Rotary Stirling refrigerator

Abstract

The utility model relates to a rotary Stirling cryocooler, which comprises a compression assembly, a pushing assembly, a rotor assembly and a stator assembly, the rotor assembly comprises a motor rotor, a balancing weight and a motor rotating shaft, the motor rotor is a disc type permanent magnet brushless motor rotor, and the stator assembly comprises a motor stator and a motor shell. The motor stator is a disc type permanent magnet brushless motor stator, and the motor rotor and the motor stator are both in a flat disc shape and are stacked in the axial direction. Through the innovative design of structural assembly of components such as the stator component, the rotor component and the motor rotating shaft of the refrigerating machine, the refrigerating machine can use the permanent magnet brushless disc type motor as a prime motor to drive the whole machine to operate, so that various advantages of the permanent magnet brushless disc type motor are fully obtained and utilized.

Description

Technical Field

[0001] The utility model relates to the technical field of Stirling refrigerators, in particular to a rotary Stirling refrigerator. Background Art

[0002] The Stirling refrigerator is a device widely used in various high-performance refrigeration scenarios, especially in the fields of space, medical care, and military. Traditional rotary Stirling refrigerators usually use radial permanent magnet brushless motors as power sources.

[0003] Traditional rotary Stirling refrigerators use radial permanent magnet brushless motors. Under certain strict installation conditions of certain dimensions, because the rotor of the radial permanent magnet brushless motor needs to ensure a certain axial length, the axial size and motor performance cannot be guaranteed to meet the technical requirements at the same time; the stator of the radial permanent magnet brushless motor is made of laminated silicon steel sheets, the stator tooth boots have low stiffness, and there is usually electromagnetic noise caused by radial electromagnetic force, and the optimization cost is high; the radial permanent magnet brushless motor has low starting torque and weak load-bearing capacity.

[0004] In addition, the traditional rotary Stirling refrigerator has a long shaft system and is more easily deformed by torsion, so the torsional stiffness is poor, and a higher shaft stiffness needs to be designed and verified to maintain its stability. The Hall sensor used in the radial permanent magnet brushless motor is installed on the stator end winding, and a PCB board is required to integrate the winding and the Hall electrical interface, which further squeezes the space in the axial direction. Utility Model Content

[0005] In view of the above defects of the prior art solutions, the main purpose of the present invention is to develop a new type of Stirling refrigerator, which can provide more efficient and stable performance in a compact space while overcoming the limitations of the traditional motor technology mentioned above.

[0006] To achieve the above-mentioned purpose, the utility model discloses a rotary Stirling refrigerator, including a compression assembly, a push assembly, a rotor assembly, and a stator assembly. The rotor assembly includes a motor rotor, a counterweight block, and a motor shaft. The motor rotor is a disc-type permanent magnet brushless motor rotor. The stator assembly includes a motor stator and a motor housing. The motor stator is a disc-type permanent magnet brushless motor stator. The motor rotor and the motor stator are both flat disc-shaped and are stacked along the axial direction.

[0007] Preferably, the motor rotor comprises a disc rotor and a rotor permanent magnet, the disc rotor is sleeved on the motor shaft, the rotor permanent magnet is attached to the axial end surface of the disc rotor, and the counterweight is sleeved on the bottom of the disc rotor.

[0008] Preferably, it also includes a large bearing seat assembly, which includes a large bearing seat and a second double-row angular contact ball bearing. The motor shaft passes through the first double-row angular contact ball bearing and the second double-row angular contact ball bearing. The second double-row angular contact ball bearing is located between the motor rotor and the first double-row angular contact ball bearing. The motor shaft is transmission-connected to the compression assembly through the first double-row angular contact bearing, and the motor shaft is assembled on the large bearing seat assembly through the second double-row angular contact bearing.

[0009] Preferably, the rotor assembly further comprises a rotor cover, which is arranged on the motor rotor, a first deep groove ball bearing is installed in a bearing chamber of the rotor cover, and the motor shaft is assembled on the inner ring of the first deep groove ball bearing.

[0010] Preferably, the motor stator is arranged around the top of the rotor outer cover, the motor housing is arranged on the motor stator, and the motor housing is threadedly fastened to the rotor outer cover through motor screws.

