JP4241192B2 - Linear compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a configuration of a linear compressor, and particularly to a low-vibration and low-noise linear compressor that is useful when used in a small-sized pulse tube refrigerator or the like.
[0002]
[Prior art]
Conventionally, Stirling refrigerators and GM refrigerators have been used as cold storage type refrigeration methods that target relatively low temperatures and obtain cold by reciprocating compression / expansion of working fluid without using phase change of refrigerant. Yes. These are characterized by the difference in the pressure vibration source, and the GM type generally uses a rotary compressor to constitute a high pressure and a low pressure source, and generates pressure fluctuations in the refrigerator by switching valves. On the other hand, in a Stirling refrigerator, pressure vibration is directly generated in the refrigerator by a piston that reciprocates in the cylinder. Both systems have a piston called a displacer that controls the movement of the working fluid in the system separately from the pressure vibration source, and compresses and expands the working fluid while reciprocating it inside the regenerator to generate heat flow. Is generated. Therefore, the control of the pressure and displacement of the working fluid greatly contributes to the refrigerating capacity.
[0003]
In recent years, in this regenerative refrigerator, a pulse tube refrigerator that uses a gas piston that is provided with a hollow tube called a pulse tube instead of a displacer and that is generated in the hollow tube has been remarkably developed. This pulse tube refrigerator has features such as a simple structure and easy vibration reduction because a displacer, which is a movable mechanism, is not required in the refrigeration unit.
[0004]
The pulse tube refrigerator was discovered in the 1960s, and the first generation basic type of the first generation had the end of the pulse tube simply closed, so the phase difference between the pressure fluctuation and the displacement described above was small, and the Stirling refrigerator Compared with GM refrigerator, the refrigerating capacity was small and not suitable for practical use. Later, in the 1980s, it was possible to control the phase difference to be larger by providing an orifice and a buffer tank at the end of the pulse tube as a second generation orifice type, and the practical application was advanced. Since then, a number of methods called third generation, which can control the phase in a wider range, have been proposed and have reached today.
[0005]
In a Stirling type pulse tube refrigerator, a linear compressor that directly drives a piston in a cylinder by a linear motor is generally used from the viewpoint of miniaturization. However, the linear compressor using a single piston has a problem that it cannot be used for an application that dislikes vibration because pulsating vibration is generated as the piston moves. In addition, this vibration has a problem of generating noise and reducing machine life. As a method for solving these problems, there is conventionally known a method in which two pistons are arranged facing each other and driven with a phase difference of 180 ° (see, for example, Patent Document 1).
[0006]
FIG. 6 is a diagram schematically showing a configuration of a conventional linear compressor described in Patent Document 1. In FIG. In FIG. 6, a compression space 63 is constituted by pistons 61A and 61B and a common cylinder 62, and the two pistons 61A and 61B are operated in mutually opposite phases. Reference numerals 64A and 64B denote drive units for driving the pistons 61A and 61B. A working fluid suction pipe 65 and a discharge pipe 66 are opened in the compression space 63. As a result, the forces acting on the compressor case due to the movements of the pistons 61A and 61B cancel each other, and vibration and noise of the compressor are prevented.
[0007]
In addition, the GM type pulse tube refrigerator has an advantage that the displacement and pressure waveforms can be ideally controlled because the working fluid sucked and discharged by the compressor can be controlled at any timing by opening and closing the valve. However, since it was necessary to provide a valve in addition to the compressor, there was a problem that the refrigerator was enlarged. As a method for solving this problem, a method of providing communication ports in the piston and the cylinder has been known (for example, see Patent Document 2).
