A self-rotating, wear-resistant elbow for pneumatic conveying

Abstract

This application discloses a self-rotating wear-resistant elbow for pneumatic conveying, relating to the field of elbow and pipe fitting technology. It improves upon the problems of severe localized erosion and wear, easy loosening of flange connections, poor sealing reliability, and inability to adapt to long-term, high-load conveying in traditional fixed elbows. The elbow includes a pipe body with flat flanges fitted at both ends. A bearing is installed between the end of the pipe body and the flat flange. A beveled flange is bolted to the outer surface of the flat flange. A sealing assembly is installed between the flat flange and the beveled flange. A driven gear is fixedly fitted to the outer surface of the pipe body. A motor bracket is installed on the outer surface of the beveled flange, and a drive motor is fixedly connected to the motor bracket. This application allows for uniform wear of the inner wall wear layer through pipe body rotation, eliminating localized concentrated erosion. Double sealing and mechanical anti-loosening ensure reliable connection. It is suitable for pneumatic conveying systems in various scenarios such as mining, metallurgy, and chemical industries.

Description

Technical Field

[0001] This invention relates to the field of elbow fittings technology, and in particular to a self-rotating, wear-resistant elbow for pneumatic conveying. Background Technology

[0002] Pneumatic conveying, as the mainstream method for efficient conveying of powder and granular materials, is widely used in industries such as mining, metallurgy, chemical, food, and environmental protection. Elbows are the core components that change the direction of material conveying. During the gas-solid two-phase flow conveying process, high-speed particles will continuously scour and impact the inner wall of the elbow, which can easily cause wear, thinning, or even perforation of the pipe wall. Therefore, the structural reliability and service life of wear-resistant elbows directly determine the operational stability of the entire conveying system. Existing technologies usually improve the wear resistance of elbows by using alloy materials, ceramic linings, welded wear-resistant layers, or thickened pipe walls to adapt to the conveying conditions of high-concentration, high-flow-rate, and high-hardness materials.

[0003] Existing wear-resistant elbows are mostly fixed structures. When materials turn, they will cause concentrated impact on a fixed area of ​​the inner wall of the elbow, resulting in excessively rapid local wear, easy lining detachment, and a relatively short service life. At the same time, the connection between the elbow and the pipeline is prone to loosening and sealing failure due to vibration. Furthermore, there is a lack of self-adaptive sealing and anti-loosening positioning structures, making it difficult to simultaneously meet the requirements of wear resistance, reliable sealing, and stable connection. Therefore, they cannot be adapted to long-term, continuous, and high-load pneumatic conveying conditions. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the problems existing in the prior art, the present invention provides a self-rotating, wear-resistant elbow for pneumatic conveying.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the present invention provides the following technical solution: a self-rotating wear-resistant elbow for pneumatic conveying, comprising a pipe body, both ends of which are fitted with flat flanges, bearings are provided between the ends of the pipe body and the flat flanges, a bevel flange is bolted to the outer surface of the flat flanges, a sealing assembly is provided between the flat flanges and the bevel flanges, a driven gear is fixedly fitted to the outer surface of the pipe body, a motor bracket is provided to the outer surface of the bevel flanges, a drive motor is fixedly connected to the motor bracket, a drive gear is fixedly connected to the output end of the drive motor, the drive gear meshes with the driven gear, a sealing ring is provided between the inner wall of the flat flange and the pipe body, and the sealing ring is fitted to the outer surface of the pipe body, a first connecting pipe is fixedly connected to one end of the bevel flange, a first flange is provided to the outer surface of the first connecting pipe, a second connecting pipe is provided to one end of the first connecting pipe, a second flange is provided to the outer surface of the second connecting pipe, the first flange and the second flange are bolted together, an anti-loosening sleeve is provided to the outer surface of the first flange, and a limit assembly is fixedly connected to the lower surface of the second flange.

[0008] As a preferred embodiment of the self-rotating wear-resistant elbow for pneumatic conveying described in this invention, the inner wall of the pipe body is provided with a wear-resistant layer, the bearing is a deep groove ball bearing, and the bearing is disposed between the outer surface of the end of the pipe body and the inner wall of the flat flange to achieve rotatable support of the pipe body.

