transmission system

Abstract

A drive sprocket is provided comprising a plurality of teeth for engaging with a drive member to transmit rotational motion, the drive member comprising a plurality of engagement slots that engage the teeth of the drive sprocket, wherein each tooth has a tooth profile defined by a first side comprising a first engagement surface and an opposing second side comprising a second engagement surface, the engagement surfaces being configured such that, when driven, a tooth engages to the engagement slots at a first contact location on the first engagement surface and also at a second contact location on the second engagement surface, wherein the first contact location is radially offset from the second contact location.

Description

[0001] The present invention relates to a transmission system comprising a drive sprocket and a drive member, and to a drive sprocket forming part of such a transmission system, and to a drive member forming part of said transmission system.

[0002] It is well known that drive sprockets or pulleys with multiple teeth are used with drive components such as power transmission chains or belts, and they are typically in the form of a generally circular sprocket with multiple teeth spaced apart around the outer circumference of the sprocket.

[0003] A variety of different drive components can be used with this type of drive sprocket.

[0004] The first type of known drive mechanism is a power transmission chain in the form of a roller chain. Roller chains have multiple engagement structures for achieving engagement with the drive sprocket. These engagement structures are in the form of receiving structures for receiving the teeth of the drive sprocket. An example of the use of roller chains is in bicycles. Roller chains for bicycles bypass a front drive sprocket in the form of a crank drive sprocket and also bypass a rear drive sprocket in the form of a gear. Known roller chains can also be used in many other different types of equipment, including, for example, tricycles, motorcycles, and chainsaws.

[0005] The second type of L-shaped drive component is a power transmission chain that includes a silent chain. The silent chain also has multiple engagement structures for achieving engagement with the drive sprocket. These engagement structures are in the form of toothed structures, designed to receive in receiving grooves formed between adjacent teeth on the drive sprocket. Silent chains are used in high-torque applications requiring high efficiency and high power transmission.

[0006] A typical application of this type is the use of a silent timing chain as the engine timing chain. Silent timing chains are also commonly referred to as HY-VO timing chains.

[0007] The third type of known drive component is a belt adapted to engage with the teeth of a sprocket.

[0008] As is well known, a drive component can transmit power between drive sprockets. For example, in the case of a front sprocket driving a sprocket on a bicycle, the known drive sprocket can drive the drive component, or in the case of a rear sprocket driving a sprocket on a bicycle, the drive sprocket can be driven by the drive component.

[0009] A known power transmission chain is formed by links that are pivotally contacted together by a pivot that extends laterally across the links.

[0010] The known drive components and known drive sprockets do not transmit power as efficiently as expected. More specifically, the known drive components are always in contact with the drive sprocket under significant loads, and under such conditions, the drive components often tend to move relative to the sprocket teeth while maintaining contact under this high load. As a result, the known power transmission chains cannot work effectively on the drive sprocket.

[0011] Known power transmission drive components include power transmission chains or belts adapted to engage with the teeth of drive sprockets or pulleys.

[0012] For example, roller chains or bushing chains, or hollow pin chains as variations of standard roller chains or bushing chains, are adapted to transmit rotational motion from one rotating shaft to another by meshing with the teeth of sprockets attached to each shaft.

[0013] A standard bushing chain includes inner links and outer links. The inner link comprises two spaced-apart inner plates connected by two bushings, with a press fit between the plates and bushings. The outer link comprises two spaced-apart outer plates connected by two pins, with a press fit between the plates and pins. In a standard roller chain, the bushing of the inner link passes through a roller that can rotate freely about the outer surface of the bushing and is contained within the inner link by the plate of the link. In hollow pin chains and standard bushing / roller chains, links are connected by pins of outer links passing through the bushings of adjacent inner links. Adjacent outer and inner links can rotate relative to each other about this pin-bushing interface while bearing a load. A series of connected links can form a loop and be hinged about multiple sprockets, thereby transmitting torque and rotational motion between sprocket shafts.

[0014] Hollow pin sleeve chains are similar to standard sleeve chains, except that the pins on the outer links are hollow. This configuration allows for easy attachment of accessories to the chain and is primarily used for transportation purposes. Accessories can be installed by inserting pins into the hollow pins of the chain. Hollow pins also reduce the weight of the chain while maintaining component rigidity.

[0015] In a known hollow pin sleeve chain, each tooth of the drive sprocket is housed between two adjacent sleeves. Each tooth contacts one of the two adjacent sleeves and transmits the load between the chain and the sprocket at this contact interface.

[0016] A drawback of such known power transmission chains is their ineffective power transmission in many situations. More specifically, the known power transmission drive component is always in contact with the drive sprocket under significant load, and under such conditions, the drive component often tends to move relative to the sprocket teeth while maintaining contact under this high load. As a result, the known power transmission components cannot function effectively on the drive sprocket.

[0017] Furthermore, when the links of a known drive component are hinged at the connecting pivot, friction causes energy loss and component wear. This results in additional efficiency losses and a shortened drive life. Summary of the Invention

[0018] According to a first aspect of the invention, a drive sprocket is provided, comprising a plurality of teeth for engaging with a drive member to transmit rotational motion, the drive member including a plurality of engagement grooves engaging the teeth of the drive sprocket, wherein each tooth has a tooth profile defined by a first side including a first engagement surface and an opposing second side including a second engagement surface, the engagement surfaces being configured such that, when driven, the tooth engages with the engagement groove at a first contact position on the first engagement surface and at a second contact position on the second engagement surface, wherein the first contact position is radially offset from the second contact position.

[0019] With this invention, during the use of the drive sprocket, each tooth of the sprocket will engage with the drive member at two contact positions on opposite sides of each tooth. Furthermore, the first contact position will be radially offset from the second contact position during use.

[0020] This arrangement reduces stress on the sprocket during use, thereby reducing wear and tear and friction loss on the drive sprocket, and thus improving transmission efficiency.

[0021] Furthermore, the radial offset between the first and second contact positions helps prevent the engagement groove of the drive component from wedging into or getting stuck on the teeth during use of the drive sprocket.

[0022] Therefore, through this invention, a firm engagement between the pitch groove and the tooth can be achieved when the drive component contacts the drive sprocket. Furthermore, when a load is transmitted between the drive sprocket and the drive component, the stress on the drive sprocket is distributed to reduce local peak stress. Further, reliably disengaging the pitch groove from the tooth can be achieved.

[0023] In embodiments of the invention, each tooth has a front and a back face, the shapes of which are defined by a first side and a second side, wherein the shape of each face is symmetrical about the radial axis of the tooth, and the sides of each face are at least partially defined by two arcs. The advantage of teeth with symmetrical front and back face shapes is that the drive sprocket can rotate in both forward and reverse directions. Symmetrical teeth also enable torque reversal during operation in applications with only one drive direction. This makes the drive sprocket more suitable for diverse applications.

[0024] In an embodiment of the invention, each arc defines one side of a tooth and has a radius R, the centers of the arcs are x apart from each other and y perpendicularly to the center of the drive sprocket, and the center of each arc is located at +x / 2,y.

[0025] In an embodiment of the invention, adjacent teeth are spaced apart from each other by the connecting portion of the sprocket.

[0026] In such embodiments of the invention, the transmission system including the drive sprocket according to an embodiment of the invention will have increased tolerance to dimensional variations within the system components.

[0027] According to a second aspect of the invention, a transmission system is provided, comprising a drive sprocket according to an embodiment of the first aspect of the invention, and further comprising a drive member adapted to engage the drive sprocket.

[0028] In an embodiment of the invention, the driving member includes a plurality of engagement slots, each of the plurality of engagement slots including a first engagement surface and a second engagement surface spaced apart from the first engagement surface, the first engagement surface and the second engagement surface forming an engagement surface pair, the engagement surface pair being rotatable about a rotation axis, wherein adjacent engagement slots are connected to each other by a connecting member.

[0029] In an embodiment of the invention, adjacent engagement grooves are connected to each other by a main link that is rotatable about the rotation axis of the engagement surface pair.

[0030] In such embodiments of the invention, the drive member can engage with the teeth of the drive sprocket such that each engagement slot is adapted to receive the teeth of the drive sprocket and engage with the teeth at a first engagement surface and a second engagement surface. Because adjacent engagement slots are connected to each other by a main link rotatable about the axis of rotation of the engagement surface pair, the teeth will thus engage with the engagement slots such that a first contact position engages with the first engagement surface and a second contact position engages with the second engagement surface.

[0031] Therefore, the teeth are firmly held in place by the engagement groove, making it possible for the teeth to move little or no relative to the groove once they have engaged. Furthermore, because the first and second contact positions are radially offset relative to each other during use of the transmission system, the teeth are less likely to get stuck or wedged into the engagement groove compared to when there is no radial offset.

[0032] In embodiments of the invention, each main link is rotatable about the axis of rotation of each adjacent engagement slot. This facilitates the hinge of the drive component.

[0033] In an embodiment of the invention, the drive member includes a plurality of first main links, the plurality of first main links being coplanar with each other and pivotally connected to each other at a first pivot point and a second pivot point, the pivot points being spaced apart from each other such that adjacent first main links are pivotable about the axis of rotation of each adjacent engagement groove.

[0034] For example, such an arrangement may be desirable when the drive components include a power transmission chain.

[0035] In an embodiment of the invention, the drive member includes a plurality of second main links, the plurality of second main links being coplanar with each other and pivotally connected to each other at a first pivot point and a second pivot point, the pivot points being spaced apart from each other such that adjacent second main links are pivotable about an axis of rotation of each adjacent engagement slot, wherein the first main link is connected to the second main link such that the first main link and the second main link are substantially parallel to each other, and the first pivot point of the first link is coaxial with the second pivot point of the second link, and the second pivot point of the first link is coaxial with the first pivot point of the second link.

[0036] In an embodiment of the present invention, each engagement groove includes a first transverse member and a second transverse member, each transverse member having a first end and a second end, the first transverse member and the second transverse member being spaced apart from each other, wherein the first engagement surface and the second engagement surface are formed on the first transverse member and the second transverse member, respectively.

[0037] In such embodiments, the secondary link may be parallel to the primary link, and the transverse member may be substantially perpendicular to both the primary and secondary links.

[0038] In an embodiment of the invention, each engagement groove includes a first link located at or near the first end of the first transverse member and the second transverse member, and a second link located at or near the second end of the transverse member, wherein the first link and the second link are parallel to each other.

[0039] In such embodiments of the invention, the first link and the second link may be positioned relative to each other, wherein the first lateral member and the second lateral member extend substantially parallel to each other and substantially perpendicular to the first link and the second link. Thus, each engagement groove is defined by the first link and the second link, as well as the first lateral member and the second lateral member.

[0040] In an embodiment of the present invention, the first transverse member and the second transverse member each have a radius r, wherein the distance between the first transverse member and the second transverse member of the joining groove is p2, and the distance between the first pivot point and the second pivot point of the main link is p.

