Tensioning device, drive system, vehicle and tensioning method

Abstract

The invention relates to a device (10) for tensioning a deformable transmission element, comprising means (18) for adjusting the tension in the transmission element, the adjusting means (18) being movable through a first stroke, and an elastic member (20) by means of which the transmission element (12) can be tensioned with a first tension, the deformation of which is limited, after the first stroke, the adjusting device can be moved through a second stroke, the device can tension the transmission element (12) with a second additional tension by means of the adjusting device (18), and the second stroke depends on a second tension to be applied in the transmission element (12). The invention also relates to a transmission system, a vehicle and a tensioning method.

Description

TECHNICAL FIELD

[0001] The present invention relates to a device for tensioning a transmission element, a drive system having the device, a vehicle having the system and a tensioning method. BACKGROUND

[0002] There are devices that are able to tension a transmission belt. These devices can be spring loaded tensioners. A disadvantage of these devices is that they vibrate during operation. One solution to the vibration is to add a damping element, but this solution has the disadvantage of being expensive and complex. These devices can also be fixed tensioners during use. A disadvantage of these devices is that they do not allow sufficient tension to be applied to the belt during operating modes where the load can be high. Alternatively, if a very high tension is applied to the belt to cope with these high load operating modes, this will cause too much friction and high stress on all elements of the transmission.

[0003] Document US3785220 describes a belt clutch device comprising a drive pulley and a pulley driven by the drive pulley through an endless belt initially loosely mounted around the drive pulley and the driven pulley. An arm is mounted so that it can pivot within the circumference of the belt at one end. A belt tension pulley is rotatably mounted at the other end of the arm and in contact with the inner surface of the belt. A return spring connected to the arm moves the tension pulley away from the inner surface of the belt. An actuating device and a connecting element connected between the actuating device and the arm are adapted to pivot the arm against the force of the return spring and to pivot the arm into a predetermined angular relationship with the belt so that the tension pulley fully tensions the belt. This document does not provide for tensioning the belt by a spring. On the other hand, the spring acts as a return spring to return the arm to the disengaged position. Document US6030305 describes a belt tensioning device. This device allows the belt to be tensioned between two pulleys without acting on the belt itself but by increasing the distance between the pulleys. The device described in this document provides a tension reference point in order to obtain the correct setting of the tension springs, the length of which varies over time, possibly because they have undergone plastic deformation under constant load.

[0004] Generally, current devices are not able to adapt to a large range of transmitted torques.

[0005] There is a need for a tensioning device that is able to adapt to a large range of transmitted torques. SUMMARY

[0006] To this end, the application proposes a device for tensioning a deformable transmission element, the device comprising means for adjusting the tension in the transmission element and an elastic member, the adjusting means being movable: by a first stroke, the device being able to tension the transmission element by the elastic member with a first tension, the deformation of the elastic member being limited, and after the first stroke; by a second stroke, the device being able to tension the transmission element by the adjusting means with a second additional tension, the second stroke depending on the second tension to be applied in the transmission element.

[0007] According to an embodiment, the device further comprises a carrier, the device being able to tension the transmission element via the carrier.

[0008] According to an embodiment, the device comprises a roller in rotational movement relative to the carrier, the carrier being able to tension the transmission element by the roller.

[0009] According to an embodiment, the elastic member is located on the carrier.

[0010] According to an embodiment, the deformation of the elastic member is limited by abutment.

[0011] According to an embodiment, the deformation of the elastic member is limited by an abutment implemented by the carrier.

[0012] According to an embodiment, the deformation of the elastic member is limited by abutment of the adjusting means against the carrier at the end of the first stroke or by abutment of the elastic member against the carrier.

[0013] According to an embodiment, by the first stroke of the adjusting means, the carrier of the device is able to tension the transmission element by the elastic member with the first tension, the deformation of the elastic member being limited, the adjusting means acting on the elastic member to cause a limited deformation of the elastic member by abutment against an abutment on the carrier, and after the first stroke; by the second stroke of the adjusting means, the carrier of the device is able to tension the transmission element by the adjusting means acting on the carrier with the second additional tension, the second stroke depending on the second tension to be applied on the transmission element.

[0014] According to an embodiment, the elastic member is chosen from the group comprising: a leaf spring, a helical spring, a helical torsion spring, a column made of an elastic material, a structural member designed to provide an appropriate stiffness to the tension to be applied in the transmission element.

[0015] According to an embodiment, the adjusting means are a screw or an eccentric.

[0016] The application also relates to a drive system comprising a deformable transmission element, a device as described previously, the device being able to tension the transmission element.

[0017] According to one embodiment, the system further includes a housing, in which the transmission element and the device are at least partially located, and the adjustment device is operable from outside the housing. The housing includes a sight glass for inspecting a first and / or second stroke of the adjustment device.