[0011] Preferably, a spring flat washer is further included, and a limiting portion located below the first deep groove ball bearing is provided on the motor shaft, and the spring flat washer is located between the first deep groove ball bearing and the limiting portion.

[0012] Preferably, the compression assembly comprises a compression piston, a compression cylinder, a compression connecting rod, a compression pin, and a third double-row angular contact ball bearing, wherein the large end of the compression connecting rod is fixed to the outer ring of the first double-row angular contact ball bearing, the small end of the compression connecting rod is fixed to the outer ring of the third double-row angular contact ball bearing, and the inner ring of the third double-row angular contact ball bearing is connected to the compression pin.

[0013] Preferably, the pushing assembly includes a guide wire mesh, a cold storage shell, an energy storage wire mesh, a hot end plug, a guide cylinder, a guide piston, a transfer fork, a pushing short pin, a pushing connecting rod and a second deep groove ball bearing, and the pushing connecting rod is transmission-connected to the motor shaft through the second deep groove ball bearing.

[0014] Preferably, it further comprises a large base, the compression assembly is arranged in the large base, and the large bearing seat assembly is fastened to the large base by threaded connection.

[0015] Preferably, the sealing portions where the internal cavity of the rotary Stirling refrigerator is connected to the outside are sealed with sealing rings.

[0016] In summary, the beneficial effects of the utility model are as follows: by adopting innovative structural design and layout, the present invention enables the refrigerator to adopt a disc permanent magnet brushless motor with a smaller volume and shorter axial size. This motor has lower electromagnetic vibration and noise, as well as higher starting torque and load capacity, thereby improving the overall performance of the refrigerator, including load capacity, environmental adaptability and noise performance; by shortening the size of the motor shaft, the rigidity of the shaft system and the operating stability of the refrigerator are improved, while better utilizing the space, making the entire refrigerator structure more compact; in terms of motor control, the FOC position sensorless method can be adopted, eliminating components such as Hall sensors and integrated PCB boards, thereby eliminating the impact of the reliability of these components on the life of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A cross-sectional view of a rotary Stirling refrigerator according to an embodiment of the utility model;

[0019] Figure 2 Another angle sectional view of the rotary Stirling refrigerator of the embodiment of the utility model;

[0020] Figure 3 A cross-sectional view of a stator assembly according to an embodiment of the present utility model;

[0021] Figure 4 A cross-sectional view of a rotor assembly according to an embodiment of the utility model;

[0022] Figure 5 A cross-sectional view of a compression assembly according to an embodiment of the utility model;

[0023] Figure 6 A cross-sectional view of a push assembly according to an embodiment of the utility model;

[0024] Figure 7 This is a cross-sectional view of a large bearing seat assembly according to an embodiment of the utility model;

[0025] Figure 8 This is an appearance diagram of a rotary Stirling refrigerator according to an embodiment of the utility model;

[0026] Fig. 9 This is a schematic diagram of the installation position relationship between the stator assembly and the rotor assembly of an embodiment of the utility model;

[0027] Fig.10 Another schematic diagram of the installation position relationship between the stator assembly and the rotor assembly of the embodiment of the utility model;

[0028] Explanation of the reference numerals: 1-motor screw; 2-first deep groove ball bearing; 3-rotor cover; 4-motor rotor; 5-motor stator; 6-O-ring one; 7-O-ring two; 8-C-ring one; 9-screw one; 10-flow guide wire mesh; 11-cold finger protection tube; 12-cold storage shell; 13-energy storage wire mesh; 14-hot end plug; 15-O-ring three; 16-guide cylinder; 17-guide piston; 18-adapter fork; 19-sliding short pin; 20-sliding Connecting rod; 21-motor shaft; 22-first double-row angular contact ball bearing; 23-compression connecting rod; 24-second deep groove ball bearing; 25-large base; 26-second double-row angular contact ball bearing; 27-large bearing seat; 28-screw two; 29-spring flat washer; 30-compression cylinder; 31-compression piston; 32-third double-row angular contact ball bearing; 33-compression pin; 34-C-ring two; 35-O-ring four; 36-counterweight; 37-motor housing. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the utility model in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the utility model belong to the utility model.

