Drum brake and wheel assembly thereof

Abstract

The utility model discloses a drum brake and a wheel assembly thereof, which relates to the field of brakes and solves the problem of high cost of drum brakes in the prior art. The technical solution to this problem is mainly a drum brake, comprising a strip support beam, a rocker arm and two brake shoes arranged oppositely, an elastic reset member capable of bringing the two brake shoes closer to each other is arranged between the two brake shoes, one end of the two brake shoes is rotatably connected to the strip support beam through a support shaft, one end of the rocker arm is rotatably connected to the strip support beam through a rotating shaft, a spreading assembly for spreading out the two brake shoes is installed on the rotating shaft, a center hole for installing a connecting shaft and a fixing part for fixing to a vehicle frame are provided on the strip support beam, and the rotating shaft, the center hole, the support shaft and the fixing part are arranged in sequence and spaced apart along the length direction of the strip support beam. The utility model is mainly used to solve the problem of high cost of drum brakes.

Description

Technical Field

[0001] The utility model relates to the field of brakes, in particular to a drum brake and a wheel assembly thereof. Background Art

[0002] Drum brakes use the brake shoes to contact the inner edge of the brake drum when braking, and the friction generated by the contact suppresses the rotation of the tire to achieve the purpose of braking. At present, conventional electric vehicle drum brakes are mainly composed of brake covers, brake shoes, brake rods, and brake arm assemblies that support and expand the brake shoes outward through reverse movement. The brake arm assembly consists of two corresponding connections with two brake shoes, and is controlled to move by the brake rod. The brake rod drives the brake arm assembly to move in the opposite direction to expand the two brake shoes outward to achieve the purpose of braking the wheels.

[0003] The brake frame in the prior art includes an installation portion for installing parts such as brake shoes and brake rods and a dustproof portion, and the dustproof portion is usually designed to be an integrated structure with the installation portion, so that the dust cover is used as a carrier to install various drum brake parts, and due to the requirements of the operating conditions, the material of the dust cover needs to be rust-proof and high-strength material, which makes the cost of die-casting high, which will lead to excessively high costs of the brake frame and increase the cost of the entire vehicle. Utility Model Content

[0004] In order to overcome the high cost problem of drum brakes in the prior art, the present invention provides a drum brake and a wheel assembly thereof, using a strip support beam as a carrier to install the parts of the drum brake. Since the strip support beam has a simple structure and a smaller volume, the cost of manufacturing the drum brake frame is reduced.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a drum brake, comprising a strip support beam, a rocker arm and two brake shoes arranged opposite to each other, an elastic reset member is provided between the two brake shoes, which can make the two brake shoes approach each other, one end of the two brake shoes is rotatably connected to the strip support beam through a support shaft, one end of the rocker arm is rotatably connected to the strip support beam through a rotating shaft, a spreading assembly for spreading the two brake shoes outward is installed on the rotating shaft, a center hole for installing the connecting shaft and a fixing part for fixing to the frame are provided on the strip support beam, and the rotating shaft, the center hole, the support shaft and the fixing part are arranged in sequence and spaced apart along the length direction of the strip support beam.

[0006] After adopting the above technical scheme, the utility model has the following advantages: a rotating shaft, a center hole, a supporting shaft and a fixing part are provided on the strip support beam. The drum brake can be installed on the wheel through the center hole for installing the connecting shaft and the fixing part for fixing with the frame on the strip support beam. Then, by installing the spreading assembly and the rocker arm on the rotating shaft, the brake line pulls the rocker arm, which can drive the rotating shaft to rotate. The rotating shaft drives the spreading assembly to spread the two brake shoes, so that the brake shoes and the wheels are in contact, and the rotation speed of the wheel is reduced to achieve the purpose of braking. The drum brakes of the prior art mostly use a fully rust-proof high-strength alloy shell to support the assembly, but this leads to high costs. The optimization of this design is that only rust-proof high-strength alloy is used in the strip support beam, which significantly reduces the mold and material costs. This innovative solution greatly reduces the production and material costs while ensuring that the strength of the braking system meets the standards, while helping to reduce the weight of the drum brake and conforming to the trend of lightweight products. Furthermore, the rotating shaft, the center hole, the supporting shaft and the fixing portion are sequentially arranged at intervals along the length direction of the strip support beam, which can further reduce the size of the strip support beam and increase the applicable scenarios of the strip support beam.