[0008]
FIG. 7 is a diagram schematically showing the configuration of the conventional pulse tube refrigerator described in Patent Document 2 in FIG. In FIG. 7, a linear compressor is housed in a cylindrical outer case, and includes a cylinder 71a, a piston 71b, a shaft 71c, a drive unit 71d that drives the piston 71b, and the like. The cylinder 71a is configured integrally with the exterior case, and is sealed at one end and filled with a working fluid. The piston 71b is built in the cylinder 71a, and the compression chamber 71e is constituted by the piston 71b, the cylinder 71a, and a sealing end thereof. The piston 71b is provided with a communication passage 71i that communicates the outer peripheral portion of the piston 71b facing the side wall of the cylinder 71a and the compression chamber 71e. A first passage 72 extending outside the compressor 71 is provided on the side wall of the cylinder 71a, and The opening part which the one end side of the 2nd channel | path 73 connects is shifted and provided in the moving direction of piston 71b. When the compressor 71 is operated and the piston 71b is displaced in the left direction and the pressure in the compression chamber 71e becomes near the maximum value, the positions of the outer peripheral portion of the communication passage 71i and the opening portion of the first passage 72 are matched and compressed. A working fluid having a pressure corresponding to the internal pressure of the chamber 71e is delivered. Further, when the piston 71b is displaced rightward and the pressure in the compression chamber 71e becomes near the minimum value, the outer peripheral portion of the communication passage 71i coincides with the position of the second passage 73 and the opening portion, and according to the internal pressure. Pressure working fluid is aspirated. From the above, it is possible to switch between discharge and suction at a predetermined timing, as in the case of the compressor unit in the GM type refrigerator.
[0009]
Although FIG. 7 illustrates a single piston, it can also be realized with an opposed piston as shown in FIG. 6 in order to reduce vibration.
[0010]
[Patent Document 1]
Japanese Patent Laid-Open No. 61-210276 (page 3, FIG. 1)
[Patent Document 2]
Japanese Patent Laid-Open No. 11-294878 (page 3-4, FIG. 1)
[0011]
[Problems to be solved by the invention]
However, the configuration of FIG. 6 has the following problems. That is, in general, when the cylinder and piston have the same diameter and clearance, the longer the sliding distance, the smaller the leakage loss. Now, considering the case where exactly the same linear compressors are opposed to each other, simply comparing with one case, the total length of the compressor is doubled, and the leakage between the piston and the cylinder is also doubled. If leakage is to be suppressed equally, the sliding distance of each piston / cylinder needs to be longer, and the overall length of the compressor becomes even longer. That is, with this configuration, there are problems of increasing the size of the apparatus and reducing the compressor efficiency.
[0012]
Further, the configuration shown in FIG. 7 has the same problem as described above when the opposed piston is used to reduce the vibration. In addition to this, it has the following problems. That is, the communication passage 71i for suction and discharge provided in the piston 71b is always connected to the compression space, and has a dead volume that does not contribute to compression. That is, there is a problem that the compression ratio is lowered even if the strokes of the piston and the cylinder are the same.
[0013]
The present invention solves such a conventional problem, and provides a low-vibration, compact and high-efficiency linear compressor, and does not cause a decrease in compression ratio when used as a GM type compressor. An object is to provide a linear compressor.
[0014]
[Means for Solving the Problems]
In order to achieve this object, the linear compressor of the present invention has a configuration in which a movable cylinder and a movable piston are arranged to face each other and reciprocate in opposite phases.
[0015]
This configuration cancels out the force acting on the outer wall of the compressor as a reaction when the movable part moves, resulting in a low-vibration and low-noise device, and there is a sliding part only on one side of the compression chamber. Therefore, a linear compressor can be obtained in which leakage loss is reduced as compared with a structure in which both sides are sliding portions.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
  The invention according to claim 1 of the present invention includes a casing that forms the outer wall of the compressor, a cylinder that is housed in the casing and is slidably supported, and that is slid on the same axis as the cylinder sliding shaft. A piston that is movably supported, and a linear drive unit that reciprocates the cylinder and the piston along a sliding axis, and each linear drive unit forms a magnetic circuit with a mover and a stator. It consists of a linear motor that generates thrust, a connecting part that connects the cylinder or piston and the mover, and an elastic body that elastically supports the connecting part with respect to the casing, and the cylinder and piston are reciprocated in opposite phases.The casing includes a suction passage and a discharge passage through which a fluid to be compressed moves, and a cylinder side surface includes a suction port and a discharge port that communicate the casing side and the compression chamber side, The compression chamber communicates with the suction flow path through the suction port in the vicinity where the volume of the compression chamber becomes maximum, and the compression chamber and the discharge flow path through the discharge port in the vicinity of where the volume of the compression chamber becomes minimum. Are configured to communicate with each other.
