TW202219399A - Fluted disc and transmission system including two fluted discs and a chain and improving meshing stability - Google Patents

Abstract

Disclosed are a fluted disc and a transmission system. The transmission system includes two fluted discs and a chain, wherein the chain includes a plurality of chain rollers, a meshing space is formed between each two of the chain rollers. At least one of the fluted discs includes a plurality of fluted structures. Each of the fluted structures forms an arc surface meshed with the circumferences of the chain rollers, a driving surface extending outwards from the arc surface, a slip surface facing away from the driving surface, and a fluted top surface connecting the driving surface and the slip surface. A connecting line between the centers of the two adjacent arc surfaces is defined as a pitch diameter, the slip surface is inclined towards the driving surface and has an included angle ranging from 45 degrees to 55 degrees with the pitch diameter. The arc surface has an end point, a start point connecting the driving surface, and a connecting point located at a center linker connecting the center of the arc surface and the center of the fluted disc. The first arc length from the start point to the connecting point is greater than the second arc length from the end point to the connecting point. Accordingly, the meshing stability can be improved by the design.

Description

Gear and transmission system

The present invention relates to a transmission system, in particular to a chainring and transmission system used in bicycles or locomotives.

Referring to FIG. 6, a conventional bicycle or locomotive transmission system 4 generally includes two chainrings 41 (only a part of which is enlarged in the figure), which are arranged at intervals in the front and rear and are formed with a plurality of locking teeth 411, and a ring that engages with the teeth. The chain 42 of the tooth 411 of the disk 41 (only a part is enlarged and shown in the figure). The chain 42 includes a plurality of chain rollers 421 , and a meshing space 422 is formed between each two of the chain rollers 421 for the corresponding locking teeth 411 to be engaged.

Each of the latching teeth 411 includes a tooth bottom area 412 in a circular arc shape, and a convex tooth area 413 connected to the tooth bottom area 412 and protruding radially outward. The tooth bottom area 412 cooperates with the convex tooth area 413 to have a circular arc surface 414 engaging with the chain roller 421 , and a driving surface 415 extending from the circular arc surface 414 to the convex tooth area 413 , a sliding surface 416 facing away from the driving surface 415 , and a tooth top surface 417 connecting the driving surface 415 and the sliding surface 416 . The arc surface 414 is divided into two half arc surfaces with a center line L connecting the center O1 of the arc surface 414 and the center O2 of the toothed plate 41 as the center. The slipping surface 416 and the driving surface 415 are mirror-symmetrical.

During transmission, due to the change of the rotation angle of the toothed plate 41, the chain roller 421 will gradually abut against the driving surface 415 and the arc surface 414 connected thereto, and will contact the circular arc surface 414 during the loading process. The sliding meshing phenomenon between the arc surface 414 and the driving surface 415 will make the force of the load dispersed and less concentrated, so it is necessary to improve it.

Accordingly, it is an object of the present invention to provide a chainring that overcomes at least one of the disadvantages of the prior art.

Therefore, the toothed disc of the present invention is suitable for engaging and driving a chain. The chain includes several chain rollers, and an meshing space is formed between every two chain rollers. The toothed disc rotates along a transmission direction and includes several teeth. Each tooth-shaped structure includes a tooth bottom area that can be embedded in the corresponding chain roller, and a convex tooth area that protrudes radially outward and can extend into the corresponding meshing space. The tooth The bottom area and the convex tooth area cooperate to form a circular arc surface meshing with the circumference of the chain, a driving surface extending from the circular arc surface toward the convex tooth area, and a sliding surface facing away from the driving surface and extending obliquely. The slipping surface, and a tooth top surface connecting the driving surface and the slipping surface, define the connecting center line between the centers of the two adjacent arc surfaces as a pitch diameter, and the distance between the slipping surface and the pitch diameter is The included angle θ is 45°~55°, the arc surface has a cut-off point, a starting point away from the cut-off point and connected to the driving surface, and a position connecting the center of the arc surface and the toothed disc. A first arc length from the starting point to the center point is greater than a second arc length from the end point to the center point.

