WO2024016613A1

WO2024016613A1 - Integrated stirling refrigerator

Info

Publication number: WO2024016613A1
Application number: PCT/CN2023/070022
Authority: WO
Inventors: 王鹏; 叶重; 张�浩; 刘应应
Original assignee: 睿创微纳(无锡)技术有限公司
Priority date: 2022-07-21
Filing date: 2023-01-03
Publication date: 2024-01-25

Abstract

The present application provides an integrated Stirling refrigerator, comprising: an eccentric axle box, a sealed cavity filled with a gas working medium therein; an eccentric shaft, rotatably arranged in the sealed cavity in an axial direction and having an eccentric section and a non-eccentric section; a stator assembly, arranged in the axial direction and fixed in the sealed cavity; a rotor assembly, arranged on the non-eccentric section in the axial direction and forming an air gap with the stator assembly in the axial direction; a compression connecting rod assembly, arranged in the sealed cavity and connected to the eccentric section; and an expansion connecting rod assembly, arranged in the sealed cavity and connected to the eccentric section, wherein the stator assembly and the rotor assembly form an axial flux motor arranged in the axial direction, to drive the eccentric shaft via the rotor assembly to rotate in the axial direction. In the integrated Stirling refrigerator in the present application, the axial flux motor is formed in the axial direction of the eccentric shaft by the stator assembly and the rotor assembly, so that the size in the axial direction can be reduced, and an overall structure is more compact.

Description

Integrated Stirling Refrigerator

Technical field

The present application relates to the field of refrigeration technology, and in particular to an integrated Stirling refrigerator.

Background technique

The cooled infrared detector can detect the slight temperature difference between the target and the background. It is not only suitable for the detection of space, long-range, dark small targets, but also has advantages in real-time high-resolution identification of ultra-high-speed and high-radar stealth targets. It is also suitable for all-round Used independently under weather conditions and complex electromagnetic environments, it has become the main supporting technology for global multi-dimensional information acquisition and battlefield situation awareness. Cooled infrared detector components have been widely used in new generation infrared reconnaissance systems, precision guided weapons, air defense and anti-missile early warning and other equipment, and their application fields have rapidly expanded. Cooled infrared detectors have irreplaceable advantages in terms of working range, target detection and tracking, especially dynamic imaging of fast-moving targets. However, the cost and large size of cooled detectors limit their battlefield applications.

With the advancement of science and technology, technological research on high operating temperature (High Operation Temperature) infrared detection devices (HOT devices) has made great breakthroughs, and the operating temperature of the detector has been greatly increased. The operating temperature of foreign medium-wave infrared detectors has been increased to the 130-150K temperature zone, and there is a trend of further increasing to 150-200K. The successful development of HOT devices has made it possible to develop smaller, lighter, and more efficient ultra-small Stirling refrigerators, and has also become a hot spot in the development of refrigerators at home and abroad.

As the operating temperature of infrared detectors increases, Stirling refrigerators have entered the development direction of smaller size, lower mass, higher performance, lower power consumption and lower cost (referred to as SWaP3). Compared with the split-type Stirling refrigerator driven by a linear motor, the integral Stirling refrigerator driven by a rotating motor has the advantages of compact structure, small size, light weight, and low power consumption. It can be widely used in infrared detection in the 80K temperature zone. on the device.

The prior art describes an integral Stirling refrigerator that uses a radial magnetic flux structure for rotational driving. However, this integral Stirling refrigerator has a larger size along the length of the eccentric shaft. The Stirling refrigerator There is still some room for reduction in size.

technical problem

Based on this, in order to solve the above technical problems, this application provides an integrated Stirling refrigerator with small size and compact structure.

Technical solutions

In order to achieve the above objectives, the technical solutions of the embodiments of the present application are implemented as follows:

The embodiment of the present application provides an integrated Stirling refrigerator, including:

The eccentric shaft box has a sealed cavity filled with gas working fluid inside;

An eccentric shaft is rotatably placed in the sealing cavity around an axial direction, and has an eccentric section eccentric to the axial direction and a non-eccentric section along the axial direction;

A stator assembly is arranged around the axis direction and fixed in the sealed cavity;

The rotor assembly is arranged on the non-eccentric section around the axis direction, and has an air gap along the axis direction between the rotor assembly and the stator assembly;

A compression connecting rod assembly is placed in the sealed cavity and connected to the eccentric section; and

An expansion connecting rod assembly is placed in the sealed cavity and connected to the eccentric section;

Wherein, the stator assembly and the rotor assembly form an axis flux motor arranged along the axial direction to drive the eccentric shaft to rotate around the axial direction through the rotor assembly.