[0041] In embodiments of the invention, the first transverse member and the second transverse member respectively include a first roller and a second roller, each of which may have a radius r and be rotatable about its respective axis. In other embodiments, the first transverse member and the second transverse member may respectively include a first pin and a second pin, each of which may have a radius r and be non-rotatable. In still other embodiments, the first transverse member and the second transverse member include a first curved surface and a second curved surface, each surface having a radius of curvature r.

[0042] According to a third aspect of the invention, a drive member is provided that forms part of a transmission system according to an embodiment of the invention.

[0043] According to a fourth aspect of the invention, a power transmission drive member is provided, adapted to engage with a drive sprocket to transmit rotational motion. The drive member includes a plurality of engagement mechanisms, each engagement mechanism including an engagement body, the engagement body including an engagement groove adapted to engage with the drive sprocket, each engagement groove including a first engagement surface and a second engagement surface spaced apart from the first engagement surface, the first engagement surface and the second engagement surface forming an engagement surface pair, the engagement surface pair being rotatable about a rotation axis of the engagement mechanism, wherein the power transmission drive member includes a carrier member, the carrier member being hinged and adapted to support the plurality of engagement mechanisms.

[0044] With this invention, each tooth of the drive sprocket will engage with the engagement body during use by contacting both the first engagement surface and the second engagement surface.

[0045] This arrangement reduces stress on the sprockets during use and the relative movement between the chain and sprockets during engagement, thereby reducing wear and tear on the drive components and drive sprockets. Furthermore, it reduces frictional losses, thus improving transmission efficiency.

[0046] Because the carrier is hinged, the joint supported by the carrier can be hinged around the drive sprocket during use.

[0047] In embodiments of the present invention, the first and second mating surfaces are positioned symmetrically about the mating body with respect to the axis of rotation.

[0048] In an embodiment of the invention, the engagement surface is configured such that, when driven, the teeth of the sprocket engage with the engagement groove at a first contact position on the first engagement surface and also engage with the engagement groove at a second contact position on the second engagement surface.

[0049] In an embodiment of the invention, the first contact position is radially offset from the second contact position during use.

[0050] This helps prevent the engagement groove of the drive component from becoming wedged or stuck on the teeth during use.

[0051] In an embodiment of the present invention, a first mating surface and a second mating surface are formed on a first pin and a second pin, respectively.

[0052] In some embodiments of the invention, the pin is integrally formed with the remainder of the coupling body, while in other embodiments, the pin is formed separately with the remainder of the coupling body. In such embodiments, the pin can be attached to the remainder of the coupling body by any convenient method and can be attached to the attachment portion, for example, by press-fit.

[0053] In some embodiments of the invention, the cross-sections of the first pin and the second pin may be circular. In other embodiments of the invention, the cross-section of one or both of the first pin and the second pin may be partially circular. For example, one of the first pin and the second pin may have a semi-circular cross-sectional shape, and the corresponding mating surface will be formed on the component with the pin having a curved surface.

[0054] In embodiments of the invention, each engagement mechanism includes two engagement bodies spaced apart from each other.

[0055] In embodiments of the invention, each engagement mechanism includes a connecting member having a first end and an opposing second end, and is attachable at the first end to a engagement body and at the second end to another engagement body, and extends collinearly with the rotation axis of the respective engagement mechanism, wherein each engagement body of the respective engagement mechanism includes a front face and an opposing back face, wherein the engagement surface of each engagement body extends from the front face of the respective engagement body, and the connecting member extends from the back face of each engagement body, the connecting member being adapted to enable the respective engagement mechanism to be connected to the carrier.

[0056] Because the connecting member extends between the back sides of each joint, the connecting member can extend into the carrier to secure each joint to the opposite side of the carrier, wherein the engagement surface of each joint extends outward away from the carrier.

[0057] In embodiments of the present invention, the connecting member is attached to the corresponding joint body by press fitting with the joint body.

[0058] This means that each joint will rotate together with the connecting member. The joint cannot rotate independently of the rotation of the connecting member.

[0059] This can be advantageous because each engaging member of the engaging mechanism will rotate together with another engaging body forming the corresponding engaging mechanism.

[0060] In other embodiments of the invention, the connecting member can be attached to the corresponding joint body by a clearance fit.

[0061] In such embodiments of the invention, the coupling body rotates freely and independently about the connecting member.

[0062] This may be advantageous in embodiments of the invention, where the carrier is, for example, a sleeve chain. Such chains do not include hollow pins.

[0063] In embodiments of the invention including a connecting member, the connecting member may extend laterally through the carrier, whereby a first coupling may be positioned on a first side of the carrier, and a second coupling may be positioned on an opposite second side of the carrier.

[0064] In such embodiments of the invention, the engagement body can thus face outward from the carrier, wherein each engagement mechanism has a first engagement body on one side of the carrier and a second engagement body on the opposite side of the carrier, such that engagement with the teeth of the drive sprocket occurs outside the carrier.

[0065] This is in contrast to known power transmission drive components such as sleeve chains, in which the chain engages with the teeth of sprockets within the chain structure.

[0066] Furthermore, because the connecting member is coaxial with the rotation axis of the engagement mechanism, each engagement body of the engagement mechanism can rotate about the axis of the connecting member, and therefore the two engagement bodies rotate about the same axis.

[0067] The connecting components can take any convenient form and may include, for example, pins.

[0068] Therefore, in such embodiments of the invention, the connecting member can be regarded as the central pin of the corresponding engagement mechanism.

[0069] Each coupling may include a receiving portion adapted to receive the connecting member, the receiving portion including a hole whose center is coaxial with the rotation axis of the corresponding coupling mechanism.

[0070] Another component can be attached or connected to the joint through the holes formed in each joint, while allowing the joint to rotate about the axis of rotation.

[0071] In an embodiment of the invention, the carrier includes hollow pins that extend laterally across the carrier at spaced intervals along its length, wherein each connecting member extends through the hollow pin, thereby connecting the engagement mechanism to the carrier.

[0072] In such embodiments of the invention, the couplings may be mounted to each end of the connecting member such that one coupling is located on one side of the carrier and the other coupling is located on the opposite side of the carrier, and both couplings are located outside the carrier, wherein the coupling surfaces extend away from the carrier.

[0073] In such embodiments of the invention, the carrier may include a hollow pin sleeve chain.

[0074] In such embodiments of the invention, the connecting member can be press-fitted to each joint. This means that the joint will rotate together with the connecting member.

[0075] In other embodiments of the invention, the carrier may take different forms and may not be a hollow pin sleeve chain. For example, the carrier may be a standard sleeve chain instead of a hollow pin sleeve chain.

[0076] In such embodiments of the invention, the carrier includes pins that extend at least partially laterally through the carrier at spaced intervals along its length, wherein each connecting member includes a carrier extending through a hole in each engagement body of a respective engagement mechanism, wherein the pins are shaped to form an interference fit with a link plate of a sleeve chain and a clearance fit with a hole in each engagement body.

[0077] In such embodiments of the invention, the coupling body can rotate independently of the sleeve about the axis of the corresponding pin.

[0078] Therefore, an advantage of the present invention is that a standard chain, such as a hollow pin sleeve chain, can be used to engage with two sprockets or a single sprocket with two sets of teeth, whereby the teeth of one or more sprockets engage with engagement grooves located on the outside of the chain.

[0079] In embodiments of the present invention, the planes of symmetry of the two joints can be parallel to each other, such that the joint surfaces of each joint are aligned with each other.

[0080] In such embodiments of the invention, the power transmission drive member may be adapted to engage with two drive sprockets spaced apart from each other, such that the teeth of the first drive sprocket engage with a coupling body on a first side of the carrier, and the teeth of the second drive sprocket engage with a coupling body on an opposite second side of the carrier.

[0081] In such embodiments of the invention, the carrier and the engagement mechanism are adapted to be hinged around a drive sprocket, thereby making contact via the engagement mechanism. Two sprockets are positioned on opposite sides of the carrier, with the teeth of one drive sprocket engaging the engagement body on a first side of the carrier, and the teeth of the second sprocket engaging the engagement body on the opposite second side of the carrier.

[0082] In some embodiments of the present invention, the power transmission drive component includes a single drive sprocket, the drive sprocket including two sets of teeth spaced apart from each other.

[0083] In such embodiments of the invention, the carrier and the engagement mechanism may be adapted to be hinged around the drive sprocket, thereby making contact via the engagement mechanism. Two sets of teeth are positioned on both sides of the carrier, wherein a first set of teeth engages with the engagement body on a first side of the carrier, and a second set of teeth engages with the engagement body on the opposite second side of the carrier.

[0084] As described above, in some embodiments of the invention, the carrier may comprise a standard hollow pin sleeve chain or a standard sleeve chain with solid pins. Such chains are available in several predetermined sizes based on specific applications and international standards. The dimensions of these known chains depend on the sprockets to which a particular known chain is designed to engage. The key dimensions are the sleeve diameter and the internal width of the chain. The internal width of the chain is the distance between the inner surfaces of the two inner plates of the inner links forming the chain.

[0085] Because the teeth of one or more drive sprockets engage with the outer coupling of the chain, this invention eliminates the need for the chain to interact with the sprocket teeth through conventional contact with the sleeve. This means the chain width can be reduced to such a degree that the sprocket teeth cannot be fitted into the remaining space.

[0086] Furthermore, the space typically occupied by the teeth of a traditional roller chain can be completely eliminated, allowing the inner links of the chain to be reduced to a single plate. This design reduces the number of chain components and allows for a significant reduction in chain width, thereby reducing the required sprocket width and, consequently, the overall system width.

[0087] In some embodiments of the present invention, the inner link may be thicker than the outer link.

[0088] In other embodiments of the invention, the inner links of the chain may include composite inner links formed of a plurality of thinner link plates. An advantage of such embodiments is that by manufacturing thinner link plates, composite link plates of the desired thickness can be easily manufactured by combining an appropriate number of thinner link plates.

[0089] In an embodiment of the invention, each engagement mechanism includes a first extension member and a second extension member, the extension members being spaced apart from each other and coaxial with each other, and each extension member having a first end and a second end, wherein the extension member extends across the width of the engagement mechanism and through each engagement body, such that the first end and the second end of each extension member extend from a first face of each engagement body away from the carrier to form a pin, wherein the first engagement surface of each engagement body is formed on the first end and the second end of the first extension member, respectively, and the second engagement surface of each engagement body is formed on the first end and the second end of the second extension member, respectively.

[0090] In such embodiments of the invention, the first extension member and the second extension member are used to connect the two coupling bodies to each other; thus, the components of the coupling mechanism are integrally formed.