[0018] According to one embodiment, the device is also capable of tensioning the transmission element when it elongates during operation, with the elastic member compensating for the elongation of the transmission element.

[0019] The present invention also relates to a vehicle having the drive system described above.

[0020] According to one embodiment, the means of transportation is a bicycle or a motorcycle.

[0021] The present invention also relates to a method for a transmission element in a tensioning drive system, the method comprising: - Provide the system as described above, - Tensioning the transmission element via the device includes: - During the first stroke of the adjusting device, the transmission element is tensioned by the elastic member with a first tension, the deformation of the elastic member is restricted, and then after the first stroke; - Through the second stroke of the adjusting device, the transmission element is tensioned by the adjusting device with a second additional tension, the second stroke depending on the second tension to be applied to the transmission element.

[0022] According to one embodiment, the device further includes a carrier that can tension the transmission element via the carrier, and the deformation of the elastic member is limited by the adjustment device abutting against the carrier at the end of the first stroke or by the elastic member abutting against the carrier.

[0023] According to one embodiment, the system further includes a housing, in which the transmission element and the device are at least partially located, and the adjustment device is operable from outside the housing. The housing includes a window, and the method includes checking a first stroke and / or a second stroke of the adjustment device through the window.

[0024] According to one embodiment, the method further includes tensioning the transmission element by the elastic member of the device when the transmission element elongates during operation, the elastic member compensating for the elongation of the transmission element.

[0025] In this document, the use of the verb "include" and its variants, as well as its inflections, does not exclude the existence of elements other than those mentioned. The use of "a," "one," or "the" to describe an element does not exclude the existence of multiple such elements.

[0026] The terms “first,” “second,” “third,” etc., are used within the scope of this document only to distinguish different elements and do not imply any order between these elements.

[0027] All preferred embodiments and advantages of the tensioning device according to the invention can be used, with appropriate modifications, in the drive system, vehicle, and tensioning method, and vice versa. Various embodiments can be considered individually or in combination. Attached Figure Description

[0028] Other features and advantages of the invention will become apparent from the following detailed description, which, for the purpose of understanding, is illustrated in the accompanying drawings: - Figure 1 This is a schematic diagram illustrating an example according to the present invention; - Figure 2 for Figure 1 A schematic diagram of its operation; - Figure 3 for Figure 1 A schematic diagram of its operation; - Figure 4 A view of another example of the present invention; - Figure 5 for Figure 4 The running view; - Figure 6 for Figure 4 The running view; - Figure 7 To show the elongation curve according to tension; - Figure 8 A graph illustrating the tensioning process.

[0029] The drawings in the accompanying drawings are not to scale. In the drawings, similar elements are generally indicated by similar reference numerals. Within the scope of this document, identical or similar elements may have the same reference numerals. Furthermore, the presence of reference numerals or letters in the drawings should not be considered limiting, even if such numerals or letters are specified in the claims. Detailed Implementation

[0030] This invention relates to an apparatus for tensioning a deformable transmission element. The apparatus includes means for adjusting the tension in the transmission element and an elastic member. The adjusting means is movable along a first stroke, during which the apparatus can tension the transmission element with a first tension via the elastic member, the deformation of which is limited. After the first stroke, the adjusting means is movable along a second stroke, during which the apparatus can tension the transmission element with a second additional tension via the adjusting means, the second stroke depending on the second tension to be applied to the transmission element. This apparatus allows for tensioning of the transmission element for both normal load operating modes and high load operating modes. Therefore, the apparatus allows for adaptation to different operating modes.

[0031] The accompanying drawing illustrates the tensioning device 10 in the drive system 11 and its operation. Device 10 allows tensioning of the transmission element 12 in the drive system 11. The transmission element 12 can be deformable. The transmission element 12 can be deformable in the sense that its shape can change. The transmission element 12 can be deformable in the sense that the transmission element 12 can elongate. The transmission element 12 can be a chain, belt, or flexible belt. If the transmission element 12 is a belt, the belt is preferably made of a flexible material and preferably has teeth or notches on its inner surface (see...). Figure 4 The transmission element 12 can transmit power between two or more pulleys or belt pulleys 14, 16. The transmission element 12 enables power to be transmitted between rotating parallel axes, and between pulleys 14 and 16; depending on the direction of rotation of the pulleys, power may be transmitted in both directions. One of these pulleys (e.g., pulley 14) can be driven by a motor not shown in the figures. Power from pulley 14 can be transmitted to pulley 16 via the transmission element 12. Specifically, during the tensioning of the transmission element 12, the center distance between pulleys 14, 16 (or more pulleys) remains constant.

