Permanent magnet air suspension air compressor

Abstract

The utility model provides a permanent magnet air suspension air compressor, which belongs to the technical field of air compressors, and comprises an air compressor shell structure, a rotor structure and a stator structure, the rotor structure comprises a hollow main shaft, a rotor iron core, a magnetic steel group and a rotor sheath; the two ends of the hollow spindle are sealed through shaft end structures respectively, and one end of the hollow spindle is connected with a thrust bearing assembly. The rotor core and the rotor sheath are sequentially sleeved on the outer side of the hollow main shaft, the magnetic steel group is a quadrupole surface-mounted magnetic steel group, and the quadrupole surface-mounted magnetic steel group is distributed in an interlayer inner cavity between the rotor core and the rotor sheath. According to the permanent magnet air suspension air compressor, the mode that the hollow main shaft is matched with the four-pole surface-mounted magnetic steel is adopted, the weight of the rotor structure is reduced through the hollow main shaft structure, meanwhile, the inherent frequency of the rotor structure is enhanced, resonance is reduced, the balance and stability of the rotor structure are improved, and the dynamic performance of the rotor is improved; and therefore, the working performance of the whole air compressor is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to air compressor technical field, more specifically, relate to a kind of permanent-magnetic air suspension air compressor. BACKGROUND

[0002] Current industry mainstream air compressor product generally adopts low-voltage motor (such as 380V, 660V etc.) driving, needs through step-down transformer to access medium-high voltage power grid (such as 10kV). This low-voltage design has the following defects:

[0003] (1) system complexity and energy efficiency loss: need to configure step-down transformer, low-voltage switch cabinet and supporting cable, equipment occupies large area and transformer itself energy consumption accounts for 3%-5% of system total loss;

[0004] (2) transmission loss is high: low-voltage power supply line current is large, cable copper loss and current square are directly proportional, energy utilization efficiency is low;

[0005] (3) high maintenance cost: multi-stage transmission or parallel unit increases mechanical loss and fault node, needs frequent maintenance.

[0006] Existing 10kV high-voltage direct-drive air compressor, by directly accessing grid voltage, saves step-down link, theoretically can reduce line loss, simplify power supply architecture and improve energy efficiency. However, the existing high-voltage air compressor technology still has the following bottlenecks:

[0007] (1) insufficient insulation reliability: traditional high-voltage motor stator winding insulation is easy to cause aging due to partial discharge, long-term operation reliability is poor;

[0008] (2) poor rotor dynamic performance: traditional rotor is heavy, and inherent frequency is low, resonance is easy to be caused at high speed, and energy efficiency is restricted;

[0009] (3) permanent magnet layout defect: existing permanent magnet rotor magnet steel fixing mode is easy to cause magnet steel displacement under high-speed centrifugal force, and affects magnetic field stability.

[0010] Therefore, a new air compressor scheme is needed, which considers high-voltage direct-drive efficiency, insulation reliability and rotor dynamic performance optimization. UTILITY MODEL CONTENT

[0011] The utility model aims at providing a kind of permanent-magnetic air suspension air compressor, to solve the problems of heavy rotor, easy resonance and poor dynamic performance.

[0012] In order to achieve the above object, the utility model provides technical scheme is: provide a kind of permanent magnet air suspension air compressor, including air compressor shell structure, rotor structure and stator structure, the rotor structure includes hollow main shaft, rotor core, magnetic steel group and rotor sheath;The both ends of the hollow main shaft are closed by means of shaft end structure respectively, one end of the hollow main shaft is connected with thrust bearing assembly;The rotor core and the rotor sheath are sequentially sleeved on the outside of the hollow main shaft, the magnetic steel group is four-pole surface-mounted magnetic steel group, the four-pole surface-mounted magnetic steel group is distributed in the interlayer inner cavity between the rotor core and the rotor sheath.

[0013] As another embodiment of the application, the both ends of the hollow main shaft have bearing connecting parts, the outer diameter of the bearing connecting part is smaller than the outer diameter of the middle part of the hollow main shaft, the outside of the bearing connecting part is sequentially sleeved with a bushing and a radial bearing seat;The end face of the bushing abuts against the shaft shoulder of the hollow main shaft.

