JP6403529B2 - Movable body support structure, linear compressor, and cryogenic refrigerator - Google Patents

Description

  The present invention relates to a movable body support structure, a linear compressor, and a cryogenic refrigerator.

  A linear compressor that compresses a working gas by an axial movement of a movable body such as a piston is known. The volume of the pressure chamber is reduced by the movement of the movable body, and the working gas inside is compressed. The movable body is elastically supported using a spring such as a leaf spring or a coil spring. The movement of the movable body is usually an axial vibration.

JP 2008-215440 A JP 2013-195043 A

  In the linear compressor, the reciprocating motion of the movable body in the axial direction gives a cycle of volume change of the pressure chamber. The range of motion of the reciprocating motion is determined by design so that desired compressor performance (for example, efficiency) is satisfied. However, depending on the design or operating conditions of the linear compressor, the movable body can be displaced due to a pressure difference acting on the movable body. As a result, the movable body can reciprocate in a somewhat different range in the axial direction from the specified axial movable range. This also changes the volume of the pressure chamber, which can affect the efficiency of the linear compressor.

  The center of the reciprocating motion of the movable body is determined by design at a specific position, for example, a neutral position of the leaf spring. As described above, when the movable range in the axial direction of the movable body deviates from the specified range, the center of movement also deviates from the specified position. The farther the center of movement is from the neutral position of the spring, the higher the load acting on the spring, and the useful life of the spring can be shortened.

  One exemplary object of an aspect of the present invention is to provide a movable body support structure capable of reciprocating a movable body within a predetermined axial movable range in a linear compressor.

  According to an aspect of the present invention, there is provided a movable body support structure in a linear compressor, which is a movable body that partitions a high pressure chamber and a low pressure chamber of a working gas inside a compressor container, and has a predetermined axial movable range. A movable body that compresses the working gas in the high-pressure chamber by the unidirectional movement in the axial reciprocation that periodically repeats the unidirectional movement and the reverse movement, and a plurality of leaf springs that are arranged in the axial direction. A plurality of leaf spring portions that elastically support the movable body on the compressor container so that each leaf spring portion can reciprocate in the axial direction of the movable body; 1 auxiliary spring portion, each first auxiliary spring portion has a first axial rigidity, and each first auxiliary spring portion is located on one side of the corresponding leaf spring portion among the plurality of leaf spring portions. A plurality of first auxiliary springs arranged adjacent to each other and arranged in the axial direction A plurality of second auxiliary spring portions, each second auxiliary spring portion having a second axial rigidity, and each second auxiliary spring portion adjacent to the opposite side of the corresponding leaf spring portion. A plurality of second auxiliary spring portions disposed, wherein the second axial rigidity is determined from the predetermined axial movable range generated by a pressure difference between the high pressure chamber acting on the movable body and the low pressure chamber. A movable body support structure is provided that is different from the first axial rigidity so as to correct a deviation in an actual axial movable range of the movable body.

  According to an aspect of the present invention, there is provided a movable body support structure in a linear compressor, which is a movable body that partitions a high pressure chamber and a low pressure chamber of a working gas inside a compressor container, and is capable of moving in one direction and moving in a reverse direction A movable body that compresses the working gas in the high-pressure chamber by the unidirectional movement in the axial reciprocating motion, and the movable body is slidably supported in the axial direction, and the movable body is interposed between the movable body and the movable body. A stationary body forming a high pressure chamber; an intake valve provided in the movable body for supplying working gas to the high pressure chamber from the low pressure chamber; and the stationary body for discharging working gas from the high pressure chamber. And a plurality of leaf springs arranged in the axial direction, wherein the leaf springs allow the movable body to reciprocate in the axial direction. Multiple plate bars elastically supported by the container And a plurality of first auxiliary spring portions arranged in the axial direction, each first auxiliary spring portion having a first axial rigidity, and each first auxiliary spring portion being said plurality of leaf spring portions A plurality of first auxiliary spring portions arranged adjacent to one direction side of the corresponding leaf spring portion, and a plurality of second auxiliary spring portions arranged in the axial direction, each of the second auxiliary spring portions. A plurality of second auxiliary spring portions each having a second axial stiffness greater than the first axial stiffness and each second auxiliary spring portion being disposed adjacent to the opposite side of the corresponding leaf spring portion. A movable body support structure is provided.