[0009] As a preferred embodiment of the self-rotating wear-resistant elbow for pneumatic conveying described in this invention, the sealing assembly includes a threaded groove formed on the outer surface of the inclined flange, a corrugated composite gasket installed inside the threaded groove, a through hole formed on the inner wall of the threaded groove, a nut movably connected to the outer surface of the inclined flange, a hexagonal head bolt threaded to the inner wall of the nut, the outer surface of the hexagonal head bolt connected to the flat flange, and a threaded sleeve provided on the outer surface of the flat flange.

[0010] As a preferred embodiment of the self-rotating wear-resistant elbow for pneumatic conveying described in this invention, the inner wall of the threaded groove has the same dimensions as the outer wall of the threaded sleeve, and the outer surface of the threaded sleeve is threadedly connected to the inner wall of the threaded groove. The outer surface of the corrugated composite gasket is fitted to the inner bottom wall of the threaded groove, and the dimensions of the corrugated composite gasket are the same as the inner wall of the threaded groove.

[0011] As a preferred embodiment of the self-rotating steering wear-resistant elbow for pneumatic conveying described in this invention, one end of the hexagonal head bolt is threaded to the inner wall of the through hole on the flat flange and the oblique flange.

[0012] As a preferred embodiment of the self-rotating wear-resistant elbow for pneumatic conveying described in this invention, the limiting component includes a mounting block fixedly connected to the lower surface of a second flange. A limiting block is movably disposed inside the mounting block, and a snap-fit ​​block is rotatably disposed inside the mounting block via a rotating shaft. A snap-fit ​​groove adapted to the snap-fit ​​block is formed on the lower surface of the limiting block, and one end of the snap-fit ​​block snaps into the snap-fit ​​groove. A mounting base is fixedly connected to the lower surface of the limiting block. A telescopic spring is disposed between the outer surface of the mounting base and the inner wall of the mounting block. A telescopic rod is also disposed between the outer surface of the mounting base and the inner wall of the mounting block, and the telescopic spring is fixedly sleeved on the outer surface of the telescopic rod.

[0013] As a preferred embodiment of the self-rotating steering wear-resistant elbow for pneumatic conveying described in this invention, the lower surface of the snap-fit ​​block is provided with a fixing groove, a connecting spring is fixedly connected to the inner bottom wall of the mounting block, and the other end of the connecting spring is connected to the inner wall of the fixing groove. The other end of the snap-fit ​​block is fixedly connected with a lever, and one side of the snap-fit ​​block is arranged in an arc shape.

[0014] As a preferred embodiment of the self-rotating wear-resistant elbow for pneumatic conveying described in this invention, the inner wall of the anti-loosening sleeve is provided with a limiting groove adapted to the limiting block, and one end of the limiting block extends into the interior of the limiting groove.

[0015] (III) Beneficial Effects

[0016] This invention provides a self-rotating, wear-resistant elbow for pneumatic conveying. It offers the following advantages:

[0017] 1. This invention uses a drive motor to drive a drive gear and a driven gear to mesh and transmit power, causing the pipe body to rotate continuously and uniformly around its own axis. This allows the wear-resistant layer on the inner wall to withstand the scouring and impact of high-speed materials evenly, completely changing the defect of traditional fixed elbows where a single location on the inner wall is subjected to concentrated erosion over a long period of time. It effectively avoids problems such as localized rapid wear, pipe wall thinning, perforation, and lining detachment. Combined with deep groove ball bearings, it achieves low friction and highly stable rotational support, ensuring smooth rotation and reducing mechanical losses. Under the pneumatic conveying conditions of high-concentration, high-flow-rate, and high-hardness materials, it can significantly reduce the overall wear rate, significantly extend the service life of the elbow, reduce the frequency of equipment replacement, and lower maintenance costs.

[0018] 2. This invention features a sealing assembly consisting of a threaded groove, a corrugated composite gasket, and a threaded sleeve between the flat flange and the oblique flange. This assembly, combined with the sealing ring at the pipe end, forms a double sealing structure, providing both self-adaptive tightening and high-pressure sealing capabilities. This effectively prevents dust leakage and gas seepage during transport. Simultaneously, the limiting assembly and anti-loosening sleeve work together, achieving automatic anti-loosening positioning of the flange connection through the locking of the limiting block and the limiting groove. The locking block, telescopic spring, and other structures ensure stable limiting status, preventing bolt loosening and connection failure due to long-term vibration. The overall device is easy to install, has good sealing performance, and high connection strength. It can adapt to complex and harsh long-cycle continuous transport conditions in mining, metallurgy, and chemical industries, making it suitable for a wider range of applications and offering higher operational safety. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 This is a partial structural schematic diagram of the present invention.

