Compressor with isolated outer stator

Abstract

The invention discloses a compressor with an isolated outer stator. According to the compressor, a motor rotor and a piston body are coaxially arranged and fixedly connected; a motor rotor is coaxially arranged between the outer stator and the inner stator of the motor stator; the first elastic component and the second elastic component are arranged at the two ends of the moving magnet type linear motor respectively and used for providing axial restoring force and radial support for the moving magnet type linear motor. The inner ring of the elastic component I is hermetically connected with the motor rotor, and the outer ring is hermetically connected with the outer stator; the inner ring of the elastic component II is hermetically connected with the piston body, and the outer ring is hermetically connected with the outer stator. According to the compressor, the outer stator and the compression cavity are physically isolated and divided into the independent closed spaces, even if impurity gas is generated in the operation process of the refrigerator, the impurity gas cannot enter the compression cavity, and the reliability of the pulse tube refrigerator is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of refrigeration technology, specifically relating to a compressor with an external stator isolation. Background Technology

[0002] Pulse tube refrigerators are widely used in infrared detection technology because they have no moving parts at the cold end, high reliability, and long lifespan. However, refrigerator failure still restricts their development. The failure mechanisms of refrigerators mainly include five aspects: working fluid leakage, mechanical wear, fatigue fracture, working fluid contamination, and environmental stress damage. Studies have shown that working fluid contamination accounts for 1 / 3 of all failure modes and is one of the main causes of refrigerator failure.

[0003] The main sources of working fluid contamination include impurity gases in helium, incomplete cleaning of parts surfaces, residual impurity gases in the filling pipeline, and dust caused by material release and wear.

[0004] To address these issues, current measures include baking and degassing the entire machine and its components, purifying helium, and controlling the use of organic materials. These measures have improved the reliability of the refrigeration unit to some extent. However, the contamination process is slow and continuous, and these measures can only delay the contamination process, not fundamentally solve the problem.

[0005] The continuous release of organic materials such as enameled wire and insulating protective blocks in linear motors is the main cause of internal contamination in refrigeration machines. Therefore, it is necessary to design a compressor that isolates the outer stator. Summary of the Invention

[0006] To completely solve the problem of continuous gas release from organic materials such as enameled wires and insulation protection blocks inside pulse tube refrigerators, which causes refrigerator failure, this invention provides a compressor with an isolated outer stator. This compressor divides the outer stator into a separate sealed space, so that even if impurity gases are generated during the operation of the refrigerator, they cannot enter the compression chamber, which greatly improves the reliability of the pulse tube refrigerator.

[0007] To achieve the above objectives, the present invention adopts the following specific technical solution: An externally stator-isolated compressor includes a housing, an outer end cover, an inner end cover, a moving magnet linear motor, an elastic component one, a piston body, a cylinder body, and an elastic component two. The moving magnet linear motor, the housing, and the outer end cover are symmetrically arranged at both ends of the cylinder body; one end of the housing is fixedly connected to the cylinder body through the moving magnet linear motor, and the other end is fixedly connected to the outer end cover; The moving magnet linear motor includes a motor mover and a motor stator; the motor mover is coaxially arranged and fixedly connected to the piston body; the motor stator includes an outer stator and an inner stator coaxially and fixedly connected to the outer periphery of the cylinder body; the outer stator is located on the outer periphery of the inner stator; the motor mover is coaxially arranged between the outer stator and the inner stator; the outer end of the outer stator is sealed with the inner end cap; The first elastic member and the second elastic member are respectively disposed at both ends of the moving magnet linear motor to provide axial restoring force and radial support for the moving magnet linear motor; the inner ring of the first elastic member is sealed to the motor mover and the outer ring is sealed to the outer stator; the inner ring of the second elastic member is sealed to the piston body and the outer ring is sealed to the outer stator.

[0008] Furthermore, the outer stator includes an outer yoke assembly and an isolation assembly; The outer yoke assembly includes a coil, a coil frame, an outer yoke, and a flange for fixing the outer yoke; both ends of the outer yoke are fixedly connected to the flange; one flange is fixedly connected between the cylinder body and the housing, and is sealed to the outer ring of the first elastic member; the outer end of the other flange is welded with the inner end cap, and is sealed to the second elastic member. The outer yoke assembly is coaxially and sealed to the outer periphery of the isolation assembly.