Accordingly, it is an object of the present invention to provide a transmission system that overcomes at least one of the disadvantages of the prior art.

Therefore, the transmission system of the present invention includes two toothed discs and a chain. The toothed discs are arranged at intervals in the front and rear, and at least one of the toothed discs is the above-mentioned toothed disc. The chain is in the shape of a closed loop and is engaged between the toothed discs. The chain includes a plurality of chain rollers arranged at intervals along a length direction, and a plurality of chain rollers arranged in a staggered arrangement on two opposite sides of the chain rollers. A chain piece and a plurality of chain shafts respectively passing through the chain rollers and connecting the chain pieces, each two of the chain rollers form an engagement space.

The effect of the present invention is: by the shape design of the above-mentioned tooth structure, the stability of meshing can be improved, the friction loss with the chain roller can be reduced, and the maximum power transmission can be achieved with the minimum energy loss. Reduce weight and improve transmission efficiency.

Referring to FIGS. 1 , 2 and 3 , an embodiment of the transmission system of the present invention includes two toothed discs 1 arranged at intervals in the front and rear and respectively rotating along a transmission direction 10 , and a ring-shaped toothed ring that engages around the teeth. Chain 2 between discs 1. The chain 2 is engaged and driven by the chainring 1 to move cyclically along a length direction 20, and includes a plurality of chain rollers 21 arranged at intervals along the length direction 20, and a plurality of chain rollers 21 are staggered and arranged in two rows. The chain pieces 22 are respectively arranged on two opposite sides of the chain rollers 21 , and a plurality of chain shafts 23 respectively pass through the chain rollers 21 and connect the chain pieces 22 . A meshing space 24 is formed. Since the structure of the chain 2 is not the focus of the present invention, the shape and the number of components can also be changed, so it is not limited to this embodiment.

The toothed plate 1 includes a plurality of toothed structures 3 formed at equal distances on the periphery. The number of toothed structures 3 of the toothed plate 1 can be increased or decreased according to requirements. Generally speaking, the toothed plate 1 is located in the front. It is a driving wheel, the chainring 1 at the rear is a driven wheel, and at least one chainring 1 in the chainring 1 is provided with the improved toothed structure 3 of the present invention, which is located in the front in this embodiment. The chainring 1 is described as an example, but the implementation is not limited to this, and it can even be arranged on several speed changing chainrings.

The toothed structures 3 are further described below, each of the toothed structures 3 includes a tooth bottom area 31 in which the corresponding chain roller 21 can be embedded, and a radially outwardly protruding and extendable tooth bottom area 31 . into the corresponding convex tooth area 32 of the meshing space 24 . The tooth bottom area 31 and the convex tooth area 32 cooperate to form a circular arc surface 33 located in the tooth bottom area 31 and meshing with the circumference of the chain roller 21 , and a circular arc surface 33 facing the A driving surface 34 extending from the protruding tooth region 32, a slipping surface 35 facing away from the driving surface 34 and connected to the arc surface 33 of another adjacent toothed structure 3, and a sliding surface 35 located at the outer end and engaging the The driving surface 34 and the tooth top surface 36 of the sliding surface 35 .

The arc length of the arc surface 33 accounts for 27-35% of the total circumference of the entire circle of the arc surface 33, and the diameter of the arc surface 33 is not less than the diameter of the chain roller 21, which can increase the contact rate , to ensure that the arc surface 33 can indeed and smoothly engage with the circumference of the chain roller 21 . The circular arc surface 33 has an end point 331 connecting the slipping surfaces 35 of the adjacent tooth structures 3 , a starting point 332 away from the end point 331 and connecting to the driving surface 34 , and a The connecting center point 333 on the center line L connecting the center O1 of the circular arc surface 33 and the center O2 of the chainring 1, a first arc length from the starting point 332 to the connecting center point 333 S1 is greater than a second arc length S2 from the cut-off point 331 to the connecting center point 333 . The connecting center line between the centers O1 of the two adjacent arc surfaces 33 is defined as the pitch diameter P.