[0091] In such embodiments of the invention, the power transmission drive member may be a chain formed of links, wherein each link includes a body portion and a first leg and a second leg, the first leg and the second leg extending from the body portion to define a space between the leg and the body portion, wherein each leg includes a hollow pin receiving portion, wherein the hollow pin receiving portion of the first leg of the link is coaxial with the axis of rotation of a first engagement mechanism, and the hollow pin receiving portion of the second leg of the link is coaxial with the axis of rotation of a second adjacent engagement mechanism, and wherein each connecting member is adapted to extend through a corresponding hollow pin and engagement body, thereby connecting the engagement body to the link such that each engagement body is rotatable about its axis of rotation, and the space of each link provides space for such rotation.

[0092] In an embodiment of the invention including a hole, the hollow pin receiving portion of the first leg of the link will be coaxial with the hole of the first coupling, and the hollow pin receiving portion of the second leg of the link will be coaxial with the hole of the second adjacent coupling, and the hollow pin will extend through the hole of the coupling.

[0093] With this invention, when the chain is under tension, little or no force is transmitted to the center pin of the engagement mechanism. This means that the center pin can rotate freely about its axis regardless of the chain's load. This improves the efficiency of power transmission because during engagement, when the engagement mechanism rotates in contact with the teeth, there is no significant load at the contact interface with the inner surface of the hollow pin chain or pin link, thereby greatly reducing frictional losses.

[0094] On the other hand, when traveling between sprockets, because the engagement mechanism can rotate freely with virtually no resistance, it may adopt an undesirable orientation relative to the teeth of the sprocket it is to engage. In other words, there may be a position where the engagement body orientation causes it to jam on the top of the teeth instead of adopting the correct position with the engagement surface on either side of the teeth. If this occurs, it may correct itself by jamming when the chain tension increases enough to pull it into place, resulting in undesirable vibration and wear, or it may remain jammed in the wrong position and disrupt the engagement of subsequent engagement mechanisms, thereby increasing the tension in the system and potentially causing the entire system to fail.

[0095] Therefore, in embodiments of the present invention, the carrier includes a rotation angle limiter adapted to restrict the rotation of the engagement mechanism.

[0096] Rotation angle limiters may include stops formed on the carrier, such as folded portions, punched portions, and punched and folded portions. Such portions provide physical stops for the rotational movement of the engagement mechanism.

[0097] In an embodiment of the invention, the rotation angle limiter may be formed on a link of the chain forming the carrier.

[0098] In each of the embodiments described above, each engagement body includes an engagement groove adapted to engage with the drive sprocket, each engagement groove including a first engagement surface and a second engagement surface spaced apart from the first engagement surface, the first engagement surface and the second engagement surface forming an engagement surface pair, the engagement surface pair being rotatable about a rotation axis of the engagement mechanism, wherein the power transmission drive member includes a carrier member that is hinged and adapted to support the plurality of engagement bodies.

[0099] With this invention, each tooth of the drive sprocket will engage with the engagement body during use by contacting both the first engagement surface and the second engagement surface.

[0100] Therefore, the engagement mechanism forming part of the present invention is a double engagement mechanism, thereby ensuring double engagement of the teeth of the sprocket engaged with the power transmission drive member according to the first aspect of the present invention.

[0101] According to a fifth aspect of the invention, a coupling mechanism is provided, which forms part of a power transmission drive member according to a first aspect of the invention.

[0102] According to a sixth aspect of the present invention, a power transmission system is provided, comprising a power transmission drive member and a drive sprocket according to a first aspect of the present invention, wherein the power transmission drive member is adapted to engage with the drive sprocket to transmit rotational motion.

[0103] According to a seventh aspect of the invention, a drive sprocket is provided, comprising a plurality of teeth for engaging with a drive member to transmit rotational motion, the drive member including a plurality of engagement grooves engaging the teeth of the drive sprocket, wherein each tooth has a tooth profile defined by a first side including a first engagement surface and an opposing second side including a second engagement surface, the engagement surfaces being configured such that, when driven, the tooth engages with the engagement groove at a first contact position on the first engagement surface and at a second contact position on the second engagement surface, the first contact position being radially offset from the second contact position, and wherein each tooth has a front face and a back face, the shape of the face of the tooth being defined by the first side and the second side such that the shape of each face is symmetrical about the radial axis of the tooth, and the first side of each face is at least partially defined by a first face arc, and the second side of each face is at least partially defined by a second face arc, wherein the distance between the center of the first face arc of each tooth and the center of the second face arc is substantially the same as the distance between the center of the first face arc of the first tooth and the center of the second face arc of the adjacent tooth.

[0104] Therefore, the present invention provides a drive sprocket in which not only are each tooth symmetrical, but all teeth are substantially the same shape, and the distance between adjacent teeth is defined by the radius of the arc forming the first and second surface arcs.

[0105] In some embodiments of the invention, the first surface arc forms the base of the first side of each tooth, and the second surface arc forms the base of the second side of each tooth, wherein the first surface arc and the second surface arc each include a roller seat curve.

[0106] In such embodiments of the invention, the roller seat curve is adapted to receive rollers or other engaging parts of a drive member adapted to engage with a sprocket.

[0107] In some embodiments of the invention, each first side and second side includes a second portion, the second portion including a convex arc extending from the respective roller seat curve toward the tip portion of the respective tooth.

[0108] In such embodiments of the invention, the second portion including the convex arc may include a working curve. The convex arc shape of the working curve allows the drive member to hinge during engagement and disengagement without contacting the sprocket teeth.

[0109] The drive sprocket may further include a support curve extending from the roller seat curve of the first tooth to the roller seat curve of the adjacent tooth.

[0110] In such embodiments of the invention, the support curve is adapted to receive the rollers or other components of the drive member to support the rollers or other components.

[0111] According to an eighth aspect of the invention, a transmission system is provided, comprising a drive sprocket according to an embodiment of the first aspect of the invention, and further comprising a drive member adapted to engage with the drive sprocket.

[0112] In an embodiment of the present invention, the driving member includes a plurality of engagement grooves, each engagement groove including a first engagement surface and a second engagement surface spaced apart from the first engagement surface.

[0113] In an embodiment of the invention, the drive member includes a roller chain, and the engagement groove is defined between adjacent rollers forming the roller chain.

[0114] The engagement groove of the drive component is considered to be a pair of parallel cylindrical rollers spaced a fixed distance from each other, thus forming the teeth of the drive component adapted to the space therein.

[0115] In embodiments of the invention where the drive component includes a roller chain, engagement grooves are defined between adjacent rollers of the roller chain.

[0116] When the groove engages with the tooth, it has only one degree of freedom. This is the hinge of the groove around the center of the corresponding roller.

[0117] In an embodiment of the invention, the roller chain has a pitch p, and the distance between the center of the first surface arc of each tooth and the center of the second surface arc, as well as the distance between the center of the first surface arc of the first tooth and the center of the second surface arc of the adjacent tooth, is substantially equal to p.

[0118] In an embodiment of the invention, two rollers will be positioned between adjacent teeth of the sprocket to form an engagement pair. This means that every other engagement groove will engage with a tooth of the sprocket, because only every other pair of rollers will be positioned around the teeth to form an engagement pair. The remaining roller pairs will be positioned between adjacent teeth of the sprocket, so the engagement grooves of these roller pairs will not contact the teeth.

[0119] This is advantageous because only half of the rollers will bear the load while the drive component is hinged to the sprocket. The other half of the rollers will act as a support, thus reducing the contact load during its hinge period. This, in turn, reduces some of the wear and friction losses in the transmission system, thereby improving transmission efficiency.

[0120] This contrasts sharply with known sprockets used in conjunction with roller chain drive components, where each roller is positioned between two adjacent teeth during the use of the sprocket.

[0121] In embodiments of the invention where the drive component is a roller chain, the radius of each roller is substantially equal to or slightly smaller than the radius of each seat curve.

[0122] With this invention, the rollers of the roller chain will be supported by the roller seat curve, such that the engagement groove defined between adjacent rollers of the drive member will engage with the teeth, so that the engagement groove engages at two contact positions.

[0123] Due to the dimensions of the arc that defines the roller seat curve, and due to the radius of each roller relative to the arc, the roller chain will engage during use of the drive system such that two rollers are positioned between adjacent teeth.

[0124] Furthermore, regardless of the number of teeth on the sprocket, the radii of the first and second arcs remain essentially the same.

[0125] This simplifies the sprocket manufacturing process.

[0126] In embodiments of the invention, during use of the transmission system, the first roller or other drive component engagement member will be a load-bearing roller or component, and the second roller or drive component component will serve as a support roller or component. When the roller or other engagement member serves as a support, it can be supported and received by the curve of the roller seat.

[0127] According to a ninth aspect of the present invention, a transmission system is provided, comprising a drive sprocket and a drive member adapted to engage with the drive sprocket, the drive sprocket including a plurality of teeth for engaging with the drive member to transmit rotational motion, and the drive member including a plurality of engagement grooves adapted to engage the teeth of the drive sprocket.

[0128] Each tooth of the drive sprocket has a tooth profile defined by a first side including a first engagement surface and an opposing second side including a second engagement surface. The engagement surfaces are configured such that, when driven, the tooth engages with an engagement groove at a first contact position on the first engagement surface and also at a second contact position on the second engagement surface, the first contact position being radially offset from the second contact position.

[0129] The drive member comprises a roller chain containing a plurality of spaced-apart rollers, each roller being spaced a predetermined distance from adjacent rollers, and connected to adjacent rollers by a rigid connecting member extending between the two adjacent rollers, thereby defining the engagement groove between the adjacent rollers.

[0130] The first engagement groove is formed by a first roller and a second roller that are adjacent to each other; the second engagement groove is formed by the first roller and a third roller; and the third engagement groove is formed by the second roller and a fourth roller, wherein the third roller is adjacent to the first roller, and the fourth roller is adjacent to the second roller.

[0131] Furthermore, the angle formed between the connecting member connecting the first roller and the second roller and the connecting member connecting the first roller and the third roller includes a first hinge angle, and the angle formed between the connecting member connecting the first roller and the second roller and the connecting member connecting the second roller and the fourth roller includes a second hinge angle.

[0132] The size of the first hinge angle formed when the first roller, the second roller, and the third roller are all in contact with the teeth is different from the size of the second hinge angle formed when the first roller, the second roller, and the fourth roller are all in contact with the teeth.

[0133] Therefore, the present invention provides a transmission system in which, when a third roller contacts a second tooth adjacent to the first tooth on the first side of the first tooth, the hinge angle at the first contact point of the first roller that contacts the first tooth is different from the hinge angle at the second contact point of the second roller that contacts the same tooth on the opposite side of the first tooth, and a fourth roller contacts a third tooth adjacent to the first tooth on the second side of the first tooth.

[0134] The driving component can be considered as including multiple hinge points, and the hinge angle is limited at the hinge points.

[0135] In embodiments of the invention, the connecting member includes a link. In such embodiments of the invention, the link is hinged about a hinge point, and the hinge angle defines the degree of hinge between the first link and the second link.

[0136] In an embodiment of the invention, rollers are located at each hinge point such that each tooth is engaged by two rollers, wherein:

[0137] The two roller contact points are located on opposite sides of the teeth;

[0138] The contact points are radially offset from each other; and

[0139] The distance between the centers of two adjacent rollers is always the same.

