A pneumatic Stirling expander without spring support
Through the design of pneumatic Stirling Expansion without spring support, the use of limiter components and O-ring structures, the assembly consistency and cost problems of traditional Stirling Expansion machines are solved, and efficient mass production of Stirling Expansion machines is achieved. and run.
Patent Information
- Application Number
- CN202111324972.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-11-10
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2041-11-10
AI Technical Summary
In traditional Stirling expanders, the piston relies on spring fixation, which makes assembly consistency difficult to achieve, increasing labor and processing costs, and affecting the performance of the refrigerator.
Design a pneumatic Stirling expander without spring support, adopting cylinder, piston, base, rear end cover and limiter components, and eliminates spring fixation through a combined structure of limiter, O-ring and fixing seat. Adjust the piston mover mass and cavity volume for dynamic balance.
Reduces processing and labor costs, avoids performance losses caused by spring installation, and allows Stirling expanders to be mass-produced and operated efficiently.
Smart Images
Figure CN113899099B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of expanders, and in particular to a pneumatic Stirling expander without spring support. Background Art
[0002] With the development of infrared detection technology and high-temperature superconducting materials, cryogenic technology is being used more and more widely, giving cryogenic refrigerators broad application prospects. In some high-end application scenarios, mechanical refrigerators can stably maintain specific low-temperature environments, such as infrared imaging instruments for military and space applications, as well as night vision equipment and surveillance and guidance systems. The urgent demand for small and efficient cryogenic refrigerators has further promoted the rapid development of products.
[0003] Mechanically driven Stirling refrigerators can be divided into two types based on the drive of the expander: electronically controlled and pneumatic. The expander of the pneumatic split Stirling refrigerator is driven by high-pressure gas instead of a motor. This further reduces the weight and volume of the entire refrigerator, effectively reduces energy consumption, and improves compactness. It has good application prospects in the fields of superconducting electronics and infrared detection. The clearance between the piston and the cylinder in the Stirling expander is required to be within micron accuracy. However, in traditional Stirling expanders, the piston is fixed by a spring, which is difficult to install and adjust, and has a significant impact on the performance of the Stirling expander. This will greatly increase labor costs and processing costs, which is not conducive to the production of refrigerators. Summary of the invention
[0004] The technical problem to be solved by the present invention is how to improve the assembly consistency of a split-type Stirling expander. In view of the above technical problem to be solved, a pneumatic Stirling expander without spring support is now proposed.
[0005] To achieve the above object, the present invention provides the following technical solutions:
[0006] A pneumatic Stirling expander without spring support includes a cylinder, a piston, a base, a rear end cover, and a limiter assembly. The rear end cover is located at the rear end of the cylinder, the base is located between the rear end cover and the cylinder, the two ends of the base are fixedly connected to the rear end cover and the cylinder respectively, the piston is arranged in a cavity formed by the cylinder, the base and the rear end cover, and the limiter assembly is arranged inside the rear end cover.
[0007] Furthermore, the limiter assembly includes a limiter, an upper O-ring, an upper fixing seat, a lower O-ring, and a lower fixing seat; the upper O-ring is fixed to the upper fixing seat via a fixing bracket, and the lower O-ring is fixed to the lower fixing seat via a fixing bracket; the upper fixing seat is fixed to the base via screws, and the lower fixing seat is fixed to the rear end cover via screws.
[0008] Furthermore, the front section of the piston is located inside the cylinder, and the other end of the piston passes through the base and the limiter assembly in sequence and is connected to the limiter through threads.
[0009] Furthermore, the limiter is a circular ring structure, and the outer diameter of the circular ring is larger than the outer diameters of the upper O-ring and the lower O-ring.
[0010] Furthermore, a plurality of through holes are provided on the circular ring of the limiter.
[0011] Furthermore, the vibration of the piston oscillator system is forced vibration under continuous excitation, and its excitation mode is simple harmonic excitation.
[0012] Furthermore, the cavity formed by the cylinder and the top of the piston is an expansion cavity, the cavity formed by the cylinder, the middle of the piston and the base is a compression cavity, and the cavity formed by the bottom of the piston, the base and the rear end cover is a back pressure cavity.
[0013] Furthermore, two ends of the base are respectively fixed to the rear end cover and the cylinder by laser welding.
[0014] Furthermore, the upper O-ring and the lower O-ring are made of nitrile rubber.
