Chain and wheel drive

Abstract

A chain and a wheel transmission device, comprising a plurality of inner plate units, a plurality of outer plate units, and a chain shaft unit. Each of the inner plate units has two inner chain plates and defines an inner engagement space. Each of the outer plate units has two outer chain plates, and each of the outer chain plates has two outer hole segments and an outer waist segment located between the outer hole segments. The outer waist segment has a convex portion and a concave portion located on both sides of a longitudinal center line. The outer waist segments of each of the outer plate units cooperate to define an outer engagement space. The outer engagement space has a wide opening side located between the side edges of the convex portion and having a width greater than the width of the inner engagement space, and a narrow opening side located between the side edges of the concave portion and having a width not less than the width of the inner engagement space. Through the shape design of the outer chain plates, the opening sizes of two opposite sides of the outer engagement space are changed, thereby improving the stability of engagement and the smoothness of speed change.

Description

Technical Field

[0001] The present invention relates to a wheel transmission device, particularly a chain and wheel transmission device used in a variable-speed bicycle or a motorcycle. Background Art

[0002] When a chain is used in a bicycle or a motorcycle with variable-speed function, since the chain is shifted between several sprockets with different diameters, the design of the chain must improve the meshing function and the variable-speed efficiency.

[0003] Refer to Figure 1 、 2 A conventional chain 1 is adapted to be wound around and engaged between two front and rear spaced sprockets (not shown) having several teeth. The chain 1 includes several pairs of inner link plates 11 arranged opposite to each other, several pairs of outer link plates 12 arranged opposite to each other and located outside the inner link plates 11, and several chain shafts 13 connecting the inner link plates 11 and the outer link plates 12. An inner meshing space 14 is formed between every two opposite inner link plates 11, and an outer meshing space 15 is formed between every two opposite outer link plates 12. The opening width of each outer meshing space 15 is greater than the opening width of each inner meshing space 14. Each outer link plate 12 has a flange portion 121 protruding in a direction away from the sprocket, and a bulging portion 122 bulging in a direction away from the other opposite outer link plate 12.

[0004] Although the chain 1 can avoid colliding with adjacent sprockets and generating noise during variable speed by the design of the flange portion 121, and can smoothly and easily introduce the teeth of the sprocket into the outer meshing space 15 in the early stage of meshing by the design of the bulging portion 122, during the operation period after introduction, that is, in the later stage of meshing, when the teeth of the sprocket penetrate to the opposite side of the bulging portion 122, since the width of the end of the teeth of the sprocket is smaller than the width of the outer meshing space 15 and can move left and right, during operation, the chain 1 will have a phenomenon of swaying left and right or tilting to one side, which is likely to cause friction with the sprocket to generate noise or derailment.

[0005] In addition, a chain guide wheel (not shown) generally used to shift the chain 1 is correspondingly engaged with the inner meshing space 14. However, since the widths of the outer meshing space 15 and the inner meshing space 14 of the chain 1 are inconsistent, during variable speed, the chain guide wheel must wait until the inner meshing space 14 with a matching width can be engaged, and then shift the chain 1 to an appropriate sprocket. Therefore, during variable speed, there will be unsmooth conditions such as pauses and slowness. Therefore, the design of the chain 1 still needs to be improved. Summary of the Invention

[0006] The object of the present invention is to provide a chain that can overcome at least one drawback of the prior art.

[0007] The chain of the present invention includes several inner plate units, several outer plate units, and a chain shaft unit. The inner plate units are arranged at intervals along an operating direction. Each inner plate unit has two relatively arranged inner link plates. Each inner link plate has two inner hole segments and an inner waist segment located between the inner hole segments. The inner waist segments of each inner plate unit cooperate to define an inner meshing space. The outer plate units are arranged at intervals along the operating direction and are offset and located outside the inner plate units. Each outer plate unit has two relatively arranged outer link plates. Each outer link plate has two outer hole segments and an outer waist segment located between the outer hole segments. The outer waist segment has a convex portion and a concave portion connected between the outer hole segments and located on both sides of a longitudinal center line. The outer waist segments of each outer plate unit cooperate to define an outer meshing space. The outer meshing space has a wide mouth side located between the side edges of the convex portion and a narrow mouth side located between the side edges of the concave portion. The width of the wide mouth side is greater than the width of the inner meshing space, and the width of the narrow mouth side is not less than the width of the inner meshing space. The chain shaft unit has several chain shafts connecting the inner hole segments and the outer hole segments.

[0008] Furthermore, the convex portion of each outer waist segment has a wide inner side face facing the outer meshing space and extending deep in a direction away from the other relatively outer waist segment, and the concave portion has a narrow inner side face facing the outer meshing space and protruding in a direction towards the other relatively outer waist segment.