  By configuring as described above, the force acting on the casing of the compressor as a reaction of motion is canceled out, and a low vibration and low noise compressor is obtained. Furthermore, since there is a sliding part only on one side of the compression chamber, the leakage loss is reduced as compared with a structure in which both sides are sliding parts, and the suction process is maximized at the timing when the pressure in the compression chamber is minimized. It is possible to obtain a linear compressor in which the timing can be clearly set so that the discharge process is performed at a certain timing.
[0017]
  The invention according to claim 2 is a casing that forms the outer wall of the compressor, a cylinder that is housed in the casing and is slidably supported, and is slid on the same axis as the cylinder sliding shaft that is housed in the cylinder. A piston that is freely supported, and a linear drive unit that reciprocally moves the cylinder and the piston along a sliding axis, and each linear drive unit forms a magnetic circuit with a mover and a stator. A linear motor that generates thrust, a connecting portion that couples the cylinder or piston and the mover, and an elastic body that elastically supports the connecting portion with respect to the casing. A reciprocating linear compressor, wherein the casing has a suction / discharge passage through which a fluid to be compressed moves, and the cylinder side is compressed with the casing side. Comprising a suction and discharge port communicating side, the suction and discharge passage and the compression chamber always irrespective of the volume of the compression chamber through the suction and discharge port are those configured so as to communicate.
  By configuring as described above, the force acting on the casing of the compressor as a reaction of motion is canceled out, and a low vibration and low noise compressor is obtained. Furthermore, since there is a sliding part only on one side of the compression chamber, a linear compressor that can reduce the leakage loss and repeat the suction / discharge process continuously as compared with a structure in which both sides are sliding parts. Can be obtained.
[0018]
  Claims3 and 4According to the invention described above, in addition to the structure of the first aspect, at least one of the cylinder and the piston comprises a flexible rod or a universal joint as a connecting portion with the mover.
[0019]
By configuring as described above, even when the mover and the axis of the cylinder or piston are displaced or driven from each other, the angle of the flexible rod or universal joint changes to absorb this. , Can slide smoothly without hitting one piece.
[0020]
  ClaimsTo 5The invention described is from claim 1FourIn addition to the configuration, at least the mass of the movable part, the equivalent spring constant resulting from the compression action of the elastic body and the working fluid, and the thrust characteristic of the linear drive part are made equal for the cylinder and the piston.
[0021]
By configuring as described above, by driving both linear drive units with the same power source, the cylinder and piston amplitudes can be made to reciprocate and cancel the force acting on the compressor casing. Can do.
[0022]
  Claims6The invention described is from claim 1FourIn addition to the configuration, displacement detection means for detecting displacement amounts of the cylinder and the piston with respect to the casing is provided, and the product of the displacement amplitude and the mass of the movable portion is operated to be equal between the cylinder and the piston.
[0023]
By comprising as mentioned above, it can be made to reciprocate so that the momentum of both movable parts may become zero in total, and the force which acts on the casing of a compressor can be offset.
[0028]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0029]
(Embodiment 1)
FIG. 1 is a view showing a cross section of a linear compressor according to Embodiment 1 of the present invention. First, the overall configuration will be described. The linear compressor 100 is roughly classified to hold the movable cylinder 4, the movable piston 5, the linear motor and the elastic bodies 10a and 10b for individually driving these, the suction / discharge path 22 through which the working fluid enters and exits, and the individual components. It is comprised from the casing 1 which comprises an outer wall.
[0030]
A movable cylinder 4 slidably mounted on a cylinder guide 3 connected to the casing 1 has a cylindrical outer shape and a cylindrical hollow portion having the same axial center as the outer shape, and is compressed together with an end surface of the movable piston 5. A chamber 6 is formed. The movable cylinder 4 and the movable element holding member 11 a are connected by a flexible rod 12 a, and the movable cylinder 4 can be slightly inclined with respect to the movable element or the casing 1. The movable piston 5 is the same as the movable cylinder 4 side except that it is slidably disposed on the inner side surface of the movable cylinder 4. Since the air gaps on the sliding surfaces of the movable cylinder 4 and the cylinder guide 3 and between the movable cylinder 4 and the movable piston 5 are leakage paths for the working fluid, they are configured to be 100 microns or less.