[0007] Furthermore, it also includes a brake line mounting piece and a brake line body, the strip support beam is provided with a mounting portion, one end of the brake line mounting piece is fixed to the mounting portion, the other end of the brake line mounting piece extends downward and is provided with a brake line mounting position, the other end of the rocker arm extends downward and is provided with a brake line connecting position, one end of the brake line body passes through the brake line mounting position and is connected to the brake line connecting position, and the rotating shaft, center hole, support shaft, mounting portion and fixing portion are arranged in sequence and spaced apart along the length direction of the strip support beam.

[0008] By adopting the above-mentioned technical solution, since the brake line mounting piece is fixed to the mounting part on the strip support beam, and the brake line mounting position is installed on the brake line connecting position, when in use, the operator pulls the brake line body, and the brake line will pull the rocker arm close to the brake line mounting piece, so that the rocker arm drives the expansion assembly on the rotating shaft to expand the brake shoe, so that the brake shoe brakes the wheel. Since the mounting piece is installed on the strip support beam, the brake line body can be directly installed on the brake line mounting position of the mounting piece and the brake line connecting position of the rocker arm. Since the brake piece is directly installed on the strip support beam, the area of ​​the strip support beam will not increase significantly, saving the manufacturing cost of the drum brake. In addition, installing all parts on the strip support beam also simplifies the installation steps and facilitates the installation of the drum brake.

[0009] Furthermore, the support shaft is installed on the mounting portion, one end of the support shaft is provided with a thread and passes through the mounting portion and the brake line mounting piece, a nut is connected to the support shaft and the brake line mounting piece is pressed against the mounting portion by the nut.

[0010] By adopting the above-mentioned technical solution, the threaded end of the support shaft is passed through the mounting portion, and the brake line mounting piece is pressed onto the mounting portion by a nut, while the brake shoe can be installed on the other end, so that the support shaft is fixed to the strip support beam while fixing the brake line mounting piece, and the brake shoe can also be installed on the other end, utilizing the space on both sides of the strip support beam, not only achieving two uses of one part, but also saving space, saving installation steps, further achieving weight reduction and simplifying installation steps, and reducing production and installation costs.

[0011] Furthermore, an independently processed dust cover is installed on the strip support beam, and the dust cover is arranged on the outer sides of the two brake shoes and shields the two brake shoes.

[0012] By adopting the above-mentioned technical solution, the dust cover design can effectively isolate external impurities such as stones and dust, ensuring that the braking performance of the brake shoe is not affected, while preventing fine dust particles from invading the interior of the expansion mechanism, thereby extending the service life of the expansion component and protecting it from damage.

[0013] Furthermore, the dust cover is detachably connected to the strip support beam.

[0014] By adopting the above-mentioned technical solution and realizing the detachable connection between the dust cover and the strip support beam, the operator can easily inspect and clean the brake shoe and the spreader assembly without the tedious removal of the entire brake disc. Compared with the traditional drum brake maintenance method, this design significantly improves the efficiency and convenience of inspecting and cleaning the brake shoe and the spreader assembly.

[0015] Furthermore, the dust cover includes an upper half cover and a lower half cover, the lower half cover is fixed to the strip support beam, one end of the upper half cover is pivotally connected to the strip support beam, and the other end is detachably connected to the strip support beam or the lower half cover.

[0016] By adopting the above-mentioned technical solution, the dust cover is divided into an upper half cover and a lower half cover, and the upper half cover is detachably connected to the strip support beam or the lower half cover, so that the upper half cover is easy to disassemble, allowing the operator to more easily inspect and clean the brake shoe and the support assembly.

[0017] Furthermore, the upper half cover and the strip support beam are pivotally connected to the fixing portion.

[0018] By adopting the above-mentioned technical solution, the pivot axis is connected to the fixed part, and the fixed part is at the edge of the strip support beam, so that the pivot axis has the longest opening and closing angle, which is convenient for operators to check and clean the brake shoe and the spreader assembly.

[0019] Furthermore, the strip support beam is made of metal, and the dust cover is made of polymer material.

[0020] With the above technical solution, metal is expensive, easy to rust, and heavy. Using metal that is not easy to rust will be even more expensive. Therefore, polymer materials are used. Replacing the manufacturing material of the dust cover with polymer materials can reduce the price and weight of the drum brake.

[0021] A wheel assembly comprises a wheel bracket and a wheel body, wherein the wheel body is rotatably connected to the wheel bracket via a connecting shaft, the wheel bracket is equipped with the above-mentioned drum brake, the fixing portion is provided with a limiting fixing groove, the wheel bracket is provided with a limiting block adapted to the limiting fixing groove, and one end of the limiting block extends into the limiting fixing groove.