[0014] As another embodiment of the application, the outside of the hollow main shaft has a protruding annular limiting part, the annular limiting part is used for abutting against the rotor core.

[0015] As another embodiment of the application, the length direction of the hollow main shaft is provided with an air inlet hole group and an air outlet hole group at intervals, the air inlet hole group and the air outlet hole group each have a plurality of through holes, and the through holes communicate the inner cavity of the hollow main shaft.

[0016] As another embodiment of the application, the shaft end structure includes a shaft end plug and a shaft end pull rod, the shaft end plug is installed at the end of the hollow main shaft to close the inner cavity of the hollow main shaft, a connecting hole is formed in the center of the shaft end plug, and the shaft end pull rod is fixed in the connecting hole;The shaft end pull rod is used for mounting an impeller and the thrust bearing assembly.

[0017] As another embodiment of the application, the four-pole surface-mounted magnetic steel group includes four magnetic steel bodies and four magnetic steel pad strips, and the magnetic steel bodies and the magnetic steel pad strips are arranged alternately.

[0018] As another embodiment of the application, the both ends of the rotor core are provided with core end plates, a plurality of through channels are formed in the rotor core, the through channels have core pull rods, the both ends of the core pull rods protrude from the both ends of the through channels, and the both ends of the core pull rods are connected with the core end plates at the both ends of the rotor core respectively.

[0019] As another embodiment of the application, the rotor structure further includes two rotor rings, the rotor rings are embedded in the rotor sheath and are in contact with the end faces of the four-pole surface-mounted magnetic steel group, and the rotor rings close the inner cavity of the rotor sheath.

[0020] As another embodiment of the present application, the stator structure comprises a stator core, a stator coil, an interlayer spacer and a stator slot wedge; the stator core has a plurality of coil mounting slots therein, each of the coil mounting slots is fixed with the stator coil, the stator coil is mounted with the interlayer spacer between the slot bottom of the coil mounting slot and the adjacent two stator coils in the same coil mounting slot; the stator slot wedge is mounted at the slot opening of the coil mounting slot; the stator coil is a flat wire, and the surface of the stator coil has an insulation layer.

[0021] As another embodiment of the present application, the air compressor shell structure has a wire outlet box structure.

[0022] The permanent magnet air suspension air compressor has the advantages that compared with the prior art, the permanent magnet air suspension air compressor adopts a hollow main shaft and four-pole surface-mounted magnetic steel cooperation mode, the hollow main shaft structure reduces the weight of the rotor structure, enhances the natural frequency of the rotor structure, reduces resonance, improves the balance and stability of the rotor structure, realizes the fusion of the stator and the high-speed rotor under 10KV high voltage conditions, improves the dynamic performance of the rotor, and further improves the working performance of the entire air compressor. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical scheme in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 The three-dimensional structure schematic diagram of the permanent magnet air suspension air compressor provided by the embodiments of the present application is shown in the figure.

[0025] Figure 2 The cross-sectional structure schematic diagram of the permanent magnet air suspension air compressor provided by the embodiments of the present application is shown in the figure.

[0026] Figure 3 The three-dimensional structure schematic diagram of the stator structure provided by the embodiments of the present application is shown in the figure.

[0027] Figure 4 The cross-sectional structure schematic diagram of the stator structure provided by the embodiments of the present application is shown in the figure.

[0028] Figure 5 The three-dimensional structure schematic diagram of the rotor structure provided by the embodiments of the present application is shown in the figure.

[0029] Figure 6 The cross-sectional structure schematic diagram of the rotor structure provided by the embodiments of the present application is shown in the figure.

[0030] Figure 7 A hollow spindle three-dimensional structure schematic diagram provided by the embodiment of the utility model;

[0031] Figure 8 A hollow spindle cross section structure schematic diagram provided by the embodiment of the utility model.