[0031]
The movable cylinder 4 and the movable piston 5 are preferably formed of an aluminum material from the viewpoint of weight reduction. By reducing the weight, the rigidity of the elastic body 52 can be kept low as described later. In addition, it is advantageous from the viewpoint of weight reduction to form the resin with sufficient strength and wear resistance. Furthermore, in order to reduce the sliding loss, the sliding surface may be coated with a fluorine resin or the like.
[0032]
The movable cylinder 4 is provided with a suction / discharge port 20 on its side surface, and the compression chamber 6 and the suction / discharge path 22 are always in communication with each other regardless of the position of the cylinder 4 via a communication portion 21 provided in the cylinder guide 3. To do.
[0033]
The linear motor on the movable cylinder 4 side includes a stator 7a and a movable element 9a. The stator 7a is provided on the inner surface side of the casing 1, and is formed by laminating rolled steel plates made of a magnetic material such as a thin electromagnetic steel plate or a silicon steel plate in a radial manner so as to form a U-shaped concave portion on the inner peripheral surface. The coil 8a is mounted in the concave portion of the outer yoke configured as described above. On the other hand, the mover 9a has a permanent magnet on the outer surface side of an inner yoke formed by laminating a rolled steel plate made of a magnetic material such as a thin electromagnetic steel plate or a silicon steel plate in a radial direction or perpendicular to the axial direction. It is constituted by wearing. The permanent magnet 32 is magnetized so that the magnetic vector faces in the radial direction. The cylindrical movable element 9a is fixed to the outer periphery of the cylindrical movable element holding portion 11a. The configuration of the linear motor is the same on the movable piston side. 7b is a stator, 8b is a coil, and 9b is a mover.
[0034]
The mover holding portions 11a and 11b are connected by elastic members 10a and 10b, which support the movers 9a and 9b and the movable cylinder 4 or the movable piston 5 so as to reciprocate along the axis, with connecting members 13a and 13b. 10a and 10b are fixed to the casing 1 at their peripheral portions. As this elastic body, a plate spring in which a spiral cutout is provided in a plate-like elastic material is used.
[0035]
The movable cylinder 4 and the movable piston 5 each have a natural frequency of the system governed by the mass of each movable part and the equivalent spring constant due to the compression action of the elastic bodies 10a and 10b and the working fluid. In the first embodiment, the thrust characteristics of the linear motor, the mass of the movable part, and the equivalent spring constant are set so as to coincide between the movable cylinder and the movable piston so that not only the natural frequency but also the displacement width coincide. .
[0036]
Next, the operation of the linear compressor configured as described above will be described. Due to the interaction between the magnetic field generated from the permanent magnets constituting the movers 9a and 9b and the magnetic field generated by passing an alternating current through the coils 8a and 8b, the movers 9a and 9b receive thrust in the axial direction, The movable piston 5 is driven. By making the direction of the alternating current flowing through the coils 8a and 8b be always opposite to the direction of the thrust acting on the respective movers 9a and 9b, the movable cylinder 4 and the movable piston 5 are synchronized with the frequency thereof. Performs reciprocating motion in opposite phase. Moreover, it is possible to operate while resonating by making the frequency of the alternating current flowing through the coils 8a and 8b substantially coincide with the natural frequency.
[0037]
As the movable cylinder 4 and the movable piston 5 reciprocate in opposite phases in this manner, the volume of the compression chamber 6 increases and decreases, and pressure pulsation is transmitted to the suction / discharge path 22 through the suction / discharge port 20 that is always in communication.
