MENT RESEARCH CO LTD, THK MENT RESEARCH CO., LTD.
Application year: 1990
Main classification: F16D41
IPC codes: F16D41, F16D15