A centrifugal compressor main shaft structure

Abstract

This utility model discloses a centrifugal compressor main shaft structure, including an impeller with a central through-hole mounting hole. A main shaft body is fitted inside the mounting hole. The end face of the impeller has a coaxial mounting groove. A flange is fixedly connected to the mounting groove by a first bolt. The flange is fixedly fitted onto the outer edge of the main shaft body. A cavity is provided inside the main shaft body, and a fastener is slidably connected within the cavity. The outer edge of the fastener abuts against a fixing member, which slidably passes through the cavity and is inserted into the mounting hole. This utility model replaces the traditional spline connection with a composite fixing method of flange bolt connection and insert-slot locking, significantly reducing the requirements for the machining accuracy of the main shaft and impeller inner holes, while avoiding the stringent limitations of heat treatment processes, thus significantly reducing processing difficulty and manufacturing costs.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal compressor technology, and in particular to a centrifugal compressor main shaft structure. Background Technology

[0002] Patent publication number CN221973831U discloses a centrifugal compressor with interstage gas filling, including a main body, an inlet pipe fixedly installed on the main body, an exhaust pipe fixedly installed on the main body, a main shaft rotatably installed inside the main body, an impeller fixedly installed on the main shaft, and a guide ring fixedly installed inside the main body. Through a unidirectional pressure limiting structure on the interstage pipe, unidirectional pressure limiting of the gas can be achieved, ensuring that the gas does not flow back during compression, thus improving the compression efficiency and stability of the system. The gas filling pipe on the interstage pipe can achieve multi-port uniform gas intake, thereby improving the gas intake efficiency and reducing the system's energy consumption. The main shaft and impeller are connected by a self-aligning bearing and a spline, ensuring stable rotation of the impeller and improving the working efficiency and reliability of the centrifugal compressor.

[0003] However, in this patent, the impeller and main shaft are connected via splines. The spline connection requires a strict match between the spline tooth profiles of the main shaft and the inner bore of the impeller, which places extremely high demands on machining accuracy and heat treatment processes. Even a slight deviation may lead to assembly difficulties or localized stress concentration, increasing manufacturing costs and process complexity. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a centrifugal compressor main shaft structure.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a centrifugal compressor main shaft structure, including an impeller, the center of which has a through mounting hole, a main shaft body being fitted inside the mounting hole, an mounting groove being coaxially provided on the end face of the impeller, a flange being fixedly connected in the mounting groove by a first bolt, the flange being fixedly fitted on the outer edge of the main shaft body, a cavity being provided inside the main shaft body, a fastener being slidably connected inside the cavity, the outer edge of the fastener abutting against a fixing member, the fixing member slidably passing through the cavity and inserted into the mounting hole.

[0006] As a further description of the above technical solution: the inner wall of the mounting groove is provided with multiple equally spaced annularly distributed threaded grooves, the outside of the flange is penetrated by multiple first countersunk holes, the first bolt is sleeved in the first countersunk hole and threadedly connected in the threaded groove; the main shaft body and impeller are initially positioned and installed by setting the flange and the first bolt.

[0007] As a further description of the above technical solution: the fastener includes a second bolt rotatably connected in the cavity, a second countersunk hole coaxially opened at the end of the main shaft body communicating with the cavity, the second bolt being rotatably connected in the second countersunk hole, a tapered screw sleeve being threaded on the outer edge of the second bolt, the tapered screw sleeve being slidably connected in the cavity, and the fixing member abutting against the outer edge of the tapered screw sleeve; by setting the fastener, it is convenient to drive the fixing member to fix the main shaft body and the impeller.

[0008] As a further description of the above technical solution: the fixing component includes multiple equidistant annularly distributed inserts in the cavity, the inserts abutting against the outer edge of the conical screw sleeve, and the bottom surface of the inserts is provided with an inclined surface adapted to the conical surface of the conical screw sleeve. The inner wall of the cavity is provided with multiple equidistant annularly distributed through slots, and one insert is slidably inserted into each through slot. The inner wall of the mounting hole is provided with multiple equidistant annularly distributed slots, and the inserts are inserted into the slots. The fixing component facilitates the final fixing of the impeller and the main shaft body.