[0030] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0031] See also Figure 1-10 The present embodiment proposes a structure of a rotary Stirling refrigerator driven by a disc-type permanent magnet brushless motor, including a compression assembly, a push assembly, a rotor assembly, and a stator assembly. The rotor assembly includes a motor rotor 4, a counterweight 36, and a motor shaft 21. The motor rotor 4 is a disc-type permanent magnet brushless motor rotor. The stator assembly includes a motor stator 5 and a motor housing 37. The motor stator 5 is a disc-type permanent magnet brushless motor stator. The motor rotor 4 and the motor stator 5 are both flat disc-shaped and are stacked along the axial direction.

[0032] The rotary Stirling refrigerator mainly includes a compression component, a push component, a rotor component, and a stator component. Figure 3-7 The compression assembly and the push assembly are based on the same principle as a typical traditional Stirling refrigerator, but the rotor assembly, the stator assembly and the related overall structure are innovatively designed for the application of disc-type permanent magnet brushless motors.

[0033] See also Figure 1 and Figure 3 The stator assembly includes a motor stator 5 and a motor housing 37. The rotor assembly also includes a rotor cover 3. The rotor cover 3 is covered on the motor rotor 4, and the top center of the rotor cover 3 has a protruding portion protruding outward to cover the top of the motor shaft 21 inside. The motor stator 5 is arranged around the top of the rotor cover 3, that is, the protruding portion. The motor housing 37 is covered on the motor stator 5. There is a gap between the motor housing 37 and the protruding portion of the rotor cover 3. The motor housing 37 is threadedly fastened to the rotor cover 3 through a motor screw 1, that is, the threaded portion of the motor screw 1 is screwed into the gap between the motor housing 37 and the protruding portion and cooperates with the outer thread of the protruding portion. The nut of the motor screw 1 presses the top inner side of the motor housing 37 to fix the motor housing 37. The motor housing 37 is provided with a lead hole for the lead wire of the motor stator 5 to pass through. The motor stator 5 is a disc-type permanent magnet brushless motor stator, and its end has no Hall device and integrated PCB board, which reduces the volume of the motor stator and can effectively shorten the axial size of the motor end. Figure 1 and Figure 4 , the rotor assembly includes a motor rotor 4 and a counterweight 36. The motor rotor 4 includes a disc rotor and a rotor permanent magnet. The disc rotor is sleeved on the motor shaft 21. The rotor permanent magnet is attached to the axial end face of the disc rotor. The counterweight 36 is sleeved on the bottom of the disc rotor. The motor shaft 21, the counterweight 36 and the motor rotor 4 are fixed by interference fit or glue. It also includes a large bearing seat assembly, the large bearing seat assembly includes a large bearing seat 27 and a second double-row angular contact ball bearing 26. The motor shaft 21 passes through the first double-row angular contact ball bearing 22 and the second double-row angular contact ball bearing 26. The second double-row angular contact ball shaft 26 is located between the motor rotor 4 and the first double-row angular contact ball bearing 22. The motor shaft 21 is connected to the compression assembly through the first double-row angular contact bearing 22. The motor shaft 21 is assembled on the large bearing seat assembly through the second double-row angular contact bearing 22.

[0034] The structure of the counterweight block 36 has been subjected to force balance check, and the stability of the operation of the refrigerator has been improved by adjusting the mass of the moving parts of the compression component and the push component and optimizing the structure of the counterweight block 36. The motor rotor 4 is a disc-type permanent magnet brushless motor rotor, and the rotor permanent magnet is attached to the axial end face of the disc rotor in the shape of a flat disc.

[0035] The installation position relationship between the stator and rotor assemblies is as follows: Fig. 9 and Fig.10 As shown, unlike the traditional Stirling refrigerator using radial permanent magnet brushless motor, the installation position relationship of the stator and rotor components of the disc permanent magnet brushless motor is axial stacking, and the main working air gap flux of the motor is generated between the axial contact surfaces. Because the axial dimension of the motor end is shortened, the axial dimension of the motor shaft 21 is also reduced, the shaft system stiffness is improved, the torsional deformation is reduced, and more stability margin is provided.

