CN220911716U

CN220911716U - Small linear refrigerator

Info

Publication number: CN220911716U
Application number: CN202321925376.4U
Authority: CN
Inventors: 邓伟峰; 白双印; 邹国东
Original assignee: Chengdu Shenyue Changtian Electronic Technology Co ltd
Current assignee: Chengdu Shenyue Changtian Electronic Technology Co ltd
Priority date: 2023-07-21
Filing date: 2023-07-21
Publication date: 2024-05-07
Anticipated expiration: 2033-07-21

Abstract

A small linear refrigerator comprises a pressure wave generator, an expansion cold finger and a shell; the pressure wave generator comprises an inner yoke, an outer yoke base plate, an outer yoke screw rod, a winding, an insulating framework, magnetic steel, a magnetic steel sleeve, a power pontoon, a pontoon plug, a power leaf spring, a leaf spring strut, a leaf spring screw rod, a hexagonal nut, a power cylinder and a hot end compression cavity, the expansion cold finger comprises a central shaft of a heat regenerator, the heat regenerator, a heat regenerator sealing cover, a pneumatic leaf spring, a leaf spring strut, a step nut, a hot end air inlet cavity and a cold end expansion cavity, and the shell comprises a cold platform, an expansion cylinder, a hot end flow director, a base, a tail cover extension rod, an outgoing lead, a lower damping leaf spring, an upper damping leaf spring, a leaf spring gasket and an inflation tube.

Description

Small linear refrigerator

Technical Field

The utility model relates to the field of regenerative cryocoolers, in particular to a small linear refrigerator.

Background

The small low-temperature refrigerator has compact structure, high cooling speed, low vibration level and high refrigerating efficiency, and the refrigerating working medium is commonly used as environment-friendly inert gas helium, so the small low-temperature refrigerator has wide application in the fields of aerospace, high-temperature superconductivity, infrared detection and biological medicine.

At present, the traditional cascade vapor compression refrigerator is used as a refrigeration source, has huge volume, larger vibration and noise and lower mechanical conversion efficiency, and cannot meet the refrigeration application requirement with higher integration level requirement.

Disclosure of utility model

The utility model aims to provide a small linear refrigerator, which solves the problems that a cascade type vapor compression refrigerator is used as a refrigeration source, the vibration and noise of the compressor are large, the mechanical conversion efficiency is low, and the cascade type vapor compression refrigerator cannot be applied to occasions with high integration requirements.

A small linear refrigerator includes a pressure wave generator, an expansion cold finger, and a housing. The pressure wave generator comprises an inner yoke, an outer yoke base plate, an outer yoke screw rod, a winding, an insulating framework, magnetic steel, a magnetic steel sleeve, a power pontoon, a pontoon plug, a power leaf spring, a leaf spring strut, a leaf spring screw rod, a hexagonal nut, a power cylinder and a hot end compression cavity, the expansion cold finger comprises a central shaft of a heat regenerator, the heat regenerator, a heat regenerator sealing cover, a pneumatic leaf spring, a leaf spring strut, a step nut, a hot end air inlet cavity and a cold end expansion cavity, and the shell comprises a cold platform, an expansion cylinder, a hot end flow director, a base, a tail cover extension rod, an outgoing lead, a lower damping leaf spring, an upper damping leaf spring, a leaf spring gasket and an inflation tube. The inner yoke is a hollow circular ring and is fixed on the power cylinder, the outer yoke is sleeved on the winding and the insulating framework and is fixed on the base, and the inner yoke and the insulating framework together form a stator of the pressure wave generator; the magnetic steel is of an annular structure and embedded in the inner surface of the magnetic steel sleeve, and the power pontoon is fixedly connected with the magnetic steel sleeve in a threaded manner to form a rotor of the pressure wave generator; the pontoon plug is connected with the power pontoon and the power leaf spring, and the periphery of the power leaf spring is fixed on the outer yoke base plate. The heat regenerator and the expansion cylinder are coaxially arranged and can move relatively, a stainless steel wire mesh and PC fibers are mixed and filled in the heat regenerator along the axial direction to serve as heat regeneration materials, and a central shaft of the heat regenerator is connected with the heat regenerator and the pneumatic plate spring; the shell is welded in a segmented mode, the upper vibration reduction plate spring and the lower vibration reduction plate spring are installed on the tail cover, and the inflation tube is communicated with the backpressure cavity of the pressure wave generator and an external air source.

