초록 ▼

A mechanism for transmitting rotational power comprising: a link extending along a closed loop and continued by a succession of portions each having a longitudinal direction tangent to the closed loop; and temporary unification means comprising a plurality of self-locking means distributed at least

A mechanism for transmitting rotational power comprising: a link extending along a closed loop and continued by a succession of portions each having a longitudinal direction tangent to the closed loop; and temporary unification means comprising a plurality of self-locking means distributed at least along an active portion of a first drive circle, and comprising at least one rigid locking element simultaneously pressing against a first support surface of the first rotating element and a second support surface of a link portion facing the locking element. The first and second support surfaces are arranged so that one locking element of the first drive circle active portion is jammed between the support surfaces and is capable of self-unlocking when the corresponding self-locking means leaves the active portion. One of the support surfaces is a tangential gripping surface that is parallel to the longitudinal direction of the link portion against which the locking element presses.

대표청구항 ▼

1. A rotary power transmission mechanism comprising: a link extending along a closed loop and consisting of a succession of portions, each of which has a longitudinal direction tangent to the closed loop;a first and second rotary element, mobile in rotation respectively around a first and second axi

1. A rotary power transmission mechanism comprising: a link extending along a closed loop and consisting of a succession of portions, each of which has a longitudinal direction tangent to the closed loop;a first and second rotary element, mobile in rotation respectively around a first and second axis;link guide means designed to guide the link along a first drive circle coaxial to the first axis and along a second drive circle coaxial to the second axis, the closed loop comprising an active portion of each of the drive circles; andmeans for temporarily unifying each link portion to successively each of the rotating elements whenever the link portion passes into the corresponding active portion;wherein the temporary unification means comprise a plurality of self-locking means distributed at least along the active portion of the first drive circle, the self-locking means comprising at least a locking element simultaneously resting upon, on the one hand, a first support surface belonging to the first rotating element, and, on the other hand, upon a second support surface belonging to a link portion facing the locking element, wherein the first and second support surfaces are arranged in such a way that at least one locking element of the active portion of the first drive circle is jammed between the first and second support surface and is able to self-unlock whenever the corresponding self-locking means leaves the active portion, and wherein at least one of said first or second support surfaces is a tangential gripping surface that is parallel to the longitudinal direction of the link portion against which the locking element rests. 2. The mechanism according to claim 1, wherein the mechanism is of the type of continuously variable transmission (CVT) ratio mechanisms in which the guide means of the link are designed in such a way that the diameter of at least the first drive circle is continuously variable. 3. The mechanism according to claim 1 in which the locking elements are capable of rolling on the first and/or second corresponding support surfaces. 4. The mechanism according to claim 1 in which the locking elements of the mechanism are chosen from among a group consisting of: balls, rollers, barrels, subassemblies equipped with a support pad on one side and rolling elements on an opposite side, cams articulated at one extremity and having a curved and rubbing support surface at the other extremity, elongated cams having two curved and rubbing support extremities. 5. The mechanism according to claim 1 in which the plurality of self-locking means is distributed along the first drive circle or along the two drive circles. 6. The mechanism according to claim 5, in which the link has a first gripping plane perpendicular to the first and second axis in which each link portion comprises at least one rigid element, wherein each of the rigid elements comprises a first gripping surface extending into the first gripping plane. 7. The mechanism according to claim 5, in which the first rotary element, or each of the two rotary elements, is equipped with a plurality of supports, radially mobile along the corresponding rotating element, wherein each of the self-locking means of the corresponding rotary element comprises at least one rigid locking element integral with the support and one return means designed to bring the locking element into a locking position. 8. The mechanism according to claim 7, in which the link has a first gripping plane perpendicular to the first and second axis in which each link portion comprises at least one rigid element, wherein each of the rigid elements comprises a first gripping surface extending into the first gripping plane, and in which each of the supports comprises said first support surface of the locking element integral with the support, wherein the same locking element, in locking position presses upon said second support surface in a zone having as its center a point known as the gripping point. 