[0009] Furthermore, the convex portion of each outer waist segment has a wide outer side face facing away from the outer meshing space and protruding in a direction away from the other relatively outer waist segment, and the concave portion has a narrow outer side face facing away from the outer meshing space and extending deep in a direction towards the other relatively outer waist segment.

[0010] Furthermore, the width of the wide mouth side is greater than the width of the narrow mouth side, and the width of the narrow mouth side is equal to the width of the inner meshing space.

[0011] Furthermore, at least one of the convex portion and the concave portion of each outer waist segment has two spaced-apart groove edges extending from the side edge of the outer waist segment towards the longitudinal center line.

[0012] Furthermore, the groove edges converge gradually from the maximum flare of the side edge of the outer waist segment towards the longitudinal center line, presenting an arc-shaped U-shape with the opening facing the side edge of the outer waist segment from the longitudinal center line.

[0013] Furthermore, the groove edges are linear.

[0014] Further, the edges of the slots are straight lines with equal widths, parallel to each other and perpendicular to the longitudinal center line.

[0015] Further, the edges of the slots are straight lines with equal widths, parallel to each other and inclined to the longitudinal center line.

[0016] Further, the edges of the slots are inclined in the reverse direction of the running direction.

[0017] Further, the convex part or the concave part of one of the outer link plates of the outer link plate unit is in a ramp shape, and the convex part or the concave part in the ramp shape gradually inclines from the longitudinal center line towards its side edge.

[0018] Further, both the convex part and the concave part of one of the outer link plates of the outer link plate unit are formed in a ramp shape, and the ramp shapes of the convex part and the concave part are connected to each other and have the same inclination slope, and are inclined in a straight line direction from the side edge of the convex part towards the side edge of the concave part.

[0019] The effect of the present invention is that by changing the opening sizes of the two opposite sides of the external engagement space, the width of the wide opening side is greater than the width of the internal engagement space, and the width of the narrow opening side is not less than the width of the internal engagement space, thereby improving the stability of meshing and the smoothness of speed change.

[0020] Another object of the present invention is to provide a wheel transmission device that can overcome at least one shortcoming of the prior art.

[0021] The wheel transmission device of the present invention includes a front sprocket, a rear sprocket spaced behind the front sprocket, a tension wheel, a chain guide wheel, and a chain as described above. The chain is in a closed loop shape and is engaged around the front sprocket, the rear sprocket, the tension wheel, and the chain guide wheel. The wide opening side of each outer link plate unit faces the front sprocket, the rear sprocket, and the tension wheel, and the narrow opening side faces the chain guide wheel.

[0022] The effect of the present invention is that due to the design that the width of the narrow opening side of the external engagement space is not less than the width of the internal engagement space, the chain guide wheel can be engaged with the external engagement space and the internal engagement space, so the smoothness of speed change can be improved. Description of the Drawings

[0023] Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein:

[0024] Figure 1 is a perspective view of a part of an existing chain;

[0025] Figure 2 is an incomplete side view of the existing chain;

[0026] Figure 3 is a side schematic view of a first embodiment of the wheel drive device of the present invention, showing the state of installing a chain between several sprockets;

[0027] Figure 4 is an incomplete bottom view of the chain of the first embodiment, showing the state of viewing from outside the closed circle of the chain;

[0028] Figure 5 is an exploded perspective view of an outer link unit of the first embodiment;

[0029] Figure 6 is a cross-sectional view of the outer link unit of the first embodiment;

[0030] Figure 7 is a side view of an outer link of the first embodiment;

[0031] Figure 8 is a side view of the outer link of a second embodiment of the wheel drive device of the present invention;

[0032] Figure 9 is a side view of the outer link of a third embodiment of the wheel drive device of the present invention;

[0033] Figure 10 is an exploded perspective view of an outer link unit of a fourth embodiment of the wheel drive device of the present invention; and

[0034] Figure 11 is a cross-sectional view of the outer link unit of the fourth embodiment. Detailed Description of the Invention