[0032] In the figure: 1, air compressor shell structure;2, outgoing line box base;3, hollow spindle;4, stator core;5, stator end plate;6, stator pressing ring;7, stator coil;8, interlayer spacer;9, stator slot wedge;10, rotor sheath;11, core end plate;12, rotor core;13, core pull rod;14, magnet steel body;15, magnet steel spacer;16, annular limiting portion;17, air inlet hole group;18, air outlet hole group;19, radial bearing seat;20, radial bearing mounting seat;21, shaft end pull rod;22, shaft sleeve;23, shaft end plug;24, thrust bearing seat. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical schemes and beneficial effects to be solved by the utility model more clear and obvious, the utility model is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model, and are not used to limit the utility model.

[0034] Please refer to Figures 1 to 8 Now, the permanent magnet air suspension air compressor provided by the utility model is described. The permanent magnet air suspension air compressor comprises an air compressor shell structure 1, a rotor structure and a stator structure, the rotor structure comprises a hollow spindle 3, a rotor core 12, a magnet steel group and a rotor sheath 10;Both ends of the hollow spindle 3 are closed by means of shaft end structure, one end of the hollow spindle 3 is connected with a thrust bearing assembly;The rotor core 12 and the rotor sheath 10 are sequentially sleeved on the outside of the hollow spindle 3, the magnet steel group is a four-pole surface-mounted magnet steel group, and the four-pole surface-mounted magnet steel group is distributed in the interlayer inner cavity between the rotor core 12 and the rotor sheath 10.

[0035] The conventional 10KV air compressor has a heavy rotor, low inherent frequency, and is prone to resonance when running at high speed. In order to adapt to the stability of 10KV, the size of the main shaft is increased, and the weight is increased. However, the carrying capacity of the air bearing is limited, which reduces the performance of the product, limits the service life, and is not conducive to the miniaturization of the product. Therefore, in the present scheme, the main shaft is designed as a hollow structure to reduce the weight of the main shaft structure and reduce the moment of inertia, so that the equipment can start and stop faster, consume less energy, and reduce the load on the air suspension bearing, improve the suspension control precision, and facilitate the integration design. In addition, the rotor structure installed on the outside of the hollow main shaft 3 adopts a four-pole surface-mounted magnetic steel, which optimizes the magnetic field distribution, improves the motor power density and efficiency, and ensures high efficiency under high pressure conditions. Reduce power consumption; the four-pole magnetic pole design makes the magnetic field harmonic smaller, reduces the torque ripple, and cooperates with the lightweight characteristics of the hollow main shaft 3 to significantly reduce vibration and noise, meeting the requirements of precision industrial scenes for equipment silence.

[0036] The cooperation of the air suspension bearing and the lightweight rotor further suppresses mechanical friction and resonance, and improves the running stability.

[0037] Compared with the prior art, the permanent magnet air suspension air compressor has a hollow main shaft 3 and a four-pole surface-mounted magnetic steel in the air compressor shell structure 1. The hollow main shaft 3 structure reduces the weight of the rotor structure while enhancing the inherent frequency of the rotor structure, reduces resonance, improves the balance and stability of the rotor structure, and realizes the fusion of the stator and the high-speed rotor under 10KV high pressure conditions. Improve the dynamic performance of the rotor, and further improve the working performance of the entire air compressor.

[0038] In some possible embodiments, please refer to Figure 7 and Figure 8 , both ends of the hollow main shaft 3 have bearing connecting parts, the outer diameter of the bearing connecting part is smaller than the outer diameter of the middle part of the hollow main shaft 3, and the outer side of the bearing connecting part is sequentially sleeved with a shaft sleeve 22 and a radial bearing seat 19; the end face of the shaft sleeve 22 abuts against the shaft shoulder of the hollow main shaft 3.

