JPH0424620B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an oil-fed Stirling cycle refrigerator equipped with a radial piston compressor.

(Prior Art) It is well known that in a Stirling cycle refrigerator, it is necessary to cause a compression piston and a displacer to reciprocate under a constant phase difference. Known drive systems for the compression piston and displacer to generate such motion include a crankshaft drive system, a rotating swash plate drive system, a Rhombic drive system, and a linear drive system. The drive system and linear drive system are drive systems for single-cylinder engines, and are not suitable for multi-cylinder systems.

Therefore, conventional techniques are known in which the crankshaft drive system (see Japanese Patent Application Laid-open No. 58-69366) or the rotary swash plate drive system (see Japanese Patent Application Laid-Open No. 54-149958) is used for multi-cylinder applications.

The above crankshaft drive system is constructed by arranging multiple cylinders coaxially in series and connecting the compression piston inserted in one cylinder and the displacer inserted in the other cylinder in the axial direction. The above rotating swash plate drive method is constructed by arranging a plurality of cylinders concentrically, and arranging a compression piston inserted into one cylinder and a displacer inserted into the other cylinder parallel to each other. It is something that will be done. Both of these types can be made to have multiple cylinders relatively easily.

(Problems to be Solved by the Invention) However, the above-mentioned prior art has a complicated structure, and there is a problem in that in order to obtain a large output, the overall weight and size must be increased. In particular, the rotating swash plate drive system is generally suitable for small refrigerators.
It is necessary to increase the diameter of the swash plate according to the piston diameter, and the strength of the swash plate and bearing part must be increased accordingly, so increasing the output inevitably increases the size of the device. .

This invention was made to solve the above-mentioned conventional problems, and its purpose is to provide a multi-cylinder oil-fed Stirling cycle refrigerator that has a simple structure, is compact, lightweight, and has high reliability. do.

(Means for Solving the Problems) In order to achieve the above object, the present invention radially arranges a plurality of compression pistons and a crosshead coaxially connected to each compression piston via a piston rod. A radial type piston drive device is constructed by slidingly contacting the connecting rod of the crosshead with the eccentric body of the crankshaft which is rotationally driven by the drive machine. In addition, a plurality of displacers are arranged concentrically with the crankshaft, and a cam groove that is displaceable in the axial direction of the crankshaft is provided on the outer periphery of a cam member fixed to one end of the crankshaft. A displacer drive device is constructed by inserting a drive body and connecting a rod for reciprocating the displacer in the axial direction of the crankshaft to the drive body. The shape of the cam groove is set so that the phase of the displacer corresponding to each compression piston can be advanced by approximately 90 degrees. Further, a first passage for lubricating oil extending from one end of the crankshaft into the body and opening at the sliding contact portion of the connecting rod is provided, and a second passage for lubricating oil extending from the sliding contact portion into the crosshead is provided. ing. Second
One end of the passage opens toward the first passage, and the other end opens into the crosshead chamber. A lubricating oil supply device supplies lubricating oil to the second passage via the first passage. Furthermore, a shielding member is fixed to the cylinder into which the compression piston and crosshead are inserted, which shields between the rear chamber of the compression piston and the crosshead chamber, and the piston rod is slidably attached to this shielding member. Penetrating.
Furthermore, the gap between the shielding member and the piston rod is hermetically sealed by a sealing device.

(Function) According to the present invention, a radial piston drive device and a displacer drive device having a plurality of displacers arranged concentrically with the crankshaft of the piston drive device are combined to produce a Stirling cycle refrigeration system. With this structure, even if the number of compression pistons and displacers is increased to improve the refrigerating capacity, the overall size of the refrigerating machine can be avoided.

Furthermore, since a radial piston drive mechanism is employed, most of the gas compression loads are canceled out in the compression chamber, making it possible to maintain the balance of compression forces relatively easily. Therefore, the load on the bearing section that supports the crankshaft can be reduced, so that the casing and the bearing section can be made more compact as a whole.

Furthermore, since the compression piston and the crosshead are arranged radially, even if the diameter of the piston is increased, the overall size of the device does not increase. Therefore, the output can be easily increased.

