Novel discrete impeller with closed impeller cover

Abstract

The invention relates to the field of design, processing and manufacturing of compressor impellers, in particular to a novel discrete wheel cover closed impeller which comprises a lower wheel cover, a middle wheel cover and an upper wheel cover, the lower wheel cover is connected with the middle wheel cover through welding, and the middle wheel cover is connected with the upper wheel cover through welding, so that the blade top leakage rate of the discrete wheel cover closed impeller is smaller, and the performance of the discrete wheel cover closed impeller is superior to that of a semi-open impeller; the impeller has better manufacturability, is more beneficial to processing and manufacturing, has larger welding contact area and higher welding strength, meanwhile, the distance between the lower impeller cover and the middle impeller cover and the distance between the middle impeller cover and the upper impeller cover are smaller than 3mm, and the leakage rate is not greatly changed, so that the performance of the impeller is basically consistent with that of a closed impeller, and the axial force level is also basically consistent with that of the closed impeller; and the performance of the discrete wheel cover closed impeller is improved.

Description

Technical Field

[0001] The invention relates to the field of compressor impeller design, processing and manufacturing, and in particular to a novel discrete wheel cover closed impeller. Background Art

[0002] The impeller, also known as the working wheel, is the most important part of the compressor rotor. The impeller rotates at high speed with the main shaft and does work on the gas. Under the action of the impeller blades, the gas rotates at high speed with the impeller. Under the action of the rotating centrifugal force and the expansion pressure flow in the impeller, the pressure, speed and temperature of the gas are increased when it flows out of the impeller.

[0003] According to the structural form, impellers are divided into semi-open and closed types. Both types of impellers are widely used in compressors. Among them, the semi-open impeller blade groove is closed on one side by the wheel disc and open on the other side, which improves the gas channel, reduces flow loss and improves efficiency. However, due to the large gap on the side of the impeller, a part of the gas flows back from the impeller outlet to the inlet, resulting in large internal leakage losses. The closed impeller consists of a wheel disc, blades and a wheel cover. This impeller is beneficial to gas flow. The wheel cover is equipped with a gas seal to reduce internal leakage losses. There is no loss caused by undercurrent between the blade grooves, so the efficiency is higher than that of the semi-open impeller. Therefore, the closed impeller is theoretically more suitable for use in compressors. However, the closed impeller also has shortcomings, mainly because it is difficult to process, and it is even impossible to process some impellers with narrow blade channels. Summary of the invention

[0004] The object of the present invention is to provide a novel discrete wheel cover closed impeller to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A novel discrete wheel cover closed impeller, comprising:

[0007] A lower wheel cover, a middle wheel cover, and an upper wheel cover, wherein the lower wheel cover and the middle wheel cover, and the middle wheel cover and the upper wheel cover are connected by welding;

[0008] The distance between the lower wheel cover and the middle wheel cover and the distance between the middle wheel cover and the upper wheel cover are less than 3 mm.

[0009] As a further solution of the present invention: the lower wheel cover, the middle wheel cover and the upper wheel cover are annular structures with successively increasing diameters, and the lower wheel cover, the middle wheel cover and the upper wheel cover form a wheel cover structure.

[0010] As a further solution of the present invention: a plurality of groups of blades are equidistantly arranged in a circle in the wheel cover structure.

[0011] As a further solution of the present invention: two lower wheel cover bevels are formed on the lower wheel cover, two middle wheel cover bevels are formed on the middle wheel cover, and two upper wheel cover bevels are formed on the upper wheel cover.

[0012] As a further solution of the present invention: the lower wheel cover groove located at the lower part forms a first lower distance with the center line of the rotating shaft of the wheel cover structure, and the lower wheel cover groove located at the upper part forms a first upper distance with the center line of the rotating shaft of the wheel cover structure;

[0013] The middle wheel cover groove at the lower part and the center line of the rotation axis of the wheel cover structure form a second lower distance, and the middle wheel cover groove at the upper part and the center line of the rotation axis of the wheel cover structure form a second upper distance;

[0014] The upper wheel cover groove at the lower part forms a third lower distance with the center line of the rotation axis of the wheel cover structure, and the upper wheel cover groove at the upper part forms a third upper distance with the center line of the rotation axis of the wheel cover structure;

[0015] The difference between the first upper spacing and the first lower spacing, and between the third lower spacing and the second upper spacing is less than 3 mm.