  Note that any combination of the above-described constituent elements and the constituent elements and expressions of the present invention replaced with each other among methods, apparatuses, systems, and the like are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the movable body support structure which can reciprocate a movable body in a predetermined | prescribed axial direction movable range in a linear compressor can be provided.

1 is a cross-sectional view schematically showing a linear compressor according to an embodiment of the present invention. The cross section seen from the dashed-dotted line A shown in FIG. It is a mimetic diagram showing a part of leaf spring unit concerning an embodiment with the present invention. It is a schematic diagram showing a cryogenic refrigerator according to an embodiment of the present invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. Moreover, the structure described below is an illustration and does not limit the scope of the present invention at all.

  FIG. 1 is a cross-sectional view schematically showing a linear compressor 10 according to an embodiment of the present invention. FIG. 2 shows a cross section viewed from the alternate long and short dash line A shown in FIG. The linear compressor 10 includes a compressor housing 12, a compressor container 14, a piston 16, a cylinder 18, a linear actuator 20, and a leaf spring unit 22. The linear compressor 10 is provided with a single piston 16 and a single cylinder 18 for receiving it. The linear compressor 10 is configured as a non-lubricated linear compressor (also referred to as an oilless linear compressor) that does not use oil to lubricate movable elements.

  The compressor housing 12 accommodates the compressor container 14. A dynamic vibration absorber 24 is provided between the compressor housing 12 and the compressor container 14 for preventing or reducing transmission of vibration of the compressor container 14 to the outside. The compressor housing 12 may be a cover member that covers the dynamic vibration absorber 24.

  The compressor container 14 is a pressure container configured to hold the working gas of the linear compressor 10 in an airtight manner. The working gas is, for example, helium gas. The compressor container 14 accommodates the piston 16, the cylinder 18, the leaf spring unit 22, and the linear actuator 20.

  The compressor vessel 14 has a working gas high pressure chamber 26 and a low pressure chamber 28 therein. A discharge pipe 30 is connected to the high pressure chamber 26, and a suction pipe 32 is connected to the low pressure chamber 28. The discharge pipe 30 penetrates the compressor housing 12 and the compressor container 14 and connects the high-pressure chamber 26 to the outside of the linear compressor 10. The suction pipe 32 passes through the compressor housing 12 and the compressor container 14 and connects the low pressure chamber 28 to the outside of the linear compressor 10. Accordingly, the low-pressure working gas 34 is recovered from the outside of the linear compressor 10 to the low-pressure chamber 28 through the suction pipe 32. Further, the high pressure working gas 36 is supplied from the high pressure chamber 26 to the outside of the linear compressor 10 through the discharge pipe 30.

  The compressor casing 12 may be configured as a pressure container that holds the working gas of the linear compressor 10 in an airtight manner together with the compressor container 14 or instead of the compressor container 14.

  The piston 16 is a movable body that partitions the high pressure chamber 26 and the low pressure chamber 28 inside the compressor container 14. The high pressure chamber 26 includes a pressurizing chamber 38 and a discharge chamber 40. The pressurizing chamber 38 is formed between the piston 16 and the cylinder 18. The discharge chamber 40 is formed in the cylinder 18. The discharge pipe 30 is connected to the discharge chamber 40.

  The piston 16 is provided with an intake valve 42 for supplying the low pressure working gas 34 from the low pressure chamber 28 to the high pressure chamber 26. The intake valve 42 is opened and closed by a pressure difference between the high pressure chamber 26 and the low pressure chamber 28. The intake valve 42 is opened when the pressure difference falls below a predetermined threshold value and closes when the pressure difference exceeds the threshold value. The cylinder 18 is provided with a discharge valve 44 for discharging the high-pressure working gas 36 from the discharge chamber 40. The discharge valve 44 is opened and closed by a pressure difference between the high pressure chamber 26 and the discharge pipe 30. When the pressure difference exceeds a predetermined threshold value, the discharge valve 44 is opened, and when the pressure difference falls below the threshold value, the discharge valve 44 is closed. Thus, the linear compressor 10 is configured as a linear compressor with a valve.