[0022] Figure 3 This is a side sectional view of the present invention.

[0023] Figure 4 This is a schematic diagram of the sealing component in this invention.

[0024] Figure 5 This is a bottom view of the first connecting pipe and the second connecting pipe in this invention.

[0025] Figure 6 This is a top view of the first connecting pipe and the second connecting pipe in this invention.

[0026] Figure 7 This is a schematic diagram of the limiting component in this invention.

[0027] Figure 8 This is a partial structural diagram of the locking component in this invention.

[0028] Figure 9 This is a schematic diagram of the anti-loosening sleeve in this invention.

[0029] In the diagram, 1. Pipe body; 101. Bearing; 102. Flat flange; 103. Diagonal flange; 104. Sealing ring; 105. Driven gear; 106. Drive gear; 107. Motor bracket; 108. Drive motor; 2. Sealing assembly; 201. Threaded groove; 202. Corrugated composite gasket; 203. Through hole; 204. Nut; 205. Hex head bolt; 206. Threaded sleeve; 3. First flange; 4. First connecting pipe; 5. Second connecting pipe; 6. Second flange; 7. Anti-loosening sleeve; 701. Limiting groove; 9. Limiting assembly; 901. Mounting block; 902. Limiting block; 903. Snap-fit ​​block; 904. Snap-fit ​​groove; 905. Fixing groove; 906. Connecting spring; 907. Mounting seat; 908. Telescopic spring; 909. Telescopic rod; 910. Lever. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0031] Example 1

[0032] Reference Figure 1 , Figure 2 , Figure 3 and Figure 4 This is the first embodiment of the present invention, which provides a self-rotating, wear-resistant elbow for pneumatic conveying, including a pipe body 1. Both ends of the pipe body 1 are fitted with flat flanges 102. A bearing 101 is provided between the end of the pipe body 1 and the flat flange 102. A beveled flange 103 is bolted to the outer surface of the flat flange 102. A sealing assembly 2 is provided between the flat flange 102 and the beveled flange 103. A driven gear 105 is fixedly fitted onto the outer surface of the pipe body 1. A motor bracket 107 is provided on the outer surface of the beveled flange 103. A drive motor 108 is fixedly connected to the motor bracket 107, and the output end of the drive motor 108 is fixedly connected to... A drive gear 106 meshes with a driven gear 105. A sealing ring 104 is provided between the inner wall of the flat flange 102 and the pipe body 1, and the sealing ring 104 is fitted on the outer surface of the pipe body 1. A first connecting pipe 4 is fixedly connected to one end of the oblique flange 103. A first flange 3 is provided on the outer surface of the first connecting pipe 4. A second connecting pipe 5 is provided at one end of the first connecting pipe 4. A second flange 6 is provided on the outer surface of the second connecting pipe 5. The first flange 3 and the second flange 6 are connected by bolts. An anti-loosening sleeve 7 is provided on the outer surface of the first flange 3. A limit component 9 is fixedly connected to the lower surface of the second flange 6.

[0033] Specifically, the inner wall of the pipe body 1 is provided with a wear-resistant layer. The bearing 101 is a deep groove ball bearing, which is located between the outer surface of the end of the pipe body 1 and the inner wall of the flat flange 102 to achieve rotatable support for the pipe body 1. The sealing assembly 2 includes a threaded groove 201 formed on the outer surface of the oblique flange 103. A corrugated composite gasket 202 is installed inside the threaded groove 201. A through hole 203 is formed on the inner wall of the threaded groove 201. A nut 204 is movably connected to the outer surface of the oblique flange 103. A hexagonal head bolt 205 is threadedly connected to the inner wall of the nut 204. The outer surface of the head bolt 205 is connected to the flat flange 102. The outer surface of the flat flange 102 is provided with a threaded sleeve 206. The inner wall size of the threaded groove 201 is the same as the outer wall size of the threaded sleeve 206, and the outer surface of the threaded sleeve 206 is threadedly connected to the inner wall of the threaded groove 201. The outer surface of the corrugated composite gasket 202 is fitted to the inner bottom wall of the threaded groove 201, and the size of the corrugated composite gasket 202 is the same as the inner wall size of the threaded groove 201. One end of the hexagonal head bolt 205 is threadedly connected to the inner wall of the through hole 203 on the flat flange 102 and the oblique flange 103.