In one embodiment, the stator structure of the pressure wave generator is configured to: the inner yoke adopts a plurality of silicon steel sheets to be stacked into a circular ring shape along the periphery of the power cylinder, V-shaped grooves are formed in two ends of the inner yoke and are embedded with the V-shaped grooves on the power cylinder and are adhered by glue, the winding coil is wound on the insulating framework in a circle by circle, the outer yoke is 8 groups of lamination units, and after being stacked, welded and fixed, the outer yoke is evenly inserted in the outer side of the insulating framework.

In one embodiment, the mover structure of the pressure wave generator is arranged to: the magnetic steel is 8 tile-shaped neodymium iron boron permanent magnets, each permanent magnet is magnetized in parallel with the inward N pole and the outward S pole along the radial direction, and the magnetic steel is magnetized and then embedded in the inner surface of the magnetic steel sleeve. The power pontoon with the coaxial assembly back spiro union of magnet steel sleeve is fixed, the inside through-hole that sets up of power pontoon is close to backpressure chamber one side terminal surface with the sleeve stopper spiro union is fixed, install on the sleeve stopper the power leaf spring will through hexagonal nut the power pontoon the pontoon stopper with the power leaf spring is locked along the axial, power leaf spring periphery spiro union is fixed on the bracing piece that outer yoke base plate extends.

In one embodiment, the inside of the heat regenerator is filled with stainless steel wire mesh within the range of 300 meshes-400 meshes and PC fibers with the porosity of 0.6-0.7 piece by piece along the axial direction according to the length ratio of 1:2, the heat regenerator is positioned on one side end face of the cold end expansion cavity and is provided with a heat regenerator sealing cover, the center of the heat regenerator sealing cover is provided with a vent hole with the diameter being half of the diameter of the heat regenerator, the end face of the heat regenerator is positioned on one side of the hot end compression cavity and is provided with a heat regenerator air inlet screen, the heat regenerator air inlet screen is fixedly connected with a heat regenerator central shaft in a screwed mode, the heat regenerator central shaft is locked with a pneumatic plate spring center through a step nut, and the periphery of the pneumatic plate spring is fixedly connected with the plate spring strut in a screwed mode.

In one embodiment, the shell is of a split structure, the joint of each section is sealed in a welding mode, and the expansion cylinder and the expansion cold finger are coaxially arranged and are radially provided with a gap with a single side of 0.005 mm-0.01 mm.

In one embodiment, the cold platform is provided with a hollow slit along the cross section of the middle part, so that the upper end surface is stressed or the lower end surface can still be ensured not to deform under the action of cold and heat.

In one embodiment, the central hole of the hot end deflector and the air inlet screen of the heat regenerator form clearance seal, and a plurality of circular air inlet holes are uniformly distributed on the inner end surface along the circumferential direction so as to be communicated with the hot end compression cavity and the interior of the heat regenerator.

In one embodiment, the outgoing line pin is arranged on the tail cover, and the outgoing line pin is subjected to pressure-bearing sealing through sintered glass beads.

In one embodiment, the upper and lower damper leaf springs are mounted on the tail cap extension rod.

In one embodiment, the molded lines of the power leaf spring, the pneumatic leaf spring and the vibration damping leaf spring are archimedes spiral lines, and the leaf spring axial restoring rigidity and the radial supporting rigidity are adjustable through the leaf spring thickness.

In one embodiment, the inside of the gas filled tube is filled with a capillary tube with a larger thermal expansion coefficient, and after helium refrigerant is filled at a lower temperature, the middle section of the gas filled tube is locally heated to enable the capillary tube to be irreversibly expanded for sealing.

The utility model has the following beneficial effects: the integration level of the refrigerating system is improved, so that the volume of the refrigerating machine is more compact, the reliability is stronger, and the coupling with external heat load is more convenient.

Drawings

FIG. 1 is an overall cross-section of a small linear refrigerator of the present utility model;

FIG. 2 is a pressure wave generator of the present utility model;

FIG. 3 is a schematic diagram of a mover structure of the present utility model;

FIG. 4 is a regenerator of the present utility model;

FIG. 5 is a passive vibration damping device of the present utility model;

FIG. 6 is a diagram of an elastic cold platform of the present utility model;

Fig. 7 shows a damping leaf spring according to the present utility model.