  The piston 16 is a hollow cylindrical member that extends in the axial direction (vertical direction in FIG. 1). The piston 16 includes a piston tip 46 facing the pressurizing chamber 38 and a piston main body 48 extending from the piston tip 46 in the axial direction toward the opposite side of the pressurizing chamber 38. A first piston recess 50 is formed at the piston tip 46, and a second piston recess 52 is formed at the piston body 48. The first piston recess 50 is a hollow portion of the piston tip 46 and forms a part of the pressurizing chamber 38. The second piston recess 52 is a hollow portion of the piston body 48 and forms a part of the low pressure chamber 28.

  A piston partition 54 is provided between the piston tip 46 and the piston body 48. The piston partition 54 is a wall that partitions the first piston recess 50 and the second piston recess 52. A piston communication hole 56 is formed at the center of the piston partition 54. The piston communication hole 56 communicates the first piston recess 50 and the second piston recess 52. The intake valve 42 is accommodated in the first piston recess 50. The intake valve 42 is configured to open and close the piston communication hole 56 by a pressure difference between the first piston recess 50 and the second piston recess 52.

  The piston 16 is supported by the compressor container 14 by a leaf spring unit 22 so as to be capable of reciprocating (for example, vibrating) in the axial direction. The radially inner portion of the leaf spring unit 22 is attached to the proximal end portion of the piston main body 48 so as to surround the piston 16 in the circumferential direction. A radially outer portion of the leaf spring unit 22 is attached to the compressor container 14.

  Further, the piston 16 includes a piston drive unit 49 that is driven by the linear actuator 20. The piston driver 49 is attached to the piston body 48.

  The cylinder 18 is a hollow cylindrical member that extends in the axial direction to receive the piston 16. The cylinder 18 is fixedly supported by the compressor container 14. The cylinder 18 includes a cylinder fixed end portion 58 that is fixed to the compressor container 14, and a cylinder main body portion 60 that extends in the axial direction from the cylinder fixed end portion 58 toward the piston 16. A discharge chamber 40 is formed in the cylinder fixed end portion 58. The cylinder main body 60 has a cylinder inner surface 62 that supports the piston 16 so as to be slidable in the axial direction. A cylinder partitioning portion 64 is provided between the cylinder fixed end portion 58 and the cylinder body portion 60. A cylinder communication hole 66 is formed at the center of the cylinder partitioning portion 64. The cylinder communication hole 66 communicates the discharge chamber 40 and the pressurizing chamber 38.

  The linear actuator 20 is configured to drive the axial reciprocation of the piston 16. By driving the linear actuator 20, the piston 16 periodically repeats forward and backward movements in the axial direction. The forward movement of the piston 16 is upward in FIG. 1, and the backward movement of the piston 16 is downward in FIG. The linear actuator 20 is, for example, a linear vibration actuator that vibrates the piston 16 in the axial direction.

  The leaf spring unit 22 is a bearing that allows the piston 16 to reciprocate in the axial direction and restricts the movement of the piston 16 in the radial direction and the circumferential direction. The leaf spring unit 22 includes a plurality of leaf spring portions 23. Although details will be described later with reference to FIGS. 2 and 3, the leaf spring unit 22 includes a plurality of first auxiliary spring portions 68 and a plurality of second auxiliary spring portions 70 in addition to the plurality of leaf spring portions 23. Is provided.