[0035] Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

[0036] Refer to Figure 3 、 4A first embodiment of the wheel transmission device 2 of the present invention comprises a plurality of front sprockets 21 (only one is shown in the figure) and a plurality of rear sprockets 22 (only one is shown in the figure) arranged in a front-to-rear interval, a tensioning wheel 23 located near the rear sprocket 22, a derailleur guide wheel 24 located between the rear sprocket 22 and the tensioning wheel 23, and a chain 3 in a closed ring shape and meshed around the corresponding front sprocket 21, the corresponding rear sprocket 22, the derailleur guide wheel 24 and the tensioning wheel 23. The front sprocket 21, the rear sprocket 22 and the tensioning wheel 23 are located in the closed circle of the chain 3, and the derailleur guide wheel 24 is located outside the closed circle of the chain 3. The peripheries of the front sprocket 21, the rear sprocket 22, the derailleur guide wheel 24 and the tensioning wheel 23 all have a plurality of latching teeth 25. The front sprocket 21 is concentrically arranged and has a different number of teeth, and the rear sprocket 22 is also concentrically arranged and has a different number of teeth. The tensioning wheel 23 is used to elastically resist the chain 3 to maintain a certain tightness of the chain 3. The derailleur guide wheel 24 is used to shift and change the meshing position of the chain 3 and the rear sprocket 22. The chain 3 is driven to move in a circle along a running direction 31.

[0037] The chain 3 includes a plurality of inner plate units 4, a plurality of outer plate units 5, and a chain shaft unit 6. Of course, the chain 3 may also include a bushing unit, a chain roller unit, etc., but they are not the focus of the present invention and will not be described here.

[0038] The inner sheet units 4 are arranged at intervals along the running direction 31, and each of the inner sheet units 4 has two inner chain sheets 41 arranged opposite to each other. Each of the inner chain sheets 41 has two inner hole sections 42 spaced apart along the running direction 31, and an inner waist section 43 located between the inner hole sections 42. The inner waist sections 43 of each inner sheet unit 4 cooperate to define an inner meshing space 44 connected up and down.

[0039] The outer sheet units 5 are arranged at intervals along the running direction 31 and staggered outside the inner sheet units 4. Each outer sheet unit 5 has two outer chain pieces 51 arranged opposite to each other. Each outer chain piece 51 has two outer hole sections 52 spaced apart along the running direction 31 and an outer waist section 53 located between the outer hole sections 52. The outer waist section 53 of each outer sheet unit 5 cooperates to define an outer meshing space 54 that is connected up and down. The outer meshing spaces 54 of the outer sheet units 5 and the inner meshing spaces 44 of the inner sheet units 4 are arranged alternately along the running direction 31 to provide Figure 3 The latching teeth 25 of the toothed discs 21 , 22 are latched.

[0040] The chain shaft unit 6 has several chain shafts 61 arranged at intervals along the running direction 31 and connecting the inner hole section 42 and the outer hole section 52. Each chain shaft 61 is connected in series with the inner hole section 42 and the outer hole section 52 which face each other inside and outside.

[0041] Referring to Figures 3 to 7 , further looking at the detailed structure of the outer piece unit 5, the outer waist section 53 of each outer link piece 51 has a convex portion 56 and a concave portion 57 which are connected between the outer hole sections 52 and located on both sides of a longitudinal center line 55. The convex portion 56 is formed on the side directly contacting the engaging teeth 25 facing the sprocket wheels 21, 22, and the concave portion 57 is formed on the other side of the longitudinal center line 55 relative to the convex portion 56. The convex portion 56 protrudes outward in a direction away from another outer link piece 51, and has a wide inner side surface 561 facing the outer engagement space 54 and extending in a direction away from another opposite outer waist section 53, and a wide outer side surface 562 facing away from the outer engagement space 54 and protruding in a direction away from another opposite outer waist section 53. The concave portion 57 is recessed inward in a direction close to another outer link piece 51, and has a narrow inner side surface 571 facing the outer engagement space 54 and protruding in a direction towards another opposite outer waist section 53, and a narrow outer side surface 572 facing away from the outer engagement space 54 and extending in a direction towards another opposite outer waist section 53.

[0042] Each outer piece unit 5, through the concave-convex design of the convex portion 56 and the concave portion 57, makes the outer engagement space 54 have a wide opening side 541 located between the side edges 564 of the convex portion 56, and a narrow opening side 542 located between the side edges 574 of the concave portion 57. The wide opening side 541 faces the front sprocket wheel 21, the rear sprocket wheel 22, and the tension wheel 23, and the narrow opening side 542 faces the chain guide wheel 24. The width T2 of the wide opening side 541 is greater than the width T1 of the inner engagement space 44. The width T2 of the wide opening side 541 may even be greater than the width T3 of the narrow opening side 542. The width T3 of the narrow opening side 542 is not less than the width T1 of the inner engagement space 44. In this embodiment, it is illustrated by taking the width T3 of the narrow opening side 542 equal to the width T1 of the inner engagement space 44 as an example.