In addition, the lubricating oil supplied to the first passage is supplied to the bearing of the connecting rod that is in sliding contact with the body through the first passage extending from one end of the crankshaft into the body, and further, the lubricating oil is Since a portion is supplied to the bearings of the crosshead via a second passage in the connecting rod, generation of frictional heat in each bearing is prevented. This prevents parts from being worn out due to seizure, improving the reliability of the bearing, and extending the life of the bearing.

In addition, the shielding member that shields the crosshead chamber and the compression chamber is fixed to the cylinder, the piston rod is slidably passed through the shielding member, and the gap between the piston rod and the shielding member is airtightly sealed.
Lubricating oil in the crosshead chamber is prevented from entering the compression chamber. Thereby, the inside of the compression chamber can be kept clean at all times, and the refrigerant can be prevented from being contaminated by oil.

Furthermore, since the oil flowing out from the second passage into the crosshead chamber has already undergone a pressure drop through the first and second passages, the oil pressure in the crosshead chamber can be kept low, so that the shielding member and the piston rod can be kept low. can be easily and reliably sealed.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a refueled Stirling cycle refrigerator. In the figure, a refueled Stirling cycle refrigerator 1 includes a radial piston drive device 2 and a displacer drive device 3 connected to each other.

The piston drive device 2 includes a speed reducer 5 and a drive device 6, and the speed reducer 5 is, for example, a planetary gear mechanism or a bevel gear mechanism. One end of the drive shaft (not shown) of the reducer 5 extends in a direction perpendicular to the direction in which the drive device 6 and the reducer 5 are connected (left-right direction in FIG. 1), and is connected to the taxi crankshaft 4.
The other end of the drive shaft on the side opposite to the crankshaft 4 is connected to a lubricating oil pump 70 with a pressure regulating valve. The lubricating oil pump 70 is driven by the reducer 5 and pumps oil into an oil reservoir 88 of the casing 28, which will be described later.
plays the role of supplying lubricating oil under pressure. The crankshaft 4 passes vertically through the airtight crankcase 7, and is rotatably supported within the crankcase 7 by roller bearings 8a, 8b. The body 9 of the crankshaft 4 has a larger diameter than the crankshaft 4 and is eccentric with respect to the crankshaft 4. The diameter and eccentric width of the body 9 are selected depending on the stroke of the compression piston 17.

As shown in FIG. 2, the crankcase 7 has four crosshead cylinders 11 and four compression piston cylinders 18 coaxially connected to each cylinder 11, which are arranged radially in the radial direction of the crankshaft 4. It is installed protrudingly. A shielding member 50 is fixed between the cylinders 11 and 18, respectively.
The rear chamber 2 inside the cylinder 18 is protected by the shielding member 50.
1 and the crosshead chamber 16 within the cylinder 11 are shielded. The shielding member 50 consists of a cylindrical portion 51 and a flange portion 52. The cylindrical portion 51 extends coaxially with the cylinders 11 and 18, and has a piston rod 15 extending from the compression piston 17 in its shaft hole.
penetrates freely. An annular seal chamber 56 surrounding the piston rod 15 is formed within the cylindrical portion 51 . Further, the lower end portion 53 of the cylindrical portion 51 is fitted into the cylinder 11, and the flange portion 52 is
It is flange-coupled to the bottom portion 18a of the cylinder 18 and the flange portion 11a of the cylinder 11. Note that 57 and 58 are seal rings, 59 is an oil stopper ring, and 57a and 58a are seal ring holders.

As shown in FIG. 1, the crosshead 12 in the crosshead cylinder 11 is connected to one end 15a of the piston rod 15 and connected to the spherical head 13 of the connecting rod 13 via a spherical bearing 19.
Connected to C. A second passage 83 for lubricating oil is provided in the crosshead 12 and connecting rod 13. The second passage 83 consists of a branch passage 60 in the crosshead 12 and a straight horizontal passage 62 in the connecting rod 13. The branch passage 60 is connected to the spherical bearing 19
It branches radially around the center, and its outer end extends from the peripheral edge of the head surface 61 to the crosshead chamber 1.
It is open facing 6. The horizontal passage 62 extends in the axial direction of the connecting rod 13 from the spherical head 13C, one end thereof communicates with the inner end of the branch passage 60, and the other end communicates with the sliding bearing 1 of the connecting rod 13.
3 and opens toward the outer circumferential surface of the body portion 9. Note that a guide ring 14 is in contact with each flange portion 13b of the connecting rod 13, thereby allowing the connecting rod 13 to swing smoothly. Furthermore, the piston ring 22 and rider ring 23 of the compression piston 17 are both made of non-lubricated material.