[0009] Furthermore, the isolation assembly includes a thin-walled cylindrical body, a front thin-walled end cap, and a rear thin-walled end cap; The thin-walled cylinder is a titanium alloy thin-walled cylinder with a wall thickness of 0.2 mm, and is coaxially arranged with the inner stator; The inner edges of the front thin-walled end cap and the rear thin-walled end cap are sealed to both ends of the thin-walled cylinder, and the outer edges of the front thin-walled end cap and the rear thin-walled end cap are sealed to the flange.

[0010] Furthermore, the housing includes an outer shell and an inner shell located within the outer shell; The inner shell is fixedly connected to the outer periphery of the outer yoke assembly; the outer end cap is sealed to the outer end of the outer shell; the inner end of the outer shell is fixedly connected to the outer yoke assembly. The inner end cap, the outer end cap, the outer yoke, the flange, the inner housing, the outer housing, and the isolation assembly together isolate the coil and the coil frame.

[0011] Furthermore, the isolation component is made of a non-magnetic material and undergoes stress-relief annealing.

[0012] Furthermore, the motor actuator includes a permanent magnet and a magnetic steel frame; The permanent magnet is made of neodymium iron boron; the magnetic steel frame is fixedly connected to the permanent magnet and the piston body.

[0013] Furthermore, both the inner stator and the outer stator are made of soft magnetic material and undergo stress-relief annealing treatment; The housing, the inner end cover, the outer end cover, and the cylinder body are all made of the same material and are welded and sealed.

[0014] Furthermore, the piston body is connected to the motor actuator by screws or welding.

[0015] Furthermore, both the first elastic member and the second elastic member are leaf springs or coil springs.

[0016] Furthermore, the compressor has a dual-motor opposed structure.

[0017] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: The compressor of this invention physically isolates the outer stator from the compression chamber, separating the organic materials such as the enameled wire and insulating protective block of the outer stator from the compression chamber. This prevents the generated impurity gases from entering the internal circulation of the refrigeration unit, ensuring the stable long-term performance of the pulse tube refrigeration unit, improving its reliability, and achieving the requirement of long service life. The isolation structure is simple and reliable, easy to process and install, and does not add excessive complexity and cost. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the compressor structure of the present invention; Figure 2 for Figure 1 A schematic diagram of the structure of the central isolation component.

[0019] Figure label: 1-Outer end cap, 2-Inner end cap, 3-Outer shell, 4-Inner shell, 5-Linear motor, 6-Elastic component one, 7-Cylinder body, 8-Piston body, 9-Elastic component two, 51-Motor mover, 521-Outer stator, 522-Inner stator, 5211-Outer yoke assembly, 5212-Isolation assembly, 52121-Front thin-walled end cap, 52122-Thin-walled cylinder, 52123-Rear thin-walled end cap. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0022] like Figure 1 and Figure 2 As shown in the structure, this embodiment provides a compressor with an externally isolated stator. In this embodiment, a compressor with a dual-motor opposed structure is used as an example for explanation. The compressor includes a housing, an outer end cover 1, an inner end cover 2, a moving magnet linear motor 5, an elastic member 6, a piston body 8, a cylinder body 7, and an elastic member 9; wherein: A moving-magnet linear motor 5, a housing, and an outer end cover 1 are symmetrically arranged at both ends of the cylinder body 7. One end of the housing is fixedly connected to the cylinder body 7 via the moving-magnet linear motor 5, and the other end is fixedly connected to the outer end cover 1. The outer end cover is used to seal both ends of the housing. The piston body 8 is coaxially arranged with the cylinder body 7 and is slidably fitted. The housing, outer end cover 1, inner end cover 2, and cylinder body 7 are all made of the same material and are welded and sealed.

[0023] A moving-magnet linear motor 5 is installed inside the housing. The moving-magnet linear motor 5 includes a motor mover 51 and a motor stator. The moving-magnet linear motor 5 can be a Redlich type moving-magnet linear motor 5. The motor mover 51 is coaxially and fixedly connected to the piston body 8, and is used to drive the piston body 8 to reciprocate within the cylinder body 7. The piston body 8 and the motor mover 51 can be fixedly connected by screws or by welding to ensure connection strength. The motor mover 51 includes a permanent magnet and a magnetic steel frame; the permanent magnet is made of neodymium iron boron; the magnetic steel frame is fixedly connected to the permanent magnet and the piston body 8, and remains coaxial with the cylinder body 7. The motor stator includes an outer stator 521 and an inner stator 522 coaxially and fixedly connected to the outer periphery of the cylinder body 7. The outer stator 521 is located on the outer periphery of the inner stator 522. The motor mover 51 is coaxially arranged between the outer stator 521 and the inner stator 522. The outer stator 521 is sealed at its outer end with an inner end cap 2. Both the inner stator 522 and the outer stator 521 are made of soft magnetic material and undergo stress-relief annealing. Soft magnetic materials include silicon steel sheets or materials with similar properties to silicon steel sheets. Soft magnetic materials such as silicon steel sheets have advantages such as low iron loss, high magnetic permeability, and excellent insulation properties.