[0043] Next, look at the outer shapes of the convex portion 56 and the concave portion 57. Both the convex portion 56 and the concave portion 57 have two spaced-apart groove edges 563 and 573. Each of the groove edges 563 and 573 extends from the side edges 564 and 574 of the outer waist section 53 toward the longitudinal center line 55. In this first embodiment, each of the groove edges 563 and 573 is formed with a maximum flare from the side edges 564 and 574 of the outer waist section 53 and converges gradually toward the longitudinal center line 55, and each is in an arc-shaped U shape with an opening facing the side edges 564 and 574 of the outer waist section 53 from the longitudinal center line 55, which allows each of the teeth 25 to be inserted and slid out more smoothly. It should be noted that the shapes of the convex portion 56 and the concave portion 57 can also be changed, and they can be the same or different from each other. In other variations of this embodiment, only one of them can be arc-shaped.

[0044] When the chain 3 is driven by the sprockets 21 and 22 to operate and move, due to the flared design of the wide-mouth side 541, a relatively wide entrance can be provided, which can facilitate the teeth 25 of the front sprocket 21 to be easily and smoothly engaged into the external engagement space 54 at the early stage of engagement. And due to the constricted design of the narrow-mouth side 542, in the later stage of engagement after insertion, when the teeth 25 of the front sprocket 21 extend into the narrow-mouth side 542, the chain 3 can be limited and easily guide the chainline correctly, reducing the phenomenon of interference and friction when the chain 3 engages with the sprockets 21 and 22, and avoiding the situation that the chain 3 sways left and right or deviates to one side. Therefore, the engagement stability can be increased during operation, and the effects of fast and smooth operation and noise reduction can be achieved.

[0045] Moreover, when the chain 3 is shifted, due to the design that the width of the narrow-mouth side 542 is the same as that of the internal engagement space 44, the chain guide pulley 24 can be inserted into the internal engagement space 44 or the narrow-mouth side 542 at any time without waiting for the timing corresponding to the internal engagement space 44, and then shift the chain 3 to an appropriate rear sprocket 22, so it has the effect of fast and smooth shifting. Not only that, at the same time, through the wide-mouth side 541, the teeth 25 of the rear sprocket 22 can be easily engaged, and the shifting effect of maintaining stable conversion of the rear sprocket 22 can also be achieved.

[0046] Refer to Figure 8 , the structure of a second embodiment of the wheel drive device of the present invention is substantially the same as that of the first embodiment, and the difference lies in that: the shapes of the groove edges 563 and 573 of each of the outer link plates 51 are different. The groove edges 563 and 573 of this second embodiment are linear, preferably of equal width and linear, and are parallel to each other and perpendicular to the longitudinal center line 55.

[0047] Refer to Figure 9, the structure of a third embodiment of the wheel drive device of the present invention is substantially the same as that of the second embodiment, except that: the groove edges 563 and 573 of this third embodiment are straight lines with equal widths, are parallel to each other and inclined to the longitudinal center line 55, and the inclination direction is inclined in the reverse direction of the running direction 31. As shown in Figure 3 , when the sprocket teeth 25 are initially engaged with the chain 3, it is easy to slide into the external engagement space 54 along the slope (see Figure 6 ), and after engagement, more contact area with the sprocket teeth 25 can be utilized through the slope to quickly transmit power.

[0048] Refer to Figure 10 , 11 , the structure of a fourth embodiment of the wheel drive device of the present invention is substantially the same as that of the second to third embodiments, except that: each of the convex portions 56 gradually expands outwardly and obliquely from the longitudinal center line 55 towards its side edge 564, so that the wide inner side surface 561 and the wide outer side surface 562 are in a slope shape, and the side edges 564 of the convex portions 56 define the wide mouth side 541 therebetween. Each of the concave portions 57 gradually converges inwardly and obliquely from the longitudinal center line 55 towards its side edge 574, so that the narrow inner side surface 571 and the narrow outer side surface 572 are in a slope shape, and the side edges 574 of the concave portions 57 define the narrow mouth side 542 therebetween. The slopes formed by the convex portions 56 and the concave portions 57 of each outer waist section 53 of this fourth embodiment are connected to each other and have the same inclination slope, and are inclined in a straight line direction from the side edge 564 of the convex portion 56 to the side edge 574 of the concave portion 57, so the ease of molding can be increased. It should be noted that in practice, the design of this fourth embodiment is not limited, and at least one of the convex portions 56 or at least one of the concave portions 57 of each outer piece unit 5 being in a slope shape can achieve the same effect.

