JP2823537B2 - Gas compression and expansion machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas compression / expansion machine for compressing or expanding a gaseous refrigerant by a piston reciprocating in a cylinder, and more particularly, to a gas for preventing heat generation of a drive motor for transmitting a driving force to the piston. The present invention relates to a compression / expansion machine.

[0002]

2. Description of the Related Art In recent years, there has been an urgent need to develop techniques for preserving various samples and various materials at extremely low temperatures in advanced technology fields such as the field of biotechnology and the field of electronic devices. In particular, gas compression / expansion machines such as Stirling refrigerating machines have attracted attention as means for achieving the above-mentioned cryogenic temperature, and are going to be widely used for various infrared sensors, freezers for cooling and biomedical devices for superconducting devices, freezers, and the like.

Here, the principle of operation of the two-piston Stirling refrigerating apparatus will be described with reference to FIG. The Stirling refrigerating apparatus 1 is filled with a gaseous refrigerant such as helium as a working gas therein, and is expanded as a working space for expanding the working gas in front of the first piston 2 fitted in the expansion cylinder portion 2a. While having the chamber 3, the compression chamber 5 as a working space for compressing the working gas is provided in front of the second piston 4 fitted in the compression cylinder portion 4a. A regenerator (regenerator) 6 and a radiator 7 are interposed and communicate with each other through a gas flow path 8.
The piston 2 and the second piston 4 are configured to reciprocate with a certain phase difference by a crank mechanism 9 as a drive mechanism driven by a drive motor.

The crank mechanism 9 has a guide portion 10 formed behind the expansion cylinder portion 2a and a compression cylinder portion 4
A guide portion 11 is formed below a, a lubricating oil 12 is accommodated in a bottom portion, and a crank 13 is disposed inside. And
A connecting rod 14 extending from the crank 13 is attached to a guide bearing 10 a of the guide portion 10 by a cross guide 16.
Is slidably fitted to the first piston 2 via an oil seal 18 provided in a through hole formed between the guide portion 10 and the expansion cylinder portion 2a. Connected to the rear.

Further, a connecting rod 19 extending from the crank mechanism 9 has a cross guide 20 slidably fitted on a guide bearing 11a of the guide portion 11, and a cross guide shaft 21 communicating with the cross guide 20 is guided. It is connected to the rear part of the second piston 4 via an oil seal 22 provided in a through hole formed between the part 11 and the compression cylinder part 4a. The oil seals 18 and 22 have P
Materials such as TFE are used.

With the above configuration, the first piston 2 and the second piston 4 reciprocate with a certain phase difference by the crank 13 driven by the rotation of the drive motor. First, the second piston 4 moves to compress the working gas such as helium filling the compression chamber 5, which is the working space of the compression cylinder chamber 31, and the compressed and heated working gas is radiated by the radiator 7. After being further cooled by the heat regenerator 6, it is guided to the expansion chamber 3 which is the working space of the expansion cylinder chamber 32. Thereafter, an expansion step in which the working gas in the expansion chamber 3 expands by the effect of the first piston 2 is performed, and the working gas is cooled to a low temperature by the expansion of the working gas, thereby cooling a cooler (not shown) and the like.
Subsequently, the low-temperature working gas in the expansion chamber 3 is pushed out by the rise of the first piston 2 and guided to the compression chamber 5 while cooling the heat regenerator 6.

The above steps are sequentially repeated to form the expansion chamber 3
When the working gas expands, it cools the cooler to gradually reach the freezing temperature.

[0008]

In the Stirling refrigerating apparatus described with reference to FIG. 2, the crank mechanism 9 is driven by the rotation of the drive motor as described above. For example, as shown in FIG. A drive motor chamber 42 for driving the crankshaft 41 is disposed in a piston drive chamber 44 having the crank mechanism 9 via a shaft bearing 43.

The drive motor chamber 42 includes a rotor 42
a and a stator 42b, and are provided airtight to the outside like the piston drive chamber 44. For this reason, conventionally, when the Stirling refrigerating apparatus was continuously operated, the drive motor chamber 42, particularly the windings of the stator 42 b, generated heat due to the supplied current, and the drive motor chamber 42 was at a high temperature.

On the other hand, drive motors generally have a tendency to decrease in efficiency as the operating temperature increases.
If the temperature is higher than a certain temperature (for example, 120 ° C.), the coating of the stator winding may be burned out, resulting in a short circuit.

Therefore, in the prior art, a radiating fin or the like is provided outside the drive motor chamber 42 in order to prevent the temperature of the drive motor chamber 42 from becoming high. However, since there is no gas flow inside the motor, sufficient heat is radiated. This has been an obstacle to improving the efficiency of the gas compression / expansion machine.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and generates a gas flow inside a drive motor to directly cool a stator which is a heat source, thereby reducing the efficiency of the apparatus due to the heat generated by the motor. An object of the present invention is to provide a gas compression / expansion device capable of preventing occurrence of electric leakage.

