CN214887905U - Closed impeller and centrifugal compressor with same - Google Patents

Abstract

The utility model provides a closed impeller and centrifugal compressor who has it, this closed impeller include rim plate and wheel cap, and rim plate one side is formed with a plurality of first blades along its circumference range on the surface, and the wheel cap can be dismantled with the rim plate and be connected to the wheel cap is formed with a plurality of second blades towards a side surface of rim plate, and a plurality of first blades dock one by one with a plurality of second blades to constitute the blade of closed impeller. The utility model discloses a rim plate and wheel cap adopt split type in the closed impeller, realize when rim plate and wheel cap shaping back separately, shortened the whole height of blade of closed impeller, and the installer of being convenient for further carries out precision optimization to first blade and second blade and handles, and the practicality is strong, easily promotes.

Description

Closed impeller and centrifugal compressor with same

Technical Field

The utility model belongs to the technical field of the compressor, especially, relate to a closed impeller and centrifugal compressor who has it.

Background

In recent years, with the maturity of high-speed motors and control technologies, the rapid development of high-speed compressors such as magnetic suspension and air suspension, the cooling capacity range of a centrifuge for users is wider and wider, and the demand of a small-cooling capacity high-speed centrifuge is increased gradually. The impeller of the small-cooling-capacity high-speed centrifuge is processed into an industrial problem, particularly a microminiature closed impeller. Although casting can be integrally formed, the requirements of small impeller surface roughness and the like are high, the casting process is difficult to directly meet the precision requirement, and the small impeller is difficult to precisely treat the inside of the small impeller by other measures due to the small size.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome at least one defect among the prior art, provide a closed impeller convenient to carry out the precision to the blade and handle.

A further object of the present invention is to improve the assembly efficiency.

Another further object of the present invention is to reduce the requirements of the strength of the connection of the wheel disc and the wheel cover.

In particular, the present invention provides a closed impeller for a centrifugal compressor, comprising:

a disk having a side surface on which a plurality of first blades arranged in a circumferential direction of the disk are formed;

the wheel cap is detachably connected with the wheel disc, a plurality of second blades are formed on the surface of one side, facing the wheel disc, of the wheel cap, and the plurality of first blades are in one-to-one butt joint with the plurality of second blades to form blades of the closed impeller.

Further, at least part of the first blades are provided with first positioning parts; and is

At least part of the second blades are provided with second positioning parts;

the first positioning portion and the second positioning portion are configured to be constrained with each other when the wheel cover is connected to the wheel disc, so as to position the wheel cover and the wheel disc.

Further, the first positioning part is a positioning concave part arranged on the first blade; and is

The second positioning part is a positioning convex part protruding out of the surface of the second blade.

Further, the inner peripheral wall of the positioning recess has an abutment section toward the direction of rotation of the shrouded impeller so as to apply thrust to the positioning boss when the shrouded impeller rotates.

Furthermore, each first blade is provided with a threaded hole, each second blade is provided with a screw hole communicated with the wheel cover, and the threaded holes and the screw holes are arranged in a one-to-one correspondence mode so that the wheel cover can be fixed on the wheel disc through screws.

Furthermore, each first blade is provided with a first positioning part; and is

The threaded hole on each first blade is arranged on the first positioning part.

Further, the wheel disc is circular; and is

The diameter of the wheel disc is not more than 80 mm.

Further, a first fillet is formed at the joint of the wheel disc and the first blade; and/or

And a second fillet is formed at the joint of the wheel cover and the second blade.

Further, the radius of each first fillet is between 1/8 and 1 of the first blade height;

the radius of each second fillet is between 1/8 and 1 of the second lobe height.

In particular, the present invention also provides a centrifugal compressor comprising a closed impeller as in any one of the above.

