KR20000012905A - Driving shaft of pulse tube refrigerator and combining structure of piston - Google Patents

Abstract

PURPOSE: A driving shaft of a pulse tube refrigerator is provided to reduce the manufacture cost and to increase the productivity as assembling by omitting the detailed process and the assembling to equalize the concentricity of a piston and a cylinder. CONSTITUTION: The driving shaft of a pulse tube refrigerator includes:a closed case(110) having a cylinder unit(110a), filling its inside with the acting gas and consisting of a closed shell(114) preventing the leakage of the acting gas by combining itself on the lower face of an upper frame(111) to cover an upper, middle and lower frame(111)(112A)(113); a driving motor(120) for generating the driving force; and a driving shaft(130A) combined to an actuator(122) of the driving motor and reciprocating in a straight line.

Description

Drive shaft and piston coupling structure of pulsating tube refrigerator

The present invention relates to a drive shaft and a piston coupling structure of the pulsating tube refrigerator, and more particularly, to prevent the friction and abrasion between the piston and the cylinder portion installed in the non-lubricated pulsating tube refrigerator using a linear motor. It can be coupled to the piston rod fixed in the flexible state.

In general, cryogenic freezers for cooling small electronic components and superconductors are mainly used for thermal regeneration refrigerators such as Stirling Refrigerator and GM Refrigerator. Increasingly, the improvement of the sealing material which generate | occur | produces friction, and the method of eliminating the moving part are calculated | required.

On the other hand, there is also a need for the development of a highly reliable cryogenic freezer that does not require long-term maintenance, and one of such cryogenic freezers is a pulse tube refrigerator.

The pulsating tube refrigeration machine is cryogenically opened at the open side of the tube by using the principle that a constant temperature is injected into a clogged tube by periodically changing the pressure to obtain a very large temperature gradient when there is little turbulent component in the gas flow. In addition, the pulsating tube freezer is a variation of a sterling freezer suitable for use as a freezer having a relatively low freezing capacity and low reliability due to a low average pressure and pressure ratio. Compared to having two motion parts, the motion part of the pulsating tube refrigerator has a difference between having only one separate compressor.

Figure 1 is a longitudinal sectional view showing a conventional pulsating tube refrigerator, a conventional pulsating tube refrigerator is to allow the piston coupled to the mover of the linear motor to pump the working gas while linearly reciprocating the cylinder without additional lubrication action And a refrigeration part 200 having a cryogenic part by a thermodynamic cycle of a working gas reciprocating in the pipe while being pumped by the drive part 100 and the driving part 100 generating the reciprocating motion of the working gas. .

The drive unit 100 is provided with a cylinder unit 110a and a sealed case 110 filled with a working gas therein, a drive motor 120 mounted inside the sealed case 110 to generate a driving force; The drive shaft 130A coupled to the mover of the drive motor 120 and performing linear reciprocating motion, connected to the drive shaft 130A, and inserted into the cylinder portion 110a of the sealed case 110 to drive shaft 130A. A linear reciprocating motion of the mover of the drive motor 120 is coupled to the upper and lower portions of the piston 140A for pumping the working gas and the sealing case 110 and the drive shaft 130A. Upper and lower support members for storing the elastic energy and converting the stored elastic energy into linear motion to induce the resonance motion of the piston 140A and guide the straightness of the moving piston 140A by receiving the linear motion of the mover. 151) consists of 152 do.

The closed case 110 is coupled to the upper frame 111 and the lower end of the upper frame 111, the cylinder portion 110a is formed so that the piston (140A) is inserted to perform a linear reciprocating motion to the inside The upper support member 151 coupled with the upper end of the drive shaft 130A is fastened, and the intermediate frame 112A to which the drive motor 120 is fixedly mounted is sealed to be coupled to the lower end of the intermediate frame 112A. The lower frame 113 to which the lower support member 152 coupled to the lower end of 130A is coupled, and sealingly coupled to the lower surface of the upper frame 111 to surround the intermediate frame 112A and the lower frame 113. And a sealing shell 114 to prevent leakage of the working gas.

The intermediate frame 112A has a motor mounting portion 112a for mounting the drive motor 120 in the middle of the inner circumferential surface thereof and protrudes in an annular shape, and an upper support member 151 is mounted on the upper side of the motor mounting portion 112a. A plurality of protruding support member mounting portions 112b are formed on the same circumference, and the inner diameter of the support member mounting portions 112b takes into account the decrease in elastic force generated when the diameter of the upper support member 151 becomes too large. It is preferable to form smaller than the outer diameter of the drive motor 120.