[0013]

The present invention comprises a cylinder chamber in which a piston reciprocates, a piston drive chamber in which a drive mechanism for reciprocating the piston is disposed, a rotor and a stator. A drive motor chamber for transmitting a driving force to the piston drive chamber is provided, and the cylinder chamber has a structure partitioned into an operating space and a back pressure space via the piston, with the reciprocating operation of the piston. In a gas compression / expansion machine for compressing or expanding a working gas filling a working space, first and second gas turbines are provided so as to communicate a back pressure space of the cylinder chamber with the drive motor chamber.
A communication pipe; first valve means provided in the first communication pipe to allow movement of the working gas from the back pressure space to the drive motor chamber; and the drive motor chamber provided in the second communication pipe. A second valve means for permitting the movement of the working gas from the pressure chamber to the back pressure space, and a heat radiating means provided in the second communication pipe.

By using this configuration, the working gas reciprocates between the back pressure space and the driving motor chamber with the reciprocating operation of the piston, and the flow of the working gas is generated inside the driving motor chamber. When the working gas heated by exchanging heat with the stator winding that generates heat in the motor chamber flows into the back pressure space through the second communication pipe, the working gas is radiated by the radiating means. In addition, the communication between the back pressure space and the drive motor chamber provides substantially the same effect as when a buffer tank or the like is connected to the back pressure space, and suppresses pressure fluctuations in the back pressure space due to the reciprocating motion of the piston. Is done.

[0015] Preferably, the first communication pipe and the second communication pipe are arranged with respect to the drive motor chamber so as to sandwich the stator. By using this configuration, the working gas inside the drive motor chamber always flows through the stator with the reciprocating operation of the piston, so that heat exchange with the stator winding that is generating heat is further promoted. Will be.

More preferably, the drive motor chamber is provided in an airtight manner with respect to the piston drive chamber via an oil seal member, or an oil absorbing member is provided in the second communication pipe. I have.

With this configuration, oil does not enter the cylinder chamber from the piston drive chamber through the drive motor chamber.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gas compression / expansion machine according to the present invention will be described below with reference to FIG. The same components as those of the above-described conventional example are denoted by the same reference numerals, and detailed description of these portions will be omitted.

In FIG. 1, reference numeral 101 denotes an oil seal 22.
And a back pressure space formed between the second piston 4 and
Reference numeral 102 denotes a first communication pipe which communicates the back pressure space 101 with the drive motor chamber 42 on the piston drive chamber 44 side.

Reference numeral 103 denotes a first radiator provided in the first communication pipe 102, and reference numeral 104 denotes a one-way valve as first valve means for permitting movement of the working gas from the back pressure space 101 to the drive motor chamber 42. It is. The one-way valve 104 is connected to the second
When the pressure in the back pressure space 101 decreases due to the rise of the piston 4 and a differential pressure equal to or more than a certain value is generated, the working gas can flow from the drive motor chamber 42 into the back pressure space 101.

Reference numeral 105 denotes the back pressure space 101 and the driving motor chamber 4
The second communication pipe communicates with the other side of the second piston drive chamber 44, and is disposed so that the stator 42 b is located between the first communication pipe 102 and the second communication pipe 105.

Reference numeral 106 denotes a second radiator provided in the second communication pipe 105. Reference numeral 107 denotes a one-way valve as second valve means for allowing movement of the working gas from the drive motor chamber 42 to the back pressure space 101. It is. The one-way valve 107 is connected to the second
When the pressure in the back pressure space 101 rises due to the lowering of the piston 4 and a differential pressure equal to or more than a certain value is generated, the back pressure space 10
1 allows the working gas to flow into the drive motor chamber 42. The first valve means 104 and the second valve means 107 are not limited to one-way valves, but may be solenoid valves or check valves.

An oil seal 108 is provided adjacent to a shaft bearing 43 provided in the crank mechanism 9 and prevents oil from entering the drive motor chamber 42 from the crank mechanism 9. Oil is prevented from entering the back pressure space 101.

As described above, by providing the first communication pipe 102, the second communication pipe 105, the first radiator 103 and the second radiator 106, when the second piston 4 descends, the back pressure space 1
The working gas 01 flows into the drive motor chamber 42 through the first communication pipe 102, and is heated by exchanging heat with the windings of the stator 42b that is generating heat.

When the second piston 4 rises, the back pressure space 10 is removed from the drive motor chamber 42 through the second communication pipe 105.
When the working gas flows into 1, the heated working gas is radiated by the second radiator 106 provided in the second communication pipe 105. Further, when the second piston 4 descends, the heat is further radiated by the first radiator 103.

