Rotary machine

Abstract

The utility model relates to a rotary machine, comprising a motor comprising a rotor, the rotor comprising a magnet; a cover plate attached to an axial end face of the rotor; and a balance block attached to the axial end face of the rotor via the cover plate. The cover plate is provided with a flat base part and a protruding part which protrudes from the base part in the axial direction and is configured to increase the spacing distance between the balance block and the rotor in the axial direction. According to the technical scheme of the utility model, the motor efficiency of a rotary machine can be improved, the size and height of the balance block can be reduced, a compact structure can be realized, and the bending moment borne by the balance block during rotation can be reduced.

Description

Technical Field

[0001] The utility model relates to the field of rotary machinery, and more particularly to a rotary machine with improvements in the structure and installation of balance weights. Background Art

[0002] The content of this part only provides background information related to the utility model, which may not constitute the prior art.

[0003] In a rotary machine including moving parts (such as a compressor, especially a scroll compressor and a rotor compressor), large vibrations and noises may be generated during the operation of the machine due to the imbalance of the movement of the moving parts (such as the rotation of the rotor). Such movement imbalance may be caused by the centroid imbalance resulting from the machining errors of the moving parts themselves and / or the components mounted thereon, or may be caused by a deliberately set eccentric rotation structure. To this end, balance weights capable of providing reverse centrifugal force are usually provided on the moving parts to compensate for such movement imbalance and thereby reduce vibrations and noises.

[0004] Some moving parts (such as the rotor of an electric motor) may include magnets. When components such as balance weights are provided on such rotors, it is desirable to avoid as much as possible the reduction of the magnetic flux of the rotor magnets caused by the balance weights and the like, and thus the reduction of the mechanical efficiency. In addition, it is usually also desirable to make improvements in aspects such as the manufacturing cost of the balance weights and the utilization of the installation space of the balance weights. In particular, it is desirable to reduce the height of the balance weights, thereby reducing the bending moment received by the balance weights during rotation with the rotor and making the structure more compact.

[0005] Taking the rotor of an electric motor as an example, there are currently two conventional balance weight arrangements: in the first arrangement, the balance weights are attached to the axial end face of the rotor through fasteners such as rivets and bolts; in the second arrangement, the balance weights are fixed on the rotating shaft connected to the rotor and are spaced apart from the axial end face of the rotor. In the first arrangement, since the balance weights and the rotor are very close, in order to avoid the reduction of the magnetic flux of the rotor magnets and the decrease of the motor efficiency, the balance weights must be made of materials with low magnetic permeability, such as zinc-aluminum alloy or copper. The density and strength of zinc-aluminum alloy are both low. When the weight and the bottom area of the balance weight (the bottom area of the balance weight is limited by the area of the axial end face of the rotor) are determined, the balance weight will have a large height and thus receive a large bending moment during rotation, resulting in the balance weight being prone to breakage and fracture. Manufacturing the balance weights with copper will result in higher production costs. The second arrangement requires a limiting structure to be provided on the balance weights and / or the rotating shaft to prevent the balance weights from rotating and axially shifting relative to the rotating shaft, increasing the complexity and cost of machining and assembly. In addition, the second arrangement requires a large installation space and is not applicable to small electric motors. Summary of the Utility Model

[0006] One object of the present utility model is to provide a balancing weight arrangement scheme that can improve the motor efficiency of a rotary machine. Another object of the present utility model is to reduce the height of the balancing weight so as to reduce the bending moment received by the balancing weight during rotation. Another object of the present utility model is to reduce the volume of the balancing weight.

[0007] One aspect of the present utility model provides a rotary machine, which includes: a motor, the motor includes a rotor, and the rotor includes a magnet; a cover plate, the cover plate is attached to the axial end face of the rotor; a balancing weight, the balancing weight is attached to the axial end face of the rotor via the cover plate. The cover plate has a flat base and a protrusion that protrudes from the base in the axial direction and is configured to increase the spacing distance between the balancing weight and the rotor in the axial direction.

[0008] In some embodiments, the cover plate includes an annular protrusion.

[0009] In some embodiments, the cover plate includes a plurality of columnar protrusions.

[0010] In some embodiments, the protrusion protrudes from the base towards the balancing weight.

[0011] In some embodiments, the cover plate further includes through holes provided in the protrusion.

[0012] In some embodiments, the axial height of the cover plate is in the range of 4 mm to 10 mm.

[0013] In some embodiments, the base and the protrusion of the cover plate are integrally formed.

[0014] In some embodiments, the cover plate is configured as a stainless steel cover plate.

[0015] In some embodiments, the balancing weight is configured as a magnetically conductive metal balancing weight.