[0140] The efficiency of the sprocket is improved by making the size of the first hinge angle unequal to the size of the second hinge angle. This is because in conventional roller chains, alternating links are hinged by two different types of hinges, referred to as sleeve hinges and pin hinges. During a pin hinge, the pin of the hinged link rotates within a sleeve of an adjacent link that remains stationary relative to the sprocket. In a sleeve hinge, the sleeve of the hinged link rotates within a roller and around a pin of an adjacent link that remains stationary relative to the sprocket. Therefore, a sleeve hinge results in slippage on both surfaces during hinge operation, while a pin hinge results in slippage on only one surface. This means that more energy is lost during sleeve hinges than during pin hinges. In conventional roller chains, the hinge type alternates for each hinge. With this invention, the net energy loss of the powertrain can be reduced by decreasing the size of the hinge angle associated with the less efficient sleeve hinge and increasing the size of the hinge angle associated with the more efficient pin hinge.

[0141] The difference in hinge angle can also be used to reduce wear at the pin-sleeve interface, which causes chain stretching (known as chain extension). The load at the pin-sleeve interface during sleeve hinge is less than the load during pin hinge. This means that sleeve hinge causes more wear than pin hinge. With this invention, net pin-sleeve wear in the drive component can be reduced by decreasing the hinge angle associated with higher wear pin hinges and increasing the hinge angle associated with lower wear sleeve hinges.

[0142] In an embodiment of the present invention, the first roller is a load-bearing roller, and the second roller is a support roller.

[0143] In an embodiment of the present invention, the size of the first hinge angle is greater than the size of the second hinge angle.

[0144] In embodiments of the invention, the size of every other hinge angle is the same. In such embodiments, the hinge angle will therefore alternate between two values.

[0145] In an embodiment of the present invention, when the first roller is a carrying roller and the second roller is a supporting roller, the first hinge angle at each carrying roller will be the same, and the second hinge angle at each supporting roller will be the same.

[0146] In other embodiments of the invention, the hinge angles at the hinge points around the sprocket may vary. The size of the hinge angle can be selected to suit the conditions at the time.

[0147] In an embodiment of the invention, the shape of each tooth surface is symmetrical about the radial axis of the tooth.

[0148] In an embodiment of the invention, the first side of each face is at least partially defined by a first face arc, and the second side of each face is at least partially defined by a second face arc.

[0149] In some embodiments of the invention, the first surface arc forms the base of the first side of each tooth, and the second surface arc forms the base of the second side of each tooth, wherein the first surface arc and the second surface arc each include a roller seat curve.

[0150] In such embodiments of the invention, the roller seat curve is adapted to receive rollers or other engaging parts of a drive member adapted to engage with a sprocket.

[0151] In some embodiments of the invention, each first side and second side includes a second portion, the second portion including a convex arc extending from the respective roller seat curve toward the tip portion of the respective tooth.

[0152] In such embodiments of the invention, the second portion including the convex arc may include a working curve. The convex arc shape of the working curve allows the drive member to hinge during engagement and disengagement without contacting the sprocket teeth.

[0153] The drive sprocket may further include a support curve extending from the roller seat curve of the first tooth to the roller seat curve of the adjacent tooth.

[0154] In such embodiments of the invention, the support curve is adapted to receive the roller to support it.

[0155] In an embodiment of the invention, the roller chain includes a plurality of inner links and a plurality of outer links. Each inner link is used to connect two rollers to form a roller pair, and each outer link is used to connect the roller pairs to each other to form the roller chain, such that a space is defined between the inner surfaces of facing inner links and between the inner surfaces of facing outer links, wherein the width of each tooth is equal to or slightly less than the distance between the inner surfaces of facing outer links, and greater than the distance between the inner surfaces of facing inner links.

[0156] In this embodiment of the invention, because the width of each tooth of the sprocket is equal to or slightly less than the distance between the inner surfaces of the facing outer links, the teeth will be mounted between the facing outer links, with a very small gap between the outer surface of the tooth and the inner surface of the facing outer link. The width of the teeth will also prevent the teeth from engaging between the facing inner links, so the sprocket will only engage with the teeth between the outer links and not with the teeth between the inner links. This helps to maintain the alignment of the roller chain during use.

[0157] This contrasts sharply with the situation in known transmission systems, where, because the width of each tooth is less than the distance between the inner surfaces of the facing inner links, the teeth of a known sprocket can engage with either an inner or outer link of the chain. This means that when the teeth of a known sprocket engage with an outer link, there will be a significant gap between the outer surface of the tooth and the inner surface of the facing outer link.

[0158] In an embodiment of the invention, each tooth of the sprocket includes a first width and a second width, the first width being equal to or slightly less than the distance between the inner surfaces of the facing inner links, and the second width being equal to or slightly less than the distance between the inner surfaces of the facing outer links.

[0159] In such embodiments, when the teeth engage between facing outer links, the portion of each tooth having a first width prevents the inner links from interfering with the teeth.

[0160] According to a tenth aspect of the invention, a sprocket is provided that forms part of a transmission system according to an embodiment of a first aspect of the invention, and further includes a drive member comprising a plurality of spaced-apart rollers. Attached Figure Description

[0161] Embodiments of the present invention will now be further described with reference to the accompanying drawings, in which:

[0162] Figure 1 This is a schematic diagram of a drive sprocket according to an embodiment of the first aspect of the present invention;

[0163] Figure 2 yes Figure 1 Detailed drawing of a portion of the drive sprocket;

[0164] Figure 3 yes Figure 1 and 2 A schematic diagram of a drive sprocket, which engages with a drive member according to an embodiment of the third aspect of the present invention and includes a power transmission chain to form a transmission system according to an embodiment of the second aspect of the present invention;

[0165] Figure 4 yes Figure 3 A more detailed schematic diagram of the transmission system;

[0166] Figure 5 yes Figure 3 and 4 A schematic diagram of the transmission system, in which the main chain link has been removed from one side;

[0167] Figure 6 , 7 And 8 is like Figure 5The schematic diagram of a portion of the transmission system shows the position of the secondary link during the rotation of the drive sprocket;

[0168] Figure 9 and 10 This is a schematic diagram showing the dimensions of the main and secondary links of the transmission chain;

[0169] Figure 11 This is a schematic diagram showing the position of the center of the arc on the side that defines the teeth of the drive sprocket relative to the center of the drive sprocket;

[0170] Figure 12 It is shown Figure 1 A schematic diagram showing the radial offset between the first and second contact positions of the teeth of the drive sprocket; and

[0171] Figure 13 It is shown Figure 1 and 2 A schematic diagram showing the dimensions of the drive sprocket.

[0172] Figure 14 It is a power transmission drive component according to an embodiment of the present invention, wherein the carrier includes a hollow pin chain having a plurality of joints hinged around a drive sprocket;

[0173] Figure 15 yes Figure 14 An exploded view of a portion of a hollow pin chain, thus showing the links of the chain;

[0174] Figure 16 yes Figure 14 Detailed diagram of the links of the hollow pin chain;

[0175] Figure 17 It is formed Figure 14 An exploded view of two engaging mechanisms, part of a power transmission drive mechanism, showing the passage through Figure 14 The connecting component of each engagement mechanism of the hollow pin chain;

[0176] Figure 18 It is formed Figure 14 A schematic diagram of the engagement mechanism of a portion of the chain;

[0177] Figure 19 This is a schematic perspective view of a coupling body suitable for forming part of a coupling mechanism to form part of a drive transmission drive member according to an embodiment of the present invention;

[0178] Figure 20 It is suitable for and Figure 14 A schematic diagram of the drive sprocket engaged with the drive components;

[0179] Figure 21 It has a width ratio Figure 14 A schematic diagram of an embodiment of a power transmission drive component that is narrower than the power transmission drive component, and whose surrounding width is also narrower than the power transmission drive component. Figure 20 The sprockets are narrower and the drive sprockets are hinged.

[0180] Figure 22 yes Figure 21 A schematic diagram of a portion of the chain;

[0181] Figure 23 yes Figure 22 The cross-sectional view of a portion of the chain shown illustrates the in-place engagement mechanism;

[0182] Figure 24 This is a schematic diagram of a portion of a chain according to another embodiment of the present invention, showing the joining body of the chain links connected to the chain;

[0183] Figure 25 There is no joint. Figure 24 A schematic diagram of the chain links;

[0184] Figure 26 This is an exploded schematic diagram of a portion of a chain according to another embodiment of the present invention, wherein the inner links are formed by a plurality of link plates;

[0185] Figure 27 This is an exploded schematic diagram of a portion of a chain according to another embodiment of the present invention, wherein the chain is a sleeve chain with solid pins;

[0186] Figure 28 yes Figure 27 A schematic perspective view of a portion of the chain shown, with the connecting parts not in place;

[0187] Figure 29 This is an exploded schematic diagram of a chain forming a power transmission drive component according to another embodiment of the present invention;

[0188] Figure 30 yes Figure 29 An exploded view of the chain section shows a hollow pin extending through the chain;

[0189] Figure 31 yes Figure 29 Top perspective view of the chain section;

[0190] Figure 32 yes Figure 29 A top perspective view of the chain portion, wherein the chain has a joining surface formed by monomers extending through the width of the chain; and

[0191] Figure 33 This is a schematic diagram of the outer link plate on which an angle limiter is formed.

[0192] Figure 34 This is a schematic diagram of a roller chain that engages with a sprocket according to an embodiment of the present invention to form a transmission system according to an embodiment of the present invention;

[0193] Figure 35 yes Figure 34 A schematic diagram of the transmission system, with some chain links removed to more clearly show how the chain rollers engage with the sprockets;

[0194] Figure 36 yes Figure 34 A perspective view of a portion of a sprocket, showing the tooth profile of the sprocket's teeth;

[0195] Figure 37 yes Figure 34 A schematic diagram of the transmission system shows how the rollers of the roller chain engage with the teeth of the sprocket;

[0196] Figure 38 yes Figure 34 A schematic diagram of the transmission system shows the location of the engagement slot during the use of the transmission system;

[0197] Figure 39 It is shown Figure 34 A schematic diagram showing the dimensions of the rollers in the roller chain;

[0198] Figure 40 yes Figure 34 A schematic diagram of the sprocket arc structure of the transmission system shown; and

[0199] Figure 41 It is shown by Figure 34 The diagram shows the motion of the rollers caused by the wear of the drive component.

[0200] Figure 42 yes Figure 34 A schematic diagram of the transmission system shows how the rollers of the roller chain engage with the teeth of the sprocket and illustrates the hinge angle.

