Impeller mounting structure for centrifugal compressor
Patent Information
- Application Number
- CN202522525308.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-28
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2035-11-28
AI Technical Summary
Traditional impeller mounting structures are prone to loosening or wear under thermal expansion and alternating loads, resulting in a short service life.
The first positioning ring of the impeller is interference-fitted with the first positioning groove of the main shaft. The connecting shaft and the central hole of the impeller form a radial flange support. The nut and the connecting shaft form a bidirectional preload system. Combined with the threaded connection of the guide cap to the impeller and the main shaft, a composite anti-loosening mechanism is formed.
This achieves precise positioning of the impeller and the main shaft, reduces wear on the mating surfaces during disassembly and assembly, minimizes the impact of thermal stress, and improves installation stability and service life.
Smart Images
Figure CN224931920U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of centrifugal compressor equipment, specifically to an impeller mounting structure for a centrifugal compressor. Background Technology
[0002] In traditional designs, impellers are typically mounted on the spindle using key connections, interference fits, or single thread fasteners. For example, a common approach is to transmit torque via a keyway and key, supplemented by axial nut tightening. However, under thermal expansion and alternating loads, traditional threaded fasteners are prone to loosening or fretting wear, resulting in a short service life.
[0003] Therefore, we propose an impeller mounting structure for a centrifugal compressor. Utility Model Content
[0004] In view of the shortcomings of the prior art, this utility model provides an impeller mounting structure for a centrifugal compressor to solve the above-mentioned problems in the prior art.
[0005] To achieve the above objectives, this utility model provides the following technical solution: An impeller mounting structure for a centrifugal compressor, characterized in that it includes an impeller, a main shaft, a connecting shaft, a nut, and a flow guide cap; The impeller has a central through hole running along the axis, and a first positioning ring extends outward from one end of the central through hole to form a first positioning groove. The end of the main shaft has a first positioning groove and a threaded connection hole located at the center of the first positioning groove. The first positioning ring of the impeller is inserted into the first positioning groove. One end of the connecting shaft passes through the central through hole of the impeller and is threadedly connected to the threaded connection hole. The other end is threadedly connected to the nut. The nut presses the impeller tightly and fixes it on the main shaft. The connecting shaft has an annular radial flange, which is supported in the central through hole of the impeller. One end of the nut has a second positioning ring sleeve, which extends into the gap between the central through hole of the impeller and the connecting shaft. The flow guide cap is threaded to the connecting shaft and fits against the axial end face of the impeller.
[0006] Furthermore, both sides of the radial flange are connected to the connecting shaft body by chamfering.
[0007] Furthermore, the connecting shaft has a relief groove on the radial flange facing the nut side.
[0008] Furthermore, the flow guide cap is penetrated by a connecting shaft.
[0009] Furthermore, the outer contour of the flow guide cap is arc-shaped and smoothly connects with the outer contour line of the impeller.
[0010] Furthermore, the other end of the connecting shaft is tapered, smoothly transitioning to the curved surface of the inner cavity of the guide cap.
[0011] This utility model provides an impeller mounting structure for a centrifugal compressor, which has the following advantages: The first positioning ring of the impeller and the first positioning groove of the main shaft form an interference fit insert structure, which realizes precise positioning in both axial and radial directions and effectively controls the concentricity error between the impeller and the main shaft.
[0012] Only a small area of radial flange supports the connecting shaft and the central perforation of the impeller. The main body of the connecting shaft, excluding the radial flange, has a large clearance fit with the central perforation, which avoids wear on the main mating surfaces caused by repeated disassembly and assembly, and reduces the impact of disassembly and assembly on balance. In addition, the large clearance design of the main body allows for thermal expansion differences and reduces thermal stress.
[0013] One end of the connecting shaft is threaded to the threaded hole of the main shaft, and the other end is threaded with the nut to form a two-way preload system: the nut extends into the gap between the impeller center hole and the connecting shaft through the second positioning ring sleeve, applying uniform axial pressure to the impeller, while the radial flange of the connecting shaft is supported on the inner wall of the center hole, providing radial constraint.
[0014] This structure upgrades the traditional single-point thread fastening to a composite anti-loosening mechanism of "positioning ring + radial flange + double thread", reducing the risk of nut disengagement.
[0015] The other end of the connecting shaft is equipped with a flow guide cap, which is threaded to the connecting shaft. This ensures good coaxiality with the impeller, main shaft, and connecting shaft, reducing the impact on dynamic balance before and after disassembly and assembly. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 for Figure 1 A magnified structural diagram of point A in the middle.
