JP2823534B2 - 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]

SUMMARY OF THE INVENTION The present invention provides a cylinder chamber in which a piston reciprocates, a piston drive chamber in which a drive mechanism for reciprocating the piston is provided, and a driving force transmitted to the piston drive chamber. A drive motor chamber is provided, and the cylinder chamber has a structure partitioned into an operating space and a back pressure space via the piston, and compresses the working gas filling the operating space with the reciprocating operation of the piston. Alternatively, in a gas compression expander to be expanded, the gas compression expander includes a communication pipe provided to communicate the back pressure space of the cylinder chamber and the drive motor chamber, and a heat radiating means provided in the communication pipe. is there.

By using this configuration, 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 is generated inside the drive motor chamber. When the working gas heated by exchanging heat with the heat generating stator winding flows into the back pressure space, the working gas is radiated by the radiating means provided in the communication pipe. 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 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 communication pipe.

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

[0017]

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
A communication pipe 102 communicates the back pressure space 101 with the drive motor chamber 42. 103 is a radiator provided in the communication pipe 102, 104 is provided adjacent to the shaft bearing 43 provided in the crank mechanism 9,
This is an oil seal for preventing oil from entering the drive motor chamber 42 from above. The oil seal 104 prevents oil from entering the back pressure space 101.

As described above, the communication pipe 102 and the radiator 10
When the second piston 4 is lowered, the working fluid in the back pressure space 101 flows into the drive motor chamber 42 when the second piston 4 descends, and exchanges heat with the winding of the stator 42b that is generating heat, thereby being heated. When the second piston 4 rises, the drive motor chamber 4
When the working fluid flows from 2 into the back pressure space 101, the heated working fluid is radiated by the radiator 103 provided in the communication pipe 102. Thereby, the second piston 4
The back pressure space 101 and the drive motor chamber 42
The flow of the working fluid is generated between them, and the moving working fluid directly cools the stator 42b, which is a heat source,
The heat absorbed by the heat radiator 10
3 dissipates heat.

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 movement 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. Further, in the above-described embodiment, the configuration in which the oil seal 104 is provided adjacent to the shaft bearing 43 has been described. However, instead of the oil seal 104, an oil adsorbing member is provided in the communication pipe 102, and the oil suction member is provided in the back pressure space 101. A configuration for preventing oil intrusion may be used. 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
The communication tube 10 connects the back pressure space 101 of the first
Although the description has been given of the case of the configuration in which the communication is performed by the two, the configuration may also be such that the back pressure space of the expansion cylinder chamber 32 and the drive motor chamber 42 communicate with each other.

[0024]

As described above, according to the present invention, the working fluid reciprocates between the back pressure space and the drive motor chamber with the reciprocating operation of the piston, and the flow of the working fluid gas inside the drive motor chamber. 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 fluctuation in the back pressure space due to the reciprocating operation of the piston is suppressed, and 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 is a schematic configuration diagram of a two-piston Stirling refrigerating apparatus showing one embodiment of a gas compression / expansion machine of the present invention.

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 Communication pipe 103 Heat dissipation means

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

Claims (3)

(57) [Claims] A cylinder chamber in which a piston reciprocates, a piston drive chamber in which a drive mechanism for reciprocating the piston is provided, and a drive motor chamber for transmitting a driving force to the piston drive chamber; In the gas compression / expansion machine, the cylinder chamber has a structure partitioned into a working space and a back pressure space via the piston, and compresses or expands a working gas filling the working space with the reciprocating operation of the piston. A gas compression / expansion machine comprising: a communication pipe provided to communicate a back pressure space of the cylinder chamber with the drive motor chamber; and a heat radiating means provided in the communication pipe. 2. A gas compression / expansion machine according to claim 1, wherein said drive motor chamber is air-tightly disposed with respect to said piston drive chamber via an oil seal member. 3. The gas compression / expansion machine according to claim 1, wherein an oil adsorbing member is provided in said communication pipe.