[0201] Figure 43 It is a schematic diagram of a polygon formed by the hinge point of a sprocket that forms part of a transmission system according to an embodiment of the present invention;

[0202] Figure 44 It is superimposed on Figure 42 On the sprocket Figure 43 A schematic diagram of a polygon, showing the rollers arranged around the sprocket;

[0203] Figure 45 yes Figure 34 A schematic diagram of a portion of a roller chain, showing the inner and outer links;

[0204] Figure 46 This is a schematic diagram of a sprocket according to another embodiment of the present invention, wherein each tooth has a first width and a second width, the second width being greater than the first width; and

[0205] Figure 47 It is shown Figure 46 sprocket and Figure 45 A schematic diagram of a standard roller linkage of the type shown. Detailed Implementation

[0206] Original Reference Figure 1 and 2 The drive sprocket according to an embodiment of the first aspect of the present invention is generally indicated by reference numeral 10.

[0207] The sprocket 10 includes a plurality of teeth 12 spaced apart from each other around the outer circumference 14 of the sprocket 10.

[0208] Each tooth has a tooth profile defined by a first side 16 including a first engagement surface 18 and opposing second sides 20 including a second engagement surface 22. Each tooth further includes a front face 24 and a back face 26, the shapes of which are defined by the first side 18 and the second side face 20, which in this embodiment include the first engagement surface and the second engagement surface. The shape of each face is symmetrical about a radial axis 28 extending along the length of each tooth.

[0209] The shape of each side 16, 20 is at least partially defined by an arc. Because each tooth 12 is symmetrical about axis 28, the dimensions of the arcs forming all sides are the same.

[0210] Now for reference Figure 11 As can be seen, in this embodiment, each arc defining one side of the tooth 12 has a radius R. The centers of the arcs are spaced x apart from each other and y perpendicularly to the center of the drive sprocket. The center of each arc is located at ±x / 2, y. Adjacent teeth 12 are separated from each other to define the connecting portion 30, for example... Figure 2 As shown. In the illustrative embodiment, the connecting portion is substantially flat. However, it should be understood that in other embodiments of the invention, the connecting portion may not be flat, or there may be no connecting portion at all.

[0211] Now go to Figures 3 to 8 According to an embodiment of the second aspect of the invention, the transmission system is generally designated by reference numeral 100. The transmission system 100 includes... Figure 1 and Figure 2The sprocket 10 shown and described above. The drive system 100 further includes a power drive chain 110. The power drive chain 110 is adapted to engage with the sprocket 10 as described below, so as to enable the transmission of power between the drive sprocket 10 and another drive sprocket (not shown).

[0212] For example, such as Figure 6 , 7 As shown in Figure 8, the power transmission chain 110 includes a plurality of engagement slots 150 extending along the chain 110. Each engagement slot 150 includes a first engagement surface 152 and a second engagement surface 154 spaced apart from the first engagement surface 152. The first engagement surface 152 and the second engagement surface 154 together form an engagement surface pair 156.

[0213] Each mating surface pair 156 is rotatable about the rotation axis 158. Adjacent mating grooves 150 are connected to each other by at least one main link 112, which is rotatable about the rotation axis 158.

[0214] In this embodiment, there is a first set of coplanar main links 114, a second set of coplanar main links 116, a third set of coplanar main links 118, and a fourth set of coplanar main links 120. Each set of main links is substantially parallel to the main links of each of the other sets.

[0215] The main links 112 that are coplanar with each other in a particular group are also pivotally connected to each other. Each main link 112 has a first pivot point 122 and a second pivot point 124, which are spaced apart from each other along each main link 112, such that adjacent main links 112 can pivot about the first main pivot point 122 and the second main pivot point 124.

[0216] In an illustrative embodiment of the invention, the first main link 114 and the second main link 116 are connected to and adjacent to each other, such that the first pivot point 122 of the first main link 114 is coaxial with the second pivot point 124 of the second main link 116, and vice versa.

[0217] Similarly, the third main link 118 and the fourth main link 120 are connected and adjacent to each other, such that the first pivot point 122 of the third main link 118 is coaxial with the second pivot point 124 of the fourth main link 120, and vice versa.

[0218] The drivetrain 110 further includes a plurality of secondary links 130, each of which is adapted to rotate substantially about a rotation axis 158 of a corresponding engagement slot 150. Each secondary link 130 is positioned substantially parallel to a corresponding primary link 112 such that the rotation axis 158 of a particular engagement slot 150 is coaxial with a first pivot point 122 or a second pivot point 124 of the corresponding primary link 112. This, in turn, means that adjacent primary links 112 can pivot about the rotation axis 158.

[0219] In this embodiment, the plurality of secondary links 132 include a plurality of primary links 138 and a plurality of secondary links 140. Each primary link 138 is adjacent to a second primary link 116, and each secondary link 140 is adjacent to a third primary link 118.

[0220] In this embodiment, two first links 138 are adjacent to each second main link 116, and two second links 140 are adjacent to each third main link 118.

[0221] In this embodiment of the invention, the first links 138 are substantially coplanar with each other, and the second links 140 are substantially coplanar with each other, the first links 138 and the second links 140 being spaced apart such that each first link 138 faces the corresponding second link 140 to form a pair of sub-links 142.

[0222] In this embodiment, each engagement groove 150 includes a first transverse member 144 and a second transverse member 146, the first and second transverse members being spaced apart from each other, and a first engagement surface 152 and a second engagement surface 154 being formed on the first and second transverse members, respectively. The first transverse member 144 and the second transverse member 146 extend laterally between corresponding first and second links forming a pair. Thus, the transverse members 144, 146 connect the secondary links together. In this embodiment, the first transverse member 144 and the second transverse member 146 each include a roller 148. In other embodiments, each transverse member 144, 146 may include a pin.

[0223] The space defined between the first and second transverse members of the secondary link forms an engagement groove 150. As shown, the engagement groove 150 is shaped and positioned to receive and engage with the teeth 12 of the sprocket 10.

[0224] In the application of the transmission system 100, the teeth 12 of the drive sprocket 10 engage with the engagement groove 150 at a first contact position 160 on the first engagement surface 18 and at a second contact position 162 on the second engagement surface 20, for example, as Figure 6As shown. Once engaged, the first contact position 160 will engage with the first engagement surface 152 of the engagement groove 150, and the second contact position 162 will engage with the second engagement surface 154 of the engagement groove 150.

[0225] Due to the relationship between the main link and the secondary link as described above, as well as the characteristics of the transverse members 144, 146 and the drive sprocket 10, during the use of the transmission system 100, the first contact position 160 is radially offset from the second contact position 162.

[0226] This results in the roller 148 maintaining contact with the first engagement surface 18 and the second engagement surface 20 of each corresponding tooth 12, and each sub-link 130 being positioned at an offset angle such that one roller 148 is radially higher on one side of the tooth 12 than the roller 148 on the other side of the tooth.

[0227] Now will be of particular reference Figures 9 to 13 The geometry of tooth 12 and transmission chain 110 is described in more detail.

[0228] First refer to Figure 9 and 10 This schematically shows a portion of the drive train 110.

[0229] It can be seen that the distance between the first p pivot point 122 and the second p pivot point 124 of the main link 112 is p, the distance between the axes of the first transverse member 144 and the second transverse member 146 is p2, and the radius of each roller 148 is r.

[0230] Now for reference Figure 11 According to Cartesian coordinates, where the origin is located at the center of the sprocket and the centerline of the teeth is parallel to the y-axis:

[0231] A symmetrical tooth geometry is proposed, which has two circular arcs with radius R, wherein the center of the arcs is located at... Wherein, R, x, and y are defined such that when the chain is hinged around the sprocket and when a load is applied to the chain:

[0232] 1. The roller of each sub-link maintains contact with the two arcs of each corresponding tooth, and;

[0233] 2. The secondary links are placed at an offset angle such that one roller on one side of the tooth is higher than the roller on the other side of the tooth.

[0234] Furthermore, a straight line of length l extends from the end of the arc towards the center line at an angle γ above the tooth, causing the chain pitch p to lengthen as the chain wears, and the corresponding pitch circle radius r... p Increase:

[0235] 1. It can maintain contact with the teeth through two rollers, and;

[0236] 2. The normal contact force acting on the load-bearing roller remains parallel to the tension in the main chain link on the high-pressure side of the chain. Now refer to Figure 12 and 13 The geometry of the sprocket will be considered in more detail.

[0237] Equations 1 and 2 below give the hinge angle α and pitch circle radius r of an n-tooth sprocket with pitch p. p .

[0238]

[0239]

[0240] The values ​​of the arc parameters R, x, and y are given by the solution of the system of equations given in equations 3 to 6, where

[0241]

[0242] x=(Rr)(cosγ+cosβ)+p2 cosδ (4)

[0243]

[0244]

[0245] Table 1 provides example values ​​of R, x, and y for given p, p2, r, n, β, and δ.

[0246]

[0247] See Figures 14 to 20 And first see Figure 14 According to embodiments of the present invention, the power transmission drive component is generally designated by reference numeral 100. The drive component 100 is shown as hinged around the drive sprocket 200. Figure 20 This is shown in more detail. Especially from... Figure 20 As can be seen, the sprocket 200 includes a first set of teeth 210 and a second set of teeth 220. The tooth sets 210 and 220 are spaced apart from each other by the sprocket body 230. In other embodiments of the present invention, the drive sprocket 200 may be replaced by two separate sprockets, each having a single set of teeth spaced apart from each other, such that the teeth of the two sprockets engage with the drive member.

[0248] In this embodiment of the invention, the driving component includes a hollow pin sleeve chain 110, which includes inner links 120 and outer links 130. The links 120 and 130 are connected together by hollow pins 140, for example, particularly as Figure 15 and 16 As shown.

[0249] The drive member 100 further includes an engagement mechanism 300, specifically as follows: Figure 18 As shown. In this embodiment of the invention, each engagement mechanism includes two engagement bodies 310. Each engagement body 310 includes an engagement groove 320 adapted to engage with a drive sprocket 200. Each engagement groove includes a first engagement surface 330 and a second engagement surface 340 spaced apart from the first engagement surface 330. The first engagement surface 330 and the second engagement surface 340 together form an engagement surface pair 350, which can surround... Figure 18 The pivot axis of the coupling mechanism, indicated by the dashed line 360, rotates.

[0250] When the drive member 100 is hinged to the sprocket 200, each tooth 240 of the drive sprocket 200 will engage with the engagement body 310 by contacting the first engagement surface 330 and the second engagement surface 340 of the engagement body 310.

[0251] In other words, the engagement mechanism 300 is adapted to engage with each tooth 240 of the sprocket 200 using the principle of double engagement, thereby making contact on both sides of each tooth 240 to achieve a strong engagement that is efficient and effective and can distribute the load of the chain across a large number of teeth of the sprocket 200.

[0252] The first engagement surface 330 and the second engagement surface 340 are configured such that when driven, the teeth 240 of the sprocket 200 engage with the engagement groove 320 of the engagement mechanism 300 at a first contact position 250 on the first engagement surface 330 and at a second contact position 260 on the second engagement surface 340.

[0253] During use, the first contact position 250 is radially offset from the second contact position 260. This helps prevent the engagement groove 320 from wedging into or getting stuck on the teeth 240 during use.