  The plurality of leaf spring portions 23 are arranged in series in the axial direction, and include, for example, at least 10 leaf spring portions 23. The plurality of leaf spring portions 23 elastically support the piston 16 on the compressor container 14 so that each leaf spring portion 23 can reciprocate in the axial direction of the piston 16. Each leaf spring portion 23 extends along a plane perpendicular to the axial direction. Each of the plurality of leaf springs 23 is, for example, one leaf spring, but is not limited thereto. Each leaf spring part 23 may be provided with a plurality of leaf springs arranged so as to overlap in the axial direction.

  The plurality of leaf spring portions 23 are arranged adjacent to each other with an interval in the axial direction. The leaf springs 23 are arranged at intervals in the axial direction so as not to contact each other. For example, the interval between the two leaf spring portions 23 adjacent in the axial direction is determined so that the two leaf spring portions 23 do not contact each other due to elastic deformation caused by the reciprocating movement of the piston 16. In order to maintain an appropriate interval, a spacer or a pressing member may be provided between the two leaf spring portions 23.

  As shown in FIG. 2, the plate spring portion 23 includes a plate spring inner peripheral portion 72, a plate spring outer peripheral portion 74 surrounding the plate spring inner peripheral portion 72, a plate spring inner peripheral portion 72, and a plate spring outer peripheral portion 74. A plurality of (three in FIG. 2) elastic arms 76 that connect the two. The leaf spring inner peripheral portion 72 is fixed to the piston 16 (for example, the piston main body portion 48). The leaf spring outer peripheral portion 74 is fixed to the compressor container 14. The elastic deformation of the elastic arm 76 allows the axial relative displacement between the leaf spring inner peripheral portion 72 and the leaf spring outer peripheral portion 74, that is, the axial relative displacement of the piston 16 with respect to the compressor container 14.

  Such a leaf spring portion 23 is also called a flexure spring and is flexible in the reciprocating direction of the piston 16 and rigid in a direction perpendicular to the reciprocating direction. Such a leaf spring is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 2008-215440 and 2013-195043. These documents are incorporated herein by reference in their entirety.

  In this way, an axial vibration system having the piston 16 as a mass element and the leaf spring unit 22 as an elastic element is constructed. This vibration system is designed to give a desired resonance frequency by appropriately setting the axial rigidity of each leaf spring portion 23 of the leaf spring unit 22, for example. The vibration system is driven by the linear actuator 20.

  The designed axial range of motion of the piston 16 is determined to provide the desired volume change cycle to the high pressure chamber 26 (eg, pressurization chamber 38). The axial movable range of the piston 16 is such that, for example, when the piston 16 moves forward, at the top dead center, the piston 16 (for example, the piston front end portion 46) abuts or contacts the opposing portion (for example, the cylinder partitioning portion 64) of the cylinder 18; When the piston 16 moves backward, the front end surface of the piston 16 may be determined to be separated from the opposed portion of the cylinder 18 by a predetermined distance at the bottom dead center. Alternatively, the axial movable range may be determined such that the tip surface of the piston 16 is separated by a certain distance without contacting the opposing portion of the cylinder 18 at the top dead center.

  Further, the axial movable range of the piston 16 may be determined so that the center position of the periodic axial elastic deformation of the leaf spring portion 23 due to the reciprocating motion of the piston 16 coincides with the neutral position of the leaf spring portion 23.

  Here, the basic operation of the linear compressor 10 will be described. As described above, the low pressure working gas 34 is recovered from the outside of the linear compressor 10 to the low pressure chamber 28 through the suction pipe 32. When the piston 16 is moving at or near the bottom dead center, the intake valve 42 is opened and the discharge valve 44 is closed. The low-pressure working gas 34 is supplied from the second piston recess 52 to the pressurizing chamber 38 through the piston communication hole 56. When the piston 16 advances from the bottom dead center to the top dead center, the intake valve 42 is closed, and the working gas in the pressurizing chamber 38 and the discharge chamber 40 is compressed and pressurized.