[0016] In some embodiments, the rotary machine is a scroll compressor.

[0017] In the present utility model, the cover plate with protrusions provided between the balancing weight and the motor rotor increases the spacing distance between the balancing weight and the rotor in the axial direction. Therefore, the balancing weight will not have a negative impact on the magnetic flux of the rotor, thereby effectively improving the motor efficiency. In addition, the material of the balancing weight is not limited, and any suitable balancing weight material can be selected according to needs. For example, a high-density material can be selected to reduce the volume of the balancing weight, especially to reduce the height of the balancing weight, so as to achieve a more compact configuration and reduce the bending moment received by the balancing weight during rotation. A material with high tensile strength and fatigue strength can also be selected to extend the service life of the balancing weight. Description of the Drawings

[0018] The embodiments of the present utility model will be described hereinafter by way of example only with reference to the accompanying drawings. In the drawings, the same features or components are denoted by the same reference numerals, and the drawings are not necessarily drawn to scale. In the drawings:

[0019] Figure 1 A perspective view of a motor rotor assembly of a rotary machine according to an embodiment of the present utility model is shown;

[0020] Figure 2 It shows along Figure 1 A schematic sectional view of the motor rotor assembly taken along the cutting line A-A in

[0021] Figure 3 A perspective view of a first cover plate of a motor rotor assembly of a rotary machine according to an embodiment of the present utility model is shown;

[0022] Figure 4 It shows Figure 3 A top view of the first cover plate in

[0023] Figure 5 It shows along Figure 4 A sectional view of the first cover plate taken along the cutting line B-B in

[0024] Figure 6 A perspective view of a motor rotor assembly of a rotary machine according to another embodiment of the present utility model is shown;

[0025] Figure 7 It shows Figure 6 A perspective view of the first cover plate in the motor rotor assembly in

[0026] Figure 8 It shows Figure 7 A top view of the first cover plate in

[0027] Figure 9 It shows along Figure 8 A sectional view of the first cover plate taken along the cutting line C-C in Detailed Embodiments

[0028] The following description is essentially exemplary only and is not intended to limit the present utility model, its application, and uses. It should be understood that in all these drawings, like reference numerals indicate the same or similar parts and features. Each drawing only schematically shows the concept and principle of the embodiments of the present utility model, and does not necessarily show the specific dimensions and their ratios of the embodiments of the present utility model. Specific parts in a specific drawing may be exaggerated to illustrate the relevant details or structures of the embodiments of the present utility model.

[0029] In the description of the embodiments of the present utility model, the orientation terms related to "upper" and "lower" are described based on the upper and lower positions of the views shown in the drawings. In practical applications, the "upper" and "lower" positional relationships used herein can be defined according to the actual situation, and these relationships can be reversed with each other.

[0030] Figure 1 FIG. 4 shows a perspective view of a motor rotor assembly 1 of a rotary machine according to an embodiment of the present utility model. Figure 2 FIG. Figure 1 FIG. 5 shows a schematic cross-sectional view of the motor rotor assembly 1 taken along the cutting line A-A in FIG. 4. The rotary machine including the motor rotor assembly 1 according to the present utility model can be configured as a scroll compressor, particularly a variable frequency scroll compressor. In particular, the motor rotor assembly 1 can be configured to be coupled to the rotating shaft of the scroll compressor to drive the rotating shaft to rotate, and drive the moving scroll member of the scroll compressor to move relative to the stationary scroll member through the rotating shaft. The motor rotor assembly 1 according to the present utility model can also be applied to any other suitable type of rotary machine.

[0031] As Figure 1 and Figure 2 shown, the motor rotor assembly 1 may include a rotor 10, a first balance weight 21, and a second balance weight 22. The rotor 10 may include magnets (not shown). For example, the magnets may be embedded at at least one axial end face of the rotor 10.

