A variable pitch silent chain

Abstract

A variable pitch silent chain belongs to the technical field of chain drives. The purpose is to provide a variable pitch silent chain to solve the problems existing in the prior art, such as many parts, large mass, large inertial force, serious impact, vibration and noise during operation, and large energy loss of the silent chain. A variable pitch silent chain of the present invention includes working link plates and guide plates. Each of the working link plates further includes intermediate link plate holes that are symmetric about the vertical center line of the working link plate. Each of the guide plates further includes upper side elliptical through holes, central elliptical through holes, and curved through holes. Two upper side elliptical through holes with the same shape are located at the upper two corners and are symmetric about the vertical center line of the guide plate. Two curved through holes with the same shape are located at the lower two corners and are symmetric about the vertical center line of the guide plate. The central elliptical through hole is located between the two curved through holes and on the vertical center line of the guide plate.

Description

Technical Field

[0001] The present invention belongs to the technical field of chain drives, and particularly relates to a variable pitch silent chain. Background Art

[0002] Variable pitch silent chains (i.e., Hy-Vo silent chains) are widely used in transmissions with high-speed and high-precision requirements. At present, most of the working link plates and guide plates of Hy-Vo silent chains are made of metal sheets through stamping. In the case of transmitting a large amount of power, in order to ensure the strength of the Hy-Vo silent chain, especially to ensure sufficient contact between the working link plate and the roller pin and the firmness of the interference fit between the guide plate and the roller pin, the metal sheet used should have a certain thickness, resulting in a large weight, large inertia force, serious impact, vibration and noise during operation, large energy loss, and reduced transmission efficiency of the Hy-Vo silent chain.

[0003] In recent years, in order to meet the "personalized" needs of different main engines and different working conditions, Hy-Vo silent chains have been continuously mutated, innovated and upgraded. With the continuous growth of the different "personalized" actual needs of many main engines, Hy-Vo silent chains show a continuous mutation trend of development, and this trend of development of mutation is a major reform and innovation of Hy-Vo silent chain drive technology.

[0004] Chinese Patent with Publication No. CN202579849U discloses a technical solution named a novel roller pin type silent chain drive system, which also relates to a Hy-Vo silent chain. However, due to the large number of rows of working link plates used and the relatively thick metal sheet used, there are many problems such as many parts, large mass, large inertia force, serious impact, vibration and noise during operation, and large energy loss in the Hy-Vo silent chain.

[0005] Chinese Patent with Publication No. CN102619928A discloses a technical solution named a novel variable pitch silent chain, which has many problems such as large mass, large inertia force, serious impact, vibration and noise during operation, and large energy loss. Summary of the Invention

[0006] The object of the present invention is to provide a variable pitch silent chain, which solves the problems existing in the prior art such as many parts, large mass, large inertia force, serious impact, vibration and noise during operation, and large energy loss in the silent chain; reduces the weight of the Hy-Vo silent chain, reduces the inertia force of the Hy-Vo silent chain, reduces the wear between the Hy-Vo silent chain and the sprocket, reduces the impact, vibration and noise during transmission, reduces energy consumption, and improves the overall transmission performance of the Hy-Vo silent chain.

[0007] To achieve the above object, a variable pitch tooth-shaped chain of the present invention includes working link plates and guide plates. N working link plates arranged parallel to each other form a first link plate group, and n - 1 working link plates arranged parallel to each other form a second link plate group. Multiple groups of the first link plate group and multiple groups of the second link plate group are arranged alternately, and adjacent first and second link plate groups are connected end to end through link holes on the working link plates, long rolling pins, and short rolling pins; the rolling pin fixing holes on the guide plates are fixedly matched with the ends of two adjacent long rolling pins;

[0008] Each of the working link plates further includes intermediate link holes that are symmetric about the vertical center line of the working link plate on the left and right;

[0009] Each of the guide plates further includes upper side elliptical through holes, a central elliptical through hole, and curved through holes; two upper side elliptical through holes with the same shape are located at the upper two corners and are symmetric about the vertical center line of the guide plate on the left and right; two curved through holes with the same shape are located at the lower two corners and are symmetric about the vertical center line of the guide plate on the left and right; the central elliptical through hole is located between the two curved through holes and on the vertical center line of the guide plate.

[0010] The contour of the intermediate link hole is composed of a first upper part semi-elliptical contour line and a first lower part semi-elliptical contour line, and the major axis of the first upper part semi-elliptical contour line is the minor axis of the first lower part semi-elliptical contour line.

