A top shaft for carrying the running chain of a chain grate in pellet production

Abstract

The utility model discloses a kind of upper supporting shafts for carrying chain grate running chain in pellet production, it includes middle section shaft sleeve, and the shaft head connected with the both ends of middle section shaft sleeve respectively;The end of shaft head is provided with interference connection section, and interference connection section is inserted into first cavity with interference;V-shaped joint is opened in the connecting place of shaft head and middle section shaft sleeve, first cavity is opened in the inside of middle section shaft sleeve, second cavity is opened in the inside of shaft head, and first cavity is communicated with second cavity;The utility model is assembled with interference by shaft head and middle section shaft sleeve, and shaft head and middle section shaft sleeve are connected by full welding in V-shaped joint, increase the integrity between shaft head and middle section shaft sleeve, increase carrying capacity and torsional strength, cooling water flowing is stored in first cavity for a long time, to cool the upper supporting shaft, prolong the service life of upper supporting shaft.

Description

Technical Field

[0001] This utility model relates to the field of chain grate machine technology, specifically to an upper support shaft used in pellet production to support the running chain of a chain grate machine. Background Technology

[0002] The chain grate is a key piece of equipment in pellet production. The chain grate's running chain bears the alternating temperatures of the pellets, ranging from room temperature to 1000°C. Ensuring that the temperature of the material (i.e., the pellets) on the running chain reaches the target values ​​required by the pellet production process at each stage is achieved by high-temperature airflow passing through the material from top to bottom, effectively "baking" the pellets. To ensure the stable operation of the high-temperature, heavy-load running chain (the running chain of a 1.2 million tons / year chain grate is 4m wide x 96m long) in alternating high and low temperature environments, the support roller shaft plays a crucial and decisive role.

[0003] A typical 1.2 million-ton / year chain grate machine consists of 50 upper support shafts and 30 lower support shafts. Of these, 30 upper support shafts, or 60%, operate in the high-temperature zone above 400℃. During normal pellet production, the service life of the chain grate machine's support shafts varies depending on actual production capacity (fatigue load), temperature, dust concentration, and air pressure (generally around one year). Especially as pellet plants continuously pursue higher compressive strength, roasting temperatures are constantly increasing (reaching 1200℃). Upper support shafts operating in the 500℃ high-temperature zone often experience cracking, leaks, and shaft breakage after only about six months of operation, significantly impacting large-scale production.

[0004] Analysis of the fracture causes revealed that the traditional multi-segment composite upper support shaft has deficiencies in terms of load-bearing strength, stress concentration locations, and processing methods, while the processing cost of a one-piece upper support shaft is extremely high. Therefore, there is an urgent need for an upper support shaft that is resistant to high temperatures, has strong load-bearing capacity, strong torque resistance, long service life, and low processing cost (economical and practical) to solve the above problems. Utility Model Content

[0005] To address the aforementioned problems in the prior art, this utility model provides an upper support shaft for supporting the running chain of a chain grate machine in pellet production, which solves the problem of easy breakage of existing upper support shafts in high-temperature zones.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A support shaft for carrying the running chain of a chain grate machine in pellet production is provided, comprising a middle section bushing and shaft heads respectively connected to both ends of the middle section bushing; one end of the shaft head is provided with an interference connection section, which is interference-fitted into a first cavity; a V-shaped joint is provided at the connection between the shaft head and the middle section bushing, the middle section bushing has a first cavity inside, and the shaft head has a second cavity inside, with the first cavity communicating with the second cavity.

[0007] This invention increases the integrity between the shaft head and the middle bushing by interference fit assembly of the shaft head and the middle bushing, and by fully welding the shaft head and the middle bushing together in the V-shaped joint, thereby increasing the load-bearing capacity and torque resistance. By storing cooling water in the first cavity for a long time to cool the upper support shaft, the service life of the upper support shaft is extended.

[0008] Furthermore, the two ends of the middle section bushing are respectively provided with first positioning holes, and the interference fit section is provided with second positioning holes that fit with the first positioning holes. A pin is inserted into the second positioning hole through the first positioning hole, and the pin is welded to the middle section bushing.

[0009] Furthermore, the second cavity includes a connected third cavity and a fourth cavity, the diameter of the fourth cavity being smaller than the diameter of the third cavity.

