Lightweight composite speed change fluted disc

Abstract

The invention discloses a light-weight composite speed change fluted disc which comprises a metal fluted disc used in a chain wheel mechanism and used for inputting power to a chain. A hollowed-out groove is formed in a disc body of the metal fluted disc, and the hollowed-out groove is annular and extends in the same direction as the disc body. And the hollow groove is filled with a high-rigidity light material. According to the metal composite fluted disc, the use amount of metal materials is reduced through the hollowed-out groove structure, the disc body is reinforced by filling light materials, the metal composite fluted disc capable of meeting the requirements for shear strength and tensile strength at the same time is formed, and the contradiction between light weight and strength of transmission parts is solved.

Description

Technical Field

[0001] This invention relates to the field of bicycle drive sprockets, and particularly to a lightweight composite geared sprocket. Background Technology

[0002] The overall weight of a professional-grade bicycle is a crucial indicator affecting riding efficiency and handling. Lightweight improvements to the freewheel and chainring, which are core transmission components, aim to optimize transmission efficiency. For example... Figure 1 and Figure 2 The exhibited existing toothed disc uses a high-strength aluminum alloy body 110 and tooth section 120, manufactured using a one-piece stamping process, replacing the original low-carbon steel material to achieve weight reduction. However, the weight of this toothed disc 100 is still as high as 100 grams, requiring further weight reduction. As a further optimization solution, one option is to change the material of the toothed disc 100 to all carbon fiber, but this process is expensive, and considering that the wear resistance of carbon fiber is far inferior to that of metal materials, it is difficult to meet the working conditions of the tooth section 120; another option is to use a metal tooth section 120 and a carbon fiber disc body 110 as a composite, but although the tensile strength of carbon fiber is far inferior to that of metal materials, its shear strength is far inferior, so this composite structure is also difficult to use in commercial mass production. Summary of the Invention

[0003] In order to overcome the above-mentioned defects of the prior art, the purpose of this invention is to provide a lightweight composite gearbox that achieves both weight reduction and strength standards based on aluminum alloy material.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A lightweight composite gearbox includes: As a metal toothed disc that inputs power to the chain in a sprocket mechanism; A perforated groove is formed on the surface of the metal toothed disc, and the perforated groove is annular and extends in the same direction as the disc surface; The hollowed-out groove is filled with a high-rigidity, lightweight material.

[0005] In a preferred embodiment of the present invention, the thickness of the hollowed-out groove ranges from 0.8 mm to 2 mm.

[0006] In a preferred embodiment of the present invention, the lightweight material is carbon fiber, and the metal gear disc is a high-strength aluminum alloy.

[0007] In a preferred embodiment of the present invention, the hollowed-out groove is located radially between the tooth and the fixing hole.

[0008] In a preferred embodiment of the present invention, the hollow groove is composed of an outer groove and an inner cavity, the outer groove is used to fill the lightweight material, and the inner cavity is located in the middle of the disc body to form a hollow structure.

[0009] In a preferred embodiment of the present invention, the thickness of the outer groove is greater than 0.8 mm and less than 2 mm, and the height is greater than 12.5 mm and less than 20.5 mm.

[0010] In a preferred embodiment of the present invention, the metal toothed disc is a 40T toothed disc.

[0011] In a preferred embodiment of the present invention, the lightweight material is multilayer carbon fiber.

[0012] In a preferred embodiment of the present invention, the high-strength aluminum alloy is AL7075.

[0013] In a preferred embodiment of the present invention, the multilayer carbon fiber is a 5-layer carbon fiber.

[0014] The beneficial effects of this invention are as follows: The present invention provides a lightweight composite geared disc that reduces the amount of metal material used by utilizing a hollow groove structure and reinforces the disc body by filling it with lightweight material, thereby forming a metal composite geared disc that can simultaneously meet the requirements of shear and tensile strength, thus solving the contradiction between lightweight and strength in transmission components. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0016] Figure 1 This is a schematic diagram of the structure of a gear disc in the prior art.

[0017] Figure 2 yes Figure 1 AA sectional view.

[0018] Figure 3 This is an exploded view of the present invention.

[0019] Figure 4 yes Figure 3 A schematic diagram of the planar structure of the intermediate gear disc.

[0020] Figure 5 yes Figure 4 BB sectional view Figure 1 .

[0021] Figure 6 yes Figure 4 BB sectional view Figure 2 .

[0022] Figure 7 yes Figure 2 Dimensioning diagram.

[0023] Figure 8 yes Figure 6 Dimensioning diagram.

[0024] Figure 9 This is a force separation diagram of the gear disc.

[0025] Figure 10 This is a schematic diagram of the geared disc and crank. Detailed Implementation

[0026] In the description of this invention, it should be noted that the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. The above description is for the purpose of simplifying the description of this invention and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0027] Unless otherwise specified, the singular forms “a,” “the,” and “the” used in this specification include the plural forms. The terms “comprising,” “including,” and “containing” used in this specification indicate the presence of the claimed feature, but do not exclude the presence of one or more other features.

[0028] Exemplary embodiments of this application will now be described with reference to the accompanying drawings. However, it should be understood that this application can be presented in many different ways and is not limited to the embodiments described below. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments. Throughout the drawings, the same reference numerals denote the same or functionally identical elements.