[0049] In summary, for the chain 3 and the wheel drive device 2 of the present invention, by changing the opening sizes of the two opposite sides of each external engagement space 54, such that the wide mouth side 541 has a large opening and the narrow mouth side 542 has a small opening, not only can the smoothness of speed change be improved, the generation of noise be reduced, but also the stability of engagement can be enhanced. In addition, by designing the width T3 of the narrow mouth side 542 to be the same as the width T1 of the internal engagement space 44, the chain guide wheel 24 can be selectively and arbitrarily engaged with the external engagement space 54 and the internal engagement space 44, and the chain can be quickly shifted without distinction and segmented, thereby improving the speed change speed and shortening the switching time. It is a design with high practicality and unprecedentedness, so the purpose of the present invention can indeed be achieved.

[0050] However, the above are only embodiments of the present invention and should not be used to limit the scope of implementation of the present invention. All simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the patent specification still fall within the scope covered by the patent of the present invention.

Claims

1. A chain, characterized in that, Comprising: A plurality of inner piece units, arranged at intervals along an operating direction, each of the inner piece units having two relatively arranged inner link pieces, each of the inner link pieces having two inner hole segments, and an inner waist segment located between the inner hole segments, the inner waist segments of each of the inner piece units cooperatively defining an inner engagement space; A plurality of outer piece units, arranged at intervals along the operating direction and offset and located outside the inner piece units, at least one of the outer piece units having two relatively arranged outer link pieces, each of the outer link pieces having two outer hole segments, and an outer waist segment located between the outer hole segments, the outer waist segment having a convex portion and a concave portion connected between the outer hole segments and located on both sides of a longitudinal center line, the convex portion protruding outward in a direction away from the other outer link piece, the concave portion recessing inward in a direction close to the other outer link piece, the outer waist segments of the outer piece units cooperatively defining an outer engagement space, the outer engagement space having a wide mouth side located between the side edges of the convex portion, and a narrow mouth side located between the side edges of the concave portion, the width of the wide mouth side being greater than the width of the inner engagement space, the width of the narrow mouth side being not less than the width of the inner engagement space, the width of the wide mouth side being greater than the width of the narrow mouth side, and the inner side surfaces of the convex portion and the concave portion being non-coplanar; and A chain shaft unit having a plurality of chain shafts connecting the inner hole segments and the outer hole segments.

2. The chain according to claim 1, characterized in that, The convex portion of each of the outer waist segments has a wide inner side surface facing the outer engagement space and extending deeply in a direction away from the other opposite outer waist segment, and the concave portion has a narrow inner side surface facing the outer engagement space and protruding into the direction of the other opposite outer waist segment.

3. The chain according to claim 2, characterized in that, The convex portion of each of the outer waist segments has a wide outer side surface facing away from the outer engagement space and protruding in a direction away from the other opposite outer waist segment, and the concave portion has a narrow outer side surface facing away from the outer engagement space and extending deeply in a direction towards the other opposite outer waist segment.

4. The chain according to claim 1, wherein The width of the narrow mouth side is equal to the width of the inner engagement space.

5. The chain according to claim 1, characterized in that, At least one of the convex portion and the concave portion of each of the outer waist segments has two spaced-apart groove edges extending from the side edge of the outer waist segment towards the longitudinal center line.

6. The chain according to claim 5, wherein The groove edges converge gradually from the maximum flare of the side edge of the outer waist segment towards the longitudinal center line, in an arc-shaped U shape with the opening facing the side edge of the outer waist segment from the longitudinal center line.

7. The chain according to claim 5, characterized in that, The groove edges are linear.

8. The chain according to claim 5, characterized in that, The groove edges are of equal width and linear, parallel to each other and perpendicular to the longitudinal center line.

9. The chain according to claim 5, characterized in that, The groove edges are of equal width and linear, parallel to each other and inclined to the longitudinal center line.

10. The chain according to claim 9, characterized in that, The groove edges are inclined in a direction reverse to the operating direction.

11. The chain according to claim 1, characterized in that, The convex portion or the concave portion of one of the outer link pieces of the outer piece unit is in a slope shape, and the convex portion or the concave portion in the slope shape is gradually inclined from the longitudinal center line towards its side edge.

12. The chain according to claim 11, characterized in that, The convex portion and the concave portion of one of the outer link pieces of the outer piece unit both form slope shapes, and the slope shapes of the convex portion and the concave portion are mutually connected.

13. A wheel transmission device, comprising: A front sprocket; A rear sprocket, spaced behind the front sprocket; A tension wheel; A chain guide pulley; and A chain according to any one of claims 1 to 12, characterized in that, The chain is in a closed loop and engages around the front sprocket, the rear sprocket, the tension wheel and the chain guide pulley. The wide mouth side of each of the outer plate units faces the front sprocket, the rear sprocket and the tension wheel, and the narrow mouth side faces the chain guide pulley.

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