[0011] The major axis direction of the first upper part semi-elliptical contour line is perpendicular to the vertical center line of the working link plate.

[0012] The ratio of the major semi-axis to the minor semi-axis of the first upper part semi-elliptical contour line of the intermediate link hole is 5:3, and the ratio of the major semi-axis to the minor semi-axis of the first lower part semi-elliptical contour line is 7:5.

[0013] The ratio of the major semi-axis to the minor semi-axis of each of the upper side elliptical through holes is 5:3, and the angles between the major semi-axes of the two upper side elliptical through holes and the horizontal direction of the guide plate are 15° and 165° respectively.

[0014] The acute opening direction of the angle between the major semi-axes of the two upper side elliptical through holes faces the central elliptical through hole.

[0015] The ratio of the major semi-axis to the minor semi-axis of the central elliptical through hole is 14:5.

[0016] The curved through hole includes a second upper part semi-elliptical contour line and a second lower part semi-elliptical contour line, and the minor axis of the second upper part semi-elliptical contour line is the major axis of the second lower part semi-elliptical contour line.

[0017] The ratio of the major axis to the minor axis of the semi-elliptical contour line of the second upper part of the curvilinear through-hole is 7:7.3, and the ratio of the major axis to the minor axis of the semi-elliptical contour line of the second lower part is 2:1. The angles between the major axes of the two semi-elliptical contour lines of the second lower part and the horizontal direction of the guide plate are 15° and 165° respectively.

[0018] The acute opening direction of the angle between the major axes of the two semi-elliptical contour lines of the second lower part faces the central elliptical through-hole.

[0019] The beneficial effects of the present invention are as follows: A variable pitch silent chain of the present invention, through the specific settings and shapes of the middle link plate holes, upper elliptical through-holes, middle elliptical through-holes and curvilinear through-holes, has the characteristics of compact and novel structure and lightweight while meeting the strength requirements of the Hy-Vo silent chain, increasing the elastic elongation of the working link plates and the guide plates, making the force on the Hy-Vo silent chain more uniform;

[0020] It is light in weight and small in inertia force, solving many problems of the Hy-Vo silent chain such as large impact vibration, serious noise and high energy consumption caused by its large weight, and improving the overall transmission performance of the Hy-Vo silent chain. Description of the Drawings

[0021] Figure 1 It is an overall structure assembly drawing of a variable pitch silent chain of the present invention;

[0022] Figure 2 It is an assembly drawing of a variable pitch silent chain of the present invention with the guide plate removed;

[0023] Figure 3 It is a schematic diagram of a working link plate in a variable pitch silent chain of the present invention;

[0024] Figure 4 It is a schematic diagram of a guide plate in a variable pitch silent chain of the present invention;

[0025] Figure 5 It is a stress distribution diagram of a working link plate of a traditional Hy-Vo silent chain;

[0026] Figure 6 It is a stress distribution diagram of a working link plate after topology optimization in the present invention;

[0027] Figure 7 It is a stress distribution diagram of a guide plate of a traditional Hy-Vo silent chain;

[0028] Figure 8 It is a stress distribution diagram of a guide plate after topology optimization in the present invention;

[0029] Wherein: 1. Working link plate, 101. Link hole, 102. Intermediate link plate hole, 103. First upper partial semi-elliptical contour line, 104. First lower partial semi-elliptical contour line, 2. Guide plate, 201. Roll pin fixing hole, 202. Upper side elliptical through hole, 203. Central elliptical through hole, 204. Curvilinear through hole, 205. Second upper partial semi-elliptical contour line, 206. Second lower partial semi-elliptical contour line, 3. Long roll pin, 4. Short roll pin. Detailed implementation mode

[0030] The implementation mode of the present invention will be further described below in conjunction with the accompanying drawings.

[0031] A variable pitch tooth-shaped chain of the present invention is particularly suitable for fields such as automotive engines, gearboxes and transfer cases, steam turbines, industrial pumps, metallurgical machinery, and chemical machinery.