[0022] By adopting the above-mentioned technical solution, the limit block on the wheel bracket extends into the limit groove, so that the brake line on the drum brake can prevent the drum brake from rotating around the center hole when the rocker arm is pulled, thereby achieving the braking of the wheel by the drum brake.

[0023] A wheel assembly comprises a wheel bracket and a wheel body, wherein the wheel body is rotatably connected to the wheel bracket via a connecting shaft, the wheel bracket is mounted with the above-mentioned drum brake, the wheel body is provided with a accommodating cavity for accommodating the brake shoe, the outer side of the accommodating cavity is opened, and the dust cover covers the opening.

[0024] By adopting the above-mentioned technical solution, the components inside the drum brake are wrapped in the dust cover and the accommodating cavity through cooperation, so as to protect them from the invasion of external impurities such as stones and dust. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The utility model is further described below in conjunction with the accompanying drawings:

[0026] Figure 1 This is a first structural schematic diagram of a drum brake of the utility model;

[0027] Figure 2 This is a front view of a drum brake of the utility model with the upper half of the cover removed;

[0028] Figure 3 This is a rear view of a drum brake of the utility model;

[0029] Figure 4 This is a second structural schematic diagram of a drum brake of the utility model;

[0030] Figure 5 A schematic diagram of a propped-up assembly;

[0031] Figure 6 It is a schematic diagram of the structures of Embodiment 2 and Embodiment 3;

[0032] Figure 7It is a schematic diagram of the prior art.

[0033] Description of the drawings: 1. Strip support beam; 11. Center hole; 12. Dust cover; 121. Upper cover; 122. Lower cover; 13. Fixing part; 131. Fixing groove; 14. Support shaft; 141. Nut; 15. Brake line body; 151. Brake line mounting piece; 152. Brake line connection position; 16. Mounting part; 2. Rocker arm; 3. Brake shoe; 4. Elastic reset piece; 5. Rotating shaft; 6. Spreading assembly; 9. Wheel bracket; 91. Limit block; 10. Wheel body. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments.

[0035] The terms "first", "second", etc. (if any) in the specification and claims of the present utility model are used to distinguish similar objects, rather than to describe a specific order or sequence. Even if "second" is used to distinguish a certain technical feature, it does not necessarily mean that it has "first". It should be understood that in the present utility model, "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. It should be understood that in the present utility model, "multiple" refers to two or more. "And / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, X and / or Y can represent: X exists alone, X and Y exist at the same time, and Y exists alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "Contains X, Y and Z", "Contains X, Y, Z" means that X, Y, and Z are all included, "Contains X, Y or Z" means that one of X, Y, and Z is included, and "Contains X, Y and / or Z" means that any one, any two, or three of X, Y, and Z are included.

[0036] The following specific embodiments are used to describe the technical solution of the utility model in detail. The following specific embodiments can be combined or replaced with each other according to actual conditions, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0037] like Figures 1 to 5As shown, the utility model provides a drum brake, including a strip support beam 1, a rocker arm 2 and two brake shoes 3 arranged opposite to each other, an elastic reset member 4 is provided between the two brake shoes 3 to enable the two brake shoes 3 to be close to each other, one end of the two brake shoes 3 is rotatably connected to the strip support beam 1 through a support shaft 14, one end of the rocker arm 2 is rotatably connected to the strip support beam 1 through one end of a rotating shaft 5, and an opening component 6 for outwardly opening the two brake shoes 3 is installed on the other end of the rotating shaft 5, and the strip support beam 1 is provided with a plurality of elastic reset members 4, one end of the two brake shoes 3 is connected to the strip support beam 1 through a support shaft 14, and one end of the rocker arm 2 is rotatably connected to the strip support beam 1 through one end of a rotating shaft 5. A center hole 11 for installing a connecting shaft and a fixing portion 13 for fixing to a vehicle frame are provided, and the rotating shaft 5, the center hole 11, the supporting shaft 14 and the fixing portion 13 are sequentially arranged at intervals along the length direction of the strip support beam 1, wherein a first mounting hole, a center hole and a second mounting hole are sequentially provided on the extending direction of the strip support beam 1, a supporting shaft 14 for rotating the brake shoe 3 around it is installed on the first mounting hole, and a rotating shaft 5 is installed on the second mounting hole, and the elastic reset member 4 is a tension spring, with two brake shoes 3 pulled at both ends, and is located close to the supporting shaft.