  When the piston 16 moves at or near the top dead center, the discharge valve 44 is opened, and the high-pressure working gas 36 is supplied from the discharge chamber 40 to the outside of the linear compressor 10 through the discharge pipe 30. When the piston 16 moves backward from the top dead center to the bottom dead center, the discharge valve 44 is closed, and the working gas in the pressurizing chamber 38 and the discharge chamber 40 is expanded and depressurized. When the piston 16 returns to or near the bottom dead center, the intake valve 42 is opened, and the low-pressure working gas 34 is supplied to the pressurizing chamber 38 again. Thus, the compression cycle in the linear compressor 10 is repeated.

  Ideally, the piston 16 vibrates in the designed axial range of motion during the compression cycle. The vibration center coincides with the neutral position of the leaf spring portion 23. However, the present inventors have found that in such a linear compressor with a valve, the piston 16 can vibrate while being pushed somewhat from the high pressure chamber 26 due to the pressure difference acting on the piston 16 during the compression cycle. . Therefore, the actual axial movable range of the piston 16 can be shifted somewhat from the designed axial movable range toward the low pressure chamber 28. Then, the volume of the pressurizing chamber 38 increases throughout the entire compression cycle, and particularly the volume of the pressurizing chamber 38 when the piston 16 is located at the top dead center increases, so that the efficiency of the linear compressor 10 can be reduced. Further, as the vibration center is further away from the neutral position of the leaf spring portion 23, the load acting on the leaf spring portion 23 at the top dead center or the bottom dead center can be increased. When a high load continuously acts, the service life of the leaf spring portion 23 can be shortened. Therefore, a method for dealing with such a problem will be described in detail below.

  A typical leaf spring support is constructed symmetrically so that the axial stiffness is equal in both reciprocating directions. In contrast, the plate spring unit 22 according to the present embodiment is configured so that its axial rigidity is asymmetric. That is, the leaf spring unit 22 is designed so that the axial rigidity differs between one direction and the opposite direction of the reciprocating motion. Therefore, for example, the second auxiliary spring portion 70 of the leaf spring unit 22 has an axial rigidity different from that of the first auxiliary spring portion 68. Thus, the deviation of the actual axial movable range of the piston 16 from the designed axial movable range caused by the pressure difference between the high pressure chamber 26 and the low pressure chamber 28 acting on the piston 16 is corrected.

  Specifically, the leaf spring unit 22 is configured so that the axial rigidity in the backward direction to the low pressure chamber 28 is larger than the axial rigidity in the forward direction to the high pressure chamber 26. Therefore, for example, the axial rigidity of the second auxiliary spring portion 70 of the leaf spring unit 22 is larger than the axial rigidity of the first auxiliary spring portion 68. Accordingly, the leaf spring unit 22 is unlikely to be displaced from the neutral position to the low pressure chamber 28 side. The axial displacement of the vibration center of the piston 16 with respect to the neutral position of the leaf spring unit 22 is corrected so that the vibration center of the piston 16 approaches or coincides with the neutral position of the leaf spring unit 22. Thus, the shift of the movable range of the piston 16 to the low pressure chamber 28 side is suppressed.

  FIG. 3 is a schematic view showing a part of the leaf spring unit 22 according to an embodiment of the present invention. As shown in FIGS. 2 and 3, each of the plurality of first auxiliary spring portions 68 is provided on one side of the corresponding leaf spring portion 23 among the plurality of leaf spring portions 23 (pressure chamber 38 side, in the drawing). (Adjacent to the top). Each of the plurality of second auxiliary spring portions 70 is disposed adjacent to the opposite side of the corresponding plate spring portion 23 among the plurality of leaf spring portions 23 (on the opposite side to the pressurizing chamber 38, downward in the drawing). . FIG. 3 illustrates the outer portions of the first auxiliary spring portion 68 and the second auxiliary spring portion 70 that are fixed to the compressor container 14.

  In the leaf spring unit 22, the first auxiliary spring portion 68, the leaf spring portion 23, and the second auxiliary spring portion 70 are arranged in the axial direction in the order described, and this is repeatedly arranged in the axial direction as a unit. Yes. That is, the first auxiliary spring portion 68 and the second auxiliary spring portion 70 are provided adjacent to each other between the two leaf spring portions 23 adjacent in the axial direction.