[0039] The outer diameter of the bearing connecting part is smaller than the outer diameter of the middle part of the hollow main shaft 3, that is, the two ends of the hollow main shaft 3 form two shaft shoulders, respectively. When installing, the shaft sleeve 22 of the air bearing is installed on the bearing connecting part. The end face of the shaft sleeve 22 is attached to the shaft shoulder end face formed by the bearing connecting part on the hollow main shaft 3. The other end face of the shaft sleeve 22 is flush with the end face of the hollow main shaft 3.

[0040] The outer side of the shaft sleeve 22 is provided with a radial bearing seat 19, and when installing, the shaft sleeve 22 and the radial bearing seat 19 are used to connect the radial bearing assembly and other structures.

[0041] When the air compressor is a two-stage air compressor, radial bearing assemblies are arranged at both ends of the hollow main shaft 3, and a thrust bearing assembly is arranged on one side of one of the radial bearing assemblies. The thrust bearing assembly can be arranged on the side of the first-stage impeller or the side of the second-stage impeller.

[0042] Optionally, the outer side of the hollow main shaft 3 has a protruding annular limiting portion 16, which is used to abut against the rotor core 12. The annular limiting portion 16 is located at the middle portion of the hollow main shaft 3 close to one end, and is used to fit and position the rotor core structure, so as to ensure that the rotor core 12 is located at the middle portion of the hollow main shaft 3.

[0043] In some possible embodiments, referring to Figures 7 to 8 , the hollow main shaft 3 is provided with an air inlet hole group 17 and an air outlet hole group 18 at intervals in the length direction, and the air inlet hole group 17 and the air outlet hole group 18 each have a plurality of through holes that communicate with the inner cavity of the hollow main shaft 3.

[0044] The hollow main shaft 3 is provided with two groups of through holes in the direction close to the two bearing connecting portions, one of which is the air inlet hole group 17 and the other of which is the air outlet hole group 18. The two groups of through holes are arranged at intervals in the axial direction of the hollow main shaft 3. In the state of rotation of the hollow main shaft 3, the air in the motor enters the cavity of the hollow main shaft 3 from the air inlet hole group 17, moves along the cavity of the hollow main shaft 3 towards the air outlet hole group 18, and is finally discharged from the air outlet hole group 18. The hollow main shaft 3 is matched with the air inlet hole group 17 and the air outlet hole group 18, the internal space of the hollow main shaft 3 is integrated with the airflow channel, the heat dissipation capacity of the rotor is enhanced, and the demagnetization of the permanent magnet due to high temperature is avoided.

[0045] In some possible embodiments, referring to Figure 8 , the shaft end structure includes a shaft end plug 23 and a shaft end pull rod 21. The shaft end plug 23 is installed at the end of the hollow main shaft 3 to close the inner cavity of the hollow main shaft 3, and a connecting hole is formed in the center of the shaft end plug 23. The shaft end pull rod 21 is fixed in the connecting hole. The shaft end pull rod 21 is used to install the impeller and the thrust bearing assembly.

[0046] The shaft end plug 23 is installed at the end in the cavity of the hollow main shaft 3, and includes an installation portion and an extension portion. The installation portion extends into the cavity of the hollow main shaft 3 and is connected with the hollow main shaft 3. The extension portion is located on the side away from the hollow main shaft 3, and is used to connect the radial bearing seat 19, the motor end plate and other structures.

[0047] A central hole is formed in the center of the shaft end plug 23, and the central hole is coaxially arranged with the hollow main shaft 3 and communicates with the inner cavity of the hollow main shaft 3. The central hole is used to install the shaft end pull rod 21.

[0048] For the two-stage air compressor, the shaft end plugs 23 at both ends are provided with shaft end pull rods 21, and the shaft end pull rods 21 are provided with the first-stage impeller and the second-stage impeller. The thrust bearing seat 24 is installed at the root of the first-stage impeller or the second-stage impeller. The radial bearing mounting seat 20 has two, and the two radial bearing mounting seats 20 are respectively installed at the root of the first-stage impeller or the second-stage impeller, and the radial bearing mounting seat 20 is connected with the corresponding radial bearing seat 19.