In one embodiment, the eccentric shaft box includes a housing and an end plate, the housing has an opening, and the end plate is sealingly connected to the opening.

In one embodiment, the opening on the housing is circular, and the end plate is in the shape of a circular plate matching the shape of the opening.

In one embodiment, the housing and the end plate are made of aluminum alloy material, and the end plate and the housing are hermetically connected through a sealing ring or welding.

In one embodiment, both ends of the eccentric shaft are respectively connected to bearings fixed on the housing and bearings fixed on the end plate.

In one embodiment, one end of the eccentric shaft is connected to the inner ring of a deep groove ball bearing fixed in the housing, and the other end is connected to the inner ring of a thrust ball bearing fixed on the inside of the end plate.

In one embodiment, the stator assembly is fixed on the inner side of the end plate and is coaxially arranged with the thrust ball bearing.

In one embodiment, motor lead pins protrude from the outside of the end plate, and the motor lead pins penetrate the end plate in the axial direction and are electrically isolated from the end plate through insulation sintering.

In one embodiment, the stator assembly includes a stator core and windings, the stator core has a bottom surface perpendicular to the axial direction, and a plurality of teeth are directed from the bottom surface toward the rotor assembly along the axial direction. Extending, said winding includes a plurality of coils, each said coil being disposed about said tooth and electrically isolated from said tooth;

The rotor assembly includes a rotor disk and a permanent magnet. The rotor disk is sleeved on the non-eccentric section. A plurality of permanent magnets are fixed on a side of the rotor disk facing the stator assembly. The permanent magnets are fixed on the side of the rotor disk facing the stator assembly. The magnets are magnetized along the axial direction, and the permanent magnets adjacent in the circumferential direction have opposite polarities.

In one embodiment, the air gap between the rotor assembly and the stator assembly is 0.2 mm.

beneficial effects

The integrated Stirling refrigerator of this application has at least the following beneficial effects: In the integrated Stirling refrigerator of this application, an axial flux motor is formed through the stator assembly and the rotor assembly in the axial direction of the eccentric shaft. Under the premise of maintaining the performance of the Triling refrigerator, the size in the axial direction can be reduced, making the overall structure more compact; in addition, the axial flux motor has the advantage of torque density compared with the traditional radial flux motor under the same outer diameter size, and can This makes the Stirling refrigerator smaller in size, weight and lower in power consumption.

Description of drawings

Figure 1 is a schematic cross-sectional structural diagram of an integrated Stirling refrigerator according to an embodiment of the present application;

Figure 2 is a partial enlarged view of the integrated Stirling refrigerator in Figure 1;

FIG. 3 is an exploded view of the stator assembly and rotor assembly in FIG. 2 .

The components in the figure are numbered as follows:

Shell 10; end plate 20; eccentric shaft 30;

Stator assembly 40 (including stator core 41, teeth 42, winding 43);

Rotor assembly 50 (including rotor disk 51 and permanent magnet 52);

Bearing 60; motor lead pin 70; compression connecting rod assembly 80; expansion connecting rod assembly 90;

Stirling Refrigerator 100.

Embodiments of the invention

The technical solution of the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments of the description.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the description of the present application are only for the purpose of describing specific embodiments and are not intended to limit the implementation of the present application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the description of this application, it needs to be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", The orientations or positional relationships indicated by "top", "bottom", "inner", "outside", etc. are based on the orientations or positional relationships shown in the drawings. They are only for the convenience of describing the present application and simplifying the description, and are not indicated or implied. The devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting the application. In the description of this application, unless otherwise stated, "plurality" means two or more.

In the description of this application, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it can be directly connected, or indirectly connected through an intermediary, or it can be internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood on a case-by-case basis.