[0034] Furthermore, the drive motor 108 is energized and started, and the output end drives the drive gear 106 to rotate at a constant speed. The drive gear 106 and the driven gear 105 mesh with each other, and the driven gear 105 drives the pipe body 1 to rotate continuously around its own axis. The bearings 101 at both ends of the pipe body 1 support the rotation within the flat flange 102, ensuring smooth and stable rotation of the pipe body 1 and reducing rotational friction and mechanical wear. The flat flange 102 and the oblique flange 103 are fastened together by hexagonal head bolts 205, nuts 204 and threaded sleeves 206. The corrugated composite gasket 202 is tightly compressed to achieve a high-pressure seal at the flange connection. Combined with the sealing ring 104 between the pipe body 1 and the flat flange 102, this forms a double seal, effectively preventing dust and gas leakage during pneumatic conveying. High-speed gas-solid two-phase flow enters the pipe body 1 from the inclined flange 103. As the pipe body 1 continues to rotate, the internal material flow forms a uniform swirling state, preventing material particles from concentrating and scouring a fixed location on the inner wall. Instead, the material acts evenly on the wear-resistant layer of the inner wall of the pipe body 1, fundamentally reducing localized wear, abrasion, and lining detachment. The first connecting pipe 4 and the second connecting pipe 5 are connected via the first flange 3 and the second flange 6. The anti-loosening sleeve 7 and the limiting component 9 cooperate to limit and prevent loosening of the flange connection, avoiding bolt loosening due to long-term conveying vibration. This ensures stable operation of the entire elbow during continuous pneumatic conveying, achieving integrated conveying and turning operation with wear resistance, sealing, and stable rotation. By setting up a flat flange 102, threaded groove 201, oblique flange 103, threaded sleeve 206, and corrugated composite gasket 202, the flat flange 102 can be connected without affecting the installation of the corrugated composite gasket 202. The flange 102 and the oblique flange 103 achieve a tight threaded connection through the threaded groove 201 and the threaded sleeve 206, which greatly improves the tightness between the flat flange 102 and the oblique flange 103. At the same time, the corrugated composite gasket 202 can maintain excellent sealing performance for a long time under conditions where temperature and pressure fluctuate easily, effectively preventing gas leakage caused by heat deformation of the gasket. It also occupies little space and greatly improves the sealing performance of the flange. The use of the corrugated composite gasket 202 and the threaded groove 201 can maintain high sealing performance under very low compressive stress.

[0035] Example 2

[0036] Reference Figure 1 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 This is the second embodiment of the present invention, which is based on the previous embodiment.

[0037] The limiting component 9 includes a mounting block 901 fixedly connected to the lower surface of the second flange 6. A limiting block 902 is movably disposed inside the mounting block 901. A snap-fit ​​block 903 is rotatably disposed inside the mounting block 901 via a rotating shaft. A snap-fit ​​groove 904 adapted to the snap-fit ​​block 903 is opened on the lower surface of the limiting block 902, and one end of the snap-fit ​​block 903 is snapped into the snap-fit ​​groove 904. A mounting base 907 is fixedly connected to the lower surface of the limiting block 902. A telescopic spring 908 is disposed between the outer surface of the mounting base 907 and the inner wall of the mounting block 901. A telescopic rod 909 is also disposed between the outer surface of the mounting base 907 and the inner wall of the mounting block 901, and the telescopic spring 908 is fixedly sleeved on the outer surface of the telescopic rod 909.

[0038] Specifically, a fixing groove 905 is provided on the lower surface of the snap-fit ​​block 903, a connecting spring 906 is fixedly connected to the inner bottom wall of the mounting block 901, and the other end of the connecting spring 906 is connected to the inner wall of the fixing groove 905. A lever 910 is fixedly connected to the other end of the snap-fit ​​block 903, and one side of the snap-fit ​​block 903 is set with an arc-shaped structure. A limiting groove 701 adapted to the limiting block 902 is provided on the inner wall of the anti-loosening sleeve 7, and one end of the limiting block 902 extends into the interior of the limiting groove 701.