The lower frame 113 has a plurality of protruding support member mounting portions 113a for fastening the lower support member 152 to the inner circumferential surface thereof on the same circumference as the support member mounting portion 112b of the intermediate frame 112. The inner diameter of the support member mounting portion 113a may also be smaller than the outer diameter of the drive motor 120.

The upper and lower support members 151 and 152 are plate-shaped leaf springs which are commonly used, and drive shaft mounting holes 151a and 152a formed at the center thereof maintain the straightness of the piston 140A. It is preferable to be formed concentrically with the cylinder part 110a of the upper frame 111 as much as possible.

The drive motor 120 is composed of a plurality of iron pieces are stacked in a cylindrical shape consisting of inner and outer laminations (121A) (121B), the outer lamination (121B) of the stator 121 and the plurality of coils (121b) is mounted; And a mover 122 interposed between the inner and outer laminations 121A and 121B of the stator 121 and coupled to the drive shaft 130A and mounted with a magnet 112b to face the coil 121b. As a conventional linear motor, the outer lamination 121B is fastened to the middle frame 112A of the sealed case 110, and the inner lamination 121A is connected to the outer lamination 121B by a separate connection ring 123. Are integrally combined.

The drive shaft 130A is integrally coupled to the mover 122 of the drive motor 120 as described above, and an upper end thereof is penetrated integrally into the piston 140A by passing through the upper support member 151. The lower end penetrates through the center of the lower support member 152 and is fastened to a separate fixing member 160.

Here, in order for the drive shaft 130A to perform the resonance motion and the straight motion, the drive shaft 130A and the upper and lower support members 151 and 152 should be integrally coupled.

On the other hand, the refrigeration unit 200 is a compression unit in which compression and expansion are generated by compression and expansion at both ends as the working gas inside the mass flow by the working gas pumped from the cylinder portion 110a of the sealed case 110 ( In 211, heat is generated, while expansion 212 in which expansion occurs includes a pulsation tube 210 that absorbs external heat, and a working gas reciprocated by being connected to the compression unit 211 of the pulsation tube 210. An orifice 220 which generates a phase difference between the mass flow and the pressure pulsation and achieves thermal equilibrium, a storage container 230 connected to the orifice 220 to temporarily retain the working gas, and the pulsating tube 210 Connected between the expansion unit 212 and the cylinder unit 110a of the driving unit 100 stores the sensible heat of the working gas pumped into the pulsating tube 210, and then stores the cylinder of the driving unit 100 in the pulsating tube 210. The temperature of the working gas back to the unit (110a) Compensator regenerator 240 and the pre-cooler 250 is connected between the regenerator 240 and the cylinder portion (110a) of the drive unit 100 to cool the operating gas of the high temperature and high pressure pumped first.

Conventional non-lubricating pulsating tube freezer configured as described above is assembled as follows.

First, the outer lamination 121B of the drive motor 120 is fastened to the motor support 112a of the intermediate frame 112A, and the inner lamination 121A is inserted into the outer lamination 121B, and then the connection ring ( 123, the inner and outer laminations 121A and 121B are integrally fastened, and the cylindrical mover 122 having the drive shaft 130A coupled to the gap between the inner and outer laminations 121A and 121B. Interposing the upper support member 151 on the support member mounting portion 112b of the intermediate frame 112A so that the driving shaft 130A penetrates the center thereof, and a lower frame at the lower end of the intermediate frame 112A. And fastening the lower support member 152 through which the lower end of the drive shaft 130A penetrates the center to the support member mounting portion 113a of the lower frame 113, and to the upper end of the drive shaft 130A. Couple the piston 140A with the upper support member 151 interposed therebetween. On the other hand, the lower end of the drive shaft 130A couples the fixing member 160 with the lower support member 152 interposed therebetween.

At this time, the piston 140A is a drive shaft mounting hole (151a) of the upper and lower support members (151, 152) so that the gap with the cylinder (110a) during the linear reciprocating motion to maintain 10 ~ 20 μm as described above 152a) and the cylinder portion 110a should maintain concentricity.

Subsequently, the upper frame 111 is fastened by allowing the piston 140A to be inserted into the cylinder part 110a at the upper end of the intermediate frame 112A, and the lower end of the upper frame 111 at the middle frame 112A and the lower part. The sealing shell 114 surrounding the frame 113 is coupled.