[0038] After adopting the above technical solution, the utility model has the following advantages: by installing the spreading component 6 and the rocker arm 2 on the rotating shaft 5, and then by placing the center hole 11 for installing the connecting shaft and the fixing part 13 for fixing with the frame, the rotating shaft 5, the center hole 11, the support shaft 14 and the fixing part 13 are arranged on the support beam. When in use, the brake line pulls the rocker arm 2, so that the rocker arm 2 drives the rotating shaft 5 to rotate, and the rotating shaft 5 drives the spreading component 6 to spread the two brake shoes 3, so that the brake shoes 3 contact with the wheel, and the rotation speed of the wheel is reduced to achieve the purpose of braking. Traditional drum brakes usually require the entire shell to be made of corrosion-resistant high-strength alloy materials to carry related components, while this design solution only needs to use this high-performance alloy in the strip support beam 1 part, which effectively reduces the mold investment and material costs, and makes the rotating shaft 5, the center hole 11, the support shaft 14 and the fixing part 13 located on the same straight line, which can further reduce the size of the strip support beam 1 and increase the applicable scenes of the strip support beam 1. This ensures that the brake system maintains the necessary strength while significantly reducing costs, including production and material costs, and is also beneficial to reducing the weight of the entire drum brake, and can meet the requirements of lightweight products. In addition, the rotating shaft, the center hole, the support shaft and the fixing part are arranged in sequence along the length direction of the strip support beam, which can further reduce the size of the strip support beam and increase the applicable scenarios of the strip support beam.

[0039] Specifically, in one embodiment, Figure 5 As shown, the specific structure of the spreading assembly 6 can be that a cam is fixed on the rotating shaft 5, and the two brake shoes 3 clamp the cam. When the cam rotates, the circumferential surface with a larger radius can spread the two brake shoes 3 outward to brake the wheel; in another embodiment, as shown in FIG. Figure 3 to Figure 4 In the embodiment, the expansion assembly 6 is composed of two gears, a gear cam and a baffle. This structure is a prior art and will not be described in detail here. It can be understood that by locating the rotating shaft, the center hole, the support shaft and the fixing part on the same straight line, the size of the strip support beam can be further reduced and the applicable scenarios of the strip support beam can be increased; the split structure of the support beam 11 and the dust cover 12 is made of two parts independently and installed together in the subsequent process.

[0040] like Figure 7 As shown, the rotating shaft 5 and the center hole 11, the supporting shaft 14 and the fixing portion 13 in the prior art are not on the same straight line.

[0041] Specifically, one end of the rocker arm 2 is mounted on the rotating shaft 5, the center hole is used to mount the connecting shaft on the frame, and the fixing portion is provided with a fixing groove for clamping the limit block on the frame to prevent the drum brake from rotating as a whole. It can be understood that the rotating shaft 5 and the center hole 11, the support shaft 14 and the fixing portion 13 of the prior art are not on the same straight line, which increases the difficulty of manufacturing the drum brake and the dust cover separately.

[0042] Furthermore, it also includes a brake line mounting piece 151 and a brake line body 15, the strip support beam 1 is provided with a mounting portion 16, one end of the brake line mounting piece 151 is fixed to the mounting portion 16, the other end of the brake line mounting piece 151 extends downward and is provided with a brake line mounting position, the other end of the rocker arm 2 extends downward and is provided with a brake line connecting position 152, one end of the brake line body 15 passes through the brake line mounting position and is connected to the brake line connecting position 152, and the rotating shaft 5, the center hole 11, the support shaft 14, the mounting portion 16 and the fixing portion 13 are arranged in sequence along the length direction of the strip support beam 1.

[0043] By adopting the above-mentioned technical solution, since the brake wire mounting member 151 is fixed to the mounting portion 16 on the strip support beam 1, and the brake wire mounting position is installed on the brake wire connecting position 152, when in use, the operator pulls the brake wire body 15, and the brake wire will pull the rocker arm 2 close to the brake wire mounting member 151, so that the rocker arm 2 drives the expansion assembly 6 on the rotating shaft 5 to expand the brake shoe 3, so that the brake shoe 3 brakes the wheel. Since the mounting member is installed on the strip support beam 1, the brake wire can be directly installed on the brake wire mounting position of the mounting member and the brake wire connecting position 152 of the rocker arm 2. The brake member is directly installed on the strip support beam 1, so that the area of ​​the strip support beam 1 will not be greatly increased, saving the manufacturing cost of the drum brake, and installing all parts on the strip support beam 1 also simplifies the installation steps and facilitates the installation of the drum brake.