[0009] As a further description of the above technical solution: two guide grooves are symmetrically opened on the inner wall of the through groove, a guide block is slidably connected in the guide groove, the guide block is fixedly connected to the insert block, a compressed spring is fixed between the inner wall of the guide groove and the guide block, and a support block is fixedly connected in the guide groove by a third bolt; by using the spring to slidably connect the insert block in the through groove, the insert block automatically retracts into the through groove after the main shaft body and the impeller are disassembled.

[0010] As a further description of the above technical solution: a slot is formed on one side of the inner wall of the guide groove, a locking block is engaged in the slot, the locking block is fixedly connected to the support block, an internally threaded cylinder is sleeved inside the spring, the guide block is slidably sleeved on the outer edge of the internally threaded cylinder, the internally threaded cylinder is fixedly connected to the bottom wall of the guide groove, the support block abuts against the top surface of the internally threaded cylinder, the top surface of the support block penetrates through a third countersunk hole, the third bolt is rotatably connected in the third countersunk hole and threadedly connected in the internally threaded cylinder; by installing the spring in the guide groove using the third bolt, the internally threaded cylinder and the support block, it is convenient to disassemble and replace a single damaged spring and the insert block.

[0011] As a further description of the above technical solution: multiple guide rods are fixedly connected in an equidistant ring within the cavity, and the conical screw sleeve is slidably sleeved on the outer edge of the multiple guide rods; by using the guide rods to slidably connect the conical screw sleeve within the cavity, the circumferential movement of the conical screw sleeve is limited.

[0012] This utility model has the following beneficial effects:

[0013] Compared with existing technologies, the centrifugal compressor main shaft structure replaces the traditional spline connection with a composite fixing method of flange bolt connection and plug-slot locking, which greatly reduces the requirements for the machining accuracy of the main shaft and impeller inner hole, while avoiding the strict limitations of heat treatment process, and significantly reducing the processing difficulty and manufacturing cost. Attached Figure Description

[0014] Figure 1 This is a three-dimensional view of the overall structure of the main shaft of a centrifugal compressor proposed in this utility model;

[0015] Figure 2 This is a main sectional view of the overall structure of the centrifugal compressor main shaft structure proposed in this utility model;

[0016] Figure 3 This utility model proposes a centrifugal compressor main shaft structure. Figure 2 Enlarged view of the structure at point A in the middle;

[0017] Figure 4 This utility model proposes a centrifugal compressor main shaft structure. Figure 3 Enlarged view of the structure at point B in the middle.

[0018] Legend:

[0019] 1. Impeller; 2. Main shaft body; 3. First countersunk hole; 4. First bolt; 5. Second countersunk hole; 6. Second bolt; 7. Mounting groove; 8. Flange; 9. Cavity; 10. Slot; 11. Insert block; 12. Mounting hole; 13. Guide rod; 14. Tapered screw sleeve; 15. Guide groove; 16. Through groove; 17. Internal threaded cylinder; 18. Third bolt; 19. Guide block; 20. Spring; 21. Support block; 22. Third countersunk hole; 23. Locking block; 24. Locking groove. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Reference Figures 1 to 4The present invention provides a centrifugal compressor main shaft structure, including an impeller 1, a central through mounting hole 12, a main shaft body 2 fitted inside the mounting hole 12, a mounting groove 7 coaxially provided on the end face of the impeller 1, a flange 8 fixedly connected inside the mounting groove 7 by a first bolt 4, the flange 8 fixedly fitted on the outer edge of the main shaft body 2, a cavity 9 provided inside the main shaft body 2, a fastener slidably connected inside the cavity 9, the outer edge of the fastener abutting against a fixing member, the fixing member slidably passing through the cavity 9 and inserted into the mounting hole 12, a plurality of equally spaced annularly distributed threaded grooves provided on the inner wall of the mounting groove 7, a plurality of first countersunk holes 3 passing through the outer side of the flange 8, the first bolt 4 fitted inside the first countersunk holes 3 and threadedly connected in the threaded grooves;

[0022] The fastener includes a second bolt 6 rotatably connected to the cavity 9, a second countersunk hole 5 coaxially opened at the end of the main shaft body 2 communicating with the cavity 9, the second bolt 6 rotatably connected to the second countersunk hole 5, a tapered screw sleeve 14 threaded on the outer edge of the second bolt 6, the tapered screw sleeve 14 slidably connected to the cavity 9, a plurality of equally spaced annularly distributed guide rods 13 fixedly connected in the cavity 9, the tapered screw sleeve 14 slidably sleeved on the outer edge of the plurality of guide rods 13, and a fixing member abutting against the outer edge of the tapered screw sleeve 14;