In a radial flux motor, the direction of the flux is radially arranged perpendicular to the axis of rotation, and the flux path is much longer compared to an axial flux motor, since the flux path goes from one rotor pole to the first tooth of the stator, Then it passes through the stator back iron to the second tooth until it reaches the other rotor pole again. Unlike radial flux motors, axial flux motors have a flux direction parallel to the axis of rotation and have a shorter and direct flux path that goes directly from one pole to the other through the air gap. The shorter flux path of the magnetic field helps increase the efficiency and power density of the motor. In addition, axial flux motors also have certain advantages over radial motors in terms of windings. Axial flux motors have relatively higher active winding copper and less overhang, which results in a greater ability to add turns and less heat caused by end effects. Based on the above, it can be seen that the axial flux motor can provide higher output power with less material and a more compact structure than the radial flux motor.

Based on this, based on the above theoretical research, this application provides an integrated Stirling refrigerator that uses an axial flux motor to drive rotation, thereby reducing the size while also reducing weight and power. consumption effect. Please refer to FIG. 1 . An integrated Stirling refrigerator 100 according to an embodiment of the present application includes a housing 10 , an end plate 20 , an eccentric shaft 30 , a stator assembly 40 , a rotor assembly 50 , a compression connecting rod assembly 80 and an expansion connecting rod assembly. 90. The eccentric shaft 30, the stator assembly 40, the rotor assembly 50, the compression connecting rod assembly 80 and the expansion connecting rod assembly 90 are all installed in the space formed by the housing 10 and the end plate 20. The rotor assembly 50, the compression connecting rod assembly 80 and The expansion connecting rod assembly 90 is installed on the eccentric shaft 30. The stator assembly 40 and the rotor assembly 50 form an axial flux motor to provide power to drive the eccentric shaft 30 to rotate. The rotation of the eccentric shaft 30 drives the compression connecting rod assembly 80 and the expansion connecting rod assembly. Rod assembly 90 performs compression and expansion respectively to achieve refrigeration.

The casing 10 has a hollow structure and an opening on one side. The end plate 20 is sealingly connected to the opening of the casing 10 . The casing 10 and the end plate 20 form an eccentric shaft box in which gas working medium is filled. More specifically, the opening on the housing 10 is circular, and the end plate 20 is in the shape of a circular plate matching the shape of the circular opening. The end plate 20 closes the opening from the outside to form a sealed cavity. The eccentric shaft 30, the stator assembly 40, the rotor assembly 50, the compression connecting rod assembly 80, the expansion connecting rod assembly 90, etc. are enclosed in a sealed cavity inside the eccentric shaft box between the housing 10 and the end plate 20, and the sealed cavity is filled with high-pressure gas. Working substance.

The shell 10 and the end plate 20 can be made of aluminum alloy material. The end plate 20 and the shell 10 are sealed by a sealing ring or welding, so that the sealed cavity formed by the two can withstand high-pressure gas (helium) working fluid. .

The eccentric shaft 30 defines an axial direction, and the eccentric shaft 30 has an eccentric section eccentric to the axial direction and a non-eccentric section along the axial direction. Both ends of the eccentric shaft 30 are installed in the sealed cavity formed by the housing 10 and the end plate 20 through the bearings 60. The eccentric section makes eccentric movement around the axis when the eccentric shaft 30 rotates around the axis. Specifically, one end of the eccentric shaft 30 is connected to the inner ring of the bearing 60 (deep groove ball bearing) installed in the housing 10, and the other end is connected to the inner ring of the bearing 60 (thrust ball bearing) fixed on the inside of the end plate 20, Thereby, the eccentric shaft 30 is installed in the housing 10 so as to be rotatable around the axis. The axial direction of the eccentric shaft 30 coincides with the center line of the opening of the housing 10 and the center line of the end plate 20. The thrust ball bearing is embedded in the center hole of the end plate 20 for the stator assembly 40 and the rotor assembly 50 to withstand the axial magnetic flux. The axial force generated during the rotation of the motor.