[0032] The motor rotor assembly 1 may further include a first cover plate 31 and a second cover plate 32. The first cover plate 31 is attached to the first axial end face 101 of the rotor 10 to prevent, for example, the magnets from detaching. Similarly, the second cover plate 32 is attached to the second axial end face 102 of the rotor 10 opposite to the first axial end face. The first balance weight 21 is attached to the first axial end face 101 of the rotor 10 via the first cover plate 31, and the second balance weight 22 is attached to the second axial end face 102 of the rotor 10 via the second cover plate 32. In the present embodiment, the rotor 10 has a cylindrical shape with a central hole 103. The first cover plate 31 and the second cover plate 32 respectively have an annular shape corresponding to the first axial end face 101 and the second axial end face 102 of the rotor 10. The first balance weight 21 and the second balance weight 22 are each in a semi-annular shape and are arranged substantially symmetrically with respect to the center of the rotor 10. The first balance weight 21 is attached to the rotor 10 via one or more rivets 40 that extend through the first balance weight 21, the first cover plate 31, the rotor 10, and the second cover plate 32. The second balance weight 22 is attached to the rotor 10 via one or more rivets 40 that extend through the second balance weight 22, the second cover plate 32, the rotor 10, and the first cover plate 31. In other embodiments, other fasteners (such as bolts, etc.) other than the rivets 40 may also be used to attach the balance weights to the rotor. The structure and arrangement of the first balance weight 21 and the first cover plate 31 may be the same as or similar to the structure and arrangement of the second balance weight 22 and the second cover plate 32. Therefore, only the first balance weight 21 and the first cover plate 31 will be described hereinafter.

[0033] Figure 3 FIG. 4 shows a perspective view of the first cover plate 31 according to an embodiment of the present invention. Figure 4 FIG. 5 shows a top view of the first cover plate 31. Figure 5 FIG. 6 shows a sectional view of the first cover plate 31 taken along the cutting line B-B in Figure 4 FIG. 7. As shown in Figures 3 to 5 FIG. 8, the first cover plate 31 is generally in an annular shape. The first cover plate 31 has a flat base portion 311 and a protruding portion 312 that protrudes axially from the base portion 311. In the present embodiment, the protruding portion 312 is formed in an annular shape. The protruding portion 312 may be integrally formed with the base portion 311. For example, the first cover plate 31 may be integrally formed with the base portion 311 and the protruding portion 312 by stamping an annular plate. Thus, the protruding portion 312 and the base portion 311 are firmly integrated as a whole and the protruding portion 312 does not move (such as rotate) relative to the base portion 311, which is advantageous for stably supporting the first balance weight 21. In other embodiments, the protruding portion 312 may also be formed as a separate component and attached to the base portion 311. Referring to Figure 1 FIG. 9 Figure 2As shown, in the assembled state, the base 311 abuts against the first axial end face 101 of the rotor 10, and the protrusion 312 protrudes from the base 311 toward the first balance weight 21. Thus, since the flat and generally large-area base 311 abuts against the first axial end face 101 of the rotor 10, the first cover plate 31 and thus the first balance weight 21 can be more stably supported on the first axial end face 101 of the rotor 10. In other embodiments, the first cover plate 31 can also be installed in the opposite orientation, that is, the base 311 abuts against an axial end face of the first balance weight 21, and the protrusion 312 protrudes from the base 311 toward the rotor 10. Thus, the first cover plate 31 spaces the first balance weight 21 and the rotor 10 apart in the axial direction. The axial height H of the first cover plate 31 (the total height of the base 311 and the protrusion 312 of the first cover plate 31) is preferably set in the range of 4 mm to 10 mm. In other embodiments, the axial height H is particularly set in the range of 6 mm to 8 mm. The inventors have found that setting the axial height H to the above height value can effectively isolate magnetism while avoiding the situation of excessive bending moment due to the too high axial position of the first balance weight 21. The first cover plate 31 can include a material with a low magnetic permeability, such as stainless steel, etc.

[0034] As Figures 3 to 5 shown, the first cover plate 31 includes a through hole 313 that axially penetrates the first cover plate 31. The through hole 313 is used to receive a rivet 40 or other fasteners to attach the first balance weight 21 to the rotor 10 via the first cover plate 31. In the present embodiment, six through holes 313 are provided and are evenly distributed in the circumferential direction of the first cover plate 31. The through holes 313 are preferably provided in the protrusion 312 of the first cover plate 31 to facilitate firmly fixing the first balance weight 21 to the rotor 10 through fasteners. In the present embodiment, the inner diameter D1 of the annular protrusion 312 is less than or equal to the diameter of the inscribed circle of the plurality of through holes 313, and the outer diameter D2 of the annular protrusion 312 is greater than or equal to the diameter of the circumscribed circle of the plurality of through holes 313.