[0032] The device 10 may also include a means 18 for adjusting the tension in the transmission element 12. The device 10 acts (directly) on the transmission element 12 to tension it (while maintaining the center distance between the pulleys, rather than by separating them). The device 10 acts (directly) on the transmission element 12. The device 10 contacts the transmission element to tension it. The tension in the transmission element 12 can be adjusted and determined by adjusting the adjusting means 18. The adjusting means 18 is movable, which allows adjustment of the tension in the transmission element 12. The adjusting means 18 can be translational and / or rotational. The adjusting means 18 can move along a stroke, allowing adjustment of the tension in the transmission element. The nature of the stroke depends on the type of activity of the adjusting means 18. The adjusting means 18 can move along a first stroke 13 and a second stroke 15, depending on the desired tension to be applied to the transmission element 12. Depending on each of the two strokes, the adjusting means 18 is continuously movable (adjustable) (i.e., according to a non-discrete number of positions of the adjusting means) to ensure precise adjustment of the tension. Tensioning of the transmission element 12 is achieved at the end of the first and second strokes. The adjusting device 18 can be a screw. The screw undergoes rotational and translational motion, where rotation of the screw enables translation. The screw has a linear translational stroke (depending on its rotation). The adjusting device 18 can also be an eccentric wheel. The eccentric wheel undergoes rotational motion. The eccentric wheel has an angular rotational stroke. The adjusting device 18 can also be: a thickness shim; a slider with lockable degrees of freedom; a lockable adjusting rod; a cam and its locking mechanism; a hydraulic piston; a pneumatic actuator, hydraulic actuator, piezoelectric actuator, or electromagnetic actuator; and associated transmission and locking mechanisms. The adjusting device is any means of achieving force adjustment and associated locking mechanisms through external components (e.g., ratchet or pawl) or through irreversibility.

[0033] The device 10 may also include an elastic member 20. The elastic member 20 allows a force to be applied to tension the transmission element 12. Deformation of the elastic member 20 allows the transmission element 12 to be tensioned. An adjusting device 18 is capable of deforming the elastic member 20. The adjusting device 18 is capable of deforming the elastic member 20 by moving along its stroke. The elastic member 20 deforms during the stroke of the adjusting device 18. Preferably, the deformation of the elastic member 20 is limited. The elastic member 20 is capable of deforming to a certain limit. The deformation of the elastic member 20 is possible to a certain extent. The elastic member 20 can deform until it involves abutment (mechanical contact). The elastic member 20 may be selected from the group consisting of leaf springs, coil springs, torsion springs, columns made of elastic material, or structural members designed to provide appropriate stiffness to the tension applied to the transmission element 12. Other examples of elastic members may be provided.

[0034] The adjusting device 18 is movable along a first stroke 13. The device 10 then tensions the transmission element 12 with a first tension via the elastic member 20. The stiffness of the elastic member 20 transmits force 17 to the transmission element 12, which is then tensioned. Under the stress state applied by the adjusting device 18, the elastic member 20 undergoes a given deformation. The deformation of the elastic member 10 applies tension to the transmission element 12.

[0035] After the first stroke 13, the adjusting device 18 moves along the second stroke 15. In other words, the adjusting device 18 moves (displaces) after the first stroke 13 ends, and then the adjusting device 18 is driven into the second stroke 15. As can be seen from these figures, the second stroke after the first stroke means that the second stroke is a continuation of the first stroke. In the second stroke, the adjusting device 18 moves a greater distance than in the first stroke. The device 10 is then able to tension the transmission element 12 with a second additional tension via the adjusting device. The second applied tension in the transmission element 12 transmitted by the adjusting device 18 is added to the first applied tension in the transmission element 12 transmitted by the elastic member 20. The second stroke 15 is a function of the second tension to be applied in the transmission element. The adjusting device 18 moves through the second stroke according to the second tension to be applied. During the movement of the adjusting device 18 in the second stroke, the elastic member 20 may be held in its restricted deformation by abutment. This allows the first tension to be maintained and controlled by the elastic member 20 during the second stroke of the adjusting device 18 when the second tension is applied. The sum of the two tensions (total tension) provides the desired tension, the optimal operating tension that allows the transmission element 12 to function properly, as determined when designing the drive system 11. Throughout both strokes of the adjusting device 18, the first and second tensions (and thus the total pressure) are precisely applied. The adjusting device 18 transmits a force 19 to the transmission element 12, which is set to the desired tension.

[0036] exist Figures 1 to 3 In the example shown, device 10 tensions transmission element 12 through movement (which could be translational movement). Figures 4 to 6 In the example shown, device 10 tensions transmission element 12 by motion (which may be rotational motion).

[0037] The device 10 may also include a carrier 24. The device 10 is capable of tensioning the transmission element 12 via the carrier 24. The carrier is movable. The carrier 24 can be as follows: Figures 1 to 3 The translational motion shown, or in other words, movement within a linear guide rail. Then, device 10 tensions transmission element 12 through the translational motion of the carrier. Therefore, Figures 1 to 3 The carrier 24 shown is a slider 24 capable of translational movement. The slider-shaped carrier 24 can push or pull the transmission element 12 to tension it. Figures 4 to 6In this configuration, the carrier 24 can rotate, or in other words, is guided to rotate. The device 10 then tensions the transmission element 12 through the rotational movement of the carrier. Therefore, Figures 4 to 6 The carrier 24 shown is a lever 24 that rotates.