The utility model discloses an among the closed impeller, because one side of rim plate is formed with a plurality of first blades along its circumference range on the surface, the wheel cap can be dismantled with the rim plate and be connected to a side surface of wheel cap orientation rim plate is formed with a plurality of second blades, and a plurality of first blades and a plurality of second blade butt joint one by one have constituted the blade of closed impeller. The wheel disc and the wheel cover are split, so that the integral height of the blades of the closed impeller can be shortened after the wheel disc and the wheel cover are respectively formed, and an installer can conveniently perform precision optimization treatment on the first blades and the second blades, so that the surface roughness of the blades meets the requirement; and this kind of mode can also make cutter etc. stretch into between adjacent first blade or the adjacent second blade, is convenient for process out the fillet at first blade and second blade, further makes the airflow channel of closed impeller more smooth, realizes the rounding off, produces the angle vortex when avoiding gas to circulate in the airflow channel.

Further, the utility model discloses an among the closed impeller, first location portion has on the first blade, has second location portion on the second blade, when the wheel lid is connected in the rim plate, first location portion retrains each other with second location portion to the position location to rim plate and wheel lid has improved packaging efficiency.

Further, the utility model discloses an among the closed impeller, the internal perisporium of location depressed part has the butt district section of orientation closed impeller rotation direction, because the rim plate links to each other with the rotor of motor, when motor drive closed impeller rotated, the rim plate was in fact as the action wheel, and the wheel cap is as from the driving wheel. When rim plate drive wheel lid rotated, at least partly of location bellying can support and lean on this butt district section, and the butt district section can be assisted with the torque of rim plate and transmit to the wheel lid like this for the predetermined position structure that location bellying and location depressed part are constituteed not only can realize the location, can transmit the torque moreover, has reduced rim plate and wheel lid joint strength's requirement.

The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.

Drawings

Some specific embodiments of the present invention will be described in detail hereinafter, by way of illustration and not by way of limitation, with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:

fig. 1 is a schematic view of the overall structure of a centrifugal compressor according to an embodiment of the present invention;

fig. 2 is a schematic sectional view of the centrifugal compressor shown in fig. 1 taken along the axial direction of the centrifugal impeller;

FIG. 3 is an enlarged view at A of FIG. 2;

fig. 4 is a schematic view of a shrouded impeller in a centrifugal compressor according to an embodiment of the present invention;

fig. 5 is an exploded view of a shrouded impeller according to an embodiment of the invention;

fig. 6 is a front view of a wheel disc in a closed impeller according to an embodiment of the present invention, wherein arrows show the rotation direction of the wheel disc;

fig. 7 is a schematic view of a shroud in a closed impeller according to an embodiment of the present invention, wherein the arrows show the direction of rotation of the shroud;

fig. 8 is an elevation view of a wheel disc in a closed impeller according to another embodiment of the present invention, showing threaded holes in locating recesses;

fig. 9 is a positional relationship diagram of blades, a shroud, and a disk of a closed impeller according to an embodiment of the present invention, in which H1 denotes a height of a first blade, H2 denotes a height of a second blade, R1 denotes a radius of a first fillet, and R2 denotes a radius of a second fillet.

Detailed Description

Referring to fig. 1 to 3, fig. 1 is a schematic view of a whole structure of a centrifugal compressor according to an embodiment of the present invention, fig. 2 is a schematic cross-sectional view of the centrifugal compressor shown in fig. 1, which is cut along an axial direction of a centrifugal impeller, and fig. 3 is an enlarged view of a portion a of fig. 2; the utility model provides a centrifugal compressor 1. The centrifugal compressor 1 may generally comprise a casing 10, a motor 40 and at least one compression unit 20, 30.

The cabinet 10 defines an accommodation space, and the motor 40 is installed in the cabinet 10. The motor 40 includes a stator 41 and a rotor 42, the stator 41 is fixed to the housing 10, and the rotor 42 is rotatable relative to the stator 41. The number of the compression units 20, 30 may be one or more. For example, the centrifugal compressor 1 may be of a single-stage compression type, and only one compression unit may be provided. The centrifugal compressor 1 may be of a multistage compression type in which a plurality of compression units 20 and 30 are provided. Each compression unit 20, 30 includes a volute 100 mounted to the casing 10 and a shrouded impeller 200 disposed within the volute 100. The shrouded impeller 200 is configured to rotate under the drive of the motor 40 to compress and discharge the airflow entering the volute 100 through the outlet of the volute 100.