In the figure:

10. the pressure wave generator, 101, an inner yoke, 102, an outer yoke, 103, windings, 104, an insulating framework, 105, magnetic steel, 106, a magnetic steel sleeve, 1061, a glue guiding groove, 107, a power pontoon, 108, a pontoon plug, 109, a power leaf spring, 110, a hexagonal nut, 111 and a power cylinder; 112. a hot end compression chamber;

20. the expansion cold finger 201, a central shaft of the heat regenerator, 202, the heat regenerator, 203, a sealing cover of the heat regenerator, 204, pneumatic leaf springs, 205, leaf spring supporting rods, 206, step nuts, 207, an air inlet screen of the heat regenerator, 208, a cold end expansion cavity, 209, a waist-shaped groove, 210 and an air inlet hole;

30. The device comprises a shell, 301, a cold platform, 302, an expansion cylinder, 303, a hot end fluid director, 304, a base, 305, a tail cover, 3051, a tail cover extension rod, 306, an outgoing line guide pin, 307, a lower damping plate spring, 308, an upper damping plate spring, 309, a plate spring gasket, 310 and an inflation tube;

401. An outer yoke base plate 402, an outer yoke screw 403, a leaf spring support 404, and a leaf spring screw.

Detailed Description

The present utility model will be further described with reference to the accompanying drawings and specific examples, which are not intended to be limiting, so that those skilled in the art will better understand the utility model and practice it.

As shown in fig. 1, the present embodiment discloses a small linear refrigerator including a pressure wave generator 10, an expansion cold finger 20, and a housing 30. The pressure wave generator 10 includes an inner yoke 101, an outer yoke 102, windings 103, an insulating skeleton 104, magnetic steels 105, a magnetic steel sleeve 106, a power pontoon 107, pontoon plugs 108, a power leaf spring 109, a hex nut 110, a power cylinder 111, and a hot-side compression chamber 112. The expansion cold finger 20 includes a regenerator central shaft 201, a regenerator 202, a regenerator cover 203, a pneumatic leaf spring 204, leaf spring struts 205, step nuts 206, a regenerator air intake screen 207, and a cold-side expansion chamber 208. The housing 30 includes a cold platform 301, an expansion cylinder 302, a hot-side inducer 303, a base 304, a tail cover 305, an outlet pin 306, a lower damper leaf spring 307, an upper damper leaf spring 308, leaf spring washers 309, and an air tube 310. In addition, the support structure is an outer yoke base 401, an outer yoke screw 402, a leaf spring strut 403, and a leaf spring screw 404. Wherein the inner yoke 101 is a hollow ring and is fixed on the outer surface of the power cylinder 111, the outer yoke 102 is sleeved on the winding 103 and the insulating framework 104 and is fixed on the base 304, and the stator of the pressure wave generator 10 is formed by the two parts together; the magnetic steel 105 is of an annular structure, is embedded on the inner surface of the magnetic steel sleeve 106, and the power pontoon 107 is fixedly connected with the magnetic steel sleeve 106 in a screw manner to form a rotor of the pressure wave generator 10; the pontoon plug 108 connects the power pontoon 107 and the power leaf spring 109, and the outer periphery of the power leaf spring 109 is fixed to the outer yoke base plate 401. The heat regenerator 202 and the expansion cylinder 302 are coaxially arranged and can move relatively, stainless steel wire mesh and PC fibers are mixed and filled in the heat regenerator along the axial direction according to the proportion of 1:2 to serve as heat regenerating materials, and a central shaft 201 of the heat regenerator is connected with the heat regenerator 202 and the pneumatic plate spring 204; the shell 30 is formed by sectional welding, a lower damping plate spring 307 and an upper damping plate spring 308 are arranged on the tail cover 305, and the air charging pipe 310 is communicated with a back pressure cavity of the pressure wave generator 30 and an external air source.

The inner yoke 101 is formed by stacking 50 silicon steel sheets with the thickness of 0.35mm and the brand number of W470 along the periphery of the power cylinder 111 into a circular ring shape, wherein V-shaped grooves are formed at two ends of each silicon steel sheet, and the V-shaped grooves are embedded with the V-shaped grooves on the power cylinder 111 and are adhered by glue. The winding 103 is made of enameled copper core wires with bare wire diameters of 0.3mm, and is wound on an insulating framework 104 in a solenoid mode in a circle-by-circle mode, and 60 turns are counted.