[0038] It is also conceivable that the carrier 24 and the elastic member 20 can be combined together.

[0039] The carrier 24 can bias the transmission element 12 by direct contact with it. Preferably, the device 10 may include a roller 28 that rotates relative to the carrier 24. The roller 28 may be located at one end of the carrier 24. The carrier 24 is able to tension the transmission element 12 by means of the roller. In other words, the roller 28 is mounted such that it can rotate (freely) on the carrier 24 and press against the transmission element 12. The connection between the carrier 24 and the roller 28 may be represented by a bearing centered on the axis of rotation 29. The pulley forming the roller 28 may be smooth or notched.

[0040] The movement of the carrier 24 presses the roller 28 against the transmission element 12, thereby tensioning the transmission element 12. The roller 28, rotating on the carrier 24, acts on the transmission element 12 while limiting friction with it. The carrier 24 and the roller 28 allow the transmission element 12 to be tensioned without hindering the transmission of motion from one pulley 14, 16 to another.

[0041] Tension is applied to the transmission element 12 via roller 28 (i.e., the third pulley), keeping the axes of rotation of the drive pulley and driven pulley fixed. Therefore, this device can be used when the pulley drive is connected to other immovable components in the environment (e.g., a drive downstream of the driven pulley). Furthermore, this invention allows for action on the slack section of the transmission element 12 (unlike the device in US6030305, where action on the two sections is achieved by moving the pulleys apart). For example, when the transmission element 12 is in the form of a notched belt or chain, this device does not interfere with the section transmitting the load, thus resulting in better dynamics. The ratio of pretension to the maximum transmitted torque is also better.

[0042] The elastic member 20 can be located on the carrier 24. The elastic member 20 can be carried by the carrier 24. In other words, the elastic member 20 can be assembled and fixed to the carrier 24. The elastic member 20 is then driven to move together with the carrier 24. The entire elastic member 20 is driven to move together with the carrier 24. The elastic member 20 changes position with the movement of the carrier 24 during equipment operation. The entire elastic member 20 changes position with the movement of the carrier 24 during equipment operation. Figures 1 to 3 The translational motion of the carrier 24 shown causes the elastic member 20 to translate. Figures 1 to 3In the example shown, the elastic member 20 may be a helical spring with one end embedded in the carrier 24. The other end of the elastic member 20 may be loaded by an adjusting device 18. The rotational movement of the carrier 24 about its axis of rotation 26 (e.g., Figures 4 to 6 (As shown) This causes the elastic member 20 to rotate about the rotation axis 26. Figures 4 to 6 In the example shown, the elastic member 20 is a blade embedded in the carrier 24 at its end 201. The elastic member 20 is suspended on the carrier 24. The elastic member 20 is acted upon at its other end 202 by the adjusting device 18. Therefore, the embedding point (the fixed point of the elastic member 20) changes position with the movement of the carrier 24 during equipment operation.

[0043] Through the first stroke of the adjusting device 18, the carrier 24 (during its movement) can be tensioned to the transmission element 12 by the elastic member 20 with a first tension. The elastic member 20 acts on the carrier 24 to tension the transmission element 12. The adjusting device 18 does not act directly on the carrier 24, but rather on the elastic member 20, which in turn acts on the carrier 24. Then, through the second stroke of the adjusting device 18, the carrier 24 (during its movement) can be tensioned to the transmission element 12 by the adjusting device 18 with a second additional tension. The adjusting device 18 acts on the carrier to tension the transmission element 12.

[0044] According to the accompanying drawings, the deformation of the elastic member 20 is limited by abutment. The deformation of the elastic member can be less than its maximum deformation. The deformation of the elastic member 20 can be limited by abutment in several ways. The first stroke of the adjusting device 18 acting on the adjusting member can be limited by abutment. The adjusting device 18 can move over a certain stroke before abutment. During this initial stroke, the adjusting device 18 deforms the elastic member 20, and at the end of the first stroke, the adjusting device 18 abuts against the abutment portion. At the end of the first stroke, the elastic member 20 deforms to a limited degree. In addition, the elastic member 20 itself can abut, which limits its deformation. When the adjusting device 18 and / or the elastic member 20 abut, the deformation of the elastic member 20 ends.