Then, the precooler 250 is directly in close contact with the front end surface of the cylinder part 110a, and fastened, and the regenerator 240, the pulsating tube 210, the orifice 220, and the storage container are connected to the precooler 250. 230 and the like in order, in some cases, may be coupled via a separate connecting pipe 260 between the cylinder portion (110a) and the precooler (250). This is for the heat generated in the cylinder 110a is not directly transferred to the precooler 250 but radiated to the outside.

On the other hand, the operation process of the conventional non-lubricated pulsating tube refrigerator is as follows.

That is, when power is applied to the drive motor 120 and the mover 122 reciprocates linearly, the drive shaft 130A coupled to the mover 122 also performs linear reciprocation, and the drive shaft ( Piston 140A integrally coupled to 130A pumps the working gas while linearly reciprocating in the cylinder portion 110a.

At this time, during the compression stroke of the piston 140A, the working gas of the cylinder 110a flows out toward the precooler 250, and the working gas precooled to a predetermined temperature in the precooler 250 is regenerator 240. Through the heat exchange is introduced into the pulsating tube 210 while storing the sensible heat therein, the working gas filled in the pulsating tube 210 by the incoming working gas is pushed toward the orifice 220 and compressed The compression end temperature of the copper tube 210 is increased, and the elevated temperature is thermally expanded by the working gas passing through the orifice 220 and radiated to the outside.

Thereafter, the pulsating tube 210 forms a thermal equilibrium state of high pressure between the compression stroke and the expansion stroke of the piston 140A, in which the working gas is continuously discharged from the pulsating tube 210 through the orifice 220. The storage vessel 230 is moved to lower the temperature of the pulsation tube 210.

Subsequently, during the expansion stroke of the piston 140A, the working gas in the pulsating tube 210 is moved toward the regenerator 240 while sucking the working gas that has flowed into the pulsating tube 210. The working gas in the pulsating tube 210 is adiabatic because the mass flow rate of the working gas flowing into the pulsating tube 210 through the orifice 220 is much smaller than the mass flow rate of the working gas exiting the pulsating tube 210. Expansion, and the adiabatic expansion of this working gas is usually generated rapidly on the regenerator 240 equipped with a cold side heat exchanger (unsigned) to form a cryogenic portion.

Then, the pulsation tube 210 is in a thermal equilibrium state of low pressure between the expansion stroke and the compression stroke of the piston 140A, in which the working gas is continuously stored through the orifice 220 While moving to the pulsating tube 210 to increase the pressure in the pulsating tube 210 to recover the initial temperature.

Meanwhile, the upper and lower support members 151 and 152 coupled to the upper and lower ends of the driving shaft 130A receive the reciprocating motion of the driving shaft 130A and store the linear reciprocating motion of the mover 122 as elastic energy. In addition, the stored elastic energy is converted into a linear motion to induce a resonant motion of the piston 140A, and the piston 140A moving by receiving the linear motion of the mover 122 is connected to the inner circumferential wall of the cylinder part 110a. You will always be guided in a straight line with a certain tolerance.

However, in the conventional non-lubricated pulsating tube refrigerator, the piston 140A to prevent friction and wear due to non-lubrication between the piston 140A and the inner wall surface of the cylinder portion 110a formed at the center of the upper frame 112A. ) And upper and lower support members 151 and 152 which are respectively provided on the upper and lower portions of the drive shaft 130A to form a disk-shaped leaf spring so as to maintain a constant gap between the inner wall surface of the cylinder portion 110a and the cylinder portion 110a. While concentricity between both ends of the drive shaft (130a) and the drive shaft (130A) acts as a spring in the axial direction and restrains the bias of the drive shaft (130A) in the radial direction to ensure the straightness of the piston (140A) and the cylinder portion (110a) and Although the concentricity of the piston 140A is maintained, this structure requires precise machining and assembly because the concentricity of each of the inner and outer diameters of the cylinder part 110a and the upper and lower support members 151 and 152 must match. to do Sikimyeo control rising production costs, there are many problems, such as the time-consuming assembly concerns the productivity is lowered, the dip can vary it compromises the quality of the equipment performance based on the coarse.

Accordingly, the present invention is to solve the above problems, the piston rod fixed to the upper end of the drive shaft so that the friction and abrasion between the piston and the cylinder portion installed in the non-lubricated pulsating tube freezer using the linear motor does not occur It can be combined in a flexible state, so that the piston can move straight without any concentricity between the piston and the cylinder, and there is no need for precision machining and assembly to match the concentricity of the piston and the cylinder. The purpose is to provide a drive shaft and a piston coupling structure of the pulsating tube refrigeration machine that can not only lower the pressure, but also improve the productivity during assembly.