The driving surface 34 has a limiting protrusion 341 connected to the starting point 332 of the arc surface 33 and protruding toward the driving direction 10 . The slipping surface 35 is an inclined straight surface, which is gradually moved away from the driving surface 34 from the tooth top surface 36 inward to the circular arc surface 33 of another adjacent tooth structure 3 . The inclined extension, the angle θ between the slip surface 35 and the pitch diameter P is 45°~55°, preferably, the angle θ between the slip surface 35 and the pitch diameter P is 48°~54° , through the design of the inclination angle of the slipping surface 35, the arc length of the arc surface 33 is reduced, which is smaller than the arc length of the conventional arc surface 414 (see FIG. 6), and the second arc length S2 It is smaller than the first arc length S1, and is also relatively smaller than half of the arc length of the conventional arc surface 414 (see FIG. 6 ), so that the weight can be reduced.

It should be noted that the inclination direction of the sliding surface 35 of the chainring 1 located at the rear is opposite to that of the chainring 1 located at the front, wherein the chainring 1 located in the front The slipping surface 35 is inclined along the driving direction 10 , that is, the driving surface 34 of each toothed structure 3 is located in front of the slipping surface 35 along the driving direction 10 , and is located at the rear. The sliding surface 35 of the toothed plate 1 is inclined against the transmission direction 10 , that is, the driving surface 34 of each toothed structure 3 is located at the edge of the sliding surface 35 along the transmission direction 10 . In the rear, the slippage of the chain 2 at the rear part of the meshing area can be avoided, which helps to improve the tension retention of the chain 2, so as to achieve the maximum power transmission effect with the minimum energy loss.

When in use, the toothed plate 1 rotates along the transmission direction 10, so as to engage and drive the chain 2 to move. As shown in FIG. When the engaging space 24 is opened, the limiting protrusion 341 first contacts the chain roller 21 , and then drives the chain roller 21 to engage with the arc surface 33 , so as to gradually complete the engagement. Due to the design of the limiting protrusions 341, the chain rollers 21 can be contacted first during engagement, and the chain rollers 21 can be guided to the arc surface 33, thus effectively shortening the contact time with the chain rollers 21. The impact and running-in of the chain rollers 21 during the initial meshing can reduce friction, reduce noise, and increase the service life, and can be more firmly engaged with the chain rollers 21 when the transmission is completed after the meshing is completed, so that the chain rollers 21 maintain meshing In the circular arc surface 33, the chain roller 21 slides between the driving surface 34 and the circular arc surface 33 without changing the rotation angle of the chainring 1, so that the force of the load will be concentrated, The power is quickly transmitted, and the maximum power transmission can be achieved with the minimum energy loss, and the labor-saving transmission efficiency can be effectively achieved.

Then, as shown in FIG. 5 , when the chain roller 21 is about to separate from the corresponding toothed structure 3 , the chain roller 21 gradually leaves the arc surface 33 first, and then leaves the driving surface 34 . Finally, the convex tooth area 32 is completely separated. In this process, compared with the conventional convex tooth area 413 (represented by an imaginary line) with a symmetrical shape, the present invention, by virtue of the inclined design of the slipping surface 35, not only can A larger space is formed for the chain rollers 21 to slide away smoothly, and materials can also be saved to achieve a lightweight function.

To sum up, the toothed plate and the transmission system of the present invention mainly improve the shape of the toothed structure 3 of the toothed plate 1, so that the circular arc surface 33 and the chain roller 21 can be stabilized during loading. In addition, the chamfered design of the slip surface 35 can reduce the weight and increase the transmission efficiency, so it can indeed achieve the purpose of the present invention.

However, the above are only examples of the present invention, and should not limit the scope of the present invention. All simple equivalent changes and modifications made according to the scope of the application for patent of the present invention and the contents of the patent specification are still within the scope of the present invention. within the scope of the invention patent.