A first passage 82 for lubricating oil is provided within the crankshaft 4 . The first passage 82 is connected to the crankshaft 4
It consists of a vertical passage 84 in the inner part and a branch passage 85 in the body part 9. The upper end of the vertical passage 84 communicates with a fuel filler port 86 projecting from the upper end of the crankshaft 4 , and its lower end reaches into the body 9 . The branch passages 85 each extend in the radial direction of the crankshaft 4 and, as shown in FIG. The inner end of the branch passage 85 communicates with the vertical passage 84, and the outer end thereof has a discharge port 87 that opens facing the slide bearing 13a.
is provided. The phase of the discharge port 87 is, in this example, one compression piston 1 during one cycle.
7 is set so that it can face the horizontal passage 62 of the connecting rod 13 when it is located at the upper end of the cylinder 18 (top dead center position).

A hollow oil reservoir 88 is provided on the upper end side of the crankshaft 4 in FIG. The oil reservoir 88 is a lubricating oil inlet passage 8 provided in the casing 28.
9 and the inlet passage 89 communicates with the pump 70 via a pipe (not shown). An opening/closing means 90 is interposed between the oil reservoir 88 and the oil supply port 86 of the crankshaft 4, as shown in FIG. The opening/closing means 90 includes a disk-shaped fixed distribution piece 91 and a disk-shaped rotation distribution piece 9.
It is composed of 2. Fixed distribution piece 91
is the casing 2 facing the oil sump 88.
8, and its peripheral edge has four through holes 93 concentrically with the crankshaft 4 and equally spaced in the circumferential direction.
is drilled. On the other hand, the rotating distribution piece 92
is press-fitted and fixed to the upper end of the crankshaft 4 while being slidably superimposed on the fixed distribution piece 91. A long hole 94 extending concentrically with the through hole 93 is bored in the peripheral portion of the rotary distribution piece 91 . As shown in FIG. 3, the elongated hole 94 has a substantially L-shaped cross section perpendicular to the axis, and communicates with the oil filler port 86 of the crankshaft 4. In this embodiment, the phase of the elongated hole 94 with respect to the crankshaft 4 is set to be in the same phase as any one of the branch passages 85 (FIG. 1) in the body 9, and the elongated hole The phase of the through hole 93 with respect to the connecting rod 13 is such that the discharge port 87 (FIG. 1) of the branch passage 85 is connected to the connecting rod 13.
The elongated hole 94 and the through hole 93 are set to coincide with each other only during the period when they face the slide bearing 13a.

Each back chamber 21 in the cylinder 18 for compression piston
As shown in FIG. 2, the first bypass pipe 7
2, and each crosshead chamber 16 in the crosshead cylinder 12 communicates via a second bypass pipe 73. As a result, pressure changes due to volume changes in the back chamber 21 and crosshead chamber 16 during one cycle cancel each other out, and the pressures in the back chamber 21 and crosshead chamber 16 are each maintained at constant pressures.

The compression chamber 20 and the back chamber 21 are filled with a working gas as a refrigerant, such as He gas, and the crosshead chamber 16 is filled with a lubricating oil pump 7.
It is filled with lubricating oil supplied from 0. As shown in FIG. 1, the compression chamber 20 is connected to the back chamber 2 via a third bypass pipe 64 and a check valve 65.
It is connected to 1. The check valve 65 allows gas to flow from the back chamber 21 to the compression chamber 20 , and the compression chamber 2 generated when the gas in the compression chamber 20 passes through the piston ring 22 and flows into the back chamber 21 .
It plays a role in preventing a drop in the maximum pressure of 0.

On the other hand, the back chamber 21 communicates with the seal chamber 56 via a fourth bypass pipe 66, a check valve 68, an oil adsorption section 69, and a passage 67. The check valve 68 is
It plays a role in compensating for gas leakage from the back chamber 21 to the seal chamber 56 via the seal ring 58.

Note that the crosshead cylinder 11 is provided with an oil drain passage 96 that communicates with the crosshead chamber 16 and the reduction gear chamber 95, and the crankcase 7 is provided with an oil drain passage 96 that communicates with the crosshead chamber 16 and the reduction gear chamber 95.
Oil drain hole 7 communicating with crank chamber 80 and reduction gear chamber 95
6 is provided.