[0049] In some possible embodiments, referring to Figure 5 and Figure 6 , the four-pole surface-mounted magnetic steel group includes four magnetic steel bodies 14 and four magnetic steel pads 15, and the magnetic steel bodies 14 and the magnetic steel pads 15 are arranged alternately.

[0050] The four magnetic steel bodies 14 and the four magnetic steel pads 15 are arranged in a ring shape and are attached to the outer periphery of the rotor core 12. The magnetic steel bodies 14 and the magnetic steel pads 15 are arranged alternately to form a four-pole surface-mounted magnetic steel group. The surface-mounted magnetic steel refers to the magnetic steel directly attached to the surface of the rotor, and the surface-mounted magnetic steel has high magnetic field utilization rate and simple process.

[0051] Specifically, the rotor core 12 is provided with a core end plate 11 at both ends, a plurality of through channels are formed in the rotor core 12, the through channels are provided with core pull rods 13, the two ends of the core pull rods 13 extend out of the two ends of the through channels, and the core pull rods 13 are connected to the core end plates 11 at both ends of the rotor core 12.

[0052] The rotor core 12 has four uniformly distributed through channels, and the length direction of the four through channels is consistent with the axial direction. The core pull rods 13 pass through the above-mentioned through channels, and the two ends of the core pull rods 13 pass through and connect the core end plates 11 at both ends, respectively.

[0053] The rotor structure further includes two rotor rings, the rotor rings are embedded in the rotor sheath 10 and are attached to the end face of the four-pole surface-mounted magnetic steel group, and the rotor rings seal the inner cavity of the rotor sheath 10.

[0054] In some possible embodiments, referring to Figures 3 to 4 , the stator structure includes a stator core 4, a stator coil 7, an interlayer pad 8, and a stator slot wedge 9; the stator core 4 has a plurality of coil mounting slots therein, each coil mounting slot is fixed with a stator coil 7, the stator coil 7 is provided with an insulating layer on the surface thereof, and the stator coil 7 is provided with the interlayer pad 8 between the bottom of the coil mounting slot and the adjacent two stator coils 7 in the same coil mounting slot; the stator slot wedge 9 is installed at the slot opening of the coil mounting slot; the stator core 4 is provided with a stator end plate 5 and a stator pressing ring 6 at both ends, the stator end plate 5 is attached to the end face of the stator core 4, and the stator pressing ring 6 is located on the side of the stator end plate 5 away from the stator core 4.

[0055] The stator structure is located outside the rotor structure. The stator core 4 of the stator structure is provided with a coil mounting groove in the inner side of which the stator coil 7 is arranged. The layer spacing strip 8 is mounted on the groove bottom of the coil mounting groove. After arranging one layer of conductive wire on the groove bottom of the coil mounting groove, the layer spacing strip 8 is added, and then another layer of conductive wire is arranged. After arranging two layers of conductive wire, the stator slot wedge 9 is mounted on the slot opening of the coil mounting groove.

[0056] The flat wire of the stator coil 7 can further compress the volume of the stator structure and reduce the occupied space. In addition, the insulation layer and the insulated stator slot wedge 9 are added outside the stator coil 7, which improves the insulation structure of the stator winding and meets the direct power supply of 10kV power supply. The insulation structure isolates the stator winding conductor from the core, other windings and the external environment, prevents short circuit or breakdown under high voltage, and ensures the safe operation of the motor under rated voltage (such as 10kV). Optionally, the mica tape is used as the inter-turn pad layer of the stator coil 7, and the polyurethane coating is coated on the outer side of the stator coil 7.

[0057] In some possible embodiments, please refer to Figure 1 The air compressor shell structure 1 is provided with an outlet box structure.

[0058] The outlet box structure includes an outlet box base 2 located on the side of the air compressor shell structure 1 and an outlet box cover body closing the base. The wiring terminal is arranged in the inner cavity of the base, the wiring terminal is connected with the electric wire, the electric wire extends into the inner cavity of the air compressor shell structure 1 through the hole on the side wall of the outlet box base 2 and the air compressor shell structure 1, and is electrically connected with the coil of the stator structure.