[0016] As a further solution of the present invention: a wheel back boss is provided on one side of the wheel cover structure.

[0017] As a further solution of the present invention: the wheel cover structure is provided with a threaded hole, and the threaded hole can increase the counterweight of the wheel cover structure or reduce the counterweight of the wheel back boss.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] Firstly, the closed impeller with discrete wheel cover has less leakage at the blade tip, better performance than the semi-open impeller, better processability, more conducive to processing and manufacturing, larger welding contact area, higher welding strength, and at the same time, the spacing between the lower wheel cover and the middle wheel cover and the spacing between the middle wheel cover and the upper wheel cover is less than 3mm, and the leakage does not change much, so its performance is basically consistent with that of the closed impeller, and the axial force level is also basically consistent with that of the closed impeller, thereby improving the performance of the closed impeller with discrete wheel cover;

[0020] Secondly, by setting the threaded holes and the wheel back boss, when the impeller mass is unbalanced due to welding, the unbalance can be adjusted by adjusting the threaded holes and the wheel back boss, so that the impeller has a better balance level. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The figure is a schematic structural diagram of an embodiment of a novel discrete wheel cover closed impeller.

[0022] Figure 2A cross-sectional view of an embodiment of a novel discrete wheel cover closed impeller.

[0023] In the figure: 1. lower wheel cover; 101. lower wheel cover groove; 2. middle wheel cover; 201. middle wheel cover groove; 3. upper wheel cover; 301. upper wheel cover groove; 4. threaded hole; 5. wheel back boss; 6. blade; 7. adjustment radius; 8. first lower spacing; 9. first upper spacing; 10. second lower spacing; 11. second upper spacing; 12. third lower spacing; 13. third upper spacing. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In addition, when an element in the present invention is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0026] See also Figure 1-2 In an embodiment of the present invention, a novel discrete wheel cover closed impeller comprises: a lower wheel cover 1, a middle wheel cover 2, and an upper wheel cover 3, wherein the lower wheel cover 1 and the middle wheel cover 2, and the middle wheel cover 2 and the upper wheel cover 3 are connected by welding, and specifically, the lower wheel cover 1, the middle wheel cover 2, and the upper wheel cover 3 are annular structures with successively increasing diameters, and the lower wheel cover 1, the middle wheel cover 2, and the upper wheel cover 3 form a wheel cover structure, and a plurality of groups of blades 6 are equidistantly arranged in a circumference in the wheel cover structure;

[0027] The spacing between the lower wheel cover 1 and the middle wheel cover 2 and the spacing between the middle wheel cover 2 and the upper wheel cover 3 are less than 3 mm, which ensures weldability and the leakage amount does not change much. Therefore, its performance is basically consistent with that of the closed impeller, and the axial force level is also basically consistent with that of the closed impeller, thereby improving the performance of the discrete wheel cover closed impeller.

[0028] Two lower wheel cover grooves 101 are formed on the lower wheel cover 1, two middle wheel cover grooves 201 are formed on the middle wheel cover 2, and two upper wheel cover grooves 301 are formed on the upper wheel cover 3. During welding, the lower wheel cover grooves 101, the middle wheel cover grooves 201 and the upper wheel cover grooves 301 have a larger welding contact area with the blades 6, and have higher welding strength than conventional welded impellers.

[0029] Through the above arrangement, the blade tip leakage of the discrete wheel cover closed impeller is less, the performance is better than that of the semi-open impeller, and it has better processability, is more conducive to processing and manufacturing, has a larger welding contact area, and has a higher welding strength. At the same time, the spacing between the lower wheel cover 1 and the middle wheel cover 2 and the spacing between the middle wheel cover 2 and the upper wheel cover 3 are less than 3mm, and the leakage amount does not change much. Therefore, its performance is basically consistent with that of the closed impeller, and the axial force level is also basically consistent with that of the closed impeller, thereby improving the performance of the discrete wheel cover closed impeller.

