JPH03199856A - Gas cycle engine - Google Patents

Abstract

PURPOSE:To equalize driving force moving the pistons of both first coil and second coils, and to reduce the vibrations of a gas cycle engine by connecting the first coil and the second coil in series and making the same currents flow through the first coil and the second coil. CONSTITUTION:When an AC power is connected to a first electric contact 24a and a second electric contact 24b, Lorentz force in the axial direction works to a first coil 20a and a second coil 20b by the interaction of the permanent magnetic fields of annular spaces 26a add 26b, and pistons 3a and 3b begin to be vibrated in the axial direction. Since the vibrations are equalized mutually and conducted in the opposite directions, an operating gas sealed into an operating space is compressed and expanded, and cold is generated in an expansion space 8. Since the coil 20a and the coil 20b are connected in series at that time, currents made to flow through the coil 20a and the coil 20b are equalized completely even when the resistance and inductance of both coils differ. Accordingly, force driving the first piston 3a and the second piston 3b is made the same, thus also reducing the unbalance of the phase and amplitude of the reciprocating motion of both pistons, then remarkably lowering the vibrations of a gas cycle engine.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to gas cycle engines, and particularly to gas cycle engines.

It relates to gas coolers such as Stirling coolers.

[Conventional technology]

FIG. 2 is a cross-sectional side view showing a schematic configuration of a conventional Stirling cycle gas cooler disclosed in, for example, Japanese Patent Application Laid-Open No. 64-63761. In the figure, (1) is a cylinder, inside which a free displacer (2) reciprocates. The working surface (4) of the first piston (3a)
0, the working surface (4b) of the second screw I-n (3b), and
The compression space (5) between the lower working surface (2a) of the free displacer (2) is connected to a cooler (6) and a communication hole (7).
).

The upper working surface (2b) of the free displacer (2) bounds an expansion space (8);
) constitutes the working space together with the compression space (5). The heat accumulator (9) provided in the free displacer (2) is connected to the working medium below through the center hole (QO) and the center hole (QO).
) and B, which communicate with the working medium above it via a radial flow duct (12). The machine is equipped with a freezer (13) as a heat exchanger for heat exchange between the expanded cold working medium and the object to be cooled.

Between the first piston (3a) and the second piston (3b) and the wall of the compression cylinder (14) are first piston seals (15al, (lea) and second piston seals (15b), respectively).

(ieb), and seals (17) and (18) are provided between the free displacer (2) and the cylinder (11).A first piston (3a) and a second piston (3b)
each includes a lightweight first sleeve (19a) and a second sleeve (19b) made of a non-magnetic material such as synthetic resin or aluminum, and the sleeves (19a) and (19
b) is wound with a conductor and connected to the first moving coil (20a).
and a second movable coil (forming 20bl, the first movable coil:
The first lead wire (22a), (23a) and the second lead wire (22) extend outward through the wall of the housing (21).
b), (23b). These leads I
! (22a), (23a), (22b),
(23b) are respectively placed outside the housing (21).
It has electrical contacts (24a), (25a) and second electrical contacts (24b), (25b). Moving coil (20a
), (20bl is the piston (3a), (3b
) is concatenated with.

A first gap (2
6a) and the second gap (26b). The above gap (26a), ' (2Bb
), a permanent magnetic field exists in the radial direction transverse to the moving direction of the moving coil (20m), (20b), and the first gap (
26a), a second gap (213b) is formed from the inner diameter to the outer diameter direction.
), the magnetic flux is directed from the outer diameter toward the inner diameter. The magnetic fields in these gaps (28a) and (26b) are permanent magnets (27a) and (27b).

Annular discs (28a), (28b), soft iron cylinder (29a).

(29b) is supplied by a closed magnetic circuit consisting of (29b).

The screws (3a) and (3b) are support springs (30a), respectively.

(30b), which is bis h :/ (3a),
The fixed center position of (3b) is secured. Also a support spring (30a).

Both ends of (30b) are locked to prevent lateral movement.

Protrusions (31a), (32a) and protrusions (3), respectively.
1b) and (32b). An elastic member (33) is provided below the free displacer (2) to limit the stroke of the free displacer (2). Moreover, FIG. 3(,) is an explanatory diagram showing the magnetic circuit of the gas cycle engine according to this conventional example, and the arrows indicate the direction of magnetic flux.

FIG. 3(b) is a graph showing the displacement of the working surface of the piston, where the horizontal axis shows the displacement of the piston, and the M axis shows time.

Next, the operation will be explained.

Electric contacts (2) are connected to the moving coils (20a) and (20b).
4a), (25a).

(3) (4) (24b), (25b) and lead wire (22a)
, (23a), (22b).

(23b) when an alternating current is passed through the moving coil (20
a).

(20b) has gaps (26m) and (26m), respectively.
b) Due to the interaction of the permanent magnetic field and the current in the axial Lorentz force acts on the piston (3a), (
3b), the assembly consisting of the sleeves (19a), (19b) and the moving coils (20a), (20b) begins to vibrate in the left-right direction.