[0059] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A permanent magnet air levitated air compressor, characterized by, The air compressor shell structure (1) comprises a rotor structure and a stator structure, the rotor structure comprises a hollow main shaft (3), a rotor core (12), a magnetic steel group and a rotor sheath (10), both ends of the hollow main shaft (3) are closed by means of shaft end structures, one end of the hollow main shaft (3) is connected with a thrust bearing assembly, the rotor core (12) and the rotor sheath (10) are sequentially sleeved outside the hollow main shaft (3), the magnetic steel group is a four-pole surface-mounted magnetic steel group, and the four-pole surface-mounted magnetic steel group is distributed in the interlayer inner cavity between the rotor core (12) and the rotor sheath (10).

2. The permanent-magnetic air-levitated air compressor of claim 1, characterized in that Both ends of the hollow main shaft (3) are provided with bearing connecting portions, the outer diameter of the bearing connecting portions is smaller than the outer diameter of the middle part of the hollow main shaft (3), and the outer side of the bearing connecting portions is sequentially sleeved with a shaft sleeve (22) and a radial bearing seat (19); the end face of the shaft sleeve (22) abuts against the shaft shoulder of the hollow main shaft (3).

3. The permanent-magnetic air-levitated air compressor of claim 2, characterized in that The outer side of the hollow main shaft (3) is provided with a protruding annular limiting portion (16), and the annular limiting portion (16) is used for abutting against the rotor core (12).

4. The permanent-magnetic air-levitated air compressor of claim 2, wherein, The length direction of the hollow main shaft (3) is provided with an air inlet hole group (17) and an air outlet hole group (18) at intervals, the air inlet hole group (17) and the air outlet hole group (18) are both provided with a plurality of through holes, and the through holes communicate the inner cavity of the hollow main shaft (3).

5. The permanent-magnetic air-levitated air compressor of claim 1, wherein, The shaft end structure comprises a shaft end plug (23) and a shaft end pull rod (21), the shaft end plug (23) is installed at the end of the hollow main shaft (3) to close the inner cavity of the hollow main shaft (3), a connecting hole is formed in the center of the shaft end plug (23), and the shaft end pull rod (21) is fixed in the connecting hole; the shaft end pull rod (21) is used for installing an impeller and the thrust bearing assembly.

6. The permanent-magnet air-levitated air compressor of claim 1, wherein, The four-pole surface-mounted magnetic steel group comprises four magnetic steel bodies (14) and four magnetic steel pad strips (15), and the magnetic steel bodies (14) and the magnetic steel pad strips (15) are alternately arranged.

7. The permanent-magnet air-ride air compressor of claim 6, wherein, Both ends of the rotor core (12) are provided with core end plates (11), a plurality of through channels are formed in the rotor core (12), the through channels are provided with core pull rods (13), both ends of the core pull rods (13) protrude from both ends of the through channels, and the core pull rods (13) are connected with the core end plates (11) at both ends of the rotor core (12) respectively.

8. The permanent-magnet air-ride air compressor of claim 7, wherein, The rotor structure further comprises two rotor rings, the rotor rings are embedded in the rotor sheath (10) and are in contact with the end faces of the four-pole surface-mounted magnetic steel group, and the rotor rings close the inner cavity of the rotor sheath (10).

9. The permanent-magnet air-levitated air compressor of claim 1, wherein, The stator structure comprises a stator core (4), a stator coil (7), an interlayer spacer (8) and a stator slot wedge (9); the stator core (4) has a plurality of coil mounting slots, each of which is fixed with the stator coil (7); the stator coil (7) is mounted with the interlayer spacer (8) between the slot bottom of the coil mounting slot and the adjacent two stator coils (7) in the same coil mounting slot; the stator slot wedge (9) is mounted at the slot opening of the coil mounting slot; the stator coil (7) is a flat wire, and the surface of the stator coil (7) has an insulating layer.

10. The permanent-magnet air-levitated air compressor of claim 1, wherein, The air compressor shell structure (1) is provided with a wire outlet box structure.

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