[0036] When the stator and rotor assemblies are installed, due to the principle of minimum magnetic resistance, they have the effect of radial automatic centering, which is more conducive to reducing assembly errors and magnetic field offsets, thereby reducing the increase in electromagnetic force waves and harmonic distortion caused by magnetic field offsets.

[0037] The driving operation of the motor stator 5 and the motor rotor 4 uses a FOC (Field-Oriented Control, spatial magnetic vector control) position sensorless control method, which eliminates devices such as Hall sensors and integrated PCB boards in the motor structure, eliminates the impact of component reliability on the motor life, and is beneficial to improving motor reliability, improving motor efficiency, and reducing electromagnetic vibration and noise.

[0038] Furthermore, a bearing chamber is provided in the protruding portion of the rotor outer cover 3, the first deep groove ball bearing 2 is installed in the bearing chamber of the rotor outer cover 3, the motor shaft 21 is assembled on the inner ring of the first deep groove ball bearing 2, the first deep groove ball bearing 2 and the bearing chamber are fixed by interference fit or glue, and also include a spring flat washer 29. A limiting portion located below the first deep groove ball bearing 2 is provided on the motor shaft 21, and the spring flat washer 29 is located between the first deep groove ball bearing 2 and the limiting portion. The spring flat washer 29 can help evenly distribute the load applied to the bearing by the shaft, and can also apply a preload to the inner ring of the first deep groove ball bearing 2.

[0039] See also Figure 1 and Figure 5 The compression assembly includes a compression piston 31, a compression cylinder 30, a compression connecting rod 23, a compression pin 33, and a third double-row angular contact ball bearing 32. The large end of the compression connecting rod 23 is fixed to the outer ring of the first double-row angular contact ball bearing 22, the small end of the compression connecting rod 23 is fixed to the outer ring of the third double-row angular contact ball bearing 32, and the inner ring of the third double-row angular contact ball bearing 32 is connected to the compression pin 33.

[0040] See also Figure 1 and Figure 6The push assembly is composed of a guide wire mesh 10, a cold storage shell 12, an energy storage wire mesh 13, a hot end plug 14, a guide cylinder 16, a guide piston 17, a transfer fork 18, a push short pin 19, a push connecting rod 20 and a second deep groove ball bearing 24. The push connecting rod 20 is connected to the push short pin 19, and the push connecting rod 20 is connected to the motor shaft 21 through the second deep groove ball bearing 24. In addition, a cold finger protection tube 11 is also provided outside the cold storage shell 12. The movement directions of the compression assembly and the push assembly are on the same horizontal plane. The push connecting rod 20 is not directly connected to the motor shaft 21, and the power output is transmitted through the second deep groove ball bearing 24.

[0041] See also Figure 1 and Figure 7 , and also includes a large base 25, the compression assembly is arranged in the large base 25, the large bearing seat assembly is fastened to the large base 25 by threaded connection, as a supporting structure of the system, the second double row angular contact ball bearing 26 and the large bearing seat 27 are fixed by interference fit or glue.

[0042] The sealing parts where the internal cavity of the refrigerator is connected to the outside are all sealed with sealing rings. Figure 1 The sealing rings used include O-ring 1 6, O-ring 2 2, O-ring 3 15, O-ring 4 35, C-ring 1 8 and C-ring 2 34. These sealing rings play a sealing role at different connection points of the compression assembly to prevent gas leakage, thereby improving the sealing performance of the overall system. In addition, screws 1 9 and screws 2 28 are included. These screws are used to firmly connect different parts of the assembly together to ensure the overall stability and safety of the assembly during operation. The spring flat washer 29 is used to provide the necessary pressure distribution when assembling the screws and reduce the stress concentration caused by screw tightening.

[0043] The utility model provides a new refrigerator structure, through innovative structural design and layout, so that the refrigerator can use a disc permanent magnet brushless motor with shorter axial size, smaller volume, less electromagnetic vibration and noise, higher starting torque and stronger load-bearing capacity, so that the refrigerator has higher load-bearing capacity, stronger environmental adaptability, reliability and better noise performance; shorten the motor shaft size, improve the shaft system stiffness and the operation stability of the refrigerator, and make full use of the space volume to make the refrigerator structure more compact; the disc motor installation layout has the effect of radial automatic centering due to the minimum magnetic resistance principle, which is more conducive to reducing assembly errors and magnetic field offsets, thereby reducing the increase of electromagnetic force waves and harmonic distortion caused by magnetic field offsets.