  The first auxiliary spring portion 68 may be disposed in contact with the adjacent leaf spring portion 23 in the neutral position, or may be disposed with a gap between the adjacent leaf spring portions 23. The same applies to the second auxiliary spring portion 70. A spacer or a pressing member may be provided between the first auxiliary spring portion 68 (or the second auxiliary spring portion 70) and the adjacent leaf spring portion 23.

  Each first auxiliary spring portion 68 is unidirectional on the plate spring portion 23 so as to follow the elastic deformation by contact with the plate spring portion 23 accompanying elastic deformation in one direction on the corresponding plate spring portion 23. Adjacent to. Each second auxiliary spring portion 70 is on the opposite side of the plate spring portion 23 so as to follow the elastic deformation by contact with the plate spring portion 23 accompanying the elastic deformation of the corresponding plate spring portion 23 in the reverse direction. Adjacent to. These auxiliary spring parts relieve stress concentration during elastic deformation of the plate spring part 23 by following elastic deformation of the plate spring part 23.

  The axial rigidity of each first auxiliary spring portion 68 is set so as to bring a desired stress concentration relaxation effect to the adjacent leaf spring portion 23. Similarly, the axial rigidity of each second auxiliary spring portion 70 is set so as to provide a desired stress concentration relaxation effect to the adjacent leaf spring portion 23. However, as described above, the axial rigidity of the second auxiliary spring portion 70 is different from the axial rigidity of the first auxiliary spring portion 68.

  As shown in FIG. 2, the first auxiliary spring portion 68 includes an auxiliary spring inner portion 78 and an auxiliary spring outer portion 80. In FIG. 2, for convenience of explanation, the first auxiliary spring portion 68 (or the second auxiliary spring portion 70) is illustrated by a broken line. The auxiliary spring inner portion 78 includes an auxiliary spring inner peripheral portion 82 and a plurality (three in FIG. 2) of inner cantilever arms 84. The auxiliary spring inner peripheral portion 82 is fixed to the piston 16 (for example, the piston main body portion 48). Each inner cantilever arm 84 is disposed adjacent to the connecting portion between the leaf spring inner peripheral portion 72 and the elastic arm 76 on one side in the axial direction. The auxiliary spring outer portion 80 includes an auxiliary spring outer peripheral portion 86 and a plurality (three in FIG. 2) of outer cantilever arms 88. The auxiliary spring outer peripheral portion 86 is fixed to the compressor container 14. Each outer cantilever arm 88 is disposed adjacent to the connecting portion between the leaf spring outer peripheral portion 74 and the elastic arm 76 on the other side in the axial direction. The second auxiliary spring portion 70 is similarly configured.

  The tip of the inner cantilever arm 84 and the tip of the outer cantilever arm 88 are separated and are not connected. Therefore, the auxiliary spring inner portion 78 and the auxiliary spring outer portion 80 are separate members separated from each other. Therefore, unlike the leaf spring portion 23, the first auxiliary spring portion 68 and the second auxiliary spring portion 70 do not support the piston 16 on the compressor container 14.

  When the elastic arm 76 elastically deforms in the axial direction in the compression cycle, the elastic arm 76 contacts the inner cantilever arm 84 and the outer cantilever arm 88 and elastically deforms in the axial direction together with the elastic arm 76. In this way, stress concentration at the connecting portion of the elastic arm 76 can be relaxed.

  As shown in FIG. 3, each of the plurality of first auxiliary spring portions 68 may include one or more first auxiliary springs 69 that are disposed so as to overlap in the axial direction. Each of the plurality of second auxiliary spring portions 70 may include one or more second auxiliary springs 71 arranged so as to overlap in the axial direction.