[0038]
FIG. 2 is a schematic view of a pulse tube refrigerator using this linear compressor. A working fluid (here, helium is used) is introduced into the regenerator 104 from the compression chamber 6 of the linear compressor 100 through the gas flow path 102. A regenerator 104 having a copper mesh laminated inside and a pulse tube 106 formed in a hollow cylinder are connected in a folded state by a cold head 105 as a cooling unit. Further, the opposite ends of the regenerator 104 and the cold head of the pulse tube 106 are held by a flange 103, which functions as a flange of a vacuum vessel when maintaining the cold head 105 at a low temperature by vacuum insulation, It also functions as a heat radiating part for the heat of the hot gas flowing in from the linear compressor 100 and the heat flowing from the cold head 105 side. The other end of the pulse tube 106 communicates with the buffer tank 108 via a thin tube 107, and this portion functions as a phase control mechanism for pressure change and displacement of the working fluid.
[0039]
As described above, according to the first embodiment, the movable cylinder 4 and the movable piston 5 having the same mass can be reciprocated in opposite phases with the same stroke. As a result, the axial force acting on the casing is always canceled out, and a linear compressor and refrigerator with low noise and vibration during operation can be obtained.
[0040]
Further, since there is only one sliding portion between the movable piston 4 and the movable cylinder 5, a highly efficient linear compressor with little leakage from the compression chamber 6 can be obtained. Furthermore, since the sliding portions of the movable piston 4 and the movable cylinder 5 are overlapped in the radial direction, a small compressor that is short in the sliding axis direction can be configured.
[0041]
In the first embodiment, the movable cylinder 4 and the movable piston 5 are held from one side by the elastic bodies 10a and 10b. However, the present invention is not limited to this. The same effect can be obtained when the cylinder is held and the cylinder or the piston is arranged outside thereof.
[0042]
In the first embodiment, a plate-like elastic body is used. However, the present invention is not limited to this, and a coil spring or a gas spring may be used.
[0043]
(Embodiment 2)
FIG. 3 is a view showing a cross section of the linear compressor according to Embodiment 2 of the present invention. The present embodiment 2 realizes a linear compressor for use in a GM type pulse tube refrigerator, but the configuration other than the linear compressor is basically the same as the Stirling type, and FIG. The configuration is the same. Further, since the overall configuration of the linear compressor and the basic structure and operation of each part are the same as those in the first embodiment, only different points will be described.
[0044]
The movable cylinder 4 is provided with a suction port 30 and a discharge port 33 on its side surfaces, and communicates with a suction path 32 and a discharge path 35 via a suction communication part 31 and a discharge communication part 34 provided in the cylinder guide 3, respectively. . However, the suction port 30 and the suction communication portion 31, and the discharge port 33 and the discharge communication portion 34 are provided so that the movable cylinder 4 is communicated in the vicinity of the position where the movable cylinder 4 is most displaced to the left and right in FIG.
[0045]
Next, the operation of the linear compressor configured as described above will be described. Since the movable cylinder 4 and the movable piston 5 are reciprocated at the same frequency and in opposite phases, the compression chamber 6 and the suction path 32 communicate with each other in the vicinity where the volume of the compression chamber 6 is maximized (minimum pressure). Is called. At this time, the discharge path 35 is closed. Conversely, the compression chamber 6 and the discharge path 35 communicate with each other in the vicinity of the minimum volume (maximum pressure) of the compression chamber 6 to perform the discharge process. At this time, the suction path 32 is closed.
[0046]
As described above, according to the second embodiment, the movable cylinder 4 and the movable piston 5 having the same mass can be reciprocated in opposite phases with the same stroke. As a result, the axial force acting on the casing is always canceled out, and a linear compressor and refrigerator with low noise and vibration during operation can be obtained.
[0047]
Further, since there is only one sliding portion between the movable piston 5 and the movable cylinder 4, a highly efficient compressor with less leakage from the compression chamber 6 can be obtained. Furthermore, since the sliding portions of the movable piston 5 and the movable cylinder 4 are overlapped in the radial direction, a small compressor having a short length in the sliding axis direction can be configured.
[0048]
Furthermore, since the suction process and the compression process can be performed at independent timings, a GM type refrigerator can be realized simply and compactly without using a high / low pressure switching valve or its control device.