Figure 1 is a longitudinal cross-sectional view showing a conventional pulsating tube refrigerator.

Figure 2 is a longitudinal cross-sectional view showing a pulsating tube freezer according to the present invention

3 is an enlarged view illustrating a portion A of FIG. 2;

Explanation of symbols on the main parts of the drawings

130; Drive shaft 140; piston

141; Fastening groove 142; Guide

170; Piston rod 171; Support rod

180; Fixing stopper 181; Insert groove

In order to achieve the above object, the present invention provides a sealed case consisting of a sealing shell which is provided with a cylinder, filled with a working gas therein, and prevents leakage of the working gas, and a driving motor mounted inside the sealed case to generate a driving force. And a piston coupled to the mover of the drive motor for linear reciprocating motion, a piston connected to the drive shaft and inserted into the cylinder portion of the sealed case to pump the working gas while performing linear reciprocating motion with the drive shaft; It is coupled to the inside of the sealed case and stores the linear reciprocating motion of the mover of the drive motor as elastic energy and converts the stored elastic energy into linear motion to induce resonant motion of the piston. Upper and lower support members for guiding straightness, and a cylinder of the sealed case The pulsating tube absorbs the heat from the compression section where the compression occurs, while the internal working gas flows by the working gas pumped from the section and generates compression and expansion at both ends, respectively. And an orifice connected to the compression section of the pulsating tube to generate a phase difference between the mass flow and the pressure pulsation of the reciprocating working gas, and to achieve thermal equilibrium; and a storage container connected to the orifice to temporarily hold the working gas. A regenerator for storing the sensible heat of the working gas connected between the expansion part and the driving part of the pulsating tube and pumped to the pulsating tube and compensating the temperature of the working gas returned from the pulsating tube to the cylinder part of the driving part, the regenerator and the driving part Example of first cooling the high and high pressure working gas connected between the cylinder parts of the pump In the pulsating tube refrigerator consisting of cold, the piston rod is fixed to the upper end of the drive shaft, the piston rod is provided with the drive shaft and the piston coupling structure of the pulsating tube refrigerator, characterized in that the piston is rotatably coupled. Is achieved.

Here, the piston rod is characterized in that the spring steel having a diameter smaller than the diameter of the drive shaft.

In addition, a fastening groove is formed in the upper center of the piston, a guide hole communicating with the fastening groove is formed in the center of the piston, the fastening groove is separated from the support rod fixed to the upper end of the piston rod seated on the top of the guide hole It is characterized in that the fixing stopper for fastening so as to prevent it is fastened and coupled.

In addition, the guide hole is characterized in that formed in communication with the fastening groove in the center of the piston in a larger diameter than the piston rod.

And, in the upper center of the fixing stopper is characterized in that the + -shaped insertion groove is formed to rotate the fixing stopper by inserting a tool when fastening the stopper to the fastening groove.

Hereinafter, preferred embodiments of the present invention for achieving the above object will be described in detail with reference to the accompanying drawings.

Figure 2 is a longitudinal sectional view showing a pulsating tube compressor according to the present invention, Figure 3 is an enlarged view showing a portion A of Figure 2, and the same reference numerals for the same parts as in the prior art will be described the present invention.

The present invention is provided with a cylinder portion (110a) is filled with a working gas therein and the upper frame to surround the upper and middle and lower frames 111, 112A, 113 and the middle and lower frames (112A) 113 ( A sealed case 110 made of a sealing shell 114 sealingly coupled to the bottom surface of the 111 to prevent leakage of working gas, and a drive motor 120 mounted inside the sealed case 110 to generate a driving force. And a drive shaft 130A coupled to the mover 122 of the drive motor 120 for linear reciprocating motion, and connected to the drive shaft 130A and inserted into the cylinder portion 110a of the sealed case 110. And a piston 140A for pumping a working gas while linearly reciprocating with the drive shaft 130A, and coupled to the inside of the sealed case 110 to perform linear reciprocation of the mover 122 of the drive motor 120. By storing it as elastic energy and converting it into linear motion Upper and lower support members 151 and 152 for inducing the resonant motion of the stone 140A and guiding the straightness of the piston 140A moving by receiving the linear motion of the mover 122, and the sealed case ( As the working gas inside is flowed by the working gas pumped from the cylinder part 110a of the 110, compression and expansion occur at both ends, respectively, and the compression part 211, which generates compression, generates heat while expansion occurs. The unit 212 generates a phase difference between the pressure pulsation and the mass flow of the pulsating tube 210 for absorbing external heat and the working gas reciprocating connected to the compression unit 211 of the pulsating tube 210. In addition, an orifice 220 to achieve thermal equilibrium, a storage container 230 connected to the orifice 220 to temporarily hold a working gas, an expansion part 212 and a driving part 100 of the pulsation tube 210. Pumped into the pulsating tube 210 connected between The regenerator 240 stores the sensible heat of the working gas and compensates the temperature of the working gas returned from the pulsation tube 210 to the cylinder portion 110a of the driving unit 100, and the regenerator 240 and the driving unit 100. In the pulsating tube refrigerator consisting of a pre-cooler (250) for cooling the high-temperature and high-pressure working gas is connected between the cylinder portion (110a) of the first), the upper end of the drive shaft 130 than the drive shaft 130 The piston rod 170 formed of a small diameter and made of spring steel is fixed, and the support rod 171 is fixed to the upper end of the piston rod 170.