[0030] See also Figure 2 The lower wheel cover groove 101 located at the bottom forms a first lower spacing 8 with the center line of the rotation axis of the wheel cover structure, and the lower wheel cover groove 101 located at the top forms a first upper spacing 9 with the center line of the rotation axis of the wheel cover structure;

[0031] The middle wheel cover groove 201 at the lower part and the center line of the rotation axis of the wheel cover structure form a second lower distance 10, and the middle wheel cover groove 201 at the upper part and the center line of the rotation axis of the wheel cover structure form a second upper distance 11;

[0032] The upper wheel cover groove 301 at the lower part and the center line of the rotation axis of the wheel cover structure form a third lower distance 12, and the upper wheel cover groove 301 at the upper part and the center line of the rotation axis of the wheel cover structure form a third upper distance 13;

[0033] The difference between the first upper spacing 9 and the first lower spacing 8 and between the third lower spacing 12 and the second upper spacing 11 is less than 3 mm, so that while ensuring the weldability of each section of the wheel cover, leakage is reduced as much as possible. At the same time, the size of the impeller axial force is basically consistent with that of the closed impeller, and the axial force of a smaller impeller can also be achieved by adjusting the radius 7.

[0034] Please refer again Figure 1-2 A wheel back boss 5 is provided on one side of the wheel cover structure, and a threaded hole 4 is provided on the wheel cover structure. The threaded hole 4 can increase the counterweight of the wheel cover structure or reduce the counterweight of the wheel back boss 5. Specifically, the threaded hole 4 can be threadedly connected with the corresponding bolt, and the corresponding counterweight block is mounted on the bolt to increase the counterweight, otherwise the counterweight can be reduced.

[0035] By setting the wheel back boss 5, the counterweight of the wheel cover structure can be increased, thereby improving the stability of the wheel cover structure during rotation, and by adding counterweight to the threaded hole 4 and removing weight from the wheel back boss 5, the welded impeller can have a balance accuracy level of G2.5 or above. That is, in this embodiment, when the impeller mass is unbalanced due to welding, the imbalance can be adjusted by adjusting the threaded hole 4 and the wheel back boss 5, so that the impeller has a better balance level.

[0036] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0037] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A new type of discrete wheel cover closed impeller, characterized in that: include: A lower wheel cover (1), a middle wheel cover (2), and an upper wheel cover (3), wherein the lower wheel cover (1) and the middle wheel cover (2), and the middle wheel cover (2) and the upper wheel cover (3) are connected by welding; The distance between the lower wheel cover (1) and the middle wheel cover (2) and the distance between the middle wheel cover (2) and the upper wheel cover (3) are less than 3 mm.

2. A novel discrete cover closed impeller according to claim 1, characterized in that: The lower wheel cover (1), the middle wheel cover (2) and the upper wheel cover (3) are annular structures with successively increasing diameters, and the lower wheel cover (1), the middle wheel cover (2) and the upper wheel cover (3) form a wheel cover structure.

3. A novel discrete wheel cover closed impeller according to claim 2, characterized in that: A plurality of groups of blades (6) are equidistantly arranged in a circumference in the wheel cover structure.

4. A novel discrete cover closed impeller according to claim 1, characterized in that: The lower wheel cover (1) is formed with two lower wheel cover bevels (101), the middle wheel cover (2) is formed with two middle wheel cover bevels (201), and the upper wheel cover (3) is formed with two upper wheel cover bevels (301).

5. A novel discrete cover closed impeller according to claim 4, characterized in that: The lower wheel cover groove (101) located at the bottom and the center line of the rotation axis of the wheel cover structure form a first lower distance (8), and the lower wheel cover groove (101) located at the top and the center line of the rotation axis of the wheel cover structure form a first upper distance (9); The middle wheel cover groove (201) located at the bottom forms a second lower distance (10) with the center line of the rotation axis of the wheel cover structure, and the middle wheel cover groove (201) located at the top forms a second upper distance (11) with the center line of the rotation axis of the wheel cover structure; The upper wheel cover groove (301) located at the lower part and the center line of the rotation axis of the wheel cover structure form a third lower distance (12), and the upper wheel cover groove (301) located at the upper part and the center line of the rotation axis of the wheel cover structure form a third upper distance (13); The difference between the first upper distance (9) and the first lower distance (8) and between the third lower distance (12) and the second upper distance (11) is less than 3 mm.

6. A novel discrete cover closed impeller according to claim 2, characterized in that: A wheel back boss (5) is arranged on one side of the wheel cover structure.

7. A novel discrete cover closed impeller according to claim 2, characterized in that: The wheel cover structure is provided with a threaded hole (4), and the threaded hole (4) can increase the counterweight of the wheel cover structure or reduce the counterweight of the wheel back boss (5).

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