[0049]
(Embodiment 3)
FIG. 4 is a view showing a cross section of the linear compressor according to Embodiment 3 of the present invention. The third embodiment realizes a linear compressor for use in a GM type pulse tube refrigerator, but the configuration other than the linear compressor is basically the same as the Stirling type, and FIG. The configuration is the same. Further, since the overall configuration of the linear compressor and the basic structure and operation of each part are the same as those in the first embodiment, only different points will be described.
[0050]
The movable cylinder 4 is provided with a suction port 40 and a discharge port 41 on its side surface, and is communicated with a suction / discharge path 43 via a suction / discharge communication portion 42 provided in the cylinder guide 3. However, the suction port 40 and the discharge port 41 are provided apart from each other in the axial direction so that the movable cylinder 4 communicates in the vicinity of the position where the movable cylinder 4 is most displaced to the left and right in FIG.
[0051]
Next, the operation of the linear compressor configured as described above will be described. Since the movable cylinder 4 and the movable piston 5 are reciprocated at the same frequency and in opposite phases with each other, the compression chamber 6 and the suction / discharge passage 43 are connected to the suction port 40 and the suction / discharge in the vicinity of the maximum volume (minimum pressure) of the compression chamber 6. The inhalation process is performed through the communication unit 42. On the contrary, the compression chamber 6 and the suction / discharge path 43 communicate with each other via the discharge port 41 and the suction / discharge communication portion 42 in the vicinity of the minimum volume (maximum pressure) of the compression chamber 6, and the discharge process is performed.
[0052]
As described above, according to the third embodiment, the movable cylinder 4 and the movable piston 5 having the same mass can be reciprocated in opposite phases with the same stroke. As a result, the axial force acting on the casing is always canceled out, and noise and vibration during operation are reduced.
[0053]
Further, since there is only one sliding portion between the movable piston 5 and the movable cylinder 4, a highly efficient compressor with less leakage from the compression chamber 6 can be obtained. Furthermore, a small compressor that is short in the axial direction can be configured.
[0054]
Furthermore, since the suction process and the compression process can be performed at independent timings, a GM type refrigerator can be realized simply and compactly without using a high / low pressure switching valve or its control device.
[0055]
(Embodiment 4)
FIG. 5 is a view showing a cross section of the linear compressor according to Embodiment 4 of the present invention. Since the overall configuration and the basic structure and operation of each part are the same as those in the first embodiment, only different points will be described.
[0056]
In the fourth embodiment, with the movable cylinder 4 and the movable piston 5, the mass of the movable part and the equivalent spring constants due to the compression action of the elastic bodies 10a and 10b and the working fluid are not matched individually but are governed by these. Match the natural frequency of the system. Specifically, the mass of the movable part and the equivalent spring constant due to the compression action are determined from the shape of the movable part of the movable cylinder 4 and the movable piston 5 and the pressure condition of the working fluid that actually acts. The spring constant of each elastic body is set to coincide with the power supply frequency for driving the linear motor.
[0057]
Further, a displacement sensor 50a is disposed on the extending portion of the movable portion axial center on the inner surface of the cylinder side shell 2a that seals the casing 1 from the movable cylinder 4 side. Here, an eddy current type displacement sensor is used, and an aluminum plate 51a serving as a sensor target is attached to the back side of the elastic body 10a facing the displacement sensor 50a. The same applies to the movable piston side. By these, the displacement width of the movable cylinder 4 and the movable piston 5 is detected.
[0058]
Next, the operation of the linear compressor configured as described above will be described. Although not shown in FIG. 5, the linear motors on the cylinder side and the piston side are driven by individual AC power sources capable of voltage control. The alternating currents flowing through the coils 8a and 8b are set in directions in which thrusts acting on the respective movers 9a and 9b are always in opposite directions, and their frequencies and phases are matched. Further, a control unit (not shown) for controlling the input voltage to the linear motor from the outputs of both displacement sensors 50a, 50b is provided. In this control unit, the input voltage is controlled so that the product of the movable part mass and the stroke of the movable cylinder 4 is equal to the product of the mass and the stroke of the movable piston movable part.