The magnetic steel 105 is formed by 8 tile-shaped neodymium iron boron permanent magnets with the trademark of 45H, each permanent magnet adopts radial parallel magnetization with an N pole facing inwards and an S pole facing outwards, and the magnetic steel is embedded on the inner surface of the magnetic steel sleeve 106 by a die after magnetization. As shown in fig. 3, 8 axial glue guiding grooves 1061 are uniformly formed in the outer surface of the magnetic steel sleeve 106, after the magnetic steel 105 with the glued outer surface is pressed into the magnetic steel sleeve 106, the magnetic steel 105 can be conveniently extruded smoothly along the glue guiding grooves 1061, assembly convenience of the magnetic steel 105 is guaranteed, after glue is dried, the power pontoon 107 and the magnetic steel sleeve 106 are coaxially assembled and axially locked and fixed by the hexagonal nut 110, a through hole is formed in the power pontoon 107, one side end surface close to a back pressure cavity is fixedly connected with the sleeve plug 108 in a screwed mode, the power leaf spring 204 is installed on the sleeve plug 108, the power pontoon 107, the pontoon plug 108 and the power leaf spring 204 are axially locked through the hexagonal nut 110, and the periphery of the power leaf spring 204 is fixedly connected with a supporting rod extending out of the outer yoke base plate 401 in a screwed mode.

As shown in fig. 2, the outer yoke 102 is an 8-pack lamination structure, each pack is formed by stacking 30 silicon steel sheets with a thickness of 0.35mm and a trade name of W470 and welded and fixed, then all 8-pack lamination units are uniformly inserted outside the insulating frame 104 around which the windings 103 have been wound to form a circumferential flap-like structure, the above together form a stator of the pressure wave generator 10, the stator is fixedly mounted on the base 304, the outer yoke substrate 401 is used for axial positioning, and the stator is locked on the base 304 by the outer yoke screw 402.

As shown in FIG. 1, the outer wall of the regenerator 202 in the expansion cold finger 20 is made of polyimide polymer nonmetal, the characteristics of wear resistance and stable chemical performance are achieved, the inner cavity of the regenerator 202 is filled with 350-mesh stainless steel wire mesh and PC fibers with the porosity of 0.7 in a mixed mode along the axial direction according to the length ratio of 1:2, a regenerator cover 203 is arranged on one side end face of the cold end expansion cavity 208 of the regenerator 202, a vent hole with the diameter of 2.5mm is arranged in the center of the regenerator cover 203, a regenerator air inlet screen 207 is arranged on one side end face of the hot end compression cavity 112 of the regenerator 202, the regenerator air inlet screen 207 is fixedly connected with a central shaft 201 of the regenerator in a screwed mode, the center of the central shaft 201 of the regenerator is locked with the center of a pneumatic plate spring 204 through a stepped nut 206, and as shown in FIG. 2, the periphery of the pneumatic plate spring 204 is fixedly connected with a plate spring support rod 403 extending along the axial direction of an outer yoke substrate 401 in a screwed mode, and a stator is locked on the plate spring support rod 403 through a plate spring screw 404.

The shell 30 of the refrigerator is of a split structure, the joint of each section is sealed in a welding mode, the expansion cylinder 302 and the heat regenerator 202 are coaxially arranged, and a single-side gap of 0.005mm is radially arranged, so that abrasion caused by relative movement is greatly reduced on the premise of ensuring basic sealing.

As shown in fig. 1 and fig. 4, the central hole of the hot end inducer 303 and the regenerator air inlet screen 207 form a gap seal, and 6 waist-shaped grooves 209 are uniformly arranged on the inner end surface of the regenerator air inlet screen 207 along the circumferential direction, so that the gas in the hot end compression chamber 112 passes through the hot end inducer 303 and enters the regenerator 202 through the waist-shaped grooves 209 in an annular air inlet mode, and meanwhile, 4 circular air inlets 210 are formed on the surface of the regenerator air inlet screen 207 to be communicated with the hot end compression chamber and the regenerator 202, so that the gas plays a role of radial air floatation support in a high-pressure working period, and the abrasion between the regenerator 202 and the hot end inducer 303 is reduced.