[0035] Figure 6 shows a perspective view of a motor rotor assembly 1' according to another embodiment of the present invention. Figure 7 shows a perspective view of the first cover plate 31' in the motor rotor assembly 1'. Figure 8 shows a top view of the first cover plate 31'. Figure 9 shows along Figure 8 the section line C-C in Figures 6 to 9 a sectional view of the first cover plate 31' taken. In

[0036] As Figures 6 to 9As shown, the first cover plate 31' includes a flat base 311' and a plurality of columnar protrusions 312' protruding from the base 311' in the axial direction. In the present embodiment, the first cover plate 31' includes six protrusions 312' evenly distributed in the circumferential direction of the first cover plate 31', and each protrusion 312' is provided with a through hole 313'. In the present embodiment, the diameter D1' of the inscribed circle of the plurality of protrusions 312' is smaller than the diameter of the inscribed circle of the plurality of through holes 313', and the diameter D2' of the circumscribed circle of the plurality of protrusions 312' is larger than the diameter of the circumscribed circle of the plurality of through holes 313'. As Figure 6 shown, in the assembled state, the base 311' abuts against the rotor 10', and the protrusions 312' protrude towards the first balance weight 21'. In other embodiments, the first cover plate 31' can also be installed in the opposite orientation, that is, the base 311' abuts against the first balance weight 21', and the protrusions 312' protrude towards the rotor 10'. As Figure 9 shown, the axial height H' of the first cover plate 31' is preferably set in the range of 4 mm to 10 mm. Other aspects of this embodiment can be the same as or similar to Figures 1 to 5 the embodiment shown, and will not be elaborated here. In other embodiments, the protrusions of the cover plate can also be set to any other suitable shape, such as strip-shaped, arc-shaped, etc.

[0037] In the above embodiment, the motor rotor assembly includes two balance weights respectively attached to two opposite end faces of the rotor. However, it should be understood that the motor rotor assembly according to the present invention can also include any other suitable number of balance weights. For example, the balance weight and the cover plate can be provided only on one axial end face of the rotor. In addition, according to the shape of the axial end face of the motor rotor, the cover plate and the balance weight can be constructed in any suitable shape.

[0038] The cover plate according to the present invention includes a flat base and protrusions protruding from the base in the axial direction, thereby increasing the spacing distance between the balance weight and the rotor in the axial direction. In the present invention, the material selection of the balance weight is not limited. For example, the material of the balance weight can be selected as a high magnetic permeability material. Preferably, the material of the balance weight can include materials with relatively high density, tensile strength, and fatigue strength, such as powder metallurgy materials, magnetic steel, and other magnetic conductive metals (high magnetic permeability materials). This is beneficial to forming the balance weight into a smaller volume, especially a smaller height, making the rotary mechanical structure including the balance weight more compact, reducing the bending moment received by the balance weight during rotation, and increasing the service life of the balance weight.

[0039] According to the present utility model, the balance weight does not need to be fixed (e.g., interference fit) to the rotating shaft, achieving that while using a high-permeability material, there is no need to add additional processing techniques to the rotating shaft (such as machining a flange on the rotating shaft for axially positioning the balance weight). In addition, according to the present utility model, since the balance weight does not need to be fixed to the rotating shaft and the axial height of the balance weight can be appropriately reduced, it is particularly advantageous for small compressors with limited installation space.

[0040] Herein, exemplary embodiments of the rotary machine according to the present utility model have been described in detail, but it should be understood that the present utility model is not limited to the specific embodiments described and illustrated above in detail. Without departing from the gist and scope of the present utility model, those skilled in the art can make various modifications and variations to the present utility model. All such modifications and variations fall within the scope of the present utility model. Moreover, all components described herein can be replaced by other technically equivalent components.

Claims

1. A rotary machine, comprising: a motor, the motor including a rotor, the rotor including a magnet; a cover plate attached to an axial end face of the rotor; a balance weight, the balance weight being attached to the axial end face of the rotor via the cover plate, wherein the cover plate has a flat base and a protrusion protruding from the base in an axial direction and configured to increase a spacing distance between the balance weight and the rotor in the axial direction.

2. The rotary machine according to claim 1, wherein The cover plate includes an annular protrusion.

3. The rotary machine according to claim 1, wherein The cover plate includes a plurality of columnar protrusions.

4. The rotary machine according to any one of claims 1 to 3, characterized in that, The protrusion protrudes from the base toward the balance weight.

5. The rotary machine according to any one of claims 1 to 3, characterized in that, The cover plate further includes a through hole provided in the protrusion, the through hole being configured to receive a fastener for attaching the balance weight to the rotor.

6. The rotary machine according to any one of claims 1 to 3, characterized in that The axial height of the cover plate is in a range of 4 mm to 10 mm.

7. The rotary machine according to any one of claims 1 to 3, characterized in that, The base and the protrusion of the cover plate are integrally formed.

8. The rotary machine according to any one of claims 1 to 3, characterized in that, The cover plate is configured as a stainless steel cover plate.

9. The rotary machine according to any one of claims 1 to 3, characterized in that, The balance weight is configured as a magnetically conductive metal balance weight.

10. The rotary machine according to any one of claims 1 to 3, characterized in that, The rotary machine is a scroll compressor.

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