[0045] Preferably, the deformation of the elastic member 20 can be limited by the abutment portion implemented by the carrier. The deformation of the elastic member 20 can be limited by the abutment portion 30 on the carrier 24 implemented by the adjusting device 18 at the end of the first stroke, or by the abutment portion 30 on the carrier implemented by the elastic member 20. The deformation of the elastic member 20 can be limited by limiting the first stroke of the adjusting device 18 at the abutment portion 30 implemented by the carrier 24. The first stroke of the adjusting device 18 can be limited by the abutment portion 30 on the carrier 24 implemented by the adjusting device 18. The first stroke of the adjusting device 18 can be limited by the abutment portion 30 on the carrier 24 implemented by the elastic member 20. At the end of the first stroke of the adjusting device 18, the adjusting member 18 and / or the elastic member 20 abut and contact the carrier 24.

[0046] The operation of the device 10 (more generally, the drive system 11) and the tensioning method according to the invention can be performed as follows. Any description of the device and its operation can be applied to the tensioning method, and vice versa.

[0047] Until the first stroke 13 of the adjusting device 18, the carrier 24 of the device is able to tension the transmission element 12 with a first tension via the elastic member 20, and the deformation of the elastic member 20 is restricted. The adjusting device 18 forces the elastic member 20 to produce restricted deformation by abutting against the abutment portion 30 on the carrier 24. During the first stroke of the adjusting device 18, the tension in the transmission element is adjusted by the deformation of the elastic member 20. The deformation of the elastic member 20 carried by the carrier 24 causes the carrier 24 to move, and the carrier 24 acts on the transmission element 12 under tension via the roller 28 (if applicable). The adjustment of the adjusting device 18 (e.g., a screw) allows the elastic member 20 (e.g., a spring) to deform, which will transmit the force (e.g., via the connector 201) to the carrier 24, thereby increasing the tension in the transmission element 12. Figures 1 to 3 The carrier 24 has translational motion. According to... Figures 4 to 6 The carrier 24 rotates around the rotation axis 26. The action of the carrier 24 on the transmission element 12 causes the transmission element 12 to be tensioned with a first tension. Figure 2 (Applicable to) Figure 5 The transmission element is shown in dashed lines. Figure 1 The position corresponding to the middle position.

[0048] After the first stroke, and through the second stroke 15 of the adjusting device 18, the carrier 24 of the device can be tensioned by the adjusting device 18 acting on the carrier 24 with a second additional tension on the transmission element 12. The adjusting device 18 abuts, and the deformation of the elastic member 20 is restricted by the abutment portion 30. The adjusting device 18 and the elastic member abut and contact the carrier 24. Through the second stroke 15, the adjusting device 18 acts on the carrier 24 abutting against the transmission element 12. In particular, the carrier 24 is acted upon by the adjusting device 18, and no longer solely by the elastic member 20, and the deformation of the elastic member 20 is restricted. According to Figures 1 to 3 The carrier 24 has translational motion. According to... Figures 4 to 6 The carrier 24 rotates around the rotation axis 26. The adjusting device 18 contacts the carrier 24 at the level of the abutment portion 30, and directly or indirectly contacts the elastic member 20 between the adjusting device 18 and the abutment portion 30. The adjusting device 18 moves in a second stroke according to the second tension to be applied in the transmission element 12. During the second stroke, the deformation of the elastic member 20 is locked, and the elastic member is driven to move together with the carrier 24. Figure 3 (Applicable to) Figure 6 The transmission element is shown in dashed lines. Figure 1 and Figure 2 The position corresponding to the middle position.

[0049] Therefore, the transmission element 12 is tensioned in a two-stage or dual-mode sequence. This two-stage tensioning sequence can correspond to tension adjustment (or pre-tensioning). This adjustment can be performed before using the drive system 11 or during maintenance operation. In the first stage, a first tension is applied to the transmission element 12 by the deformation of the elastic member 20. At the end of the first stage, the deformation of the elastic member 20 is limited by abutment. In this first stage, the tension of the transmission element is controlled by the deformation of the elastic member. The elastic member is sized to apply a (relatively) stable (and known) force (and thus tension) to the transmission element 12 when it deforms to its limit. Then, in the second stage, in addition to the first tension, a second tension is applied to the transmission element 12 by an adjusting device 18, which continues its stroke while the elastic member is restrained. During the second stage, the device is able to directly tension the transmission element 12. The stroke of the adjusting element 18 continues according to the additional second tension to be applied to the transmission element 12. In this second stage, the tension of the transmission element 12 is controlled in motion by changing the passagepoint of the transmission element. Tension can be controlled by the displacement (or movement) of device 10 (or, if necessary, by the movement of carrier 24 acted upon by adjusting device 18). This displacement transmitted by the adjusting device is calculated based on the relationship between the tension in transmission element 12 and the final tension. Movement of device 10 particularly allows movement of elastic member 20 without altering its deformation.

[0050] In other words, by adjusting the adjusting device 18 (e.g., the screw), the elastic member is subjected to stress, which produces a first stroke 13 of the transmission element 24 until the elastic member abuts. At this precise moment, the tension of the transmission element is known according to the characteristics of the elastic member (e.g., the force constant kx of the spring). The tension of the transmission element can then be increased to the desired tension by running a second stroke 15 with a fixed displacement (e.g., by rotating the screw according to the fixed displacement). The second stroke 15 is, for example, a screw rotation that may be a non-integer number, thus giving a desired displacement associated with the characteristics of the screw (e.g., the pitch).