Next, the configuration of the displacer drive device 3 will be explained. A cam member 30 coaxial with the crankshaft 4 is provided at the upper end of the crankshaft 4 in FIG. A key (not shown) is provided between the crankshaft 4 and the cam member 30 for transmitting rotational motion.
is inserted. On the outer peripheral surface of the cam member 30,
A cam groove 32 with a rectangular cross section extending in the circumferential direction is formed. The cam groove 32 is curved in a sinusoidal shape in the circumferential direction, and four roller-shaped driving bodies 33 are inserted into the cam groove 32 at equal intervals in the circumferential direction. . Each drive body 33 is rotatable about an axis perpendicular to the crankshaft 4 by a grease-sealed roller bearing (not shown), and is connected to four rods 34 concentrically with the crankshaft 4 by bolts and bolts. They are individually fastened with nuts 95. Each rod 34 extends coaxially with the crankshaft 4 and is reciprocatably supported within the airtight casing 28 by low vapor pressure, grease-sealed bearings 36a, 36b.

Each rod 34 is individually connected to each displacer 41 in four displacer cylinders 40 extending coaxially with the rod 34.
The displacer 41 has a relatively large diameter first displacer 41 connected to the tip of the rod 34.
a, and a relatively small-diameter second displacer 41b connected to the first displacer. 1st
An airtight back chamber 42 is provided at the connection between the displacer 41a and the rod 34, and this back chamber 42 is connected to the compression chamber in the compression piston cylinder 18 via a passage 43 and a heat exchanger 44. It is connected to 20. The heat exchanger 44 is configured by incorporating a plurality of water cooling pipes.

Inside the first displacer 41a, a first regenerator 38a made up of layered wire mesh (cold storage material) is incorporated, and inside the second displacer 41b, lead particles (cold storage material) are incorporated. A second regenerator 38b filled with water is incorporated. 1st displacer 4
1a and the second displacer 41b is provided with an airtight first expansion chamber 46a, and in the vicinity of this first expansion chamber 46a, each first expansion chamber of the displacer cylinder 40 is provided. A first annular cold head 47a is provided which communicates with all of the cold heads 46a. Further, an airtight second expansion chamber 46b is provided at the tip of the second displacer 41b, and each second expansion chamber of the displacer cylinder 40 is provided in the vicinity of the second expansion chamber 46b. An annular second cold head 47 that communicates with all of 46b.
b is provided. First and second expansion chambers 46
a, 46b are the first and second regenerators 38a, 3
It communicates with the rear chamber 42 on the rod 34 side via 8b.

Next, the operations of the radial piston drive device 2 and the displacer drive device 3 will be explained.

First, when the drive device 6 is activated, the crankshaft 4 is reduced to a constant rotational speed by the reduction gear 5 and driven to rotate. The rotational movement of the eccentric body 9 of the crankshaft 4 is transferred to the crosshead 12 via a plain bearing 13a.
and is converted into a reciprocating motion of the compression piston 17. Due to the eccentricity of the body 9, the four crossheads and compression pistons 17 reciprocate within the cylinders 11 and 18 with a phase difference of 90 degrees.

Furthermore, the rotational torque of the crankshaft 4 is transmitted to the cam member 30 and converted into reciprocating motion of the rod 34 via a drive body 33 inserted into the cam groove 32 of the cam member 30. Due to the sinusoidal shape of the cam groove 32, the four displacers 41 move toward the cylinder 4 90 degrees ahead of the phase of the corresponding compression piston 17.
Each reciprocates within 0.