[0010] Furthermore, multiple first keyways are evenly provided on the side wall of the middle section bushing.

[0011] Furthermore, a second keyway is provided on the shaft head.

[0012] Furthermore, a protective bushing is fitted onto the middle section bushing.

[0013] Furthermore, a fiber felt is provided between the bushing and the intermediate bushing.

[0014] This utility model discloses an upper support shaft for supporting the running chain of a chain grate machine in pellet production, the beneficial effects of which are: 1. This utility model increases the integrity between the shaft head and the middle section bushing by interference fit assembly of the shaft head and the middle section bushing, and by fully welding the shaft head and the middle section bushing in the V-shaped joint, thereby increasing the load-bearing capacity and torque resistance. By storing flowing cooling water in the first cavity for a long time, it is intended to cool the upper support shaft and extend its service life.

[0015] 2. This utility model adds a protective bushing and fiber felt to the middle section bushing to further resist the oxidation and erosion of the upper support shaft body by high temperature heat source, high temperature dust and airflow. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an upper support shaft for carrying the running chain of a chain grate machine in pellet production, according to the present invention.

[0017] Figure 2 For the present utility model Figure 1 A cross-sectional view at point AA.

[0018] Figure 3 For the present utility model Figure 1 A schematic diagram of the structure at point C.

[0019] Figure 4 This is a schematic diagram of the structure of the middle section bushing of this utility model.

[0020] Figure 5 This is a schematic diagram of the structure of the shaft head of this utility model.

[0021] Figure 6 This is an assembly diagram of the upper support shaft of this utility model.

[0022] Figure 7 For the present utility model Figure 6 A schematic diagram of the structure at point BB.

[0023] Among them, 1. Middle section bushing; 11. First cavity; 12. First positioning hole; 13. First keyway; 2. Shaft head; 21. Second cavity; 22. Interference connection section; 23. Second positioning hole; 24. Third cavity; 25. Fourth cavity; 26. Second keyway; 3. V-shaped joint; 4. Protective bushing; 5. Fiber felt. Detailed Implementation The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of this utility model as defined and determined by the appended claims, these changes are obvious. All utility model creations utilizing the concept of this utility model are within the scope of protection.

[0024] Example 1 refer to Figures 1-7 This embodiment provides an upper support shaft for supporting the running chain of a chain grate machine in pellet production. Its purpose is to solve the problem that existing upper support shafts in high-temperature zones are prone to breakage. The specific structure of this embodiment will be described in detail below.

[0025] An upper support shaft for carrying the running chain of a chain grate machine in pellet production includes a middle section bushing 1 and shaft heads 2 connected to both ends of the middle section bushing 1.

[0026] Specifically, one end of the shaft head 2 is provided with an interference connection section 22, which is inserted into the first cavity 11; a V-shaped joint 3 is provided at the connection between the shaft head 2 and the middle section bushing 1; the middle section bushing 1 is provided with the first cavity 11, and the shaft head 2 is provided with the second cavity 21, which are connected to each other.

[0027] In this embodiment, both the middle bushing 1 and the shaft head 2 are made of 35CrMo material to ensure high temperature resistance, oxidation resistance, and high strength. The cross-sections of the first cavity 11 and the second cavity 21 are both circular.

[0028] An interference fit section 22 is provided at one end of the shaft head 2. The outer wall dimension of the interference fit section 22 matches the inner cavity dimension of the first cavity 11, so that the interference fit section 22 is inserted into the first cavity 11 with interference fit. The interference fit is required to be H7 / p6, the interference amount is 0.03-0.05, and the coaxiality error of the middle section bushing 1 and the two shaft heads 2 is less than 0.03mm.

[0029] A V-shaped joint 3 is provided at the connection between the shaft head 2 and the middle section bushing 1. The shaft head 2 and the middle section bushing 1 are fully welded together in the V-shaped joint 3, thereby increasing the integrity between the shaft head 2 and the middle section bushing 1, and increasing the load-bearing capacity and torque resistance.

[0030] Meanwhile, the second cavity 21 is connected to the external circulating cooling water, and circulating cooling water is injected into the first cavity 11 to cool the upper support shaft and extend its service life.

[0031] Specifically, the two ends of the middle section bushing 1 are respectively provided with first positioning holes 12, and the interference connection section 22 is provided with second positioning holes 23 that fit with the first positioning holes 12. A pin passes through the first positioning hole 12 and is inserted into the second positioning hole 23, and the pin is welded to the middle section bushing 1.