[0059]
As described above, according to the fourth embodiment, the momentums of the movable portions of the movable cylinder 4 and the movable piston 5 always coincide with each other, and the directions are opposite. Accordingly, there is no time change in the momentum of the entire linear compressor, and a linear compressor with less vibration and noise can be obtained.
[0060]
In addition, since there is only one sliding portion between the movable piston 5 and the movable cylinder 4, a highly efficient linear compressor with little leakage from the compression chamber 6 can be obtained. Furthermore, a small compressor that is short in the axial direction can be configured.
[0061]
Further, it is not necessary to intentionally match the masses of the movable parts of the cylinder and the piston having different shapes, and the degree of freedom in design is increased.
[0062]
Although the eddy current type displacement sensors 50a and 50b are used in the fourth embodiment, the present invention is not limited to this, and other types of sensors such as an optical sensor may be used.
[0063]
【The invention's effect】
As is apparent from the above, the present invention reciprocates the movable cylinder and the movable piston in opposite phases with the movable cylinder and the movable piston facing each other.
[0064]
According to this configuration, when the movable part moves, the force acting on the outer wall of the compressor as a reaction is canceled, and an effect is obtained that a low-vibration and low-noise compressor is obtained. Furthermore, a reduction in the mechanical life due to vibration can be suppressed, and a highly reliable pulse tube refrigerator can be realized.
[0065]
Furthermore, since there is a sliding portion only on one side of the compression chamber, a leakage loss is small and a highly efficient compressor can be obtained as compared with a structure in which both sides are sliding portions.
[0066]
Furthermore, since the sliding portions of the piston and the cylinder are overlapped in the radial direction, a compact compressor that is short in the sliding axis direction can be configured.
[0067]
Further, in the present invention, at least one of the cylinder and the piston is configured such that the connecting portion with the mover is formed of a flexible rod or a universal joint.
According to this configuration, even when the mover and the axis of the cylinder or the piston are displaced or driven from each other, the connecting means absorbs this, and the piston can slide smoothly without being hit by one piece. it can. For this reason, the loss of a sliding part can be reduced and efficiency can be improved. In addition, it is possible to provide a compressor having excellent assembling performance by providing a sufficient margin for the accuracy of shaft alignment during assembly. In addition, since it becomes difficult to be affected by the shift of the shaft center due to the influence of gravity, the degree of freedom with respect to the arrangement direction of the compressor is increased, and it is easy to incorporate into a device together with downsizing.
[0068]
Further, the present invention is configured such that the mass of the movable part, the equivalent spring constant resulting from the compression action of the elastic body and the working fluid, and the thrust characteristic of the linear drive part are configured equally on the cylinder side and the piston side. Are opposed to each other and reciprocated in opposite phases.
[0069]
According to this configuration, the movable cylinder and the movable piston can be reciprocated with the same stroke. As a result, the axial force acting on the outer wall of the compressor is always canceled out, and a compressor and refrigerator having low noise and vibration during operation can be obtained.
[0070]
Furthermore, if attention is paid only to the direction of current, both linear motors can be driven by a single AC power source, and an inexpensive and simple system can be configured.
[0071]
In the present invention, the displacement amplitudes of the cylinder and the piston are detected to face each other and are reciprocated in the opposite phase so that the product of the displacement amplitude and the mass of the movable part becomes equal between the cylinder and the piston. In addition, the driving power source of each linear driving unit is controlled to operate.
[0072]
According to this configuration, the absolute value of the sum of the momentums of both movable parts can be made zero or very small. As a result, a compressor with less vibration and noise can be obtained.
[0073]
Furthermore, it is not necessary to force the masses of the cylinders and pistons having different shapes to coincide with each other, thereby increasing the degree of freedom in design.
[0074]
Further, the present invention is provided with a suction port and a discharge port on the side surface of the cylinder, and the compression chamber communicates with the suction flow path or the suction discharge flow path through the suction port in the vicinity where the volume of the compression chamber is maximized. Since the compression chamber and the discharge channel or the suction / discharge channel are communicated with each other through the discharge port in the vicinity of the minimum volume, the suction process and the compression process can be performed at independent timings. By using this compressor, a compact and low-vibration GM refrigerator can be realized without using a high-low pressure switching valve or its control device.