The stator assembly 40 is installed and fixed on the inner side of the end plate 20 and coaxially with the thrust ball bearing. The rotor assembly 50 is coaxially installed and fixed on the non-eccentric section of the eccentric shaft 30 . An air gap is formed between the rotor assembly 50 and the stator assembly 40 along the axial direction, so that the stator assembly 40 and the rotor assembly 50 form an axial flux motor, which generates power to drive the eccentric shaft 30 to rotate around the axial direction after being energized. In a specific embodiment, the air gap between the rotor assembly 50 and the stator assembly 40 is about 0.2 mm, which facilitates unobstructed rotation of the rotor assembly 50 and does not affect the performance of the closed magnetic circuit.

Please refer to FIGS. 2 and 3 in conjunction. The stator assembly 40 includes a stator core 41 and a winding 43. The stator core 41 has a bottom surface perpendicular to the axial direction. A plurality of teeth 42 extend from the bottom surface toward the rotor assembly 50 along the axial direction. Winding receiving slots are formed between adjacent teeth 42 (see Figure 3). The winding 43 is a three-phase electric winding. The three-phase electric winding includes a plurality of coils, each coil is arranged around the teeth 42 of the stator core 41 and is electrically isolated from the teeth 42 by insulating tape.

The rotor assembly 50 has a rotor disk 51 , the central hole of the rotor disk 51 is inserted into the non-eccentric section of the eccentric shaft 30 , and a plurality of permanent magnets 52 are fixed on the side of the rotor disk 51 facing the stator assembly 40 . Each permanent magnet 52 at least partially passes through the hole of the rotor disk 51 , and is fixed to the hole of the rotor disk 51 by adhesive means so as to be evenly distributed relative to the circumferential direction of the rotor disk 5 . The permanent magnets 52 are axially magnetized along the installation position, and the polarities between two circumferentially adjacent permanent magnets 52 are opposite.

The stator assembly 40 is fixed on the inner side of the end plate 20, and the motor lead pins 70 protrude from the outer side of the end plate 20. The motor lead pins 70 penetrate the end plate 20 (stator fixed plate) along the axial direction, and are connected to the end plate 20 through insulation sintering. (stator fixed plates) are electrically isolated for providing three-phase alternating current to the windings 43 of the stator assembly 40 .

The insulation sintering between the motor lead pins 70 and the end plate 20 can, on the one hand, ensure that the insulation between the motor lead pins 70 and the end plate 20 does not conduct, and on the other hand, it can ensure that the high-pressure gas (helium) in the shell 10 does not It will leak from around the motor lead pin 70.

The compression link assembly 80 and the expansion link assembly 90 are connected to the eccentric section of the eccentric shaft 30 . Under the rotational drive of the axial flux motor formed by the stator assembly 40 and the rotor assembly 50 , the eccentric shaft 30 drives the compression connecting rod assembly 80 and the expansion connecting rod assembly 90 to perform eccentric motion. The compression connecting rod assembly 80 is connected to one end of the compression piston assembly located inside the housing 10 , the expansion connecting rod assembly 90 is connected to one end of the push piston assembly located inside the housing 10 , and the end of the push piston assembly located outside the housing 10 is connected to the regenerator.

The working process of the above-mentioned integrated Stirling refrigerator 100 is as follows: under the control of the motor drive controller, power is supplied to the stator assembly 40 through the motor lead pins 70, and the winding 43 of the stator assembly 40 is energized to drive the rotor assembly 50 to rotate around the axis. , driving the eccentric shaft 30 to rotate around the axis direction, and the compression connecting rod assembly 80 and the expansion connecting rod assembly 90 connected to the eccentricity section of the eccentric shaft 30 to perform reciprocating motion. When the eccentric shaft 30 drives the compression connecting rod assembly 80 and the expansion connecting rod assembly 90 to reciprocate, the piston assembly makes a reciprocating linear motion to compress the high-pressure gas in the sealed cavity of the housing 10, thereby realizing a reverse Stirling cycle and obtaining cooling capacity. , causing the regenerator to alternately replace heat and generate cold energy.