[0254] In this embodiment of the invention, the first mating surface 330 and the second mating surface 340 are formed on the first pin 280 and the second pin 290, respectively.

[0255] Pins 280 and 290 can be integrally formed with the rest of the assembly 310.

[0256] In another embodiment of the invention, pins 280, 290 may be formed separately from the rest of the coupling 310, such as Figure 19 As shown. In this embodiment, the coupling body 310 includes a pin hole 370, the shape of which allows pins 280 and 290 to be press-fitted into the pin hole 370.

[0257] In another embodiment of the invention, pins 280 and 290 have a semi-circular cross-section, wherein a mating surface is formed on the curved portion of pins 280 and 290.

[0258] In another embodiment, the first engagement surface 330 and the second engagement surface 340 are formed from folded sheets. Alternatively, the engagement body 310 is shaped to optimize engagement with the sprocket teeth 240.

[0259] Each of the coupling bodies 310 includes a hole 270, the center of which is coaxial with the rotation axis 360 of the coupling mechanism.

[0260] Each engagement mechanism 300 further includes a connecting member 400 having a first end 410 and a second end 420. The connecting member 400 is attachable at its first end 410 to a first engagement body 310 and at its second end 420 to a second engagement body 310, such that it extends coaxially with the rotation axis of the respective engagement mechanism.

[0261] In this embodiment of the invention, the first end 410 and the second end 420 of the connecting member 400 each fit into the hole 270 of the coupling body 310, such that the two coupling bodies 310 of the coupling mechanism 300 rotate together with the connecting member 400 about the rotation axis 360. In other words, the coupling body 310 cannot rotate independently of the connecting member. Therefore, the hole 270 serves as a receiving portion adapted to receive the connecting member 400.

[0262] In some embodiments of the invention, the hole 270 is irregularly shaped. This can facilitate the orientation of the coupling 310 relative to the connecting member 400.

[0263] In this embodiment of the invention, each connecting member 400 extends through the hollow pin 140, thereby connecting the engagement mechanism 300 to the chain 110, such that a first engagement body 310 is located on one side of the chain 110, and the other engagement body 310 is located on the other side of the chain. Thus, both engagement bodies 310 are outside the chain 110, with engagement surfaces extending away from the chain, and the connecting member 400 extends laterally across the chain. Furthermore, both engagement bodies 310 rotate about the rotation axis 360.

[0264] Therefore, with the present invention, a standard hollow pin sleeve chain can be easily adjusted so that it can engage with two sprockets, or, as in this embodiment, the hollow pin sleeve chain can engage with a single sprocket 200 having two sets of teeth 210, 220, whereby the teeth 240 of the sprocket 200 engage with a groove 320 positioned outside the chain.

[0265] Now for reference Figures 21 to 23According to another embodiment of the invention, the power transmission drive member 1100 is shown as hinged around a drive sprocket 1200 having teeth 1240.

[0266] In this embodiment of the invention, the power transmission drive component 1100 includes a hollow pin chain 1110, the proportion of which is, for example... Figure 34 The type shown is a conventional hollow pin chain narrow. Chain 1110 includes components similar to... Figure 3 The inner link 1120 and outer link 1130 of the chain 110 and 120, respectively, no longer require the chain 1110 to be wide enough to accommodate the sprocket teeth. This is because the teeth 1240 of the sprocket 1200 engage on the outside of the chain 1110, and their engagement method is the same as described above regarding... Figures 14 to 20 The embodiments shown are described in the same manner.

[0267] Since the width of chain 1110 is smaller than the width of chain 110, the space between the two sets of teeth of sprocket 1200 is correspondingly smaller than the space between the two sets of teeth of sprocket 200.

[0268] exist Figure 24 and 25 In the alternative embodiment shown, the inner link 1120 is replaced by a single plate 1135, which includes a first hollow pin receiving portion and a second hollow pin receiving portion, the hollow pin receiving portion being adapted to receive a hollow pin in a manner similar to the previous embodiment described above.

[0269] In all other respects, the power transmission drive component 1100 contains corresponding components and operates in the same manner as the power transmission drive component 100.

[0270] Now go to Figure 26 This illustrates another embodiment of the invention. In this embodiment, the inner link 1135 has been replaced by a plurality of thinner link plates 1235 forming the composite inner link. From a manufacturing point of view, this may be advantageous, and it also means that by having a plurality of link plates 1235, the thickness of the composite link can be varied according to the application.

[0271] Now go to Figure 27 and 28 This illustrates another embodiment of the power transmission drive chain according to an embodiment of the present invention.

[0272] In this embodiment of the invention, the power transmission drive component includes a sleeve chain 4200, the sleeve chain including a solid pin 4300 extending through the width of the chain 4200.

[0273] Each of the pins 4300 has a pin extension 4320 at either end. Each pin 4300 passes through a hole in an outer link plate 4130, an inner link plate 4120, and a sleeve 4150. The size and shape of the pins are such that there is an interference fit between each pin and the corresponding outer link plate 4130. Each pin extends between corresponding engagement bodies 310, and each pin extension 4320 is adapted to pass through a hole 270 in each engagement body 310. The size and shape of each pin extension are such that there is a clearance fit between each pin extension 4320 and the corresponding engagement body 310.

[0274] In such embodiments of the invention, each engagement 310 is capable of rotating independently about the corresponding pin extension 4320.

[0275] Each pin 4300 may have a head formed at each of its ends to prevent each engagement body 310 from disengaging from the corresponding pin 4300.

[0276] Now for reference Figures 29 to 32 This shows a portion of a power transmission drive member 2100 according to another embodiment of the present invention.

[0277] In this embodiment, each engagement mechanism 2300 includes two engagement bodies 2310 spaced apart from each other. Each engagement mechanism further includes a first extension member 2500 and a second extension member 2510 extending through each engagement body and for connecting the two engagement bodies 2310 to each other.

[0278] Each extension member 2500, 2510 extends through the coupling body 2310 to form pins 2280, 2290, on which a first coupling surface 2330 and a second coupling surface 2340 are formed. Thus, the first coupling surface and the second coupling surface of the two coupling bodies 2310 are integrally formed.

[0279] The drive component 2100 includes a chain 2110, a portion of which is specifically shown in Figure 30 The chain comprises an outer link 2120 and an inner link 2130 connected together by a hollow pin 2140.

[0280] Each link 2120, 2130 includes a body portion 2520 and a first leg 2530 and a second leg 2540 integrally formed with the body portion 2520, extending from the body portion 2520 to define a space 2550 between the legs 2530, 2540 and the body portion 2520. Each leg 2530, 2540 includes a hollow pin receiving portion 2560, and each link 2120, 2130 is positionable on the coupling body 2310 such that the hollow pin receiving portion 2560 of the first leg 2530 of the link is coaxial with the rotation axis of the first coupling mechanism, and the hollow pin receiving portion 2560 of the second leg of the link is coaxial with the rotation axis of the second adjacent coupling mechanism. This means that the hollow pin receiving portion 2560 is coaxial with the hole 2270 of the coupling body 2310.

[0281] Each engagement mechanism 2300 further includes a center pin 2570 passing through a corresponding hollow pin 2140.

[0282] Each hollow pin 2140 engages with a hollow pin receiving portion 2560 passing through the corresponding inner link 2130. A center pin 2570 extends through the hollow pin 2140 and corresponding holes 2270 of the two engaging bodies 2310, wherein the engaging bodies 2310 are positioned on either side of the outer link 2120.

[0283] This arrangement allows the engagement mechanism to rotate about its respective axis of rotation. Space 2550 provides space for rotation.

[0284] Engaging mechanism 2300 and engaging body 2310 are equivalent to engaging mechanism 300 and engaging body 310, and function in the same manner. Specifically, the first engaging surface 2330 and the second engaging surface 2340 form an engaging groove 2320 equivalent to the engaging groove 320, and thus result in double engagement of the sprocket teeth in the pitch groove, as described with reference to the previous embodiment.

[0285] Now go to Figure 33 Another embodiment of the outer link plate 3120 including rotation angle limiters is shown. These limiters are designed to prevent excessive rotation of the joint during use.

[0286] exist Figure 33 In the illustrated embodiment, the outer link plate 3120 includes a limiter 3600 formed by a bent portion of the outer link plate 3120. The angle limiter 3600 restricts the rotational movement of the coupling 3310 and thus reduces the likelihood that the coupling will get stuck.

[0287] In this invention, and as described above, each tooth of the drive sprocket engages with the engagement body via both a first engagement surface and a second engagement surface. This dual engagement reduces stress on the sprocket and relative movement between the chain and the sprocket during use, thereby reducing wear and tear on the drive components and the drive sprocket. Furthermore, frictional losses are reduced, thereby improving transmission efficiency.

[0288] Now for reference Figure 34 and 35 The transmission system according to an embodiment of the present invention is generally designated by reference numeral 2. The transmission system includes a sprocket 4 and a drive member including a roller chain 6.

[0289] In this embodiment of the invention, the roller chain 6 is a standard roller chain comprising a plurality of rollers 8 extending laterally across the transmission member and spaced apart along the length of the drive member to form a chain. The rollers are connected to each other in a known manner by links 10. The roller chain 6 is hinged between adjacent rollers 8. Engagement grooves 40 are defined between adjacent rollers 8. Each engagement groove 40 is adapted to engage with a tooth 12, which will be described in more detail below.

[0290] However, with the present invention, during the use of the transmission system 2, only every other engagement slot 40 will engage with the teeth. The remaining every other engagement slot 40 will effectively engage with the space between adjacent teeth 12.

[0291] Now go to Figure 36 The sprocket 4 is shown in more detail.

[0292] The sprocket 4 includes a plurality of teeth 12, all of which are substantially identical in shape to each other. Each tooth has a tooth surface or tooth profile 14 that is symmetrical about the radial axis R of the sprocket 4.

[0293] The tooth profile 14 is defined by a first side 16 including a first engagement surface 18 and a second side 20 defining a second engagement surface 22. Each of the first side 16 and the second side 20 includes a base 24 forming a roller seat curve 25. Each side further includes a portion 26 extending from the roller seat curve toward the tip 28 of the tooth. The portion 26 is convex and defines a working curve 29.

[0294] The sprocket 4 includes an additional curve 30 forming a support curve 31 extending between adjacent teeth.

[0295] Specifically, such as Figure 37 and 38As shown, in the application of the transmission system 2, every other engagement slot 40 will engage with the corresponding tooth 12, while the remaining every other engagement slot 40 will not engage the tooth. This is because, due to the size of the sprocket, and especially the profile of the teeth, relative to the size of the rollers 8, when the roller chain 6 engages with the sprocket 4, the two rollers 8 will be positioned between adjacent teeth. This again means that every other engagement slot 40 will engage with the tooth 12, and every other engagement slot effectively engages with the space between adjacent teeth 12 of the sprocket.

