Arc tooth-shaped chain transmission structure

Abstract

The utility model relates to the technical field of machinery. An arc tooth-shaped chain transmission structure comprises a tooth-shaped chain and a chain wheel which are in transmission connection, the tooth-shaped chain comprises an inner chain plate, the inner chain plate comprises a contact face used for making contact with the chain wheel, and the contact face comprises two arc-shaped faces and a connecting face connected with the two arc-shaped faces; arc-shaped notches which are distributed in the circumferential direction and matched with the arc-shaped faces are formed in the outer wall of the chain wheel, the opening ends of the adjacent arc-shaped notches are connected through connecting parts, and the connecting parts are in direct surface contact with the connecting faces. By optimizing the arc-shaped tooth-shaped chain transmission structure, the inner chain plate and the chain wheel contact area are matched in shape, mutually matched surface contact is adopted, the chain is guided in and out smoothly, the shape is more reasonable, and the increase of the contact surface of the chain and the chain wheel is helpful for the stability of chain transmission. The tooth number of the chain wheel of the cover structure is not limited below 17, and the application is wider.

Description

Technical Field

[0001] The utility model relates to the technical field of machinery, in particular to a toothed chain transmission structure. Background Art

[0002] GB / T10855-2016 has detailed specifications for the sprocket shape of the toothed chain. Its tooth shape is quite different from that of the sleeve roller sprocket and the spur involute gear. As the number of teeth decreases, the tooth angle becomes smaller and the tooth shape becomes sharper, which affects the gear strength and is not conducive to gear hobbing. The national standard recommends that the number of teeth be more than 17, while in reality sprockets with less than 17 teeth are often used. Therefore, the scope of use of the toothed chain is limited.

[0003] Currently, there is a lack of a toothed chain transmission structure that can be applied to sprockets with less than 17 teeth. Utility Model Content

[0004] In view of the problems existing in the prior art, the utility model provides an arc toothed chain transmission structure, which solves at least one of the above technical problems.

[0005] The technical solution of the utility model is: an arc toothed chain transmission structure, comprising a toothed chain and a sprocket in transmission connection, characterized in that the toothed chain comprises an inner chain plate, the inner chain plate comprises a contact surface for contacting the sprocket, the contact surface comprises two arcuate surfaces and a connecting surface connecting the two arcuate surfaces;

[0006] The outer wall of the sprocket is provided with arc-shaped notches which are arranged circumferentially and match the arc-shaped surface. The open ends of adjacent arc-shaped notches are connected by a connecting portion, and the connecting portion is in direct surface contact with the connecting surface.

[0007] The utility model optimizes the arc-shaped toothed chain transmission structure, facilitates the shape of the inner chain plate and the sprocket contact area to match each other, adopts mutually matching surface contact, and the chain is smoothly introduced and exported, and the shape is more reasonable. The increase in the contact surface between the chain and the sprocket should be helpful for the stability of the chain transmission. The number of sprocket teeth does not need to be limited to less than 17, and the application is more extensive.

[0008] Further preferably, the toothed chain comprises an outer link plate, the outer link plate is oval in shape, and the outer contour of the outer link plate comprises two semicircular structures matching the curvature of the arc surface and a connecting line segment connecting two ends of the two semicircular structures.

[0009] Further preferably, the outer contour of the inner link plate includes a curved surface, the connecting surface, another curved surface and an outer connecting surface connected in sequence;

[0010] The connecting surface and the outer connecting surface are parallel to each other, and the distance W=Dd;

[0011] D = 0.75 * chain pitch, and d is the diameter of the pin shaft that rotatably connects the inner link plate and the outer link plate.

[0012] Further preferably, the diameter D of the arc surface = 0.75 * chain pitch.

[0013] Further preferably, the diameter D1 of the pitch circle of the sprocket = P / SIN(π / Z), where Z is the number of teeth of the sprocket and P is the chain pitch.

[0014] Further preferably, the diameter D2 of the addendum circle of the sprocket is less than the diameter of the pitch circle, and the diameter D2 of the addendum circle of the sprocket = 2d - 0.75P - 1 + D1 * COS(π / Z);

[0015] d is the diameter of the pin shaft that rotatably connects the inner link plate and the outer link plate, Z is the number of teeth of the sprocket, and P is the chain pitch.

[0016] Further preferably, the axial tooth width M of the sprocket = (number of chain plate layers - 2) * single chain plate thickness - 2;

[0017] The number of chain plate layers is the sum of the number of layers of the inner link plate and the outer link plate in the axial direction;

[0018] The single chain plate thickness is the thickness of the outer link plate, and the thickness of the outer link plate matches the thickness of the inner link plate.