As shown in fig. 5, a tail cap extension rod 3051 is provided at the center of the tail cap 305, and the passive vibration damping device is composed of a lower vibration damping plate spring 307 and an upper vibration damping plate spring 308, which are set with an axial interval distance of 3mm through a plate spring washer 309 so that the lower vibration damping plate spring 307 and the upper vibration damping plate spring 308 do not interfere with each other during operation. The outgoing line pin 306 is disposed on the tail cap 305, and the outgoing line pin 306 is pressure-bearing sealed by a sintered glass bead. The inside of the gas tube 310 is filled with a capillary tube with a larger thermal expansion coefficient, and after helium refrigerant is filled at a lower temperature, the middle section of the gas tube 30 is locally heated to cause irreversible expansion of the capillary tube for sealing.

As shown in fig. 6, a hollow slit is arranged in the middle of the cold platform 301 along the cross section, so that the lower end surface can still be ensured not to deform under the stress or cold and hot actions of the upper end surface.

As shown in fig. 7, the molded lines of the power leaf spring 109, the pneumatic leaf spring 204, the lower damper leaf spring 307, and the upper damper leaf spring 308 are archimedes' spiral lines, and the leaf spring axial restoring rigidity and the radial supporting rigidity are adjusted by the leaf spring thickness.

The refrigeration principle of the small linear refrigerator of the embodiment is as follows: when alternating current is supplied to windings 103 in pressure wave generator 10, an alternating electromagnetic field is generated, a closed magnetic field is formed in outer yoke 102 and inner yoke 101, and magnetic steel 105 located between outer yoke 102 and inner yoke 101 generates axial reciprocating oscillation due to Lenz effect, and simultaneously drives power pontoon 107 to move together, so that helium in hot-end compression chamber 112 is compressed and expanded periodically and alternately. When helium is compressed, the power pontoon 107 moves downwards, high-pressure helium in the hot-end compression cavity 112 enters the heat regenerator 202 through the hot-end flow director 303, heat is transferred to the filler in the heat regenerator 202, and then the high-pressure low-temperature helium enters the cold-end expansion cavity 208 through the heat regenerator cover 203 to further expand and absorb heat of the cold platform 301 to refrigerate; when helium expands, the power pontoon 107 moves upwards, low-pressure helium in the cold-end expansion chamber 208 enters the heat regenerator 202 through the heat regenerator cover 203, absorbs heat from the filler in the heat regenerator 202, becomes low-pressure high-temperature helium, and enters the hot-end compression chamber 112 through the hot-end deflector 303, thereby completing a working cycle.

The utility model has the following beneficial effects: the small linear refrigerator improves the integration level of the refrigerating system, so that the refrigerator is more compact in size, higher in reliability and more convenient to couple with external heat load.

The above-described embodiments are merely preferred embodiments for fully explaining the present utility model, and the scope of the present utility model is not limited thereto. Equivalent substitutions and modifications will occur to those skilled in the art based on the present utility model, and are intended to be within the scope of the present utility model. The protection scope of the utility model is subject to the claims.

Claims

1. A small linear refrigerator, comprising a pressure wave generator, an expansion cold finger and a shell; the pressure wave generator comprises an inner yoke, an outer yoke base plate, an outer yoke screw rod, a winding, an insulating framework, magnetic steel, a magnetic steel sleeve, a power pontoon, a pontoon plug, a power leaf spring, a leaf spring strut, a leaf spring screw rod, a hexagonal nut, a power cylinder and a hot end compression cavity, wherein the expansion cold finger comprises a central shaft of the heat regenerator, a sealing cover of the heat regenerator, a pneumatic leaf spring, a leaf spring strut, a step nut, a hot end air inlet cavity and a cold end expansion cavity, and the shell comprises a cold platform, an expansion cylinder, a hot end flow director, a base, a tail cover extension rod, an outlet guide pin, a lower damping leaf spring, an upper damping leaf spring, a leaf spring gasket and an inflation tube; the inner yoke is a hollow circular ring and is fixed on the power cylinder, the outer yoke is sleeved on the winding and the insulating framework and is fixed on the base, and the inner yoke and the insulating framework together form a stator of the pressure wave generator; the magnetic steel is of an annular structure and embedded in the inner surface of the magnetic steel sleeve, and the power pontoon is fixedly connected with the magnetic steel sleeve in a threaded manner to form a rotor of the pressure wave generator; the pontoon plug is connected with the power pontoon and the power plate spring, and the periphery of the power plate spring is fixed on the outer yoke base plate; the heat regenerator and the expansion cylinder are coaxially arranged and can move relatively, a stainless steel wire mesh and PC fibers are mixed and filled in the heat regenerator along the axial direction to serve as heat regeneration materials, and a central shaft of the heat regenerator is connected with the heat regenerator and the pneumatic plate spring; the shell is welded in a segmented mode, the upper vibration reduction plate spring and the lower vibration reduction plate spring are installed on the tail cover, and the inflation tube is communicated with the backpressure cavity of the pressure wave generator and an external air source.