[0296] See Figure 37 This schematically illustrates how the roller 8 engages with the sprocket 4 during the use of the transmission system 2.

[0297] When considering a pair of rollers 8 positioned on either side of tooth 12, one roller 32 will be the carrying roller, and the second roller 8 will be the supporting roller 34.

[0298] Roller seat curve 25 provides the initial placement position for the engaging rollers 8 of the roller chain 6. For both the load-bearing and support rollers, this curve helps distribute the contact load over a larger area, thereby reducing material stress, at least in the initial stages when chain wear is low. If the drive direction is reversed, roller seat curve 25 allows the rollers to easily switch between support and load positions.

[0299] The carrying roller 32 will engage with the tooth 12 on the first engagement surface 36, and the supporting roller 34 will engage with the tooth on the second engagement surface 38.

[0300] The first engagement surface 36 and the second engagement surface 38 are radially offset from each other. This allows the pair of rollers 8 of the engagement teeth 12 to engage in a double engagement manner, because the roller chain contacts the sprocket teeth 12 at two contact points 37 and 39 on the engagement surfaces 36 and 38 in each tooth of the sprocket.

[0301] The two contact points 37 and 39 are therefore located on opposite sides of the tooth relative to its radial centerline R, and are radially offset from each other and therefore asymmetrical relative to the radial centerline R.

[0302] The combination of these features results in a strong engagement between the drive sprocket teeth and the roller chain 6, and ensures that the roller 8 does not wedge into the teeth. Furthermore, there is almost no relative movement between the teeth and the roller 8 upon contact.

[0303] The first contact point 37 carries and transmits the load between the roller chain 6 and the teeth 12. The second contact point 39 supports and thus stabilizes the roller chain 6 on the sprocket 4 and increases the load distribution on the sprocket teeth 12.

[0304] like Figure 36 and 37As shown, each tooth 12 further includes a working curve 26 that extends from the roller seat curve toward the tip 28 of the tooth.

[0305] The working curve 26 is convex, and the convex arc forming the working curve 26 curves towards the tooth centerline R. The surface of the working curve 26 contacts the carrying roller 32, thereby realizing torque transmission between the roller chain 6 and the sprocket 4. Because the chain pitch is elongated due to internal wear, this surface also accommodates the creeping of the carrying roller, such as... Figure 40 As shown.

[0306] Each tooth tip 28 does not need to have a sharp profile. This is because when the engagement groove 40 is at the point of engagement with the tooth 12, it has only a single degree of freedom, namely the hinge of the engagement groove around the center of the roller.

[0307] The working curve is the primary load-bearing contact surface located on the upper part of each tooth flank. It is this surface that contacts the load-bearing roller 32, enabling torque transmission between the chain and the sprocket. As the chain pitch elongates due to internal wear, this surface also accommodates the creep of the load-bearing roller, thus ensuring that the sprocket can transmit the load throughout the chain's lifespan.

[0308] Turn to Figure 36 The sprocket further includes a support curve 50 that extends between the roller seat curves of adjacent teeth.

[0309] The support curve is designed to accommodate the support roller 34. The support curve can also accommodate some movement of the support roller 34 during the life of the roller chain 6 as the worn chain takes on a different position on the sprocket.

[0310] See details Figure 37 and 38 The joint groove 40 is indicated by line 42.

[0311] The endpoints of line 42 of each mating groove lie on a circle 44 known as the pitch circle. The pitch circle defines the center point of all roller seat curves 25.

[0312] In this embodiment of the invention, the radius of the curve of each roller seat is slightly larger than the radius of each roller. This results in the engagement groove 40 being slightly offset from the pitch circle 44. This, in turn, ensures that the rollers adopt their respective load-bearing and support positions and prevents the engagement groove from getting stuck on the teeth.

[0313] See Figure 39 The dimensions of roller chain 6 are shown in more detail.

[0314] from Figure 39 As can be seen, the distance between adjacent rollers (called chain pitch) can be represented by the letter p, and the diameter of each roller can be represented by d. rexpress.

[0315] See now Figure 40 , showed Figure 34 A schematic diagram of a portion of the transmission system 2. Circle radius r p This represents the pitch circle. For a sprocket 4 with n / 2 teeth, this is a circle passing through all vertices of a regular polygon with n sides. The length of each side of the regular polygon is ρ. Figure 40 The three sides of a regular polygon of length ρ are shown.

[0316] The radius of the arc forming the first and second surface arcs can be determined by r. s Represented. Having a radius r s The center of the roller seat curve 25 is located at each vertex of the regular polygon forming the tooth base. The radius of the arc can be compared with the radius of the roller and given as a ratio ρ. Furthermore, the steepness of the working curve relative to the centerline of the tooth at the contact point of the bearing roller 32 can be represented by Θ. In an embodiment of the invention, the ratio ρ is found to be 1.01, regardless of the number of teeth on the sprocket 12.

[0317] It was found that Θ varies depending on the number of teeth forming the sprocket.

[0318] The following is a representative, but not exhaustive, list of Θ values:

[0319] Number of sprocket teeth Θ (degrees) 6 0.3 8 2.3 10 2.7 25 5.4 30 4.5 32 4.2

[0320] Therefore, it can be seen that in the transmission system according to an embodiment of the present invention, the teeth 12 of the sprocket 4 will have a profile that is almost unchanging with the number of teeth forming the sprocket.

[0321] Therefore, through embodiments of the present invention, a standard roller chain, such as a roller chain conforming to ISO 606, can engage a sprocket, thereby achieving double engagement.

[0322] In an embodiment of the invention where the sprocket 4 has n teeth, the roller seat arc has a fixed radius r for all n teeth. s And this radius is slightly larger than the radius of each roller 8.

[0323] First see Figure 34 and 35 The transmission system according to an embodiment of the present invention is generally designated by reference numeral 2. The transmission system includes a sprocket 4 and a drive member including a roller chain 6.

[0324] In this embodiment of the invention, the roller chain 6 is a standard roller chain comprising a plurality of rollers 8 extending laterally across the transmission member and spaced apart along the length of the drive member to form a chain. The rollers are connected to each other in a known manner by links 10. The roller chain 6 is hinged between adjacent rollers 8. Engagement grooves 40 are defined between adjacent rollers 8. Each engagement groove 40 is adapted to engage with a tooth 12, which will be described in more detail below.

[0325] However, with the present invention, during the use of the transmission system 2, only every other engagement slot 40 will engage with the teeth. The remaining every other engagement slot 40 will effectively engage with the space between adjacent teeth 12.

[0326] Now go to Figure 36 The sprocket 4 is shown in more detail.

[0327] The sprocket 4 includes a plurality of teeth 12, all of which are substantially identical in shape to each other. Each tooth has a tooth surface or tooth profile 14 that is symmetrical about the radial axis R of the sprocket 4.

[0328] The tooth profile 14 is defined by a first side 16 including a first engagement surface 18 and a second side 20 defining a second engagement surface 22. Each of the first side 16 and the second side 20 includes a base 24 forming a roller seat curve 25. Each side further includes a portion 26 extending from the roller seat curve toward the tip 28 of the tooth. The portion 26 is convex and defines a working curve 29.

[0329] The sprocket 4 includes an additional curve 30 forming a support curve 31 extending between adjacent teeth.

[0330] Specifically, such as Figure 37 As shown, in the application of the transmission system 2, every other engagement slot 40 will engage with the corresponding tooth 12, while the remaining every other engagement slot 40 will not engage the tooth. This is because, due to the size of the sprocket, and especially the profile of the teeth, relative to the size of the rollers 8, when the roller chain 6 engages with the sprocket 4, the two rollers 8 will be positioned between adjacent teeth. This again means that every other engagement slot 40 will engage with the tooth 12, and every other engagement slot effectively engages with the space between adjacent teeth 12 of the sprocket.

[0331] See Figure 37 This schematically illustrates how the roller 8 engages with the sprocket 4 during the use of the transmission system 2.

[0332] When considering a pair of rollers 8 positioned on either side of tooth 12, one roller 32 will be the carrying roller, and the second roller 8 will be the supporting roller 34.

[0333] Roller seat curve 25 provides the initial placement position for the engaging rollers 8 of the roller chain 6. For both the load-bearing and support rollers, this curve helps distribute the contact load over a larger area, thereby reducing material stress, at least in the initial stages when chain wear is low. If the drive direction is reversed, roller seat curve 25 allows the rollers to easily switch between support and load positions.

[0334] The carrying roller 32 will engage with the tooth 12 on the first engagement surface 36, and the supporting roller 34 will engage with the tooth on the second engagement surface 38.

[0335] The first engagement surface 36 and the second engagement surface 38 are radially offset from each other. This allows the pair of rollers 8 of the engagement teeth 12 to engage in a double engagement manner, because the roller chain contacts the sprocket teeth 12 at two contact points 37 and 39 on the engagement surfaces 36 and 38 in each tooth of the sprocket.

[0336] The two contact points 37 and 39 are therefore located on opposite sides of the tooth relative to its radial centerline R, and are radially offset from each other and therefore asymmetrical relative to the radial centerline R.

[0337] The combination of these features results in a strong engagement between the drive sprocket teeth and the roller chain 6, and ensures that the roller 8 does not wedge into the teeth. Furthermore, there is almost no relative movement between the teeth and the roller 8 upon contact.

[0338] The first contact point 37 carries and transmits the load between the roller chain 6 and the teeth 12. The second contact point 39 supports and thus stabilizes the roller chain 6 on the sprocket 4 and increases the load distribution on the sprocket teeth 12.

[0339] like Figure 37 As shown, each tooth 12 further includes a working curve 26 that extends from the roller seat curve toward the tip 28 of the tooth.

[0340] The working curve 26 is convex, and the convex arc forming the working curve 26 curves towards the tooth centerline R. The surface of the working curve 26 contacts the carrying roller 32, thereby realizing torque transmission between the roller chain 6 and the sprocket 4. As the chain pitch is elongated due to internal wear, this surface also accommodates the climbing of the carrying roller.

[0341] Turn to Figure 36 The sprocket further includes a support curve 50 that extends between the roller seat curves of adjacent teeth.

[0342] As described above, the rollers 8 of the roller chain 6 are hinged relative to each other by connecting the links of the chain that connect adjacent rollers to each other.

[0343] exist Figure 44 The diagram shows two hinge angles a1 and a2.２ And now we will explain these hinge angles further.

[0344] The first roller 32 and the second roller 34 are shown forming a first engagement groove 401 that meshes with the first tooth 112. The third roller 322 contacts the second tooth 212 and is positioned on one side of the first roller 32. The third roller 322 and the first roller 32 together form a second engagement groove 402.

[0345] The fourth roller 422 is positioned adjacent to the second roller 34 and in contact with the third tooth 312. The second roller 34 and the fourth roller 422 together form the third engagement groove 403.

[0346] In this embodiment of the invention, the first roller 32 is a load-bearing roller, and the second roller 34 is a support roller. Every other roller, starting with the load-bearing roller 32, will also be a load-bearing roller. See also... Figure 42 The fourth roller 422 is also a load-bearing roller. This pattern will repeat itself around sprocket 4.