[0044] The utility model optimizes the structural design to make the selection of assembly process more free, and the relevant process can be adjusted according to the use requirements. If it is necessary to reduce the use of unnecessary glue to reduce the release of polluted gas, an interference fit can be used in the corresponding matching position to reduce the risk of working fluid contamination during operation; if higher maintainability and higher disassembly convenience are required, glue fixing can be selected in the corresponding matching position.

[0045] The above figures are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present application, and are not intended to be limiting. It is easy to understand that the processes shown in the above figures do not indicate or limit the time sequence of these processes. In addition, it is also easy to understand that these processes can be performed synchronously or asynchronously, for example, in multiple modules.

[0046] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be performed without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A rotary Stirling refrigerator, comprising a compression assembly, a push assembly, a rotor assembly, and a stator assembly, characterized in that: The rotor assembly includes a motor rotor, a counterweight and a motor shaft. The motor rotor is a disc-type permanent magnet brushless motor rotor. The stator assembly includes a motor stator and a motor housing. The motor stator is a disc-type permanent magnet brushless motor stator. Both the motor rotor and the motor stator are flat disc-shaped and are stacked axially.

2. The rotary Stirling refrigerator according to claim 1, characterized in that: The motor rotor comprises a disc rotor and a rotor permanent magnet. The disc rotor is sleeved on the motor shaft, the rotor permanent magnet is attached to the axial end surface of the disc rotor, and the counterweight is sleeved on the bottom of the disc rotor.

3. The rotary Stirling refrigerator according to claim 1, characterized in that: It also includes a large bearing seat assembly, which includes a large bearing seat and a second double-row angular contact ball bearing. The motor shaft passes through the first double-row angular contact ball bearing and the second double-row angular contact ball bearing. The second double-row angular contact ball bearing is located between the motor rotor and the first double-row angular contact ball bearing. The motor shaft is transmission-connected to the compression assembly through the first double-row angular contact bearing, and the motor shaft is assembled on the large bearing seat assembly through the second double-row angular contact bearing.

4. The rotary Stirling refrigerator according to claim 1, characterized in that: The rotor assembly also includes a rotor cover, which is arranged on the motor rotor. A first deep groove ball bearing is installed in a bearing chamber of the rotor cover, and the motor shaft is assembled on the inner ring of the first deep groove ball bearing.

5. The rotary Stirling refrigerator according to claim 4, characterized in that: The motor stator is arranged around the top of the rotor outer cover, the motor housing is arranged on the motor stator, and the motor housing is threadedly fastened with the rotor outer cover through motor screws.

6. The rotary Stirling refrigerator according to claim 4, characterized in that: It also includes a spring flat washer. The motor shaft is provided with a limiting portion located below the first deep groove ball bearing. The spring flat washer is located between the first deep groove ball bearing and the limiting portion.

7. The rotary Stirling refrigerator according to claim 3, characterized in that: The compression assembly includes a compression piston, a compression cylinder, a compression connecting rod, a compression pin, and a third double-row angular contact ball bearing. The large end of the compression connecting rod is fixed to the outer ring of the first double-row angular contact ball bearing, the small end of the compression connecting rod is fixed to the outer ring of the third double-row angular contact ball bearing, and the inner ring of the third double-row angular contact ball bearing is connected to the compression pin.

8. The rotary Stirling refrigerator according to claim 1, characterized in that: The push assembly includes a guide wire mesh, a cold storage shell, an energy storage wire mesh, a hot end plug, a guide cylinder, a guide piston, a transfer fork, a push short pin, a push connecting rod and a second deep groove ball bearing. The push connecting rod is transmission-connected to the motor shaft via the second deep groove ball bearing.

9. The rotary Stirling refrigerator according to claim 3, characterized in that: It also includes a large base, the compression assembly is arranged in the large base, and the large bearing seat assembly is fastened to the large base through threaded connection.

10. The rotary Stirling refrigerator according to claim 1, characterized in that: The sealing points where the internal cavity of the rotary Stirling refrigerator is connected to the outside are all sealed with sealing rings.

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