In addition, a fastening groove 141 is formed at an upper center of the piston 140, and a guide hole 142 having a diameter larger than that of the piston rod 170 and communicating with the fastening groove 141 at the center of the piston 140. Is formed, and the fastening groove 141 for fixing the support rod 171 fixed to the upper end of the piston rod 170 seated on the upper end of the guide hole 142 to prevent the departure from the fastening groove 141 Is fastened and coupled, the upper center of the fixed stopper 180, the + -shaped insertion groove 181 for rotating the fixed stopper 180 by inserting a tool when fastening the fixed stopper 180 to the fastening groove 141. ) Is formed and configured.

Lubrication-free pulsating tube freezer of the present invention configured as described above is assembled as follows.

First, the outer lamination 121B of the driving motor 120 is fastened to the motor support 112a of the intermediate frame 112, and the inner lamination 121A is inserted into the outer lamination 121B, and then the connection ring ( The inner and outer laminations 121A and 121B are integrally fastened using the 123, and the lower end of the piston rod 170 is inserted into the fastening groove 141 formed in the upper center of the piston 140 to thereby fasten the fastening groove ( The support rod 171 fixed to the upper end of the piston rod 170 is seated on the upper end of the guide hole 142 having a larger diameter than the piston rod 170 in communication with the 141, the piston rod in the fastening groove 141 The fastening stopper 180 is fastened to fix the support bar 171 of the upper end to prevent the separation, and the lower end of the piston rod 170 to which the piston 140 is coupled is coupled to the upper end of the drive shaft 130. Let's do it.

Next, the intermediate frame 112 is interposed between the inner and outer laminations 121A and 121B through a cylindrical mover 122 integrally coupled with the drive shaft 130 in the same manner as in the related art. The lower frame 113 is fastened to the lower frame 113, and the support member mounting portion 113a of the lower frame 113 fastens the lower support member 152 through which the lower end of the drive shaft 130 passes through the center, and the drive shaft ( The fixing member 160 is coupled to the lower end of the 130 with the lower support member 152 interposed therebetween.

After that, the upper frame 111 is fastened to the upper end of the intermediate frame 112 by inserting the piston 140 into the cylinder portion 110a, and the lower end of the upper frame 111 and the intermediate frame 112. After coupling the sealing shell 114 surrounding the lower frame 113, the precooler 250 is directly in close contact with the front end surface of the cylinder portion 110a and fastened, and the regenerator 240 is connected to the precooler 250. , The pulsating tube 210, the orifice 220, the storage container 230, and the like are combined in this order.

On the other hand, when power is applied to the drive motor 120 during the operation of the non-lubricated pulsating tube refrigerator according to the present invention and the mover 122 is linear reciprocating motion, to the mover 122 in the same manner as in the prior art The combined drive shaft 130 also has a linear reciprocating motion, and the piston 140 rotatably coupled to the upper end of the piston rod 170 coupled to the upper end of the drive shaft 130 is in the cylinder portion 110a. The machine is operated by pumping a working gas in a linear reciprocating motion.