[0024] Elastic component 6 is located at one end of the moving magnet linear motor 5, and elastic component 9 is located at the other end. Elastic components 6 and 9 provide axial restoring force and radial support for the moving magnet linear motor 5. The inner ring of elastic component 6 is sealed to the motor mover 51, and the outer ring is sealed to the outer stator 521. The inner ring of elastic component 9 is sealed to the piston body 8, and the outer ring is sealed to the outer stator 521. Both elastic components 6 and 9 are leaf springs or coil springs.

[0025] In the compressors mentioned above, such as Figure 2 As shown, the outer stator 521 includes an outer yoke assembly 5211 and an isolation assembly 5212; the outer yoke assembly 5211 is coaxially and fixedly connected to the outer periphery of the isolation assembly 5212. The outer yoke assembly 5211 includes a coil, a coil frame, an outer yoke, and a flange for fixing the outer yoke; both ends of the outer yoke are fixedly connected to flanges; one flange is an inner flange, which is close to and fixedly connected to the cylinder body 7; the other flange is an outer flange, which is away from the cylinder body; the inner flange is fixedly connected between the cylinder body 7 and the outer shell 3, and is sealed to the outer ring of the elastic member 6; an inner end cap 2 is welded to the outer end of the outer flange, and is sealed to the elastic member 9. The isolation assembly 5212 includes a thin-walled cylindrical body 52122, a front thin-walled end cap 52121, and a rear thin-walled end cap 52123. The thin-walled cylindrical body 52122 is a titanium alloy thin-walled cylindrical body with a wall thickness of 0.2 mm and is coaxially arranged with the outer stator 521. The inner edge of the front thin-walled end cap 52121 is sealed to one end of the thin-walled cylindrical body 52122, and the outer edge of the front thin-walled end cap 52121 is sealed to the inner flange. The inner edge of the rear thin-walled end cap 52123 is sealed to the other end of the thin-walled cylindrical body 52122, and the outer edge of the rear thin-walled end cap 52123 is sealed to the outer flange. The isolation assembly 5212 is made of non-magnetic material and undergoes stress-relief annealing treatment. It has pre-reserved welding process bosses and is welded to the outer yoke assembly 5211 to form a whole. The thin-walled cylinder 52122 can be pre-machined with a machining allowance. After welding is completed, the outer stator 521 will be assembled and precision machined to ensure that the inner hole of the outer stator 521 is coaxial with the motor mover 51.

[0026] like Figure 1As shown, the housing includes an outer shell 3 and an inner shell 4 located within the outer shell 3; the inner shell 4 is fixedly connected to the outer periphery of the outer yoke assembly 5211; an outer end cap 1 is sealed to the outer end of the outer shell 3; the inner end of the outer shell 3 is fixedly connected to the inner flange of the outer yoke assembly 5211; the inner end cap 2 is welded and sealed to the outer flange of the outer yoke assembly 5211; the inner end cap 2, outer end cap 1, outer yoke, outer flange, inner flange, inner shell 4, outer shell 3, and isolation assembly 5212 together isolate the coil and coil frame of the outer yoke assembly 5211. Both the inner shell 4 and the outer shell 3 are welded and sealed to the inner flange of the outer yoke assembly 5211 of the outer stator 521, using a welding method that ensures welding quality and strength.

[0027] The compressor described above physically isolates the outer stator 521 from the compression chamber through the inner end cover 2, outer end cover 1, isolation component 5212, outer yoke component 5211, inner shell 4, and outer shell 3. This isolates the enameled wire and insulating protective block of the outer stator 521 from the compression chamber, preventing the generated impurity gas from entering the internal circulation of the refrigeration machine. This ensures the stable long-term performance of the pulse tube refrigeration machine, improves its reliability, and meets the requirements for a long service life. The isolation structure is simple and reliable, easy to process and install, and does not add excessive complexity and cost.