[0032] See the attached Figure 1 - attached Figure 4 As shown in the attached drawings, a variable pitch tooth-shaped chain of the present invention includes a working link plate 1 and a guide plate 2. N mutually parallel working link plates 1 form a first link plate group, and n - 1 mutually parallel working link plates 1 form a second link plate group. Multiple groups of the first link plate group and multiple groups of the second link plate group are arranged alternately. Adjacent first and second link plate groups are connected end to end through the link holes 101 on the working link plate 1, long roll pins 3, and short roll pins 4; the roll pin fixing holes 201 on the guide plate 2 are fixedly connected with the ends of two adjacent long roll pins 3 by interference fit;

[0033] Each of the working link plates 1 further includes intermediate link plate holes 102 that are symmetric about the vertical center line of the working link plate 1 on the left and right;

[0034] Each of the guide plates 2 further includes upper side elliptical through holes 202, central elliptical through holes 203, and curvilinear through holes 204; two upper side elliptical through holes 202 with the same shape are located at the upper two corners and are symmetric about the vertical center line of the guide plate 2 on the left and right; two curvilinear through holes 204 with the same shape are located at the lower two corners and are symmetric about the vertical center line of the guide plate 2 on the left and right; the central elliptical through hole 203 is located between the two curvilinear through holes 204 and on the vertical center line of the guide plate 2.

[0035] In this embodiment, the first link plate group includes 8 working link plates 1, the second link plate group includes 8 working link plates 1, and the overall arrangement is staggered in an 8×9 manner. The materials of the working link plate 1 and the guide plate 2 are both 50CrVA, and the materials of the long roll pins 3 and the short roll pins 4 are both 20CrNiMo.

[0036] The contour of the middle link plate hole 102 is composed of a first upper part semi-elliptical contour line 103 and a first lower part semi-elliptical contour line 104. The major axis of the first upper part semi-elliptical contour line 103 is the minor axis of the first lower part semi-elliptical contour line 104.

[0037] The major axis direction of the first upper part semi-elliptical contour line 103 is perpendicular to the vertical center line of the working link plate 1.

[0038] The ratio of the major semi-axis to the minor semi-axis of the first upper part semi-elliptical contour line 103 of the middle link plate hole 102 is 5:3, and the ratio of the major semi-axis to the minor semi-axis of the first lower part semi-elliptical contour line 104 is 7:5.

[0039] The ratio of the major semi-axis to the minor semi-axis of the upper side elliptical through-hole 202 is 5:3. The angles between the major semi-axes of the two upper side elliptical through-holes 202 and the horizontal direction of the guide plate 2 are 15° and 165° respectively.

[0040] The acute opening direction of the angle between the major semi-axes of the two upper side elliptical through-holes 202 faces the central elliptical through-hole 203.

[0041] The ratio of the major semi-axis to the minor semi-axis of the central elliptical through-hole 203 is 14:5.

[0042] The curved through-hole 204 includes a second upper part semi-elliptical contour line 205 and a second lower part semi-elliptical contour line 206. The minor axis of the second upper part semi-elliptical contour line 205 is the major axis of the second lower part semi-elliptical contour line 206.

[0043] The ratio of the major semi-axis to the minor semi-axis of the second upper part semi-elliptical contour line 205 of the curved through-hole 204 is 7:7.3, and the ratio of the major semi-axis to the minor semi-axis of the second lower part semi-elliptical contour line 206 is 2:1. The angles between the major semi-axes of the two second lower part semi-elliptical contour lines 206 and the horizontal direction of the guide plate 2 are 15° and 165° respectively.

[0044] The acute opening direction of the angle between the major semi-axes of the two second lower part semi-elliptical contour lines 206 faces the central elliptical through-hole 203.

[0045] According to the strength requirements of the Hy-Vo tooth-shaped chain such as the structure and working conditions of the working link plate 1 of the traditional Hy-Vo tooth-shaped chain, a finite element analysis was carried out on it. See the appendix Figure 5, which is the stress distribution diagram of the working link plate 1 of the traditional Hy-Vo tooth-shaped chain. Its stress characteristic is that the two sides of the two link holes of the working link plate 1 bear greater stress, and the stress of the materials in other regions is smaller, especially the upper half of the center of the two link holes, which hardly bears the load. According to the stress distribution of the working link plate 1 and the structural topology optimization theory, the present invention reasonably removes the materials with smaller stress in the upper half of the center of the working link plate 1. The mass of the removed materials accounts for 10.81% of the original mass, and at the same time, it is ensured that the obtained intermediate link hole 102 is symmetric about the vertical center line of the working link plate 1 on the left and right.