[0075]
Further, the present invention is provided with a suction / discharge port on the side surface of the cylinder, and is configured to always communicate the compression chamber and the suction / discharge channel via the suction / discharge port regardless of the volume of the compression chamber. A low-vibration linear compressor capable of repeating the discharge process can be obtained. By using this compressor, a small and low vibration Stirling type pulse tube refrigerator can be realized.
[Brief description of the drawings]
FIG. 1 is a sectional view of a linear compressor showing a first embodiment of the present invention.
FIG. 2 is a schematic view of a pulse tube refrigerator showing Embodiment 1 of the present invention.
FIG. 3 is a sectional view of a linear compressor showing a second embodiment of the present invention.
FIG. 4 is a sectional view of a linear compressor showing a third embodiment of the present invention.
FIG. 5 is a sectional view of a linear compressor showing a fourth embodiment of the present invention.
FIG. 6 is a schematic diagram showing the configuration of a conventional linear compressor.
FIG. 7 is a schematic diagram showing the configuration of a conventional linear compressor.
[Explanation of symbols]
1 casing
3 Cylinder guide
4 Movable cylinder
5 Movable piston
6 Compression chamber
7 Stator
8 coils
9 Mover
10 Elastic body
11 Mover holder
12 Flexible rod
20 Inlet / outlet
21 Communication Department
22 Inhalation / discharge route

Claims (7)

A casing that forms an outer wall of the compressor, a cylinder that is housed in the casing and is slidably supported, a piston that is housed in the cylinder and is slidably supported on the same axis as the cylinder sliding shaft, and A linear drive unit that reciprocates each of the cylinder and the piston along the sliding axis, and each linear drive unit forms a magnetic circuit with a mover and a stator to generate thrust, and The linear compressor includes a connecting portion that couples the cylinder or piston and the mover, and an elastic body that elastically supports the connecting portion with respect to the casing, and reciprocates the cylinder and piston in opposite phases. The casing is provided with a suction flow path and a discharge flow path through which a fluid to be compressed moves, and a suction side communicating with the casing side and the compression chamber side on the side of the cylinder. The compression chamber and the suction flow path through the suction port in the vicinity where the volume of the compression chamber is maximized, and compression is performed through the discharge port in the vicinity of the volume of the compression chamber being minimized. A linear compressor characterized in that a chamber and the discharge flow path communicate with each other . A casing that forms an outer wall of the compressor, a cylinder that is housed in the casing and is slidably supported, a piston that is housed in the cylinder and is slidably supported on the same axis as the cylinder sliding shaft, and A linear drive unit that reciprocates each of the cylinder and the piston along the sliding axis, and each linear drive unit forms a magnetic circuit with a mover and a stator to generate thrust, and The linear compressor includes a connecting portion that couples the cylinder or piston and the mover, and an elastic body that elastically supports the connecting portion with respect to the casing, and reciprocates the cylinder and piston in opposite phases. The casing includes a suction / discharge passage through which a fluid to be compressed moves, and a suction / discharge port that communicates the casing side and the compression chamber side on the side of the cylinder. Provided, the linear compressor in which the suction and discharge flow passage and the compression chamber always irrespective of the volume of the compression chamber through the suction and discharge port and wherein the communicating.   2. The linear compressor according to claim 1, wherein at least one of the cylinder and the piston is configured by a flexible rod at a connecting portion with the mover.   The linear compressor according to claim 1, wherein at least one of the cylinder and the piston is constituted by a universal joint at a connecting portion with the movable element. And mass of at least the movable portion, the equivalent spring constant due to the compressive action of the elastic body and the working fluid, and a thrust force characteristic of the linear drive unit from claim 1, characterized in that the equally cylinder side and piston side 4 linear compressor according to. Comprising a displacement detector for detecting a displacement amount with respect to the cylinder and the piston of the casing, respectively, claims 1, mass of product of displacement amplitude and the movable portion, characterized in that the driving to be equal respectively cylinder and piston 4 The linear compressor described. The linear compressor according to claim 1, wherein the suction flow path and the discharge flow path are common.

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