[0023] The fastener includes multiple equidistant annularly distributed inserts 11 within the cavity 9. The inserts 11 abut against the outer edge of the conical screw sleeve 14, and the bottom surface of the inserts 11 is provided with an inclined surface adapted to the conical surface of the conical screw sleeve 14. Multiple equidistant annularly distributed through slots 16 are opened on the inner wall of the cavity 9, and an insert 11 is slidably inserted into each through slot 16. Multiple equidistant annularly distributed slots 10 are opened on the inner wall of the mounting hole 12, and the inserts 11 are inserted into the slots 10. Two guide slots 15 are symmetrically opened on the inner wall of the through slots 16, and guide blocks 19 are slidably connected in the guide slots 15. The guide blocks 19 are fixedly connected to the inserts 11. A compressed spring 20 is fixed between the inner wall of the guide slots 15 and the guide blocks 19. A support block 21 is fixedly connected in the guide slots 15 by a third bolt 18. The number and distribution of slots 10 are the same as those of the first countersunk holes 3, and each first countersunk hole 3 corresponds to one slot 10.

[0024] A slot 24 is opened on one side of the inner wall of the guide groove 15. A locking block 23 is engaged in the slot 24. The locking block 23 is fixedly connected to the support block 21. An internal threaded cylinder 17 is sleeved inside the spring 20. The guide block 19 is slidably sleeved on the outer edge of the internal threaded cylinder 17. The internal threaded cylinder 17 is fixedly connected to the bottom wall of the guide groove 15. The support block 21 abuts against the top surface of the internal threaded cylinder 17. The top surface of the support block 21 passes through the third countersunk hole 22. The third bolt 18 is rotatably connected in the third countersunk hole 22 and threadedly connected in the internal threaded cylinder 17.

[0025] The composite fixing method, which uses flange 8 bolt connection and insert 11-slot 10 locking, replaces the traditional spline connection, significantly reducing the requirements for the machining accuracy of the spindle and impeller 1 inner hole, while avoiding the strict limitations of heat treatment process, significantly reducing machining difficulty and manufacturing cost. The flange 8 is fixed to the threaded groove on the end face of the impeller 1 by the first bolt 4, realizing quick alignment and pre-tightening of the spindle and impeller 1. Rotating the second bolt 6 pushes the tapered screw sleeve 14 to move axially, forcing the insert 11 to extend radially and embed into the slot 10 in the inner hole of the impeller 1, forming a rigid interlock, effectively resisting the centrifugal force and torque during high-speed rotation, improving connection reliability. The insert 11 is pre-locked by spring 20. Pressed tightly within the guide groove 15, it automatically resets during disassembly to avoid interference; components such as the spring 20 and guide block 19 are fixed with an internal threaded cylinder 17 and a third bolt 18, allowing for individual replacement of damaged parts without the need for complete disassembly of the main shaft, making maintenance convenient and cost-effective; the guide rod 13 limits the circumferential direction of the tapered screw sleeve 14, ensuring that it moves only axially, avoiding uneven force on the insert 11 due to skew, thereby ensuring the dynamic balance performance of the impeller 1 during high-speed operation; the inclined surface of the insert 11 and the tapered screw sleeve 14 forms a self-locking effect, making it less prone to loosening under vibration conditions; at the same time, the evenly distributed design of the insert 11 disperses stress concentration, extending the service life of the main shaft and impeller 1.

[0026] Working principle: When installing the main shaft body 2 and the impeller 1, firstly, the main shaft body 2 is installed in the positioning hole in the impeller 1. Then, the main shaft body 2 is rotated, and the first countersunk hole 3 on the outer flange 8 of the main shaft body 2 is aligned with the threaded groove in the mounting groove 7. Then, the first bolt 4 is used for initial fixing. Next, the second bolt 6 is rotated, and the second bolt 6 drives the tapered screw sleeve 14 to move axially. When the tapered screw sleeve 14 moves, under the cooperation of its tapered surface and the inclined surface of the bottom surface of the insert 11, the tapered screw sleeve 14 drives the insert 11 to extend out of the through groove 16 and insert into the slot 10 in the positioning hole. At the same time, the spring 20 is compressed, and the installation of the impeller 1 and the main shaft body 2 is finally fixed. If the insert 11 is damaged, rotate the second bolt 6 to retract the tapered screw sleeve 14, and at the same time, the compressed spring 20 will reset, causing the insert 11 to retract from the slot 10 into the through groove 16. Then remove the first bolt 4, and then disassemble the main shaft body 2 and the impeller 1. Then remove the third bolt 18 at the damaged spring 20 on the outside of the main shaft body 2, and then take out the support block 21. Then remove the damaged spring 20 or insert 11 from the main shaft body 2, and then install a new spring 20 or insert 11. Then install the support block 21 back into the guide groove 15 and use the slot 24 and the block 23 for limiting. Finally, use the third bolt 18 to fix it, and then install the main shaft body 2 and the impeller 1.