[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention adjusts the piston's mover mass and cavity volume to match the dynamic balance of the piston when the expander is working, thereby eliminating the limitations brought by the spring, reducing processing and labor costs, and avoiding performance losses caused by installation, so that the Stirling expander can be mass-produced and efficiently operated. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a structural schematic diagram of a pneumatic Stirling expander without spring support of the present invention;
[0017] Figure 2 A schematic diagram of a limiter assembly of a pneumatic Stirling expander without spring support according to the present invention;
[0018] Figure 3 A schematic diagram of a limiter of a pneumatic Stirling expander without spring support according to the present invention;
[0019] Figure 4 It is a schematic diagram of the structure of the fixing seat involved in the pneumatic Stirling expander without spring support of the present invention;
[0020] In the figure: 1-cylinder; 2-piston; 3-base; 4-rear end cover; 5-limiter assembly; 501-limiter; 502-upper O-ring; 503-upper fixing seat; 504-lower O-ring; 505-lower fixing seat. DETAILED DESCRIPTION
[0021] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0022] like Figures 1 to 4 As shown, this specific embodiment discloses a pneumatic Stirling expander without spring support, including a cylinder 1, a piston 2, a base 3, a rear end cover 4, and a stopper assembly 5. The rear end cover 4 is located at the rear end of the cylinder 1, the base 3 is located between the rear end cover 4 and the cylinder 1, and the two ends of the base 3 are fixedly connected to the rear end cover 4 and the cylinder 1 respectively. The piston 2 is arranged in a cavity formed by the cylinder 1, the base 3 and the rear end cover 4, and the stopper assembly 5 is arranged inside the rear end cover 4. Figure 2 As described above, the stopper assembly 5 includes a stopper 501, an upper O-ring 502, an upper fixing seat 503, a lower O-ring 504, and a lower fixing seat 505; the upper O-ring 502 is fixed to the upper fixing seat 503 through a fixing bracket, and the lower O-ring 504 is fixed to the lower fixing seat 505 through a fixing bracket, which can effectively reduce the vibration and noise generated by the impact of the stopper 501; the upper fixing seat 503 is fixed to the base 3 through screws, and the lower fixing seat 505 is fixed to the rear end cover 4 through screws. Figure 3 As shown, the limiter 501 is a circular ring structure, and its outer diameter is larger than the outer diameters of the upper O-ring 502 and the lower O-ring 504, which can play a limiting role. The limiter 501 is provided with a plurality of through holes on the circular ring, which can effectively reduce the flow resistance and match the mover mass.
[0023] Specifically, the front section of the piston 2 is located inside the cylinder 1 , and the other end of the piston 2 passes through the base 3 and the stopper assembly 5 in sequence and is connected to the stopper 501 through threads.
[0024] Preferably, the vibration of the oscillator system of the piston 2 is forced vibration under continuous excitation, and its excitation mode is simple harmonic excitation.
[0025] Specifically, the cavity formed by the cylinder 1 and the top of the piston 2 is an expansion cavity, the cavity formed by the cylinder 1 and the middle of the piston 2 and the base 3 is a compression cavity, and the cavity formed by the bottom of the piston 2, the base 3 and the rear end cover 4 is a back pressure cavity; the aerodynamic equation of the piston 2 is:
[0026] ,
[0027] Among them, m is the mass of piston 2, c is the damping of piston 2, k is the gas stiffness supporting piston 2, x represents the displacement of piston 2, represents the speed of piston 2, represents the acceleration of piston 2, F eis the aerodynamic force of the expansion chamber on piston 2, F c is the aerodynamic force of the compression chamber on piston 2, F b The aerodynamic force of all back pressure chambers of piston 2;
[0028] The pressure equation in each cavity is:
[0029] ;
[0030] Among them, P0 is the inflation pressure, P m is the pressure wave amplitude, ω is the angular frequency, and t is the time. According to the above equation, the mass of the piston 2 mover and the volume of the cavity can be adjusted to achieve the dynamic balance of the moving piston 2 and achieve a pneumatic Stirling expander without spring support.
[0031] Preferably, both ends of the base 3 are fixed to the rear end cover 4 and the cylinder 1 respectively by laser welding.
[0032] Preferably, the upper O-ring 502 and the lower O-ring 504 are made of nitrile rubber.
Claims
1. A pneumatic Stirling expander without spring support, characterized in that: The invention comprises a cylinder (1), a piston (2), a base (3), a rear end cover (4), and a stopper assembly (5), wherein the rear end cover (4) is located at the rear end of the cylinder (1), the base (3) is located between the rear end cover (4) and the cylinder (1), the two ends of the base (3) are respectively fixedly connected to the rear end cover (4) and the cylinder (1), the piston (2) is arranged in a cavity formed by the cylinder (1), the base (3) and the rear end cover (4), and the stopper assembly (5) is arranged inside the rear end cover (4); the stopper assembly (5) comprises a stopper (501) , an upper O-ring (502), an upper fixing seat (503), a lower O-ring (504), and a lower fixing seat (505); the upper O-ring (502) is fixed to the upper fixing seat (503) via a fixing bracket, and the lower O-ring (504) is fixed to the lower fixing seat (505) via a fixing bracket; the upper fixing seat (503) and the base (3) are fixed via screws, and the lower fixing seat (505) and the rear end cover (4) are fixed via screws; the vibration of the oscillator system of the piston (2) is forced vibration under continuous excitation, and its excitation mode is simple harmonic excitation.
2. The pneumatic Stirling expander according to claim 1, characterized in that: The front section of the piston (2) is located inside the cylinder (1), and the other end of the piston (2) passes through the base (3) and the stopper assembly (5) in sequence and is connected to the stopper (501) via threads.
3. The pneumatic Stirling expander according to claim 1, characterized in that: The stopper (501) is a circular ring structure, and the outer diameter of the circular ring is larger than the outer diameters of the upper O-ring (502) and the lower O-ring (504).
4. The pneumatic Stirling expander according to claim 3, characterized in that: The circular ring of the stopper (501) is provided with a plurality of through holes.
5. The pneumatic Stirling expander according to claim 1, characterized in that: The cavity formed by the cylinder (1) and the top of the piston (2) is an expansion cavity, the cavity formed by the cylinder (1) and the middle of the piston (2) and the base (3) is a compression cavity, and the cavity formed by the bottom of the piston (2) and the base (3) and the rear end cover (4) is a back pressure cavity.
6. The pneumatic Stirling expander according to claim 1, characterized in that: The two ends of the base (3) are respectively fixed to the rear end cover (4) and the cylinder (1) by laser welding.
7. The pneumatic Stirling expander according to claim 1, characterized in that: The upper O-ring (502) and the lower O-ring (504) are made of nitrile rubber.