Furthermore, the lubricating oil pump 70 directly connected to the reducer 5 is driven by the operation of the driving machine 6, and thereby,
The lubricating oil enters the inlet passage 8 of the casing 28 at a predetermined pressure.
9 and is supplied to an oil sump 88. On the other hand, the rotary distribution piece 91 is rotationally driven by the rotation of the crankshaft 4, and the lubricating oil in the oil reservoir 88 is released when the long hole 94 of the rotary distribution piece 91 and the through hole 93 of the fixed distribution piece 92 coincide with each other. , that is, the outlet 87 of the branch passage 85 of the body 9 is connected to the horizontal passage 62 of the connecting rod 13.
is fed into the vertical passage 84 of the crankshaft 4. A portion of the lubricating oil discharged from the discharge port 87 is distributed between the sliding bearing 13a of the connecting rod 13 and the body portion 9.
The remaining lubricating oil is supplied to the spherical bearing 19 through the horizontal passage 62. The lubricating oil for the spherical bearing 19 is further supplied into the crosshead chamber 16 through a branch passage 60 in a substantially pressureless state. A portion of the lubricating oil accumulated in the crosshead chamber 16 lubricates the inner wall of the cylinder 12, and the remaining lubricating oil is led into the reducer chamber 95 through the oil drain passage 96. The lubricating oil accumulated in the crank chamber 80 is also guided to the reduction gear chamber 95 via the oil drain hole 76. The lubricating oil in the reducer 95 is collected into the lubricating oil pump 70 via a filter (not shown), and is again supplied to the oil reservoir 88 for lubrication.

Next, four steps per cycle of the Stirling cycle refrigerator 1, that is, an isothermal compression step, an isovolume step,
The isothermal expansion process and the isovolume process will be explained.

First, in the isothermal compression process, when the compression piston 17 rises from a state where the displacer 41 is located at the upper end of the displacer cylinder 40 and the compression piston 17 is located at the lower end of the compression piston cylinder 18, the compression chamber The working gas in 20 is compressed and flows into back chamber 42 through heat exchanger 44 and passage 43 . At this time, a part of the generated gas compression heat is absorbed by the water-cooled cylinder 18, and the remaining compression heat is absorbed by the heat exchanger 44, so ideally, the compression process is an isothermal compression process.

Next, in the equal volume process, the displacer 4
1 descends, the working gas in the back chamber 42 passes through the first regenerator 38a and flows into the first expansion chamber 46a, and some of the working gas flows into the second regenerator 38a.
8b and flows into the second expansion chamber 46b.
At this time, the working gas is supplied to the first and second regenerators 3
When passing through the regenerators 8a and 38b, the regenerator absorbs heat and is cooled, and the pressure also decreases, becoming a low-temperature gas at a predetermined pressure in the first and second expansion chambers 46a and 46b. This is an isovolumic change with a constant volume.

Next, in the isothermal expansion step, when the compression piston 17 descends, the first and second expansion chambers 46
The low temperature gas inside a and 46b cools down due to expansion. At this time, the first and second cold heads 4
Heat is removed from 7a and 47b, and the low-temperature gas eventually undergoes isothermal expansion at a constant temperature. The amount of heat taken by the low temperature gas is the refrigeration output of the refrigerator 1.

Next, in the equal volume process, the displacer 4
1 rises, the first and second expansion chambers 46a,
The low temperature gas in 46b is transferred to the first and second regenerators 3
8a, 38b, flows into the rear chamber 42 on the rod 34 side, and further flows into the compression chamber 20 through the heat exchanger 44. At this time, the low-temperature gas cools each of the regenerator materials in the first and second regenerators 38a and 38b, becomes high in temperature, and increases in pressure. This is an isovolumic change with a constant volume.

By repeating the above series of operations, continuous refrigeration output can be obtained in the first and second cold heads 47a and 47b.

In the above configuration, a radial piston drive device 2 and a plurality of displacers 4 arranged concentrically with the crankshaft 4 of the piston drive device 2 are provided.
Since the Stirling cycle refrigerator 1 is constructed by combining the displacer drive device 3 with the displacer drive device 3 having the Enlargement can be avoided.

Furthermore, since the compression piston 17 and the crosshead 12 driven by the eccentric crank mechanism are arranged radially, most of the gas pressure load in the compression piston cylinder 18 is canceled out, and the crankshaft 4
The compressive load on the bearing that supports this can be reduced. Therefore, the bearing portion and the crankcase 7 can be made more compact.

Furthermore, since the gas pressure load is offset, the diameter of the compression piston 17 can be increased, thereby increasing the output. Moreover,
Since the compression piston cylinders 18 are provided radially, even if the cylinder diameter is increased, the axial dimension (vertical direction in FIG. 1) of the entire refrigerator does not increase. Further, since the radial piston compressor has a structure that is flat with respect to the axial direction of the crankshaft 4, it is advantageous in reducing the axial dimension.