[0029] Figures 3 to 5 This lightweight composite geared disc is showcased. Unlike traditional geared disc structures, it features a hollowed-out groove 111 on the disc body 110. The groove 111 extends in the same direction as the disc body 110, forming a ring and located radially between the teeth 120 and the fixing hole 130. The hollowed-out groove 111 is filled with a lightweight material 200. The disc body 110 is made of high-strength aluminum alloy. The hollowed-out groove 111 structure reduces the amount of aluminum alloy used, thus achieving weight reduction. The hollowed-out groove 111 is reinforced by filling the cavity with a lighter and more rigid lightweight material 200, simultaneously meeting the requirements for weight reduction and geared disc strength.

[0030] For the thickness of the hollow groove 11, that is, the vertical dimension of the cross section, its maximum value b2max = (maximum diameter - minimum diameter) / 2; the maximum diameter is the tooth root circle of the tooth part 120 minus the redundancy (generally about 4-8mm), and the tooth root circle is obtained according to the pitch circle - the height of the tooth part 120; the minimum diameter is the diameter of the tooth pattern minus the redundancy (generally about 2-4mm).

[0031] In some embodiments, the gear 100 is a 40T gear 111, and the thickness of the slot 111 ranges from 0.8 mm to 2 mm. The height ranges from 12.5 mm to 20.5 mm.

[0032] Furthermore, the hollow groove 111 is composed of an outer groove 113 and an inner cavity 112. From a transverse cross-sectional view, the inner cavity 112 is located in the middle of the tooth body 110 relative to the outer groove 113. The purpose of this arrangement is to use the outer groove 113 to accommodate the lightweight material 200, while the inner cavity 112 makes the tooth disc a hollow structure, which is beneficial for the stability of the tooth disc during high-speed rotation.

[0033] In some embodiments, the aluminum alloy material of the disk body 110 is 7-series aerospace aluminum alloy, and the lightweight material is carbon fiber. Preferably, the 7-series aerospace aluminum alloy is AL7075, and the carbon fiber is T700SC.

[0034] Reference Figures 6 to 10 According to the theory of plane moment of inertia, the moment of inertia ly (mm) 4 = b*((ha+hb) / 2)³ / 12, Section modulus Wy (mm³) = Iy*(section width / 2), F2max = yield strength * Wy, F1max = F2max * L2 / L1, Fmax = F1max * L1 / L. Where F2 is the torque applied to lever arm L2, F1 is the torque applied to lever arm L1, and L is the input lever arm of foot crank 200.

[0035] For a 40T AL7075 aluminum alloy gear disc with a tensile strength of 570MPa, when a hollowed-out groove 111 with dimensions b1=12mm and h1=2.5mm is cut, the maximum force and theoretical strength of the gear disc are as follows:

[0036] The structure's strength only reaches 84% ​​of the standard.

[0037] For T700SC multilayer carbon fiber with a tensile strength of 2500 MPa, filled into the outer groove 113 with b2=16 mm and h2=1.2 mm, the maximum stress and theoretical strength of this lightweight material 200 are as follows:

[0038] The independent structure's strength meets the standard of 56%.

[0039] Preferably, the multilayer carbon fiber is a 5-layer carbon fiber from the TORAY-TXX series or the TOHO TENAX-HTA series.

[0040] A lightweight carbon fiber material 200 is filled into the outer groove 113 to form an integral structure with the disc body 110. In cross-section, an aluminum alloy disc body 110 structure for bearing shear and tensile forces is consistently arranged vertically on the toothed disc 100, with the lightweight material 200 only providing tensile reinforcement. This achieves approximately 84 + 56 = 140% of the theoretical strength under industry standards, meeting industry requirements.

[0041] Because the density of 7-series aerospace aluminum alloy is 2.75 g / cm³. 3 It can be concluded that by creating the hollowed-out groove 111, the amount of aluminum alloy material used can be reduced by 43g. Taking into account the mass of the added carbon fiber material for reinforcement, the actual weight reduction is 33g. For a 40T gear disc with a base material of pure metal and a mass of 104g, this represents a weight reduction of approximately 31%.

Claims

1. A lightweight composite geared disc, characterized in that, include: As a metal toothed disc that inputs power to the chain in a sprocket mechanism; A perforated groove is formed on the surface of the metal toothed disc, and the perforated groove is annular and extends in the same direction as the disc surface; The hollowed-out groove is filled with a high-rigidity, lightweight material.

2. The lightweight composite geared disc as described in claim 1, characterized in that, The hollowed-out groove is located radially between the teeth and the fixing hole.

3. A lightweight composite geared disc as described in claim 2, characterized in that, The lightweight material is carbon fiber, and the metal gear disc is a high-strength aluminum alloy.

4. A lightweight composite geared disc as described in claim 2, characterized in that, The thickness of the hollowed-out groove ranges from 0.8 mm to 2 mm.

5. A lightweight composite geared disc as described in claim 4, characterized in that, The hollowed-out groove is composed of an outer groove and an inner cavity. The outer groove is used to fill the lightweight material, and the inner cavity is located in the middle of the disc body to form a hollow structure.

6. A lightweight composite geared disc as described in claim 5, characterized in that, The outer groove has a thickness greater than 0.8 mm and less than 2 mm, and a height greater than 12.5 mm and less than 20.5 mm.

7. A lightweight composite geared disc as described in claim 5, characterized in that, The metal gear disc is a 40T gear disc.

8. A lightweight composite geared disc as described in claim 5, characterized in that, The lightweight material is multi-layered carbon fiber.

9. A lightweight composite geared disc as described in claim 5, characterized in that, The high-strength aluminum alloy is AL7075.

10. A lightweight composite geared disc as described in claim 8, characterized in that, The multilayer carbon fiber consists of 5 layers of carbon fiber.

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