[0028] The working principle of the compressor is as follows: When an alternating current is applied to the coil, the excitation current of the coil will generate an alternating magnetic field that interacts with the magnetic field of the permanent magnet. As the alternating current periodically changes the direction of the current in the winding coil, the permanent magnet generates an axial force, which drives the magnetic steel frame to move and pushes the piston 8 in the cylinder 7 to reciprocate. At this time, the gas in the compression chamber undergoes periodic compression and expansion, thereby compressing the low-temperature, low-pressure gas into a high-temperature, high-pressure gas. The gas is periodically drawn in and discharged through the gas flow channel and the compression chamber, generating pressure waves.

[0029] As time goes by and temperature changes, the organic materials inside the compressor will release impurity gases. Because the outer stator 521 is isolated, the generated impurity gases will not diffuse to the compression chamber side, thereby improving the reliability of the compressor and helping to achieve the technical target of long service life. The structure is simple and reliable, does not introduce other risks, is easy to process and install, does not increase costs excessively, and has broad application prospects.

[0030] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the invention. Therefore, if these modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

[0031] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A compressor with external stator isolation, characterized in that, It includes a housing, an outer end cover, an inner end cover, a moving magnet linear motor, an elastic component one, a piston body, a cylinder body, and an elastic component two; The moving magnet linear motor, the housing, and the outer end cover are symmetrically arranged at both ends of the cylinder body; one end of the housing is fixedly connected to the cylinder body through the moving magnet linear motor, and the other end is fixedly connected to the outer end cover; The moving magnet linear motor includes a motor mover and a motor stator; the motor mover is coaxially arranged and fixedly connected to the piston body; the motor stator includes an outer stator and an inner stator coaxially and fixedly connected to the outer periphery of the cylinder body; the outer stator is located on the outer periphery of the inner stator; the motor mover is coaxially arranged between the outer stator and the inner stator; the outer end of the outer stator is sealed with the inner end cap; The first elastic member and the second elastic member are respectively disposed at both ends of the moving magnet linear motor to provide axial restoring force and radial support for the moving magnet linear motor; the inner ring of the first elastic member is sealed to the motor mover and the outer ring is sealed to the outer stator; the inner ring of the second elastic member is sealed to the piston body and the outer ring is sealed to the outer stator.

2. The compressor as described in claim 1, characterized in that, The outer stator includes an outer yoke assembly and an isolation assembly; The outer yoke assembly includes a coil, a coil frame, an outer yoke, and a flange for fixing the outer yoke; both ends of the outer yoke are fixedly connected to the flange; one flange is fixedly connected between the cylinder body and the housing, and is sealed to the outer ring of the first elastic member; the outer end of the other flange is welded with the inner end cap, and is sealed to the second elastic member. The outer yoke assembly is coaxially and sealed to the outer periphery of the isolation assembly.

3. The compressor as described in claim 2, characterized in that, The isolation assembly includes a thin-walled cylindrical body, a front thin-walled end cap, and a rear thin-walled end cap; The thin-walled cylinder is a titanium alloy thin-walled cylinder with a wall thickness of 0.2 mm, and is coaxially arranged with the inner stator; The inner edges of the front thin-walled end cap and the rear thin-walled end cap are sealed to both ends of the thin-walled cylinder, and the outer edges of the front thin-walled end cap and the rear thin-walled end cap are sealed to the flange.

4. The compressor as described in claim 3, characterized in that, The housing includes an outer shell and an inner shell located within the outer shell; The inner shell is fixedly connected to the outer peripheral side of the outer yoke assembly; The outer end cap is sealed to the outer end of the outer casing. The inner end cap, the outer end cap, the outer yoke, the flange, the inner housing, the outer housing, and the isolation assembly together isolate the coil and the coil frame.

5. The compressor as described in claim 4, characterized in that, The isolation component is made of non-magnetic material and undergoes stress-relief annealing.

6. The compressor as claimed in claim 1, characterized in that, The motor actuator includes a permanent magnet and a magnetic steel frame; The permanent magnet is made of neodymium iron boron; the magnetic steel frame is fixedly connected to the permanent magnet and the piston body.

7. The compressor as claimed in claim 1, characterized in that, Both the inner stator and the outer stator are made of soft magnetic material and undergo stress-relief annealing treatment; The housing, the inner end cover, the outer end cover, and the cylinder body are all made of the same material and are welded and sealed.

8. The compressor as claimed in claim 1, characterized in that, The piston body is connected to the motor actuator by screws or welding.

9. The compressor as claimed in claim 1, characterized in that, Both the first elastic component and the second elastic component are leaf springs or coil springs.

10. The compressor according to any one of claims 1-9, characterized in that, The compressor has a dual-motor opposed-position structure.

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