Further, since the forced lubrication method described below is adopted, good lubrication of each bearing portion 13a, 19 is achieved. That is, the gas pressure P1 in the compression chamber 20 during one cycle changes sinusoidally between the maximum pressure P3 and the minimum pressure P2, as shown in FIG. is maintained at a constant pressure. Here, if the pressure in the back chamber 21 is set equal to the above-mentioned minimum pressure P2, the gas load P4 acting on the compression piston 17 will be the differential pressure between the above-mentioned P1 and P2, and the crank angle of the displacer 41 will be 180 degrees to 270 degrees. In the range of , the value is almost zero. Therefore, the plain bearing 13 of the connecting rod 13
Since a is raised above the outer peripheral surface of the body portion 9 within the above crank angle range, the lubricating oil in the first passage 82 can be sufficiently supplied to the sliding bearing 13a. In addition, since the discharge port 87 of the first passage 82 is opened facing the second passage 83, the spherical bearing 1
9 can also be supplied with a sufficient amount of lubricating oil. This prevents the generation of frictional heat in each bearing 13a, 19, improves the reliability of the parts, and extends the life of the bearings 13a, 19.

Also, the crosshead chamber 1 is protected by the shielding member 50.
6 and the rear chamber 21, and both chambers 16, 21 are sealed with oil and gas by the seal rings 57, 58, so that the inside of the rear chamber 21 and the compression chamber 20 are always kept clean. This prevents contamination of the refrigerant gas with oil, prevents contamination of the inside of the heat exchanger 44 and the regenerator material, reduces heat transfer performance, and increases pressure loss, and improves refrigeration performance. It will be planned.

Furthermore, by setting the lubricating oil supply pressure by the lubricating oil pump 70 to be slightly higher than the pressure inside the crosshead chamber 16, the bearing 1
A sufficient lubrication effect of 3a, 19 can be obtained, and further,
Due to the pressure loss in the first and second passages 82, 83, the oil that reaches the crosshead chamber 16 becomes almost pressureless. By suppressing the amount of lubricating oil supplied to the crosshead chamber 16 to the minimum necessary in this way, the inside of the crosshead chamber 16 becomes an atmosphere in which oil exists in the form of a mist, and when the oil is filled with high pressure. Compared to the above, the oil seal between the shielding member 50 and the piston rod 15 can be easily and reliably sealed.

Furthermore, in this embodiment, lubricating oil was intermittently supplied into the first passage 82 by the opening/closing means 90;
The capacity of the pump 70 can be reduced, and the entire device can be downsized. Moreover, the first
Since the opening timing of the passage 82 is made to coincide with the period during which the first passage 82 and the second passage 83 communicate with each other, it is possible to prevent unnecessary discharge of lubricating oil into the crank chamber 80, and to achieve good efficiency. Good refueling effect can be obtained.

In addition, 50 seal rings 57 and 58 of the shielding member
Since a seal chamber 56 is provided in between and an oil stopper ring 59 is attached to the piston rod 15, it is assumed that oil adhering to the surface of the piston rod 15 passes through one seal ring 57 and enters the seal chamber 56. However, since this oil is dammed up by the oil stopper ring 59 and the other seal ring 58, the back chamber 2
Oil intrusion into the first side is reliably prevented.

Furthermore, since the cam member 30 is used as a method of driving the disk spacer 41, the cam member 30
The shape of the cam groove 32 of
By making appropriate changes within a range that does not interfere with the reciprocating motion of the displacer 41, it is possible to easily achieve the thermodynamically most desirable reciprocating motion of the displacer 41.

Further, since the piston drive device 2 and the displacer drive device 3 are connected by a key provided between the crankshaft 4 and the cam member 30, each reciprocating movement of the compression piston 17 and the displacer 41 The phase difference can be arbitrarily selected. This phase difference greatly affects the refrigeration output. In an ideal state, the refrigeration output is zero when the phase difference is 0 degrees, and the phase difference is 90 degrees.
refrigeration output reaches its maximum at 30°F. However, in reality, the optimum value exists near 90 degrees, which is slightly outside 90 degrees due to pressure loss and other factors.

In the above embodiment, the connecting rod 13 is directly slidably connected to the body 9, but a bearing such as a needle bearing may be interposed between the connecting rod 13 and the body 9.