9. The mechanism according to claim 8, in which the first support surface is an appreciably plane locking surface having a locking angle (36, Υ) with respect to the first gripping plane. 10. The mechanism according to claim 1, in which the normal to the locking surface has a supplementary angle (β) with respect to a plane perpendicular to a radius that passes through the gripping point. 11. The mechanism according to claim 1 further comprising a plurality of supports rotationally integral with the first rotating element and arranged along the first drive circle, in which each self-locking means has a tangent plane defined as being parallel to the first axis and tangent to the closed loop at the location of the self-locking means and comprises at least one connecting element consisting of a connecting solid or several connecting solids resting, two-by-two, on a mutual support surface, in which when the self-locking means is in a locking configuration, the connecting element is resting on one of the supports through a mutual support surface and on a portion of the link through another mutual support surface,in which at least one of the mutual support surfaces is a disengagement surface whose normal presents, with respect to the tangent plane, an angle (ε) greater than or equal to a disengagement angle,and in which each connecting element comprises said locking element consisting of all or part of the connecting solids, the locking element being, in its locking configuration, jammed between two mutual locking support surfaces situated on either side of the locking element. 12. The mechanism according to claim 11 in which the mutual support surfaces together define a reference direction (R), which is the direction of a force that would be transmitted to the support if the link portion exerted on the connecting element a force without radial component, and in which the disengagement angle is defined as being the smallest angle of inclination (ε) of the normal to the disengagement surface with respect to the tangent plane, angle of inclination for which the reference direction is outside the cone of friction on the disengagement surface. 13. The mechanism according to claim 11 in which the disengagement angle is defined as having a tangent equal to the coefficient of friction (μ) on the disengagement surface. 14. The mechanism according to claim 11 in which the support presents an overall U shape receiving the corresponding link portion arriving in the active portion, and in which the link portion is pinched between a force (F) exerted by the connecting element of the self-locking means between a branch of the U and the link portion and a counterreaction having an opposing axial component exerted between the other branch of the U and the same link portion. 15. The mechanism according to claim 11 in which the link portion comprises an actuating surface through which the link portion exerts, whenever it approaches the corresponding support, an actuating force having a radial component, which actuating force is then transmitted to the support via the connecting element, and in which the angle (ε) of the disengagement surface is less than a predetermined maximum angle so that the appearance of the actuating force gives to the force (F) exerted by the connecting element between the support and the link portion a direction included in the cone of friction of the disengagement surface. 16. The mechanism according to claim 11 in which at least one of the mutual locking support surfaces that is not a disengagement surface has a normal parallel to the tangent plane and in which the connecting element is integral with the support. 17. The mechanism according to claim 16, in which the mutual locking support surface whose normal is parallel to the tangent plane belongs to the support and in which the connecting element is indistinguishable with the locking element and comprises a gripping wedge that cooperates with a gripping plane of the link that is also the disengagement surface. 18. The mechanism according to claim 16, in which the connecting element is indistinguishable with the locking element and comprises a longitudinal carriage movable in parallel to the tangent plane, the connecting and locking element also comprising a gripping wedge, located on the longitudinal carriage and sliding radially on the longitudinal carriage along the disengagement surface. 19. The mechanism according to claim 18 in which the connecting and locking element also comprises a series of parallel rollers placed between a sliding surface of the longitudinal carriage and the mutual locking support surface belonging to the support. 20. The mechanism according to claim 1, in which the locking elements are rigid. 21. A method of rotational power transmission between two rotating elements utilizing a link in a closed loop, the method comprising the steps: of linking, in which each link portion circulates from one rotary element to another,of the self-locking of link portions whenever these are around one of the rotating elements, andof the self-unlocking of link portions whenever these circulate from one rotating element to the other,wherein the self-locking occurs by jamming a locking element between the rotating element and said portion, the transmission of mechanical power occurring through friction upon a surface parallel to the tangent to the corresponding portion of the closed loop.