At this time, in the present invention, the piston rod 170 is formed of a diameter smaller than the diameter of the drive shaft 130 is fixed to the upper end of the drive shaft 130, the support rod is fixed to the upper end of the piston rod 170 ( 171 is fastened by a fixing stopper 180 in a state of being seated in the fastening groove 141 in the upper center of the piston 140, and the piston rod 170 communicates with the fastening groove 141 in the center of the piston 140. Since the piston 140 having the guide hole 142 having a larger diameter is rotatably coupled to the upper end of the piston rod 170, the piston 140 may linearly reciprocate in the cylinder portion 110a. Even if the concentricity between the 140 and the cylinder portion 110a does not coincide, the piston 140 can be rotated in any direction with respect to the piston rod 170, thereby causing the piston 140 to friction and wear on the cylinder portion 110a. Do straight movements unreasonably so that it is prevented Method is possible can further ensure the straightness of the cylinder part (110a) of the piston (140).

Therefore, in the present invention, the piston 140 can move straight without difficulty to prevent friction and abrasion in the cylinder portion 110a, so that the piston moving by receiving the linear movement of the mover 122 at the upper end of the drive shaft 130 ( 140 may not be provided with an upper support member 151 for guiding the inner circumferential wall of the cylinder portion (110a) to always perform a linear movement with a certain tolerance, the lower coupled to the lower end of the drive shaft (130) The support member 152 may be replaced by a coil spring.

As described above, the present invention is a flexible state to the piston rod fixed to the upper end of the drive shaft so that friction and abrasion between the piston and the cylinder portion installed in the non-lubricated pulsating tube refrigerator using the linear motor does not occur. Since it can be rotated and combined, even if the concentricity of the piston and the cylinder does not coincide, the piston can perform a straight forward movement smoothly and smoothly in the cylinder, and there is no need for precision machining and assembly to match the concentricity of the piston and the cylinder. Accordingly, it is possible to reduce manufacturing costs and increase productivity during assembly, thereby greatly improving the efficiency and reliability of the refrigerator.

Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the above-described embodiments, and the present invention may be commonly used in the technical field to which the present invention pertains without departing from the gist of the present invention as claimed in the following claims. Anyone with knowledge will be able to make various changes.

Claims (5)

It is coupled to a sealed case consisting of a sealing shell provided with a cylinder portion and filled with a working gas therein to prevent leakage of the working gas, a drive motor mounted inside the sealed case to generate a driving force, and a mover of the drive motor. And a piston connected to the drive shaft and inserted into the cylinder of the sealed case and pumping the working gas while performing a linear reciprocating motion with the drive shaft, coupled to the inside of the sealed case. A support member for storing linear reciprocating motion of the mover as elastic energy and converting the stored elastic energy into linear motion to induce resonant motion of the piston and guiding the linearity of the moving piston by receiving the linear motion of the mover; Internal workings are caused by the working gas pumped from the cylinder part of the case. As the mass flows, compression and expansion occur at both ends to generate heat in the compression section where compression occurs, while in the expansion section where expansion occurs, a pulsation tube absorbs external heat and reciprocates connected to the compression section of the pulsation tube. Between an orifice for generating a phase difference between the mass flow of the working gas and a pressure pulsation and achieving thermal equilibrium, a storage container connected to the orifice for temporarily holding the working gas, and an expansion portion and a driving portion of the pulsating tube. A regenerator which stores the sensible heat of the working gas which is connected and pumped to the pulsating tube and compensates the temperature of the working gas returned from the pulsating tube to the cylinder part of the drive unit, and the high temperature and high pressure connected between the regenerator and the cylinder part of the drive unit and pumped In the pulsating tube refrigerator comprising a precooler for first cooling the working gas of the The piston rod to the upper end of the shaft is fixed, the drive shaft and the piston coupling structure of the piston to the top end, the pulse tube refrigerator characterized in that the piston is rotatably engaged in the load. 2. The drive shaft and piston coupling structure of a pulsating tube refrigerator according to claim 1, wherein the piston rod is made of spring steel having a diameter smaller than that of the drive shaft. According to claim 1, A fastening groove is formed in the upper center of the piston, a guide hole communicating with the fastening groove is formed in the center of the piston, the fastening groove is fixed to the upper end of the piston rod seated on the upper end of the guide hole The drive shaft and the piston coupling structure of the pulsating tube refrigerator, characterized in that the fastening stopper for fastening the support rod to prevent the separation is coupled. 4. The drive shaft and the piston coupling structure of the pulsating tube refrigerator according to claim 3, wherein the guide hole is formed in communication with a fastening groove in the center of the piston with a diameter larger than that of the piston rod. 4. The drive shaft and the piston coupling of the pulsating tube refrigerator according to claim 3, wherein a + -shaped insertion groove is formed at the upper center of the fixing stopper to insert a tool when the fixing stopper is fastened to the coupling groove to rotate the fixing stopper. rescue.