In some particular embodiments, such as those shown in fig. 1 and 2, the centrifugal compressor 1 may be of the two-stage compression type, with two compression units. It can be seen that one of the two compression units 20, 30 is necessarily a low pressure stage, and the other is a high pressure stage, as shown in fig. 1 and 2, the compression unit 20 on the left side of the drawing is a low pressure stage, and the compression unit 30 on the right side is a high pressure stage. The outlet of the volute 100 of the compression unit 20 of the low pressure stage communicates with the inlet of the volute 100 of the compression unit 30 of the high pressure stage through a connection pipe 50. Specifically, an inlet end of the connection pipe 50 is provided with a flange 51 to interface with a flange 60 of an outlet of the volute 100 of the compression unit 20 of the low pressure stage, and an outlet end of the connection pipe 50 is provided with a flange 52 to connect with the volute 100 of the compression unit 30 of the high pressure stage. It is preferable that the compression unit 20 of the low pressure stage and the compression unit 20 of the high pressure stage are respectively located at both axial sides of the motor 40, so that the shrouded impellers 200 of the two compression units 20, 30 are respectively directly connected to the motor 40, and it is advantageous to partially cancel the axial forces of the two shrouded impellers 200.

An inlet flow channel 101, a volute flow channel 102 and an outlet flow channel 103 which are connected in sequence along the airflow direction are defined in the volute 100, namely, the flow channel of the volute 100 is divided into three sections. The inlet of inlet flow path 101 forms the inlet of volute 100 as described herein, and the outlet of outlet flow path 103 forms the outlet of volute 100. The intake runner 101 extends in the axial direction (x-axis direction) of the shrouded impeller 200.

Referring to fig. 4 to 7, fig. 4 is a schematic view of a closed impeller in a centrifugal compressor according to an embodiment of the present invention, fig. 5 is an exploded view of a closed impeller according to an embodiment of the present invention, fig. 6 is a front view of a wheel disc in a closed impeller according to an embodiment of the present invention, and fig. 7 is a schematic view of a wheel cap in a closed impeller according to an embodiment of the present invention, in which an arrow indicates a rotation direction of the wheel cap. The closed impeller 200 has an inlet 201 facing the inlet flow channel 101 and an outlet 202 facing the volute flow channel 102, and the air flow entering from the inlet flow channel 101 firstly enters the closed impeller 200 from the inlet 201 of the closed impeller 200, is compressed by the closed impeller 200 and then is discharged to the outlet 202, enters the volute flow channel 102, and finally is discharged from the outlet flow channel 103 to the centrifugal compressor 1.

The closed impeller 200 may further include a wheel disc 210 and a wheel cover 220, wherein a plurality of first blades 212 arranged along a circumferential direction of the wheel disc 210 are formed on one side surface of the wheel disc 210, the wheel cover 220 is detachably connected to the wheel disc 210, a plurality of second blades 222 are formed on one side surface of the wheel cover 220 facing the wheel disc 210, and the plurality of first blades 212 and the plurality of second blades 222 are in one-to-one butt joint to form blades of the closed impeller 200 (as shown in fig. 4).

In the present embodiment, the blades of the shrouded impeller 200 are divided into two parts, i.e., a first blade 212 formed on the disk 210 and a second blade 222 formed on the shroud 220, and the disk 210 and the shroud 220 may be separately machined (e.g., cast, etc.) to directly form the first blade 212 and the second blade 222 on the disk 210 and the shroud 220, respectively. When the wheel disk 210 and the wheel cover 220 are connected together, the first blade 212 is butted against the second blade 222, so that the wheel disk 210 and the wheel cover 220 form a blade of the closed impeller 200, and an airflow passage 2102 of the closed impeller 200 is formed between two adjacent blades.

Referring to fig. 5 to 7, the first blades 212 and the second blades 222 may be uniformly arranged along the circumferential direction of the wheel disc 210 and the wheel cover 220, respectively, and are located outside the wheel disc 210 and the wheel cover 220, a mounting hole 218 may be formed in the middle of the wheel disc 210, and the wheel disc 210 may be further mounted on the rotor 42 of the motor 40 by extending a fastener (e.g., a rivet, a screw 300, etc.) into the mounting hole 218, so that the rotor 42 drives the wheel disc 210 to rotate. The shroud 220 may be provided in the shape of a ring, and an inner ring of the shroud 220 extends away from the second vane 222 to form a connecting section 228, an interior of the connecting section 228 may also define the inlet 201 of the shrouded impeller 200.