[0039] Furthermore, through the cooperation of the limiting component 9 and the anti-loosening sleeve 7, automatic anti-loosening positioning is achieved after the first flange 3 and the second flange 6 are connected. During operation, the limiting block 902 extends towards the anti-loosening sleeve 7 under the elastic thrust of the telescopic spring 908 and the telescopic rod 909, and its end extends into the limiting groove 701 on the inner wall of the anti-loosening sleeve 7, forming a rigid limit to prevent the first flange 3 and the second flange 6 from rotating relative to each other, thus avoiding loosening of the connecting bolts due to vibration during pneumatic conveying. The locking block 903 rotates around the pivot under the elastic force of the connecting spring 906, and one end of it locks into the locking groove 90 at the bottom of the limiting block 902. Within 4, the limiting block 902 is locked to prevent it from accidentally retracting and to ensure a stable and reliable limiting state. The arc-shaped structure on one side of the locking block 903 facilitates the smooth insertion and installation of the limiting block 902. When disassembly and maintenance are required, the lever 910 can be turned to rotate the locking block 903, causing it to disengage from the locking groove 904 and releasing the locking of the limiting block 902, thus achieving quick disassembly. Through the above-mentioned structure of mechanical locking, elastic limiting, and anti-loosening sleeve 7, the flange connection remains in a tight state under long-term vibration and high-pressure impact pneumatic conveying conditions, further improving the stability and safety of the overall device operation.

[0040] Working Principle: When performing pneumatic conveying operations, this device first connects to the conveying pipeline via the inclined flange 103 and the first connecting pipe 4. The first flange 3 and the second flange 6 are fastened together with bolts to form a complete conveying passage. During operation, the drive motor 108 starts and drives the drive gear 106 to rotate. The drive gear 106 meshes with the driven gear 105, thereby driving the pipe body 1 to rotate continuously and uniformly around its own axis. The bearings 101 at both ends of the pipe body 1 provide low-friction support inside the flat flange 102, ensuring smooth and stable rotation of the pipe body 1 and preventing jamming or shaking. The flat flange 102 and the inclined flange 103 are connected by hexagonal head bolts 205. The nuts 204 and threaded sleeves 206 are tightened, and the corrugated composite gasket 202 in the threaded groove 201 is pressed to form the first seal. The sealing ring 104 between the pipe body 1 and the flat flange 102 forms the second seal. The double sealing structure can effectively prevent dust leakage and gas seepage during the high-pressure gas-solid two-phase flow. After the high-speed gas-solid two-phase flow enters the pipe body 1, as the pipe body 1 continues to rotate, the internal material flow forms a uniform swirling state, so that the particles will not concentrate on impacting a fixed area of ​​the inner wall, but will uniformly scour the wear-resistant layer of the inner wall of the pipe body 1. This fundamentally solves the problems of severe local wear, easy wear-through, and easy detachment of the inner lining of traditional fixed elbows, and significantly extends the service life.

[0041] Meanwhile, the limiting component 9 and the anti-loosening sleeve 7 work together to prevent the flange connection from loosening: the limiting block 902 extends into the limiting groove 701 under the push of the telescopic spring 908 and the telescopic rod 909, restricting the relative rotation of the first flange 3 and the second flange 6. The locking block 903 is locked into the locking groove 904 under the action of the connecting spring 906, locking the limiting block 902 to ensure that the connection does not loosen under long-term vibration conditions. When disassembly is required, the locking can be released by turning the lever 910, realizing quick maintenance. The whole device achieves wear-resistant, sealed, stable, and long-life pneumatic conveying turning operation through the coordinated work of the three structures of rotational friction reduction, double sealing, and automatic anti-loosening. It can adapt to complex conveying conditions of high concentration, high flow rate, and high load.