As a result, the flow of the working gas is generated between the back pressure space 101 and the drive motor chamber 42 in accordance with the reciprocating movement of the second piston 4, and the moving working gas directly causes the stator 42b, which is a heat source, to generate heat. After cooling, the heat absorbed is dissipated by the first and second radiators 103 and 106. As described above, in this embodiment, the first and second radiators 103 and 106 dissipate heat, but if the amount of heat radiation is small, only the first and second radiators 103 or the second radiator 106 may be used. However, when provided in the second radiator 106, since the working gas flowing into the back pressure space 101 is radiated, the working space 5 is not thermally affected.
For this reason, there is no possibility that the efficiency of the device is reduced by the thermal work by the back pressure space 101.

Conventionally, a buffer tank is connected to the back pressure space 101 so that the back pressure space 101 does not work due to the reciprocating motion of the second piston, and pressure fluctuation in the back pressure space 101 is suppressed as much as possible. However, with the above configuration, it is not necessary to separately provide a buffer tank, and the entire apparatus can be reduced in size and weight.

In the above embodiment, the case where the present invention is applied to a two-piston Stirling refrigerating apparatus has been described. However, the present invention can be applied to other gas compression / expansion machines. In the above-described embodiment, the configuration in which the oil seal 108 is provided adjacent to the shaft bearing 43 has been described. However, instead of the oil seal 108, an oil absorbing member is provided in the second communication pipe 105, and the back pressure space 101 is provided. It may be configured to prevent oil from entering the oil. As the oil adsorbing member, an oil filter made of a porous material through which a working gas can pass but mist oil or the like is adsorbed is used.

Further, in the above embodiment, the shaft bearing 43
Is described in the crank mechanism 9, but the crankshaft 41 is penetrated by the rotor 42 a, and the end of the penetrated shaft is pivotally supported by a shaft bearing provided on the side wall of the drive motor chamber 42. It may be configured.

In the above embodiment, the compression cylinder chamber 3
Although the configuration in which the back pressure space 101 and the drive motor chamber 42 communicate with each other by the communication pipe has been described, a configuration in which the back pressure space of the expansion cylinder chamber 32 communicates with the drive motor chamber 42 may also be used. Absent.

[0031]

As described above, according to the present invention, the working gas reciprocates between the back pressure space and the drive motor chamber as the piston reciprocates, and the flow of the working gas in the drive motor chamber is reduced. Therefore, the stator, which is a heat source, is directly cooled to prevent a reduction in the efficiency of the device due to the heat generated by the motor and the occurrence of electric leakage.

Further, pressure fluctuations in the back pressure space due to the reciprocating motion of the piston are suppressed, so that it is not necessary to newly connect a buffer tank to the back pressure space, and the entire apparatus can be reduced in size and weight.

[Brief description of the drawings]

FIG. 1 shows one embodiment of a gas compression / expansion machine of the present invention.
It is a schematic block diagram of a piston type Stirling refrigerating device.

FIG. 2 is a schematic configuration diagram of a conventional two-piston Stirling refrigerating apparatus.

FIG. 3 is a schematic configuration diagram of a cross section taken along line AA in the conventional device in FIG. 2;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Stirling refrigerating device 2 first piston 3 expansion chamber (working space) 4 second piston 5 compression chamber (working space) 6 heat regenerator 8 gas flow path 9 crank mechanism (drive mechanism) 31 compression cylinder chamber 32 expansion cylinder chamber 42 Drive motor chamber 44 Piston drive chamber 101 Back pressure space 102 First communication pipe 103 First radiator 104 One-way valve (first valve means) 105 Second communication pipe 106 Second radiator (radiator) 107 One-way valve ( Second valve means)

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F25B 9/14 520

Claims (4)

(57) [Claims] The piston driving chamber includes a cylinder chamber in which a piston reciprocates, a piston driving chamber in which a driving mechanism for reciprocating the piston is disposed, and a rotor and a stator. A drive motor chamber for transmitting the pressure, and a structure in which the cylinder chamber is partitioned into a working space and a back pressure space via the piston, and a working gas that fills the working space as the piston reciprocates. A first and second communication pipes provided to communicate the back pressure space of the cylinder chamber with the drive motor chamber; and a first communication pipe provided in the first communication pipe; First valve means for permitting movement of the working gas from the back pressure space to the drive motor chamber, and being provided on the second communication pipe, permitting movement of the working gas from the drive motor chamber to the back pressure space Second valve means, the gas compressor expander, characterized by comprising a heat radiation means provided in the second communication pipe, the that. 2. The gas compression / expansion machine according to claim 1, wherein the first communication pipe and the second communication pipe are arranged with respect to the drive motor chamber so as to sandwich the stator. 3. The gas compression / expansion machine according to claim 1, wherein the drive motor chamber is air-tightly disposed with respect to the piston drive chamber via an oil seal member. 4. A gas compression / expansion machine according to claim 1, wherein an oil adsorbing member is provided in said second communication pipe.