As described in the background section, the processing of impellers for low-capacity high-speed centrifuges is currently an industrial problem, especially for microminiature closed impellers. Although casting can be integrally formed, the requirements of small impeller surface roughness and the like are high, the casting process is difficult to directly meet the precision requirement, and the small impeller is difficult to precisely treat the inside of the small impeller by other measures due to the small size.

In order to overcome the defects in the prior art, the closed impeller 200 in this embodiment adopts the way that the blades are respectively arranged on the wheel disc 210 and the wheel cover 220, and the wheel disc 210 and the wheel cover 220 are split, so that the overall height of the blades of the closed impeller 200 can be shortened after the wheel disc 210 and the wheel cover 220 are respectively formed, and an installer can further perform precision optimization processing on the first blade 212 and the second blade 222, so that the surface roughness of the blades meets the requirements; in addition, in this way, a cutter and the like can extend into the space between the adjacent first blade 212 or the adjacent second blade 222, so that a fillet 240 is conveniently machined on the first blade 212 and the second blade 222, and further, the airflow channel 2102 of the closed impeller 200 is smoother, smooth transition is realized, and angular vortexes are prevented from being generated when air circulates in the airflow channel 2102.

Referring to fig. 6 and 7, in order to further improve the processing efficiency, the closed impeller 200 of the present embodiment may further include a pre-positioning structure on a split basis, so that the wheel disc 210 and the wheel cover 220 are pre-positioned during the assembling process.

Specifically, at least a part of the first blades 212 has the first positioning portion 214 thereon, and at least a part of the second blades 222 has the second positioning portion 224 thereon, and the first positioning portion 214 and the second positioning portion 224 are configured to constrain the first positioning portion 214 and the second positioning portion 224 to each other when the wheel cover 220 is connected to the wheel disc 210, so as to position the wheel disc 210 and the wheel cover 220.

In the present embodiment, the number of the first blades 212 may be plural, and the first positioning portion 214 may be provided on a part of or all of the plural first blades 212. For example, when there is one first positioning portion 214, it may be provided on any one of the first blades 212; when there are a plurality of first positioning portions 214, each first positioning portion 214 may be correspondingly disposed on one first blade 212, or several first positioning portions 214 of the plurality of first positioning portions 214 are disposed on one first blade 212; for another example, when the number of the first positioning portions 214 is 3, the 3 first positioning portions 214 may be provided on 3 different first blades 212, or may be provided on 2 first positioning portions 214 (one first positioning portion 214 is provided with 1, and the other first positioning portion 214 is provided with 2), or may be provided on all of the 3 second positioning portions 224 collectively provided on one of the first blades 212.

The above solutions can achieve the positioning of the wheel disc 210 and the wheel cover 220, but it should be noted that the above description is only for more clearly describing the technical solutions of the present embodiment, and should not be construed as limiting the present application. Those skilled in the art can make simple modifications and further alternatives based on the above description, which are not set forth herein.

Referring to fig. 6 and 7, in some embodiments, the first positioning portion 214 is a positioning concave portion opened on the first blade 212, and the second positioning portion 224 is a positioning convex portion protruding from the surface of the second blade 222.

The first blade 212 is recessed inwardly to form a positioning recess, and correspondingly, the top end of the second blade 222 is protruded to form a positioning protrusion matched with the positioning recess. When the wheel cover 220 and the wheel disc 210 are assembled, the positioning protrusions may protrude into their corresponding positioning recesses to position the wheel cover 220 and the wheel disc 210.

In some embodiments, when the positioning protrusions and the positioning recesses are in one set (one positioning protrusion and one positioning recess are in one set), the positioning protrusions and the positioning recesses may also be configured in a non-circular shape, such as a triangle, a quadrangle, or other shapes, respectively, so that the positioning protrusions and the positioning recesses cooperate with the shapes, thereby enabling the positioning of the wheel cover 220 and the wheel disc 210 when the positioning protrusions and the positioning recesses are only in one set.