[0019] Further preferably, the root circle diameter D3 of the sprocket = pitch circle diameter of the sprocket - diameter of the arc surface;

[0020] The diameter D of the arc surface = 0.75 * P;

[0021] The diameter D1 of the pitch circle of the sprocket = P / SIN(π / Z);

[0022] Z is the number of teeth of the sprocket, and P is the chain pitch.

[0023] Further preferably, the maximum value D4 of the rim diameter of the sprocket = D1 * COS(π / Z) - 0.75P;

[0024] D1 = P / SIN(π / Z), Z is the number of teeth of the sprocket, and P is the chain pitch.

[0025] Advantages of the present utility model compared with the prior art:

[0026] The present utility model has improved the shapes of the inner and outer link plates of the existing silent chain and the tooth profile of the sprocket, making the transmission more stable and increasing the service life; the matching sprocket is highly similar in shape to the sprocket of the roller chain, and can be processed with the hob for processing ordinary sprockets, with strong universality of the processing tool and simplified processing technology; the number of teeth of the sprocket does not need to be limited to more than 17 teeth, and the application range is wider. Description of the Drawings

[0027] Figure 1 Schematic diagram of a structure at the mating position of the inner link plate and the sprocket in Specific Embodiment 1 of the present utility model;

[0028] Figure 2 Schematic diagram of the structure of the tooth-shaped chain in Specific Embodiment 1 of the present utility model;

[0029] Figure 3 Schematic diagram of the structure of the sprocket in Specific Embodiment 1 of the present utility model;

[0030] Figure 4 Schematic diagram of the structure at the outer link plate in Specific Embodiment 1 of the present utility model;

[0031] Figure 5 Schematic diagram of the structure of the inner link plate in Specific Embodiment 1 of the present utility model;

[0032] Figure 6 Schematic diagram of the structure of the outer link plate in Specific Embodiment 1 of the present utility model;

[0033] Figure 7 Cross-sectional view of the sprocket in Specific Embodiment 1 of the present utility model. Specific embodiments

[0034] Refer to Figures 1 to 7 , Specific Embodiment 1, an arc tooth-shaped chain drive structure, including a tooth-shaped chain and a sprocket 2 in transmission connection. The tooth-shaped chain includes an inner link plate 1. The inner link plate 1 includes a contact surface for contacting the sprocket 2. The contact surface includes two arc surfaces and a connecting surface connecting the two arc surfaces. An arc-shaped notch arranged circumferentially and matching the arc surface is provided on the outer wall of the sprocket 2. The open ends of adjacent arc-shaped notches are connected by a connecting portion, and the connecting portion is in direct surface contact with the connecting surface. By optimizing the arc tooth-shaped chain drive structure, the present utility model facilitates the shape matching of the contact area between the inner link plate 1 and the sprocket 2, adopts a mutually matching surface contact, the introduction and export of the chain are smooth, the shape is more reasonable, and the increase in the contact surface area between the chain and the sprocket 2 should be helpful for the stability of the chain drive. The number of teeth of the sprocket 2 does not have to be limited to less than 17, and the application is more extensive.

[0035] The arc surface and the connecting surface are connected by a transition fillet. The radius R1 of the transition fillet is 1 mm.

[0036] The outer contour of the inner link plate further includes an upper connecting surface. An arc-shaped extension part that extends the arc surface to connect the upper connecting surface is provided on the arc surface, and the arc-shaped extension part has the same curvature as the arc surface. The upper connecting surface is parallel to the connecting portion.

[0037] The tooth-shaped chain includes an outer link plate 3. The outer link plate 3 is waist-shaped. The outer contour of the outer link plate 3 includes two semi-circular structures that match the curvature of the arc surface and connecting line segments connecting the two ends of the two semi-circular structures.

[0038] Both the inner link plates and the outer link plates are provided with two round holes. The round holes of the inner link plates are concentric with the arc surface. The round holes of the outer link plates are concentric with the semi-circular structure.

[0039] Adjacent inner link plates are rotatably connected by a pin shaft passing through the round holes. The inner link plate adjacent to the end of the pin shaft is hinged to the outer link plate through the pin shaft.

[0040] The outer contour of the inner link plate 1 includes an arc surface, a connecting surface, another arc surface and an outer connecting surface connected in sequence; the connecting surface and the outer connecting surface are parallel to each other, and the distance W = D - d; D = 0.75 * chain pitch, and d is the diameter of the pin shaft for rotatably connecting the inner link plate 1 and the outer link plate 3.

[0041] The diameter D of the arc surface = 0.75 * chain pitch.

[0042] The diameter D1 of the pitch circle of the sprocket 2 = P / SIN(π / Z), where Z is the number of teeth of the sprocket 2 and P is the chain pitch.