[0347] When the first roller 32 contacts the first tooth 112 and the third roller 322 also contacts the second tooth 212, the first roller 32 and the third roller 322 are positioned on their respective mating surfaces, and the second roller 34 is in this position, and a first hinge angle a1 is formed at the hinge point 400, which in this embodiment coincides with the axis of the first roller 32.

[0348] Now consider the second roller 34 and the fourth roller 422. When the second roller 34 and the fourth roller 422 are in contact with the corresponding teeth 12, and the first roller 322 is in contact with the teeth 112, the second hinge angle α ２ It forms at the second roller 34.

[0349] In this example, the magnitude of the first hinge angle α1 at the point defined above is greater than the magnitude of the second hinge angle α at the point defined above. ２ .

[0350] Similarly, every other roller starting with the second roller 34 is a support roller. Therefore, in this embodiment, the third roller 322 is also a support roller, and this pattern will repeat around the sprocket 4 itself.

[0351] In this embodiment, every other hinge angle will be the same. This means that hinge angle a1 will be at each load roller, and hinge angle a2 will be at each support roller.

[0352] Adjacent rollers are connected to each other by links that provide a rigid connection between adjacent rollers.

[0353] In this embodiment, the first roller 32 is connected to the second roller 34 via link 450. The third roller 322 is connected to the first roller 32 via link 452, and the second roller 34 is connected to the fourth roller 422 via link 454.

[0354] As shown by the hinge angle, links 450, 452, and 454 are hinged relative to each other.

[0355] Because in this embodiment, the hinge angle at each load-bearing roller 32, 422 is greater than the hinge angle α2 at each support roller 34, 322, each load-bearing roller 332 will be hinged for a longer duration than each support roller 34. This can improve the efficiency of the transmission system.

[0356] Therefore, with the present invention, selective hinge can be achieved by setting different hinge angles at each tooth, or by following a regular pattern as in this embodiment.

[0357] From the perspective of both power transmission efficiency and chain wear, this is desirable. Hinging under load leads to unavoidable friction between adjacent chain links. This results in energy loss and component wear. The magnitude of these losses is roughly proportional to the size of the hinge angle.

[0358] The losses associated with each articulation alternate with the alternating inner and outer links of a standard power drive roller chain. Articulating the outer links is more efficient than articulating the inner links, while articulating the inner links results in less chain elongation than the outer links. By using selective articulation, the magnitude of the beneficial or detrimental effects of a given articulation can be manipulated to improve the overall performance of the drivetrain.

[0359] Specifically, such as Figure 43 and 44 As shown, in a transmission system according to an embodiment of the present invention, the hinge point 400 defines an n-sided irregular polygon 500.

[0360] In an embodiment of the invention where the first hinge angle is a1 and the second hinge angle is a2, this pattern is repeated for each pair of links around the sprocket circumference.

[0361] Therefore, the relationship between these new hinge angles and the original exterior angle 'a' of the n-sided polygon is a1 + a2 = 2a, as shown below. Figure 43 As shown.

[0362] To achieve this n-sided irregular polygon, a sprocket with n / 2 teeth was used, where the teeth are located between every other vertex of the polygon's edges. This is in Figure 44 The diagram shows this more clearly.

[0363] Now go to Figures 45 to 47The diagram schematically illustrates a sprocket 904 according to another embodiment of the invention. The sprocket 904 forms part of a transmission system 1002 comprising the sprocket 904 and the roller chain 6.

[0364] The parts of the transmission system 1002 that are equivalent to the transmission system 2 described above will be given corresponding reference numerals for reference.

[0365] Specifically, such as Figure 45 As shown, the roller chain 6 includes a plurality of rollers 8. The rollers 8 are connected to adjacent rollers via inner links 810 and outer links 820.

[0366] Inner link 810 is used to connect two rollers 8 together to form roller pair 850. Outer link is used to connect roller pair 850 together to form roller chain 6.

[0367] The distance between the inner surfaces 860 of the inner link 810 is Figure 45 The distance between the inner surfaces 870 of the facing outer links 820 is indicated by reference numeral d1. As shown in the attached figure, the distance between the inner surfaces 870 of the facing outer links 820 is indicated by reference numeral d2. Figure 45 As shown, d2 is greater than d1.

[0368] Now go to Figure 46 and 47 The sprocket 904 is described in more detail.

[0369] The sprocket includes a plurality of teeth 12 spaced apart around the sprocket. Each tooth has a first width 914(d1) equal to or slightly smaller than the distance between the inner surfaces of the facing inner links 800.

[0370] Each tooth 12 also has a second width 915, which is equal to or slightly smaller than the distance (d2) between the inner surfaces 870 of the outer links 820.

[0371] In this embodiment of the invention, each tooth includes an intermediate tooth portion 920 and outer tooth portions 922, 924, the intermediate tooth portion and the outer tooth portions together defining a second width.

[0372] When sprocket 904 engages with roller chain 6, the teeth will be positioned between the two outer links, such as... Figure 47 As shown. The widths of the outer tooth portions 922 and 924, together with the width of the intermediate portion 920, result in a total tooth width equal to or slightly less than the distance (d2) between the inner surfaces of the facing outer links, and greater than the distance (d1) between the inner surfaces of the facing inner links. This means that the engagement between the tooth 12 and the chain 6 results in almost no gap between the tooth and the chain. Furthermore, the presence of the outer tooth portions 922 and 924 prevents the teeth from engaging between the inner links, and thus substantially maintains chain alignment during use of the drive transmission system.

[0373] In addition, the presence of the middle section 920 prevents the inner link from interfering with the teeth during use.

Claims

1. A drive sprocket including a plurality of teeth for engaging with a drive member to drive rotational motion, the drive member including a plurality of engagement slots for engaging the teeth of the drive sprocket, wherein each of the plurality of teeth has a fixed position on the drive sprocket and has a tooth profile defined by a first side including a first engagement surface and an opposing second side including a second engagement surface, the engagement surfaces being configured such that, when driven, a tooth engages with one of the engagement slots at a first contact position on the first engagement surface and at a second contact position on the second engagement surface, wherein the first contact position is radially offset from the second contact position.

2. The drive sprocket of claim 1, wherein the drive member comprises a roller chain, and each engagement groove is defined between adjacent rollers forming the roller chain, such that in use, two rollers of the roller chain are positioned between adjacent teeth of the plurality of teeth.

3. The drive sprocket according to claim 1 or claim 2, wherein each tooth has a front and a back face, the shape of the face of the tooth is defined by the first side and the second side, wherein the shape of each face is symmetrical about the radial axis of the tooth, and the side of the face is defined at least partially by two circular arcs.

4. The drive sprocket according to claim 1 or claim 2, wherein adjacent teeth are spaced apart from each other to define the connecting portion of the sprocket.

5. The drive sprocket of claim 1, wherein each tooth has a front and a back face, the shape of the face of the tooth is defined by the first side and the second side such that the shape of each face is symmetrical about the radial axis of the tooth, and the first side of each face is at least partially defined by a first face arc, and the second side of each face is at least partially defined by a second face arc, wherein the distance between the center of the first face arc of each tooth and the center of the second face arc is substantially the same as the distance between the center of the first face arc of the first tooth and the center of the second face arc of the adjacent tooth.

6. The drive sprocket of claim 5, wherein the first surface arc of each tooth includes a base on the first side of the tooth, and the second surface arc of each tooth includes a base on the second side of the corresponding tooth, wherein the first surface arc and the second surface arc each include a roller seat curve.

7. The drive sprocket of claim 6, wherein each first side and second side includes a second portion, the second portion including a convex arc extending from the respective roller seat curve toward the tip portion of the respective tooth.

8. The drive sprocket according to claim 6 or claim 7, further comprising a support curve extending from the roller seat curve of the first tooth to the roller seat curve of the adjacent tooth.

9. A transmission system comprising a drive sprocket according to claim 5 and a drive member adapted to engage with the drive sprocket.

10. The drive system of claim 9, wherein the drive member comprises a roller chain, and adjacent rollers forming the roller chain define a plurality of engagement slots, each engagement slot comprising a first engagement surface and a second engagement surface spaced apart from the first engagement surface.

11. The transmission system of claim 10, wherein the roller chain has a pitch p, and the distance between the center of the first surface arc of each tooth and the center of the second surface arc, and the distance between the center of the first surface arc of the first tooth and the center of the second surface arc of the adjacent tooth are substantially equal to p.

12. A transmission system comprising a drive sprocket according to claim 1 and a drive member adapted to engage with said drive sprocket. The drive member comprises a roller chain containing a plurality of spaced-apart rollers, each roller being spaced a predetermined distance from adjacent rollers, and connected to adjacent rollers by a rigid connecting member extending between the two adjacent rollers, thereby defining the engagement groove between the adjacent rollers. in, The first engagement groove is formed by a first roller and a second roller that are adjacent to each other; the second engagement groove is formed by the first roller and a third roller; and the third engagement groove is formed by the second roller and a fourth roller, wherein the third roller is adjacent to the first roller and the fourth roller is adjacent to the second roller. Furthermore, the angle formed between the connecting member connecting the first roller and the second roller and the connecting member connecting the first roller and the third roller includes a first hinge angle, and the angle formed between the connecting member connecting the first roller and the second roller and the connecting member connecting the second roller and the fourth roller includes a second hinge angle. The size of the first hinge angle formed when the first roller, the second roller, and the third roller are all in contact with the teeth is different from the size of the second hinge angle formed when the first roller, the second roller, and the fourth roller are all in contact with the teeth.

13. The transmission system of claim 12, wherein the drive member includes a plurality of hinge points, and the hinge angle is defined at the hinge points.

14. The transmission system according to claim 12 or claim 13, wherein the first roller includes a load-bearing roller and the second roller includes a support roller.

15. The transmission system according to claim 12 or claim 13, wherein the magnitude of the first hinge angle is greater than the magnitude of the second hinge angle.

16. The transmission system according to claim 12 or claim 13, wherein each of the other hinge angles is substantially the same in magnitude.

17. The transmission system of claim 12 or claim 13, wherein the roller chain comprises a plurality of inner links and a plurality of outer links, each of the plurality of inner links being used to connect two rollers to form a roller pair, and each of the plurality of outer links being used to connect the roller pairs to each other to form the roller chain, such that a space is defined between the inner surfaces of the facing inner links and between the inner surfaces of the facing outer links, wherein the width of each tooth of the sprocket is equal to or slightly less than the distance between the inner surfaces of the facing outer links, and greater than the distance between the inner surfaces of the facing inner links.

18. The transmission system of claim 17, wherein each tooth of the sprocket includes a first width and a second width, the first width being equal to or slightly less than the distance between the inner surfaces of the facing inner links, and the second width being equal to or slightly less than the distance between the inner surfaces of the facing outer links.

Images