When location bulge and location depressed part are the multiunit, location bulge and location depressed part can be arbitrary shape, for example polygon, cylindric etc. just can realize fixing a position wheel cover 220 and rim plate 210 after every location bulge correspondingly stretches into location depressed part.

Referring to fig. 6, in some embodiments, the inner circumferential wall of the positioning recess has an abutting section 214a facing the rotation direction of the shrouded impeller 200 so as to apply a pushing force to the positioning protrusion when the shrouded impeller 200 rotates.

Since the wheel 210 is connected to the rotor 42 of the motor 40, when the closed impeller 200 is driven by the motor 40 to rotate, the wheel 210 actually serves as a driving wheel and the wheel cover 220 serves as a driven wheel. When the wheel disc 210 drives the wheel cover 220 to rotate, at least one part of the positioning convex part can abut against the abutting section 214a, so that the abutting section 214a can transfer the torque of the wheel disc 210 to the wheel cover 220 in an auxiliary manner, the positioning structure formed by the positioning convex part and the positioning concave part not only can realize positioning, but also can transfer the torque, and the requirement on the connection strength of the wheel disc 210 and the wheel cover 220 is reduced.

Referring to fig. 5 to 7, in some embodiments, the wheel disc 210 and the wheel cover 220 may be fastened by screws. Specifically, each first vane 212 has a threaded hole 216, each second vane 222 has a threaded hole 226 communicating with the wheel cover 220, and the threaded holes 216 and the threaded holes 226 are arranged in a one-to-one correspondence so as to fix the wheel cover 220 to the wheel disc 210 by screws 230.

During assembly, an installer may first pre-position the wheel disc 210 and the wheel cover 220 by using the first positioning portion 214 and the second positioning portion 224, then insert the screw 230 through the screw hole 226 and into the screw hole 216 of the first blade 212, and finally connect the screw 230 with the screw hole 216 to fasten the wheel disc 210 and the wheel cover 220.

In some embodiments, in order to balance the whole closed impeller, the plurality of threaded holes 216 may be disposed on a circumference concentric with the wheel disc 210, so as to prevent the closed impeller 200 from being eccentric, and further prevent abnormal phenomena such as vibration and noise from occurring during the high rotation of the closed impeller 200.

Referring to fig. 8, fig. 8 is a front view of a wheel disc in a closed impeller according to another embodiment of the present invention, in which a screw hole is shown in a positioning recess. In some embodiments, each first vane 212 has a first positioning portion 214, and the threaded hole 216 of each first vane 212 opens into the first positioning portion 214. Since each first blade 212 has a threaded hole 216 and each first blade 212 has a first positioning portion 214, the threaded hole 216 can be disposed on the first positioning portion 214, i.e., in the positioning recess, so that the fastening effect is better.

In some embodiments, the wheel disc 210 may be configured to be circular and may be configured to have a diameter no greater than 80mm, such as 80mm, 70mm, 60mm, and the like. When the closed impeller 200 is miniaturized, the existing casting process cannot meet the requirement of the precision of the internal blade, and particularly when the diameter of the wheel disc 210 is not larger than 80mm, the whole size is too small, so that a processing worker cannot perform a precision processing procedure on the internal blade. By using the split assembly method of the present embodiment, that is, the wheel disc 210 and the wheel cover 220 are respectively cast, the first blade 212 or the second blade 222 is exposed outside, and then precision processing is performed on the first blade 212 or the second blade, which can process qualified blades on the basis of realizing the miniaturization of the closed impeller 200.

Referring to fig. 9, fig. 9 is a schematic diagram illustrating a position relationship between a wheel disc, a wheel cover and a blade in a closed impeller according to an embodiment of the present invention; in some embodiments, the disk 210 is formed with a first fillet 242 at the junction with the first blade 212 and/or the shroud 220 is formed with a second fillet 244 at the junction with the second blade 222. That is, either the connection between the wheel disc 210 and the first blade 212 or the connection between the wheel cover 220 and the second blade 222 may have a first fillet 242 or a second fillet 244, or the connection between the wheel disc 210 and the first blade 212 and the connection between the wheel cover 220 and the second blade 222 may have a first fillet 242 and a second fillet 244, respectively.