[0042] It should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

Claims

1. A self-rotating, wear-resistant elbow for pneumatic conveying, comprising a pipe body (1), characterized in that: Both ends of the pipe body (1) are fitted with flat flanges (102). A bearing (101) is provided between the end of the pipe body (1) and the flat flange (102). An oblique flange (103) is bolted to the outer surface of the flat flange (102). A sealing assembly (2) is provided between the flat flange (102) and the oblique flange (103). A driven gear (105) is fixedly fitted on the outer surface of the pipe body (1). A motor bracket (107) is provided on the outer surface of the oblique flange (103). A drive motor (108) is fixedly connected to the motor bracket (107). A drive gear (106) is fixedly connected to the output end of the drive motor (108). The drive gear (106) and the driven gear (101) are connected to each other. 5) Engagement, a sealing ring (104) is provided between the inner wall of the flat flange (102) and the pipe body (1), and the sealing ring (104) is sleeved on the outer surface of the pipe body (1). One end of the oblique flange (103) is fixedly connected to a first connecting pipe (4). The outer surface of the first connecting pipe (4) is provided with a first flange (3). One end of the first connecting pipe (4) is provided with a second connecting pipe (5). The outer surface of the second connecting pipe (5) is provided with a second flange (6). The first flange (3) and the second flange (6) are connected by bolts. The outer surface of the first flange (3) is provided with an anti-loosening sleeve (7). The lower surface of the second flange (6) is fixedly connected with a limit assembly (9).

2. The self-rotating, wear-resistant elbow for pneumatic conveying according to claim 1, characterized in that: The inner wall of the pipe body (1) is provided with a wear-resistant layer, and the bearing (101) is a deep groove ball bearing. The bearing (101) is located between the outer surface of the end of the pipe body (1) and the inner wall of the flat flange (102) to realize the rotatable support of the pipe body (1).

3. The self-rotating, wear-resistant elbow for pneumatic conveying according to claim 1, characterized in that: The sealing assembly (2) includes a threaded groove (201) on the outer surface of the oblique flange (103), a corrugated composite gasket (202) is installed inside the threaded groove (201), a through hole (203) is provided on the inner wall of the threaded groove (201), a nut (204) is movably connected to the outer surface of the oblique flange (103), a hexagonal head bolt (205) is threaded to the inner wall of the nut (204), the outer surface of the hexagonal head bolt (205) is connected to the flat flange (102), and a threaded sleeve (206) is provided on the outer surface of the flat flange (102).

4. A self-rotating, wear-resistant elbow for pneumatic conveying according to claim 3, characterized in that: The inner wall of the threaded groove (201) has the same dimensions as the outer wall of the threaded sleeve (206), and the outer surface of the threaded sleeve (206) is threadedly connected to the inner wall of the threaded groove (201). The outer surface of the corrugated composite gasket (202) is fitted to the inner bottom wall of the threaded groove (201), and the dimensions of the corrugated composite gasket (202) are the same as the inner wall of the threaded groove (201).

5. A self-rotating, wear-resistant elbow for pneumatic conveying according to claim 3, characterized in that: One end of the hexagonal head bolt (205) is threaded to the inner wall of the through hole (203) on the flat flange (102) and the oblique flange (103).

6. A self-rotating, wear-resistant elbow for pneumatic conveying according to claim 1, characterized in that: The limiting component (9) includes a mounting block (901) fixedly connected to the lower surface of the second flange (6). A limiting block (902) is movably arranged inside the mounting block (901). A snap-fit ​​block (903) is rotatably arranged inside the mounting block (901) via a rotating shaft. A snap-fit ​​groove (904) adapted to the snap-fit ​​block (903) is opened on the lower surface of the limiting block (902), and one end of the snap-fit ​​block (903) is snapped into the snap-fit ​​groove (904). A mounting seat (907) is fixedly connected to the lower surface of the limiting block (902). A telescopic spring (908) is arranged between the outer surface of the mounting seat (907) and the inner wall of the mounting block (901). A telescopic rod (909) is also arranged between the outer surface of the mounting seat (907) and the inner wall of the mounting block (901), and the telescopic spring (908) is fixedly sleeved on the outer surface of the telescopic rod (909).

7. A self-rotating, wear-resistant elbow for pneumatic conveying according to claim 6, characterized in that: The lower surface of the snap-fit ​​block (903) is provided with a fixing groove (905). A connecting spring (906) is fixedly connected to the inner bottom wall of the mounting block (901), and the other end of the connecting spring (906) is connected to the inner wall of the fixing groove (905). The other end of the snap-fit ​​block (903) is fixedly connected with a lever (910), and one side of the snap-fit ​​block (903) is set with an arc-shaped structure.

8. A self-rotating, wear-resistant elbow for pneumatic conveying according to claim 1, characterized in that: The inner wall of the anti-loosening sleeve (7) is provided with a limiting groove (701) that is adapted to the limiting block (902), and one end of the limiting block (902) extends into the interior of the limiting groove (701).

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