The rotary axial flux motor has many advantages such as small size, light weight, and high power density. Under the same outer diameter, the axial flux motor can provide a 30% torque density advantage compared to the traditional radial flux motor. As the operating temperature of infrared detectors increases, Stirling refrigerators develop in the direction of SWaP3, and axial flux motors can take full advantage of their advantages in size, weight and performance compared to radial flux motors. The integrated Stirling refrigerator of this application applies a rotating axial flux motor to the Stirling refrigerator, thereby reducing the volume and weight of the refrigerator while ensuring the performance of the Stirling refrigerator. Adopting this structural form can make the integrated Stirling refrigerator more compact, smaller in size and weight, and lower in power consumption.

It should be noted that, in this document, the terms "comprising", "comprises" or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article or device that includes a series of elements not only includes those elements, It also includes other elements not expressly listed or inherent in the process, method, article or apparatus. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, method, article, or device that includes that element.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application. All are covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

An integrated Stirling refrigerator is characterized by including:

The eccentric shaft box has a sealed cavity filled with gas working fluid inside;

The eccentric shaft (30) is rotatably placed in the sealing cavity around an axial direction, and has an eccentric section eccentric to the axial direction and a non-eccentric section along the axial direction;

The stator assembly (40) is arranged around the axis direction and fixed in the sealed cavity;

The rotor assembly (50) is arranged on the non-eccentric section around the axial direction, and has an air gap along the axial direction between it and the stator assembly (40);

A compression connecting rod assembly (80) is placed in the sealed cavity and connected to the eccentric section; and

The expansion connecting rod assembly (90) is placed in the sealed cavity and connected to the eccentric section;

Wherein, the stator assembly (40) and the rotor assembly (50) form an axis flux motor arranged along the axial direction to drive the eccentric shaft (30) to rotate around the axial direction through the rotor assembly. .
The integrated Stirling refrigerator according to claim 1, characterized in that: the eccentric shaft box includes a housing (10) and an end plate (20), the housing (10) has an opening, and the end plate (20) 20) Sealingly connected to the opening.
The integrated Stirling refrigerator according to claim 2, characterized in that: the opening on the housing (10) is circular, and the end plate (20) is in a shape matching the shape of the opening. round plate shape.
The integrated Stirling refrigerator according to claim 2, characterized in that: the housing (10) and the end plate (20) are made of aluminum alloy material, and the end plate (20) and the The shells (10) are sealed and connected through sealing rings or welding.
The integrated Stirling refrigerator according to claim 2, characterized in that: both ends of the eccentric shaft (30) are respectively connected to a bearing (60) fixed on the housing (10) and a bearing (60) fixed on the housing (10). There is a bearing (60) on the end plate (20).
The integrated Stirling refrigerator according to claim 5, characterized in that: one end of the eccentric shaft (30) is connected to the inner ring of a deep groove ball bearing fixed in the housing (10), and the other end Connected to the inner ring of the thrust ball bearing fixed on the inside of the end plate (20).
The integrated Stirling refrigerator according to claim 6, characterized in that the stator assembly (40) is fixed inside the end plate (20) and is coaxially arranged with the thrust ball bearing.
The integrated Stirling refrigerator according to claim 5, characterized in that: motor lead pins (70) protrude from the outside of the end plate (20), and the motor lead pins (70) extend along the axis The direction passes through the end plate (20) and electrical isolation is formed between the end plate (20) and the end plate (20) through insulating sintering.
The integrated Stirling refrigerator according to any one of claims 1 to 8, characterized in that: the stator assembly (40) includes a stator core (41) and a winding (43), and the stator core (41) 41) has a bottom surface perpendicular to the axial direction, a plurality of teeth (42) protruding from the bottom surface along the axial direction toward the rotor assembly (50), the winding (43) includes a plurality of coils, Each said coil is arranged around said tooth (42) and is electrically isolated from said tooth (42);

The rotor assembly (50) includes a rotor disk (51) and a permanent magnet (52). The rotor disk (51) is sleeved on the non-eccentric section, and a plurality of the permanent magnets (52) are fixed on the non-eccentric section. On the side of the rotor disk (51) facing the stator assembly (40), the permanent magnets (52) are magnetized along the axial direction, and the circumferentially adjacent permanent magnets (52) have opposite polarities.
The integrated Stirling refrigerator according to claim 9, characterized in that: the air gap between the rotor assembly (50) and the stator assembly (40) is 0.2 mm.