The first fillet 242 and the second fillet 244 not only can improve the strength of the root of the first blade 212 and the second blade 222 and relieve the local stress concentration, but also can make each airflow channel 2102 smoother, eliminate the corner vortex phenomenon of the airflow, and ensure the uniformity of the flow field.

Referring to fig. 9, H1 indicates the height of the first blade 212, H2 indicates the height of the second blade 222, R1 indicates the radius of the first fillet 242, and R2 indicates the radius of the second fillet 244 in fig. 9; further, the radius R1 of the first rounded corner 242 may also be configured to be between 1/8 and 1 of the first blade H1, and the radius R2 of the second rounded corner 244 may also be configured to be between 1/8 and 1 of the second blade height H2, e.g., 1/8, 1/5, or 1, etc. The utility model discloses the people finds through many times of experiments, can guarantee to obtain better air current field under the prerequisite that does not influence airflow channel 2102 area through the aforesaid injecing to further improve the compression effect.

In particular, when the ratio of the radius R1 of the first fillet 242 to the height H1 of the first blade H1 is 1, and when the ratio of the radius R2 of the second fillet 244 to the height H2 of the second blade is 1, that is, the radius R1 of the first fillet 242 is equal to the height of the first blade H1, the radius R2 of the second fillet 244 is equal to the height H2 of the second blade 222, the inner wall of the through-flow channel 212 is integrally composed of the first fillet 242 and the second fillet 244, so that the inner wall of the through-flow channel 212 is arc-shaped as a whole.

Thus, it should be appreciated by those skilled in the art that while a number of exemplary embodiments of the invention have been shown and described in detail herein, many other variations and modifications can be made, consistent with the principles of the invention, which are directly determined or derived from the disclosure herein, without departing from the spirit and scope of the invention. Accordingly, the scope of the present invention should be understood and interpreted to cover all such other variations or modifications.

Claims (10)

1. A shrouded impeller for a centrifugal compressor, comprising:

a disk having a side surface on which a plurality of first blades arranged in a circumferential direction of the disk are formed;

the wheel cover is detachably connected with the wheel disc, a plurality of second blades are formed on the surface of one side, facing the wheel disc, of the wheel cover, and the first blades are in one-to-one butt joint with the second blades to form the blades of the closed impeller.

2. Shrouded impeller according to claim 1,

at least part of the first blade is provided with a first positioning part; and is

At least part of the second blades are provided with second positioning parts;

the first positioning portion and the second positioning portion are configured to be constrained with each other when the wheel cover is connected to the wheel disc, so as to position the wheel cover and the wheel disc.

3. Shrouded impeller according to claim 2,

the first positioning part is a positioning concave part arranged on the first blade; and is

The second positioning part is a positioning protruding part protruding out of the surface of the second blade.

4. Shrouded impeller according to claim 3,

the inner peripheral wall of the positioning recess has an abutment section facing the direction of rotation of the shrouded impeller so as to apply thrust to the positioning boss when the shrouded impeller rotates.

5. Shrouded impeller according to claim 3,

each first blade is provided with a threaded hole, each second blade is provided with a screw hole communicated with the wheel cover, and the threaded holes and the screw holes are arranged in a one-to-one correspondence mode so that the wheel cover can be fixed on the wheel disc through screws.

6. Shrouded impeller according to claim 5,

each first blade is provided with a first positioning part; and is

The threaded hole in each first blade is opened in the first positioning portion.

7. Shrouded impeller according to claim 1,

the wheel disc is circular; and is

The diameter of the wheel disc is not more than 80 mm.

8. Shrouded impeller according to claim 1,

a first fillet is formed at the joint of the wheel disc and the first blade; and/or

And a second fillet is formed at the joint of the wheel cover and the second blade.

9. Shrouded impeller according to claim 8,

each of the first rounded corners has a radius between 1/8 and 1 of the first vane height;

each of the second rounded corners has a radius between 1/8 and 1 of the second vane height.

10. A centrifugal compressor, characterized by comprising a shrouded impeller according to any of claims 1 to 9.

Images