[0027] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A centrifugal compressor main shaft structure comprising an impeller (1), characterized in that: The impeller (1) has a central through-hole (12), and a main shaft body (2) is fitted inside the through-hole (12). The end face of the impeller (1) is coaxially provided with a mounting groove (7). A flange (8) is fixedly connected inside the mounting groove (7) by a first bolt (4). The flange (8) is fixedly fitted on the outer edge of the main shaft body (2). A cavity (9) is provided inside the main shaft body (2). A fastener is slidably connected inside the cavity (9). The outer edge of the fastener abuts against a fixing member. The fixing member slidably passes through the cavity (9) and is inserted into the through-hole (12).

2. A centrifugal compressor main shaft structure according to claim 1, characterized in that: The inner wall of the mounting groove (7) is provided with multiple equally spaced annularly distributed threaded grooves. The outside of the flange (8) is penetrated by multiple first countersunk holes (3). The first bolt (4) is sleeved in the first countersunk hole (3) and threadedly connected in the threaded groove.

3. A centrifugal compressor main shaft structure according to claim 1, characterized in that: The fastener includes a second bolt (6) rotatably connected in the cavity (9), and a second countersunk hole (5) coaxially opened at the end of the main shaft body (2) communicating with the cavity (9). The second bolt (6) is rotatably connected in the second countersunk hole (5). A tapered screw sleeve (14) is threaded on the outer edge of the second bolt (6). The tapered screw sleeve (14) is slidably connected in the cavity (9). The fixing member abuts against the outer edge of the tapered screw sleeve (14).

4. A centrifugal compressor main shaft structure according to claim 3, characterized in that: The fastener includes multiple equidistant annularly distributed inserts (11) in the cavity (9). The inserts (11) abut against the outer edge of the conical screw sleeve (14), and the bottom surface of the inserts (11) is provided with an inclined surface adapted to the conical surface of the conical screw sleeve (14). Multiple equidistant annularly distributed through slots (16) are opened on the inner wall of the cavity (9), and one insert (11) is slidably inserted into each through slot (16). Multiple equidistant annularly distributed slots (10) are opened on the inner wall of the mounting hole (12), and the inserts (11) are inserted into the slots (10).

5. A centrifugal compressor main shaft structure according to claim 4, characterized in that: Two guide grooves (15) are symmetrically opened on the inner wall of the through groove (16). A guide block (19) is slidably connected in the guide groove (15). The guide block (19) is fixedly connected to the insert block (11). A compressed spring (20) is fixed between the inner wall of the guide groove (15) and the guide block (19). A support block (21) is fixedly connected in the guide groove (15) by a third bolt (18).

6. A centrifugal compressor main shaft structure according to claim 5, characterized in that: A slot (24) is opened on one side of the inner wall of the guide groove (15). A locking block (23) is engaged in the slot (24). The locking block (23) is fixedly connected to the support block (21). An internal threaded cylinder (17) is sleeved inside the spring (20). The guide block (19) is slidably sleeved on the outer edge of the internal threaded cylinder (17). The internal threaded cylinder (17) is fixedly connected to the bottom wall of the guide groove (15). The support block (21) abuts against the top surface of the internal threaded cylinder (17). The top surface of the support block (21) passes through the third countersunk hole (22). The third bolt (18) is rotatably connected in the third countersunk hole (22) and threadedly connected in the internal threaded cylinder (17).

7. A centrifugal compressor main shaft structure according to claim 3, characterized in that: Multiple guide rods (13) are fixedly connected in a ring at equal intervals inside the cavity (9), and the tapered screw sleeve (14) is slidably sleeved on the outer edge of the multiple guide rods (13).

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