2. A compact linear chiller according to claim 1 wherein: the stator structure of the pressure wave generator is provided with: the inner yoke adopts a plurality of silicon steel sheets to be stacked into a circular ring shape along the periphery of the power cylinder, V-shaped grooves are formed in two ends of the inner yoke and are embedded with the V-shaped grooves on the power cylinder and are adhered by glue, the winding coil is wound on the insulating framework in a circle by circle, the outer yoke is 8 groups of lamination units, and after being stacked, welded and fixed, the outer yoke is evenly inserted in the outer side of the insulating framework.

3. A compact linear chiller according to claim 1 wherein: the mover structure of the pressure wave generator is arranged as follows: the magnetic steel is 8 tile-shaped neodymium iron boron permanent magnets, each permanent magnet is magnetized in parallel with the inward N pole and the outward S pole along the radial direction, the magnetic steel is magnetized and then embedded in the inner surface of the magnetic steel sleeve, the power pontoon is fixed in a screwed connection manner after being coaxially assembled with the magnetic steel sleeve, a through hole is formed in the power pontoon, the end face close to one side of the back pressure cavity is fixed in a screwed connection manner with the sleeve plug, the power leaf spring is arranged on the sleeve plug, the power pontoon is locked in the axial direction through the hexagonal nut in a screwed connection manner with the periphery of the power leaf spring, and the power leaf spring is fixed on a supporting rod extending from the outer yoke base plate.

4. A compact linear chiller according to claim 1 wherein: the inside stainless steel wire mesh and the PC fibre of aperture ratio 0.6~0.7 of 300 mesh ~400 mesh within range are filled to the back heater along axial according to 1:2 length proportion, the back heater is located one side terminal surface of cold junction expansion chamber sets up the back heater closing cap, back heater closing cap center sets up the diameter is the air vent of back heater diameter half, the back heater is located one side terminal surface of hot junction compression chamber sets up the back heater air inlet screen, back heater air inlet screen with back heater center pin spiro union is fixed, back heater center pin with pneumatic leaf spring center passes through the step nut locking, pneumatic leaf spring periphery spiro union is fixed on the leaf spring pillar.

5. A compact linear chiller according to claim 1 wherein: the shell is of a split structure, the joint of each section is sealed in a welding mode, and the expansion cylinder and the expansion cold finger are coaxially arranged and radially provided with a gap with a single side of 0.005 mm-0.01 mm.

6. A compact linear chiller according to claim 1 wherein: the cold platform is provided with a hollow slit along the cross section of the middle part, so that the upper end surface is stressed or the lower end surface can still be ensured not to deform under the action of cold and heat.

7. A compact linear chiller according to claim 1 wherein: the central hole of the hot end flow director and the air inlet screen of the heat regenerator form clearance seal, and a plurality of round air inlets are uniformly arranged on the inner end surface along the circumferential direction so as to be communicated with the hot end compression cavity and the interior of the heat regenerator.

8. A compact linear chiller according to claim 1 wherein: and the outgoing line guide pin is arranged on the tail cover and is subjected to pressure-bearing sealing through sintered glass beads.

9. A compact linear chiller according to claim 1 wherein: the upper damping leaf spring and the lower damping leaf spring are mounted on the tail cover extension rod.

10. A compact linear chiller according to claim 1 wherein: the molded lines of the power leaf spring, the pneumatic leaf spring and the damping leaf spring are Archimedes spiral lines, and the leaf spring thickness is used for adjusting the axial restoring rigidity and the radial supporting rigidity of the leaf spring.

11. A compact linear chiller according to claim 1 wherein: and after helium refrigerant is filled at a lower temperature, the middle section of the inflation tube is locally heated to enable the capillary tube to be irreversibly expanded for sealing.