(Effects of the Invention) As explained above, according to the present invention, the displacer drive includes a radial piston drive device and a plurality of displacers arranged concentrically with the crankshaft of the piston drive device. Since the refrigerator is constructed by combining these devices, even if the number of compression pistons and displacers is increased in order to improve the refrigerating capacity, it is possible to avoid increasing the size of the refrigerator as a whole.

Also, the radial arrangement of the compression pistons and crossheads cancels out most of the gas pressure loads on each cylinder. Therefore, the bearing portion and the casing can be made lightweight and compact. Furthermore, even if the cylinder diameter is increased in order to increase the output, the device is prevented from becoming complicated or large.

In addition, since lubricating oil is supplied to each bearing part of the connecting rod and the crosshead chamber, wear of parts due to friction is prevented and reliability is increased. Furthermore, the life of the bearing section is also extended. Further, since the rear chamber and the crosshead chamber are shielded by the shielding member, and the shielding member and the piston rod are airtightly sealed, contamination of the refrigerant by the shaft is reliably prevented. This makes it possible to improve the refrigeration performance.

Furthermore, since the lubricating oil is supplied to the second passage of the connecting rod through the first passage of the crankshaft, the supply pressure of lubricating oil in the crosshead chamber is significantly reduced due to the pressure drop in the first and second passages. Thereby, the seal ring can easily and reliably seal the oil between the crosshead chamber and the rear chamber.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a refueled Stirling cycle refrigerator according to the present invention, and FIG. 2 is a -
3 is an enlarged sectional view of the vicinity of the opening/closing means, FIG. 4 is a sectional view taken along the - line in FIG. 3, and FIG. 5 shows the relationship between the crank angle and the pressure in the compression chamber. This is a graph showing. 1...Refueling type Stirling cycle refrigerator, 2
... Radial piston drive device, 3 ... Displacer drive device, 4 ... Crankshaft, 6 ... Drive machine, 9 ... Body, 12 ... Crosshead, 13
... Connecting rod, 15 ... Piston rod, 16 ... Crosshead chamber, 17 ... Compression piston, 30 ... Cam member, 32 ... Cam groove, 33 ... Drive body, 34
...Rod, 38a, 38b...Regenerator, 41...
... Displacer, 21, 42 ... Rear chamber, 44
... Heat exchanger, 46a, 46b ... Expansion chamber, 50
...shielding member, 57, 58 ... sealing device, 6
0,62... passage, 70... lubricating oil supply device, 8
2...first passage, 83...second passage, 90...opening/closing means.

Claims (1)

[Claims] 1. The refrigerant compressed by the compression piston is sent through a heat exchanger to the rear chamber on one side of the displacer, passes through a regenerator in the displacer, and is expanded on the other side of the displacer. In an oil-fed Stirling cycle refrigerator that cools the refrigerant by flowing it into a chamber, a plurality of compression pistons and a crosshead coaxially connected to each compression piston via a piston rod are arranged radially. A radial piston drive device comprising a connecting rod of a crosshead in sliding contact with the eccentric body of a rotationally driven crankshaft, and a plurality of displacers arranged concentrically with the crankshaft, A cam groove that is displaceable in the axial direction of the crankshaft is provided on the outer periphery of a cam member fixed to one end, and the displacer is reciprocated in the axial direction of the crankshaft by a drive body inserted into this cam groove. a displacer drive device in which the shape of the cam member is set so that the phase of the corresponding displacer advances approximately 90 degrees with respect to each compression piston; A first passage for lubricating oil extends into the body and opens at the sliding contact portion of the connecting rod, and extends from the sliding contact portion of the connecting rod into the crosshead, with one end opening toward the first passage and the other end opening toward the first passage. a second passage for lubricating oil that opens into the crosshead chamber; a lubricating oil supply device that supplies lubricating oil to the second passage through the first passage; It is characterized by comprising a shielding member that shields between the back chamber and the crosshead chamber of the piston and through which the piston rod is slidably passed, and a sealing device that airtightly seals the gap between the shielding member and the piston rod. Lubricated Stirling cycle refrigerator. 2. The oil-supplied Stirling cycle refrigerator according to claim 1, wherein the lubricating oil supply device includes an opening/closing means for opening the first passage only during a period when the first passage and the second passage communicate with each other.