[0046] At the same time, the finite element analysis of the guide plate 2 of the traditional Hy-Vo tooth-shaped chain is also carried out. See the appendix Figure 7 , which is the stress distribution diagram of the guide plate 2 of the traditional Hy-Vo tooth-shaped chain. The results show that the materials in the region between the two roller pin holes of the guide plate 2 bear greater stress, and the stress of the materials in other regions is very small, especially the lower half of the two roller pin holes and the two upper corners far away from the two roller pin holes hardly bear the load. According to the stress distribution of the guide plate 2 and the structural topology optimization theory, the present invention reasonably removes the materials in the regions with smaller stress. The mass of the removed materials accounts for 15.36% of the original mass. The obtained guide plate 2 is respectively provided with two upper side elliptical through holes 202 and curved through holes 204 with the same shape in pairs and symmetric about the vertical center line of the guide plate 2 at the four upper and lower corners on both sides, and a central elliptical through hole 203 near the center of the guide plate 2.

[0047] The present invention conducts finite element analysis on the working link plate 1 and the guide plate 2 obtained after structural topology optimization. See the appendix Figure 6 and the appendix Figure 8 , which are respectively the stress distribution diagram of the working link plate 1 after topology optimization and the stress distribution diagram of the guide plate 2 after topology optimization. It can be seen from this that the maximum working stress and the stress distribution situation hardly change. The present invention not only makes the force on the Hy-Vo tooth-shaped chain more uniform during transmission, but also is lighter in weight and smaller in inertia force than the traditional working link plate 1 and guide plate 2. It can reduce the impact and vibration during transmission, reduce noise, reduce wear, and improve the transmission efficiency of the Hy-Vo tooth-shaped chain.

Claims

1. A variable pitch tooth-shaped chain, comprising working link plates (1) and guide plates (2). N mutually parallel working link plates (1) form a first link plate group, and n - 1 mutually parallel working link plates (1) form a second link plate group. Multiple groups of the first link plate group and multiple groups of the second link plate group are arranged alternately. Adjacent first and second link plate groups are connected end to end through the link holes (101) on the working link plates (1), long pins (3) and short pins (4); the pin fixing holes (201) on the guide plates (2) are fixedly matched with the ends of two adjacent long pins (3). It is characterized in that each of the working link plates (1) further includes intermediate link holes (102) that are symmetric about the vertical center line of the working link plate (1). each of the guide plates (2) further includes upper side oval through holes (202), central oval through holes (203) and curved through holes (204); two upper side oval through holes (202) with the same shape are located at the upper two corners and are symmetric about the vertical center line of the guide plate (2); two curved through holes (204) with the same shape are located at the lower two corners and are symmetric about the vertical center line of the guide plate (2); the central oval through hole (203) is located between the two curved through holes (204) and on the vertical center line of the guide plate (2). The contour of the intermediate link hole (102) is composed of a first upper semi-elliptical contour line (103) and a first lower semi-elliptical contour line (104). The major axis of the first upper semi-elliptical contour line (103) is the minor axis of the first lower semi-elliptical contour line (104). The major axis direction of the first upper semi-elliptical contour line (103) is perpendicular to the vertical center line of the working link plate (1). The ratio of the major semi-axis to the minor semi-axis of the first upper semi-elliptical contour line (103) of the intermediate link hole (102) is 5:3, and the ratio of the major semi-axis to the minor semi-axis of the first lower semi-elliptical contour line (104) is 7:

5. The ratio of the major semi-axis to the minor semi-axis of the upper side oval through hole (202) is 5:

3. The angles between the major semi-axes of the two upper side oval through holes (202) and the horizontal direction of the guide plate (2) are 15° and 165° respectively. The acute opening directions of the included angles of the major semi-axes of the two upper side oval through holes (202) face the central oval through hole (203). The ratio of the major semi-axis to the minor semi-axis of the central oval through hole (203) is 14:

5. The curved through hole (204) includes a second upper semi-elliptical contour line (205) and a second lower semi-elliptical contour line (206). The minor axis of the second upper semi-elliptical contour line (205) is the major axis of the second lower semi-elliptical contour line (206). The ratio of the major semi-axis to the minor semi-axis of the second upper semi-elliptical contour line (205) of the curved through hole (204) is 7:7.3, and the ratio of the major semi-axis to the minor semi-axis of the second lower semi-elliptical contour line (206) is 2:

1. The angles between the major semi-axes of the two second lower semi-elliptical contour lines (206) and the horizontal direction of the guide plate (2) are 15° and 165° respectively. The acute opening direction of the included angle of the major semi-axes of the two second lower partial semi-elliptical contour lines (206) faces the central elliptical through-hole (203).

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