[0051] Device 10 allows the tensioning sequence to be adapted to the characteristics of transmission element 12. The first stage tensions transmission element 12 to a known value, independent of deviations caused by manufacturing tolerances of transmission element 12 or other surrounding mechanical components. The second stage completes the tensioning of transmission element 12 by adding a known displacement to the initial position obtained during the first stage.

[0052] The drive system 11 may include a housing 22 (in) Figures 4 to 6 It can be seen in the text, but it also applies to other texts. Figures 1 to 3The transmission element 12 and the device 10 can be at least partially housed within the housing 22. This provides them with protection (e.g., dustproof, shockproof, etc.). The transmission element 12 can be at least partially located within the housing 22. The transmission element 12 may be entirely or partially within the housing 22 of the device 10. The device 10 can also be at least partially located within the housing 22. For example, the adjusting device 18 can extend between the outside and inside of the housing 22. The adjusting device 18 can also be located within the housing 22 and operated from the outside of the housing 22. The housing 22 can also support the various elements constituting the invention.

[0053] The housing 22 may include a window (not visible in the figure) for inspecting the first and / or second strokes of the adjusting device 18. This visual inspection ensures reliable tension without the need for special tools to measure force, torque, or tension. The window allows the adjusting device 18 to follow the first stroke. When the adjusting device 18 is at the abutment 30 (potentially against the carrier 24, if applicable), the window allows identification of the adjusting device 18. When the adjusting device 18 contacts the carrier 24, the window allows identification of the adjusting device 18, and possibly the elastic member. This allows detection that tension is at the end of the first stage. The window also allows the adjusting device 18 to follow the second stroke. The second stroke can also be determined by controlling the actuation of the adjusting device 18. The second stroke can be determined by further movement of the adjusting device 18. For example, an additional rotation of the adjusting member 18 in the form of a screw determines the second stroke and thus determines a second additional tension. The window may cover a portion of the enclosed housing 22. This section can be transparent (so that the tensioning process can be visually followed) or opaque (once the tensioning process is complete). The end of the first stroke can be communicated to the operator by other means, such as by electronic components that close the circuit at the contacts.

[0054] During operation of the drive system 11 at nominal load, the device 10 places the transmission element 12 under tension; the regulating device applies tension to the transmission element using an elastic member 20, which is constrained in deformation. The elastic member 20 is located at the abutment portion 30, possibly against the carrier 24, and its effect is suppressed. As the load in the drive system 11 increases during operation, the transmission element may elongate, resulting in a decrease in tension in the transmission element 12. The force exerted on the device 10 by the transmission element 12 may become less than the force required to maintain the elastic member 20 in its constrained deformation. In this case, there is a risk that the transmission element may deviate from its path or no longer transmit power correctly. The elastic member 20 then allows the elongation of the transmission element 12 to be compensated. The carrier 24 (more generally, the device 10) is able to maintain tension in the transmission element via the elastic member 20. The elastic member 20, carried by the carrier 24, is moved by the carrier 24 during the second stroke of the regulating member 18, thereby allowing the elastic member 20 to reapply tension in the elongated transmission element 12. This system is suitable for implementation in applications operating at nominal tension (widely used), which is significantly different from and lower than the maximum tension (rare cases).

[0055] After tensioning on both strokes of the adjusting device 18, the proposed device and system thus offer two operating modes: one for nominal load conditions and another for high load conditions. In normal operating mode, under nominal load, the device and system operate as a fixed tension mechanism, which is ideal for preventing vibration. In this mode, the device is as rigid as possible. In the "anti-slip" operating mode, under high load conditions, the device and system are converted into a tensioning system with elastic members. In this mode, due to the elastic members, the device can absorb significant elongation of the transmission elements. The combination of these two modes provides a good compromise for three conflicting requirements: operating with the highest possible stiffness to avoid vibration associated with alternating deformation cycles between the transmission elements and the elastic members; allowing the transmission elements to reach maximum elongation to transmit maximum torque without jumps (i.e., without loss of engagement or excessive slippage); and having the lowest possible preload (during adjustment, at the end of the two tensioning phases) to reduce friction throughout the system and forces on the transmission components (e.g., bearings).

[0056] The advantages of this device and system are: it eliminates the need to apply high levels of pretension to the transmission components to address any rare risk of loosening under higher loads. It also avoids greater static friction and higher loads on pulleys and bearings. Thanks to this invention, the transmission components can be tensioned (pre-tensioned) at a lower tension corresponding to the nominal condition under normal loads, while still being able to be tensioned under high loads to ensure proper operation. Furthermore, this device and system solves the problem of measuring tension for adjustment (tensioning)—elastic elements (e.g., springs) facilitate proper adjustment.