[0044] Furthermore, the support shaft 14 is installed on the mounting portion 16 , one end of the support shaft 14 is provided with a thread and passes through the mounting portion 16 and the brake line mounting member 151 , a nut 141 is connected to the support shaft 14 and the brake line mounting member 151 is pressed against the mounting portion 16 by the nut 141 .

[0045] By adopting the above-mentioned technical solution, the threaded end of the support shaft 14 is passed through the mounting portion 16, and the brake line mounting piece 151 is pressed onto the mounting portion 16 by the nut 141, and the brake shoe 3 can be installed on the other end, so that the support shaft 14 is fixed to the strip support beam 1 while fixing the brake line mounting piece 151, and the brake shoe 3 can also be installed on the other end, utilizing the space on both sides of the strip support beam 1, not only achieving two uses of one part, but also saving space, saving installation steps, further achieving weight reduction and simplifying installation steps, and reducing production and installation costs.

[0046] Specifically, one end of the support shaft 14 is a smooth cylindrical surface and is clamped in the middle by two radially extending truncated cones. The other end has a thread and can pass through the mounting portion 16, and the truncated cone can prevent the support shaft 14 from passing through the mounting portion 16. The mounting portion 16 of the strip support beam 1 can then be clamped together with the nut 141. The installation sequence is to first pass the threaded end of the support shaft 14 through the mounting portion 16 and the brake line mounting member 151, and then press the brake line mounting member 151 onto the mounting portion 16 through the nut 141, and then install the two brake shoes 3 on the cylindrical surface of the support shaft 14.

[0047] Furthermore, an independently processed dust cover 12 is installed on the strip support beam 1 , and the dust cover 12 is arranged on the outer sides of the two brake shoes 3 and shields the two brake shoes 3 .

[0048] By adopting the above-mentioned technical solution, the design of the dust cover 12 can effectively isolate external impurities such as stones and dust, ensuring that the braking performance of the brake shoe 3 is not affected, while preventing fine dust particles from invading the interior of the expansion mechanism, thereby extending the service life of the expansion component 6 and protecting it from damage.

[0049] Furthermore, the dust cover 12 is detachably connected to the strip support beam 1 .

[0050] By adopting the above-mentioned technical solution, through realizing the detachable connection between the dust cover 12 and the strip support beam 1, the operator can easily inspect and clean the brake shoe 3 and the spreader assembly 6 without the tedious removal of the entire brake disc. Compared with the traditional drum brake maintenance method, this design significantly improves the efficiency and convenience of inspecting and cleaning the brake shoe 3 and the spreader assembly 6.

[0051] Furthermore, the dust cover 12 includes an upper half cover 121 and a lower half cover 122, the lower half cover 122 is fixed to the strip support beam 1, one end of the upper half cover 121 is pivotally connected to the strip support beam 1, and the other end is detachably connected to the strip support beam 1 or the lower half cover 122.

[0052] By adopting the above-mentioned technical solution, the dust cover 12 is divided into an upper half cover 121 and a lower half cover 122, and the upper half cover 121 is detachably connected to the strip support beam 1 or the lower half cover 122, so that the upper half cover 121 is easy to disassemble, allowing the operator to more easily check and clean the brake shoe 3 and the support assembly 6.

[0053] Specifically, the detachable connection of the other end of the upper cover 121 or the lower cover 122 is a snap connection or a bolt connection.

[0054] Furthermore, the upper half cover 121 and the strip support beam are pivotally connected to the fixing portion 13 .

[0055] By adopting the above technical solution, the pivot shaft is connected to the fixing portion 13 so that the pivot shaft has the longest opening and closing angle, which makes it convenient for operators to check and clean the brake shoe 3 and the spreader assembly 6.

[0056] Furthermore, the strip support beam is made of metal, and the dust cover 12 is made of polymer material.

[0057] With the above technical solution, metal is expensive, easy to rust, and heavy. Using metal that is not easy to rust will be even more expensive. Therefore, polymer materials are used. Replacing the manufacturing material of the dust cover 12 with polymer materials can reduce the price and weight of the drum brake.

[0058] Specifically, the support beam is made of common metal materials such as aluminum alloy or steel, and the dust cover 12 is made of common polymer materials such as plastic.