1: Gear plate 10: Transmission direction 2: Chain 20: length direction 21: Chain Roll 22: chain piece 23: Chain shaft 24: Meshing Space 3: tooth structure 31: tooth bottom area 32: convex tooth area 33: Arc surface 331: Cutoff Point 332: starting point 333: Connecting Hearts 34: Drive Surface 341: Limiting convex part 35: slip surface 36: tooth top surface O1: The center of the arc surface O2: the center of the chainring L: center connection S1: first arc length S2: Second arc length P: pitch diameter θ: included angle

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: 1 is a schematic side view of an embodiment of a transmission system of the present invention; Figure 2 is a fragmentary exploded perspective view of the embodiment; 3 is an incomplete partial cross-sectional side view of the embodiment, illustrating a state in which a chain is engaged with a chainring; Fig. 4 is an incomplete partial cross-sectional side view of the embodiment, illustrating the state in which the chain is about to be engaged with the chainring; Fig. 5 is an incomplete partial cross-sectional side view of the embodiment, illustrating the state in which the chain is about to disengage the chainring; and Figure 6 is an incomplete partial cross-sectional side view of a conventional chain, illustrating a state in which a chain is engaged with a chainring.

1: Gear plate

10: Transmission direction

2: Chain

21: Chain Roll

22: chain piece

23: Chain shaft

24: Meshing Space

3: tooth structure

31: tooth bottom area

32: convex tooth area

33: Arc surface

331: Cutoff Point

332: starting point

333: Connecting Hearts

34: Drive Surface

341: Limiting convex part

35: slip surface

36: tooth top surface

O1: The center of the arc surface

O2: the center of the chainring

L: center connection

S1: first arc length

S2: Second arc length

P: pitch diameter

θ: included angle

Claims (9)

A toothed plate is suitable for engaging and driving a chain, the chain includes several chain rollers, and a meshing space is formed between every two of the chain rollers, the toothed plate rotates along a transmission direction, and includes several tooth-shaped structures, Each of the toothed structures includes a tooth bottom area that can be embedded with the corresponding chain roller, and a convex tooth area that protrudes radially outward and can extend into the corresponding meshing space. The tooth bottom area and The convex tooth area cooperates to form a circular arc surface meshing with the circumferential circle of the chain, a driving surface extending from the circular arc surface toward the convex tooth area, and a sliding surface facing away from the driving surface and extending obliquely, And a tooth top surface connecting the driving surface and the slipping surface, the connecting center line between the centers of the adjacent two arc surfaces is defined as a pitch diameter, and the angle θ between the slipping surface and the pitch diameter is 45°~55°, the arc surface has a cut-off point, a starting point that is far away from the cut-off point and is connected to the driving surface, and a center that connects the center of the arc surface and the center of the toothed plate For the connecting center point on the connecting line, a first arc length from the starting point to the connecting center point is greater than a second arc length from the ending point to the connecting center point. The chainring according to claim 1, wherein the included angle θ between the slipping surface and the pitch diameter is 48°˜54°. The toothed disc according to claim 1, wherein the arc length of the arc surface accounts for 27-35% of the total circumference of the arc surface. The chainring according to claim 1, wherein the diameter of the arc surface is not smaller than the diameter of the chain roller. The toothed plate according to claim 1, wherein the slipping surface is an inclined straight surface, which is extended from the tooth top surface inward and gradually inclined toward the arc surface of the other tooth structure. The chainring according to claim 1, wherein the driving surface has a limiting convex portion connected to the starting point of the circular arc surface and protruding toward the driving direction. A transmission system comprising: Two chainrings, spaced front and rear, at least one of the chainrings is the chainring described in claim 1; and A chain, in the form of a closed loop, is engaged between the toothed discs, the chain includes a plurality of chain rollers arranged at intervals along a length direction, and a plurality of chain rollers arranged in a staggered arrangement on two opposite sides of the chain rollers The chain piece, and several chain shafts respectively passing through the chain rollers and connecting the chain pieces, an engagement space is formed between every two chain rollers. The transmission system according to claim 7, wherein the chainring located at the front is the chainring according to claim 1, and the slipping surface of the chainring is inclined along the transmission direction, and each time along the transmission direction The driving surface of the toothed structure is located in front of the slipping surface. The transmission system according to claim 7, wherein the chainring located at the rear is the chainring according to claim 1, and the slipping surface of the chainring is inclined against the transmission direction, and every time along the transmission direction The driving surface of a toothed structure is located behind the slipping surface.

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