Now, the first moving coil (20a) and the second moving coil (20a)
b) with the same characteristics, the two gaps (26a) and the gap (26
b) When currents with the same phase and amplitude are passed through the first moving coil (20a) and the second moving coil (20b) under the condition that the strength of the magnetic field is equal, two gaps (2Ba) and a gap (26b) are created.
Since the direction of the magnetic field at is opposite, the first moving coil (
20a) and the second moving coil (20b) are shown in Fig. 3(b).
As shown in the figure, they vibrate in opposite directions with the same amplitude, and as a result, the compression space (
The volume of - will change periodically due to vibration. The compression space (
When the volume of 5) changes, the working gas sealed in the working space is subjected to pressures m and m, and the pressure of the gas fluctuates. Furthermore,
The pressure fluctuation B causes a periodic pressure difference fluctuation between both ends of the heat storage device (9), and as a result, the free displacer (2) is caused by the pressure difference and the resonance of the elastic member (33).
3a), at the same frequency as (3b).

And they start to move in different phases.

Piston (3aL (3b) and free displacer (
2) When the working gas (e.g. helium) in the working space moves with different phases, it constitutes a thermodynamic cycle, better known as the inverted Stirling cycle, generating refrigeration in the expansion space (8). .

Regarding the above-mentioned "'Reverse Stirling Cycle" and its principle of cold generation, please refer to the 2nd document "Cryoeolers (G
, Walker, Plenum Press, New
York, 1983. pp. 177-123).

[Problem to be solved by the invention]

Conventional gas cycle engines are configured as described above, so if there is a difference in resistance or inductance between the first and second coils, a difference will occur in the current flowing through the first and second coils. This causes a difference in the phase and amplitude of the reciprocating motion between the first and second pistons, and as a result,
There was a problem that the vibration of the gas cycle engine increased.

This invention was made to solve the above-mentioned problems, and its purpose is to improve the extremely low vibration of gas cycle engines.

[Means to solve the problem]

The gas cycle engine according to the present invention has a first coil and a second coil connected in series.

By making the current flowing through the first and second coils the same, the unbalance in phase and amplitude of the reciprocating motion of the first and second pistons can be minimized.

Reduce vibrations in gas cycle engines.

[For production]

In this gas cycle engine, the first coil and the second coil are connected in series, and since the same current flows through the first coil and the second coil, the piston of the first coil and the second coil is driven to move. The forces become equal, and this causes the first piston and the second screw! - The unbalance of the phase and amplitude of the reciprocating motion of the engine is also reduced, which reduces the vibration of the gas cycle engine.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (34) is external wiring, and by connecting the first electrical contact (25a) and the second electrical contact (25b), the first coil (200) and the second coil (20b) are electrically connected in series. Components with the same reference numerals as those in FIG. 3 indicate the same or corresponding parts, and the explanation thereof will be omitted here.

The operation of the two embodiments will be explained below. In the figure,
When an AC power source (not shown) is connected to the first electrical contact (24a) and the second electrical contact (24b), the first coil (24b)
0a) and the second coil (20b), the lead wires (
An alternating current flows through 22a), (23a), external wiring (34), lead @ (22bl and (22b). Then.

The moving coils (20a) and (20b) have an annular gap (
26a) and (26b) due to the interaction of the permanent magnetic field and the current.

An axial Lorentz force acts, and as a result, the piston (3
a) and (3b) begin to vibrate in the axial direction. Otsu no Furi (7)
) (8) This is because the motions are the same vibration and in opposite directions.

The working gas sealed in the working space undergoes compression and expansion,
As a result, refrigeration will be generated in the expansion space (8) according to exactly the same operating principle as explained in the conventional example.

Here, the difference between the two embodiments and the conventional example is as follows. In other words, in the two embodiments, since the first coil (20a) and the second coil (20b) are connected in series, the resistance and inductance of the first coil (20a) and the second coil (20b) Even if there is a difference, the first coil (20a)
The current flowing through the second coil (20b) is exactly the same. In this way, the forces driving the first piston (3a) and the second piston (3b) become equal, which reduces the unbalance in the phase and amplitude of the reciprocating motion of the two pistons, reducing vibrations in the gas cycle engine compared to the conventional example. This is a significant reduction in comparison.

〔Effect of the invention〕

As described above, according to the present invention, the unbalance in the phase and amplitude of the reciprocating motion of the first piston and the second piston is reduced, so that a gas cycle engine with extremely low vibration can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view showing a gas cycle engine according to an embodiment of the present invention, FIG. 2 is a cross-sectional side view showing a conventional gas cycle engine, and FIG. 3(a) is a cross-sectional side view showing a conventional gas cycle engine. Explanatory diagram showing the principle of movement, and the third
Figure (b) is a curve diagram showing the displacement of the working surface of the piston. (3a)・First piston, (3b)・Second screw)・N. (20a)...first moving coil, (20b) is the second moving coil, (26a), (26b) - gap,
(27a), (27b) Permanent magnet, (34
)...External wiring. Note that in the two figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] By passing an alternating current through the first and second moving coils inserted into the gap between the magnetic fluxes created by the permanent magnets, the first piston and second piston connected to each of the moving coils are made to have the same phase and amplitude. 1. A gas cycle engine configured to vibrate in opposite directions to compress and expand working gas, characterized in that first and second moving coils are electrically connected in series by external wiring.