[0017] In the picture: 1. Impeller; 1a. First positioning ring; 1b. Central perforation; 2. Spindle; 2a. First positioning groove; 3. Connecting shaft; 3a. Radial flange; 3b. Unsinking groove; 4. Nuts; 4a. Second positioning ring; 5. Airflow deflector cap; 5a. Inner cavity. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0019] See attached document Figure 1-2 An impeller 1 mounting structure for a centrifugal compressor includes an impeller 1, a main shaft 2, a connecting shaft 3, a nut 4, and a flow guide cap 5; The impeller 1 has a central through hole 1b that runs through the axis, and a first positioning ring 1a that extends outward from one end of the central through hole 1b and is coaxially arranged. The main shaft 2 has a first positioning groove 2a that is coaxially arranged at its end and a threaded connection hole located at the center of the first positioning groove 2a. The first positioning ring 1a of the impeller 1 is inserted into the first positioning groove 2a and is press-fitted with the first positioning groove 2a. One end of the connecting shaft 3 passes through the central through hole 1b of the impeller 1 and is threaded to the threaded connection hole. The other end is threaded to the nut 4. The nut 4 presses and fixes the impeller 1 to the main shaft 2. The connecting shaft 3 has an annular radial flange 3a, which is supported in the central through hole 1b of the impeller 1. The gap between the radial flange 3a and the central through hole 1b is H7 / g6. One end of the nut 4 has a second positioning ring 4a, which extends into the gap between the central through hole 1b of the impeller 1 and the connecting shaft 3. The gap between the second positioning ring 4a and the central through hole 1b is H8 / f8, which is slightly looser than the gap between the radial flange 3a and the central through hole 1b, allowing for a slight difference in thermal expansion and avoiding friction caused by misalignment during high-speed rotation. The flow guide cap 5 is threadedly connected to the connecting shaft 3 and fits against the axial end face of the impeller 1. The nut 4 is housed in the inner cavity 5a of the flow guide cap 5.
[0020] In this embodiment, the two sides of the radial flange 3a are respectively connected to the main body of the connecting shaft 3 by chamfering. The connecting shaft 3 has a relief groove 3b on the side of the radial flange 3a facing the nut 4.
[0021] In this embodiment, the guide cap 5 is penetrated by the connecting shaft 3. The outer contour of the guide cap 5 is arc-shaped or streamlined and smoothly connects with the outer contour line of the impeller 1.
[0022] In some embodiments, the other end of the connecting shaft 3 is a tapered cone (cone angle 15°~30°, not shown in the figure), which smoothly transitions with the outer curved surface of the guide cap 5. The streamlined curved surface of the guide cap 5 guides the airflow smoothly, but the cylindrical shaft end of the connecting shaft 3, which passes through the other end of the guide cap 5, abruptly blocks the streamline. This improvement can effectively reduce airflow separation.
[0023] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0024] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. An impeller mounting structure for a centrifugal compressor, characterized in that: Includes impeller, main shaft, connecting shaft, nut and guide cap; The impeller has a central through hole running along the axis, and a first positioning ring extends outward from one end of the central through hole to form a first positioning groove. The end of the main shaft has a first positioning groove and a threaded connection hole located at the center of the first positioning groove. The first positioning ring of the impeller is inserted into the first positioning groove. One end of the connecting shaft passes through the central through hole of the impeller and is threaded to the threaded connection hole. The other end is threaded to the nut. The nut presses and fixes the impeller to the main shaft. The connecting shaft has an annular radial flange, which is supported in the central through hole of the impeller. One end of the nut has a second positioning ring sleeve, which extends into the gap between the central through hole of the impeller and the connecting shaft. The flow guide cap is threaded to the connecting shaft and fits against the axial end face of the impeller.
2. The impeller mounting structure of a centrifugal compressor as described in claim 1, characterized in that: The radial flange is connected to the connecting shaft body on both sides by chamfering.
3. The impeller mounting structure of a centrifugal compressor as described in claim 2, characterized in that: The connecting shaft has a relief groove on the radial flange facing the nut side.
4. The impeller mounting structure of a centrifugal compressor as described in claim 1, characterized in that: The flow guide cap is penetrated by a connecting shaft.
5. The impeller mounting structure of a centrifugal compressor as described in claim 4, characterized in that: The outer contour of the flow guide cap is arc-shaped and smoothly connects with the outer contour line of the impeller.
6. The impeller mounting structure of a centrifugal compressor as described in claim 5, characterized in that: The other end of the connecting shaft is tapered, smoothly transitioning to the curved surface of the inner cavity of the guide cap.