[0032] In this embodiment, the pin is made of 35CrMo. It passes through the first positioning hole 12 and the second positioning hole 23, and is welded to the outer wall of the middle bushing 1. The pin is then fitted with an interference fit and a full welded V-shaped joint 3 to improve the integrity between the shaft head 2 and the middle bushing 1, thereby increasing the load-bearing capacity and torque resistance.

[0033] Specifically, the second cavity 21 includes a connected third cavity 24 and a fourth cavity 25, the diameter of the fourth cavity 25 being smaller than the diameter of the third cavity 24.

[0034] In this embodiment, the diameter of the fourth cavity 25 is smaller than the diameter of the third cavity 24, and the diameter of the third cavity 24 is smaller than the diameter of the first cavity 11, thereby increasing the residence time of the circulating cooling water in the first cavity 11, and then the heat is carried away by the circulation.

[0035] Specifically, multiple first keyways 13 are evenly provided on the side wall of the middle section bushing 1.

[0036] Specifically, a second keyway 26 is provided on the shaft head 2.

[0037] In this embodiment, the two ends of each first keyway 13 and second keyway 26 are offset from the limit points on both sides of the roller to be installed, that is, the length of the first keyway 13 and the second keyway 26 is less than the width of the roller to be installed by 20mm, so as to avoid stress concentration.

[0038] Optionally, both ends of each first keyway 13 and second keyway 26 are rounded to avoid stress concentration.

[0039] Specifically, a protective bushing 4 is fitted onto the middle section bushing 1.

[0040] Specifically, a fiber felt 5 is provided between the bushing 4 and the middle bushing 1.

[0041] In this embodiment, the bushing 4 is made of Q235-A material. By installing the bushing 4 on the upper support shaft in the high-temperature area of ​​the chain grate machine, and bundling the bushing 4 with 50mm thick fiber felt 5, the bushing 4 completely isolates the external hot airflow and pressurized dust, further resisting the oxidation and erosion of the upper support shaft by the high-temperature heat source, high-temperature dust and airflow.

[0042] Optionally, the fiber felt 5 can be made of thermal insulation cotton.

[0043] Although the specific embodiments of the utility model have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this patent. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims still fall within the scope of protection of this patent.

Claims

1. An upper support shaft for supporting the running chain of a chain grate machine in pellet production, characterized in that: It includes a middle section bushing (1) and a shaft head (2) connected to both ends of the middle section bushing (1); one end of the shaft head (2) is provided with an interference connection section (22), which is interference-fitted into the first cavity (11); a V-shaped joint (3) is provided at the connection between the shaft head (2) and the middle section bushing (1). The middle section bushing (1) has a first cavity (11) inside, and the shaft head (2) has a second cavity (21) inside. The first cavity (11) and the second cavity (21) are connected.

2. The upper support shaft for supporting the running chain of a chain grate machine in pellet production according to claim 1, characterized in that: The middle section bushing (1) has a first positioning hole (12) at each end. The interference connection section (22) has a second positioning hole (23) that matches the first positioning hole (12). A pin passes through the first positioning hole (12) and is inserted into the second positioning hole (23), and the pin is welded to the middle section bushing (1).

3. The upper support shaft for supporting the running chain of a chain grate machine in pellet production according to claim 1, characterized in that: The second cavity (21) includes a connected third cavity (24) and a fourth cavity (25), wherein the diameter of the fourth cavity (25) is smaller than the diameter of the third cavity (24).

4. The upper support shaft for supporting the running chain of a chain grate machine in pellet production according to claim 1, characterized in that: Multiple first keyways (13) are evenly provided on the side wall of the middle section bushing (1).

5. The upper support shaft for supporting the running chain of a chain grate machine in pellet production according to claim 1, characterized in that: The shaft head (2) is provided with a second keyway (26).

6. The upper support shaft for supporting the running chain of a chain grate machine in pellet production according to claim 1, characterized in that: A protective bushing (4) is fitted on the middle section bushing (1).

7. The upper support shaft for supporting the running chain of a chain grate machine in pellet production according to claim 6, characterized in that: A fiber felt (5) is provided between the bushing (4) and the middle bushing (1).

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