[0057] When using chain or belt drive components, a pretension T0 can be applied, which may or may not be zero (at zero torque). During operation, tension (proportional to torque) is applied to one section of the drive component and removed from another. Tension Ts applied to the least taut (or slack) section and tension Th applied to the tautest section can be obtained. When the torque in the drive becomes too high, the tension Ts in the slack section becomes zero, which can lead to drive failure (e.g., skipped teeth in the case of notched chains or belts, especially in fixed tensioning devices). This device addresses such drive failures due to the elastic member 20, which functions to compensate for slack while maintaining tension.

[0058] This is Figure 7 It is shown schematically in the middle. Figure 7 The curve 32 shows the elongation E of the transmission element 12 on the x-axis as a function of the tension Ts (in the slack section) on the y-axis. The curve 32 corresponds to the stiffness slope of the transmission element. The tension in the slack section of the transmission element decreases as its elongation increases. Curve 32 on the y-axis corresponds to zero torque. Along curve 32, as torque increases, curve 32 reaches E on the x-axis: the taut section becomes tighter, and the slack section becomes looser, such that the tension in the slack section becomes zero at E on the x-axis. Curve 34 shows the normal operating mode 36 of the device 10 and system 11. As the load in the system increases, the transmission element 12 exerts a reduced reaction force on the device 10. Curve 38 shows that beyond a certain elongation 40 of the transmission element (or in other words, a certain elongation or elongation threshold), the device 10 switches to an anti-jump mode 42 controlled by the stiffness of the elastic member 20. When the transmission element elongates, the device is able to keep the transmission element 12 under tension, and the elastic member 20 compensates for the elongation of the transmission element.

[0059] according to Figure 7Comparing curve 32 with 34 / 38, for normal system operation (normal mode, curve 34), a smaller tension can be applied to the transmission element, and the elastic member 20 allows tension to be applied to compensate for the elongation of the transmission element when the elongation exceeds a certain threshold (anti-jump mode, curve 38).

[0060] Figure 8 The tensioning process is shown. Figure 8 The change in pretension T0 is shown as a function of the adjustment amount S of the adjustment device 18. Figure 8 The behavior of device 10 and system 11 during tensioning is illustrated. According to curve 44, and according to the first stroke 13, from the perspective of device 10, the slope depends primarily on the stiffness of the elastic member 20 and the stiffness of the transmission element 12. Point 48 corresponds to the contact point at the abutment (i.e., the deformation limit of the elastic member). According to curve 46, and according to the second stroke 15, from the perspective of device 10, the slope depends primarily on the stiffness of the transmission element 12. Point 50 corresponds to the pre-tensioning of the device, or in other words, the nominal adjustment point of the device.

[0061] Device 10 uses an elastic member (e.g., a spring) whose stiffness and initial length are controlled. Device 10 operates at an ideal operating point, minimizing tension on the transmission elements to achieve maximum torque transmission. The device uses known deformation (on the first stroke) and known stiffness to obtain this desired tension during the first stroke and a second tension resulting from the second stroke. According to the invention, the first stroke is performed until the limit deformation (e.g., by contact with the abutment), after which the second stroke (e.g., a known length) is applied. Under normal conditions, this device is more rigid and exhibits less parasitic vibration compared to the prior art, particularly to document US6030305.

[0062] Device 10 allows for an increased service life of the transmission system 11, while being lightweight, simple, compact, and inexpensive. Device 10 is a simple device that allows systems with highly variable torque to be effectively tensioned. This device offers the advantages of anti-slip operation and ease of adjustment (alone or in combination).

[0063] The present invention also relates to any device including a drive system in which a transmission element is implemented and tensioned. The present invention particularly relates to vehicles including a drive system. For example, the vehicle may be a bicycle or a motorcycle. A bicycle or motorcycle may include a transmission element 12, which may be a belt or drive chain between a chain assembly and / or a power unit on one side and a wheel on the other side. The advantages mentioned for the device (lightweight, simple, compact, and inexpensive device) are particularly applicable in the context of vehicles that are constantly seeking these advantages.

[0064] The invention has been described above with reference to specific embodiments, which are illustrative and should not be considered limiting. In general, it will be apparent to those skilled in the art that the invention is not limited to the examples shown and / or described above.

Claims

1. Device (10) for tensioning a deformable transmission element, comprising: - means (18) for adjusting the tension in the transmission element, - an elastic member (20), the adjusting means (18) being movable: - by a first stroke (13), the device being able to tension the transmission element (12) by the elastic member (20) with a first tension, the deformation of the elastic member being limited, and, after the first stroke (13), - by a second stroke (15), the device being able to tension the transmission element (12) by the adjusting means (18) with a second additional tension, the second stroke depending on the second tension to be applied in the transmission element (12).