[0043] The diameter of the addendum circle of the sprocket 2 is smaller than the diameter of the pitch circle, and the diameter D2 of the addendum circle of the sprocket 2 = 2d - 0.75P - 1 + D1 * COS(π / Z); d is the diameter of the pin shaft for rotatably connecting the inner link plate 1 and the outer link plate 3, Z is the number of teeth of the sprocket 2, and P is the chain pitch.

[0044] The axial tooth width M of the sprocket 2 = (number of chain plate layers - 2) * single chain plate thickness - 2; the number of chain plate layers is the sum of the number of layers of the inner link plate 1 and the outer link plate 3 in the axial direction; the single chain plate thickness is the thickness of the outer link plate 3, and the thickness of the outer link plate 3 matches the thickness of the inner link plate 1.

[0045] The root circle diameter D3 of the sprocket 2 = the pitch circle diameter of the sprocket 2 - the diameter of the arc surface; the diameter D of the arc surface = 0.75 * P; the diameter D1 of the pitch circle of the sprocket 2 = P / SIN(π / Z); Z is the number of teeth of the sprocket 2 and P is the chain pitch.

[0046] The maximum value D4 of the rim diameter of the sprocket 2 = D1 * COS(π / Z) - 0.75P; D1 = P / SIN(π / Z), Z is the number of teeth of the sprocket 2, and P is the chain pitch.

[0047] The chamfer depth S can be flush with the root circle, and the single-sided chamfer width N can be taken about 1.5 mm.

[0048] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and retouches can still be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. A circular arc toothed chain transmission structure, comprising a toothed chain and a sprocket connected in a transmission manner, characterized in that: The toothed chain includes inner link plates, and each inner link plate includes a contact surface for contacting a sprocket. The contact surface includes two arc surfaces and a connecting surface connecting the two arc surfaces; The outer wall of the sprocket is provided with circumferentially arranged arc-shaped notches that match the arc surfaces. The open ends of adjacent arc-shaped notches are connected by a connecting portion, and the connecting portion is in direct surface contact with the connecting surface.

2. The arc tooth profile chain drive structure according to claim 1, characterized in that: The toothed chain includes outer link plates. The outer link plates are waist-shaped, and the outer contour of the outer link plates includes two semi-circular structures that match the curvature of the arc surfaces and connecting line segments connecting the two ends of the two semi-circular structures.

3. The arc tooth profile chain drive structure according to claim 1, characterized in that: The outer contour of the inner link plate includes an arc surface, the connecting surface, another arc surface, and an outer connecting surface that are sequentially connected; The connecting surface and the outer connecting surface are parallel to each other, and the spacing W = D - d; D = 0.75 * chain pitch, and d is the diameter of the pin shaft for rotatably connecting the inner link plate and the outer link plate.

4. A circular arc tooth profile chain drive structure according to claim 1, characterized in that: The diameter D of the arc surface = 0.75 * chain pitch.

5. A circular arc tooth profile chain drive structure according to claim 1, characterized in that: The diameter D1 of the pitch circle of the sprocket = P / SIN(π / Z), where Z is the number of teeth of the sprocket and P is the chain pitch.

6. The arc-shaped tooth chain drive structure according to claim 1, wherein: The diameter of the addendum circle of the sprocket is less than the diameter of the pitch circle, and the diameter D2 of the addendum circle of the sprocket = 2d - 0.75P - 1 + D1 * COS(π / Z); d is the diameter of the pin shaft for rotatably connecting the inner link plate and the outer link plate, Z is the number of teeth of the sprocket, and P is the chain pitch.

7. A circular arc tooth profile chain drive structure according to claim 1, characterized in that: The axial tooth width M of the sprocket = (number of link plate layers - 2) * single link plate thickness - 2; The number of link plate layers is the sum of the number of layers of the inner link plates and the outer link plates in the axial direction; The single link plate thickness is the thickness of the outer link plate, and the thickness of the outer link plate matches the thickness of the inner link plate.

8. A circular arc tooth-shaped chain drive structure according to claim 1, characterized in that: The root circle diameter D3 of the sprocket = pitch circle diameter of the sprocket - diameter of the arc surface; The diameter D of the arc surface = 0.75 * P; The diameter D1 of the pitch circle of the sprocket = P / SIN(π / Z); Z is the number of teeth of the sprocket and P is the chain pitch.

9. A circular arc tooth profile chain drive structure according to claim 1, characterized in that: The maximum value D4 of the rim diameter of the sprocket = D1 * COS(π / Z) - 0.75P; D1 = P / SIN(π / Z), where Z is the number of teeth of the sprocket and P is the chain pitch.

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