[0059] Embodiment 2:

[0060] like Figure 6 As shown, a wheel assembly includes a wheel bracket 9 and a wheel body 10, wherein the wheel body 10 is rotatably connected to the wheel bracket 9 via a connecting shaft, the wheel bracket 9 is equipped with the above-mentioned drum brake, the fixing portion 13 is provided with a limiting fixing groove 131, and the wheel bracket 9 is provided with a limiting block 91 adapted to the limiting fixing groove 131, and one end of the limiting block 91 extends into the limiting fixing groove 131.

[0061] By adopting the above-mentioned technical solution, the limiting block 91 on the wheel bracket 9 extends into the limiting groove, so that the brake line on the drum brake can prevent the drum brake from rotating around the center hole 11 when the rocker arm 2 is pulled, thereby achieving the braking of the wheel by the drum brake.

[0062] Embodiment 3:

[0063] like Figure 6 As shown, a wheel assembly includes a wheel bracket 9 and a wheel body 10, wherein the wheel body 10 is rotatably connected to the wheel bracket 9 via a connecting shaft, the wheel bracket 9 is mounted with the above-mentioned drum brake, and the wheel body 10 is provided with a accommodating cavity for accommodating the brake shoe 3, the outer side of the accommodating cavity is opened, and the dust cover 12 covers the opening.

[0064] By adopting the above-mentioned technical solution, through the cooperation between the dust cover 12 and the accommodating cavity, the internal components of the drum brake are wrapped therein, so as to protect them from the invasion of external impurities such as stones and dust.

[0065] In addition to the above-mentioned preferred embodiments, the present invention also has other implementation modes. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection requested by the present invention.

Claims

1. A drum brake, characterized in that: It includes a strip support beam, a rocker arm and two brake shoes arranged opposite to each other, one end of the two brake shoes is rotatably connected to the strip support beam through a support shaft, one end of the rocker arm is rotatably connected to the strip support beam through a rotating shaft, and a spreading assembly for spreading the two brake shoes outward is installed on the rotating shaft. The strip support beam is provided with a center hole for installing the connecting shaft and a fixing part for fixing to the frame, and the rotating shaft, the center hole, the support shaft and the fixing part are arranged in sequence and spaced apart along the length direction of the strip support beam.

2. A drum brake according to claim 1, characterized in that: It also includes a brake line mounting piece and a brake line body, the strip support beam is provided with a mounting portion, one end of the brake line mounting piece is fixed to the mounting portion, the other end of the brake line mounting piece extends downward and is provided with a brake line mounting position, the other end of the rocker arm extends downward and is provided with a brake line connecting position, one end of the brake line body passes through the brake line mounting position and is connected to the brake line connecting position, and the rotating shaft, center hole, support shaft, mounting portion and fixing portion are arranged in sequence along the length direction of the strip support beam.

3. A drum brake according to claim 2, characterized in that: The support shaft is installed on the mounting portion, one end of the support shaft is provided with a thread and passes through the mounting portion and the brake line mounting piece, a nut is connected to the support shaft and the brake line mounting piece is pressed against the mounting portion by the nut.

4. A drum brake according to claim 1, characterized in that: An independently processed dust cover is installed on the strip support beam, and the dust cover is arranged on the outer sides of the two brake shoes and covers the two brake shoes.

5. A drum brake according to claim 4, characterized in that: The dust cover is detachably connected to the strip support beam.

6. A drum brake according to claim 4, characterized in that: The dust cover comprises an upper half cover and a lower half cover, the lower half cover is fixed to the strip support beam, one end of the upper half cover is pivotally connected to the strip support beam, and the other end is detachably connected to the strip support beam or the lower half cover.

7. A drum brake according to claim 6, characterized in that: The upper half cover and the pivot axis of the strip support beam are connected to the fixing portion.

8. A drum brake according to claim 4, 5, 6 or 7, characterized in that: The strip support beam is made of metal, and the dust cover is made of polymer material.

9. A wheel assembly, comprising a wheel support and a wheel body, wherein the wheel body is rotatably connected to the wheel support via a connecting shaft, wherein: The drum brake according to claim 1 is installed on the wheel bracket, a limiting fixing groove is provided on the fixing portion, a limiting block adapted to the limiting fixing groove is provided on the wheel bracket, and one end of the limiting block extends into the limiting fixing groove.

10. A wheel assembly, comprising a wheel support and a wheel body, wherein the wheel body is rotatably connected to the wheel support via a connecting shaft, wherein: The drum brake according to claim 4 is installed on the wheel bracket, and a receiving cavity for receiving the brake shoe is provided on the wheel body. The outer side of the receiving cavity is opened, and the dust cover covers the opening.

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