2. The device (10) according to the preceding claim, wherein During the displacement of the adjusting means (18) on the second stroke, the elastic member (20) can remain in its limited deformation.

3. Device (10) according to one of the preceding claims, further comprising a carrier (24), the device being able to tension the transmission element (12) via the carrier.

4. Device (10) according to the preceding claim, comprising a roller (28) in rotational movement relative to the carrier (24), the carrier being able to tension the transmission element (12) by the roller.

5. The apparatus (10) according to one of claims 3 or 4, wherein, The elastic member (20) is located on the carrier (24).

6. The device (10) according to the preceding claim, wherein The elastic member (20) changes position as a function of the movement of the carrier (24) during operation of the device.

7. The apparatus (10) according to claim 5 or 6, wherein The fixed point of the elastic member (20) to the carrier (24) changes position as a function of the movement of the carrier (24) during operation of the device.

8. The apparatus (10) according to one of claims 3 to 7, wherein The deformation of the elastic member (20) is limited by abutment.

9. The apparatus (10) according to one of claims 3 to 8, wherein The deformation of the elastic member (20) is limited by an abutment achieved by the carrier.

10. The apparatus (10) according to one of claims 3 to 9, wherein The deformation of the elastic member (20) is limited by an abutment achieved by the adjusting means (18) against the carrier (24) at the end of the first stroke or by the elastic member (20) against the carrier.

11. Device (10) according to one of claims 3 to 10, in which: - by the first stroke (13) of the adjusting means, the carrier (24) of the device is able to tension the transmission element (12) by the elastic member (20) with the first tension, the deformation of the elastic member being limited, the adjusting means (18) acting on the elastic member (20) to cause a limited deformation of the elastic member by abutment against an abutment (30) on the carrier, and, after the first stroke, - by the second stroke (15) of the adjusting means, the carrier (24) of the device is able to tension the transmission element (12) by the adjusting means (18) acting on the carrier with the second additional tension, the second stroke depending on the second tension to be applied in the transmission element.

12. The apparatus (10) according to one of the preceding claims, wherein Said elastic member (20) is selected from the group comprising a leaf spring, a helical spring, a helical torsion spring, a column made of elastic material, a structural element designed to provide the appropriate stiffness to the tension to be applied in the transmission element (12).

13. The apparatus (10) according to one of the preceding claims, wherein Said adjustment device (18) is a screw or an eccentric.

14. A drive system (11) comprising: - a deformable transmission element (12), - a device (10) according to one of the preceding claims, said device being able to tension said transmission element (12).

15. The system (11) according to the preceding claim, further comprising a housing (22), said transmission element (12) and said device (10) being at least partially located inside said housing, said adjustment device being operable from the outside of said housing, said housing comprising a window for checking said first stroke (13) and / or said second stroke (15) of said adjustment device (18).

16. The system (11) according to claim 14 or 15, wherein Said device (10) is also able to tension said transmission element (12) during operation when said transmission element is elongated, said elastic member (20) compensating for the elongation of said transmission element.

17. A vehicle having a drive system (11) according to one of claims 14 to 16.

18. The vehicle according to the preceding claim, said vehicle being a bicycle or a motorcycle.

19. A method of tensioning a transmission element in a drive system (11), said method comprising: - providing a system (11) according to one of claims 14 to 16, - tensioning said transmission element (12) by means of said device (10), comprising: • by means of said first stroke (13) of said adjustment device, said transmission element (12) is tensioned by means of said elastic member (20) with a first tension, the deformation of said elastic member being limited, then after said first stroke, • by means of said second stroke (15) of said adjustment device, said transmission element (12) is tensioned by means of said adjustment device (18) with a second additional tension, said second stroke depending on a second tension to be applied in said transmission element.

20. The method according to the preceding claim, said device (10) further comprising a carrier (24), said device being able to tension said transmission element (12) via said carrier, the deformation of said elastic member (20) being limited by means of said adjustment device (18) abutting against said carrier (24) at the end of said first stroke or by means of said elastic member (20) abutting against said carrier.

21. The method according to one of claims 19 or 20, said system (11) further comprising a housing (22), said transmission element (12) and said device (10) being at least partially located inside said housing, said adjustment device (18) being operable from the outside of said housing, said housing comprising a window, said method comprising checking said first stroke and / or said second stroke of said adjustment device (18) through said window.

21. The method according to one of claims 19 or 20, said system (11) further comprising a housing (22), said transmission element (12) and said device (10) being at least partially located inside said housing, said adjustment device (18) being operable from the outside of said housing, said housing comprising a window, said method comprising checking said first stroke and / or said second stroke of said adjustment device (18) through said window.

22. The method according to any one of claims 19 to 21, further comprising tensioning the transmission element (12) by the elastic member (20) of the device during operation when the transmission element is elongated, the elastic member (20) compensating for the elongation of the transmission element.

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