  The first auxiliary spring 69 has the same dimensions as the second auxiliary spring 71 and is made of the same material. Therefore, the axial rigidity of the first auxiliary spring 69 alone is equal to the axial rigidity of the second auxiliary spring 71 alone. However, in the present embodiment, the number of first auxiliary springs 69 arranged in the axial direction is different from the number of second auxiliary springs 71 arranged in the axial direction. Therefore, the axial rigidity of the first auxiliary spring portion 68 is different from the axial rigidity of the second auxiliary spring portion 70. As described above, since the first auxiliary spring 69 and the second auxiliary spring 71 are shared, it is not necessary to prepare dedicated members for the first auxiliary spring portion 68 and the second auxiliary spring portion 70, respectively.

  For example, as shown in FIG. 3, one first auxiliary spring 69 and two second auxiliary springs 71 are provided for each plate spring portion 23. Accordingly, the axial rigidity of the second auxiliary spring portion 70 is larger than the axial rigidity of the first auxiliary spring portion 68. Therefore, the amount of axial deformation of the leaf spring unit 22 in the compression cycle is smaller in the backward direction than in the forward direction.

  As described above, in the present embodiment, the deviation of the actual axial movable range from the designed axial movable range of the piston 16 caused by the pressure difference between the high pressure chamber 26 and the low pressure chamber 28 acting on the piston 16 is detected. As corrected, the axial stiffness of the second auxiliary spring portion 70 is greater than the axial stiffness of the first auxiliary spring portion 68. Therefore, the piston 16 can reciprocate in or around the designed axial range of motion. Accordingly, a desired volume change cycle is generated in the high-pressure chamber 26, and the linear compressor 10 can be operated with a desired performance.

  Further, since the axial rigidity of the second auxiliary spring part 70 is larger than the axial rigidity of the first auxiliary spring part 68, the reciprocating movement of the piston 16 is performed at or near the neutral position of the leaf spring unit 22. The center position of is corrected. Therefore, it is possible to prevent an excessive load from acting on the leaf spring portion 23.

  In the above, this invention was demonstrated based on the Example. It will be understood by those skilled in the art that the present invention is not limited to the above-described embodiment, and various design changes are possible, various modifications are possible, and such modifications are within the scope of the present invention. By the way.

  In an embodiment, in order to make the axial stiffness different between the first auxiliary spring portion and the second auxiliary spring portion, dedicated members may be prepared for the first auxiliary spring portion and the second auxiliary spring portion, respectively. Good.

  For example, the first auxiliary spring portion may have a size different from that of the second auxiliary spring portion. For example, the first auxiliary spring portion may have a different axial thickness than the second auxiliary spring portion. In this case, one leaf spring portion may be provided with one first auxiliary spring and one second auxiliary spring, and the first auxiliary spring and the second auxiliary spring may have different thicknesses. Since the second auxiliary spring portion has higher axial rigidity than the first auxiliary spring portion, the second auxiliary spring portion may be thicker in the axial direction than the first auxiliary spring portion.

  Alternatively, the first auxiliary spring portion may have a length different from that of the second auxiliary spring portion in a plane perpendicular to the axial direction. For example, the inner (or outer) cantilever arm of the first auxiliary spring part may have a different length from the inner (or outer) cantilever arm of the second auxiliary spring part. The second auxiliary spring part may be longer than the first auxiliary spring part because the second auxiliary spring part has greater axial rigidity than the first auxiliary spring part.

  In an embodiment, the first auxiliary spring portion may be made of a material different from that of the second auxiliary spring portion in order to make the axial rigidity different between the first auxiliary spring portion and the second auxiliary spring portion. Since the second auxiliary spring portion has higher axial rigidity than the first auxiliary spring portion, the second auxiliary spring portion may be made of a material having higher rigidity than the first auxiliary spring portion. For example, the first auxiliary spring portion may be formed of stainless steel, and the second auxiliary spring portion may be formed of a titanium magnesium alloy. In this case, the leaf spring part may also be formed of stainless steel like the first auxiliary spring part.

  In the exemplary embodiment described above, the piston 16 is displaced toward the low-pressure chamber 28 during the operation of the linear compressor 10, so that the second auxiliary spring portion 70 has higher axial rigidity than the first auxiliary spring portion 68. However, depending on the design or operating conditions of the linear compressor, the piston may be displaced toward the high pressure chamber during operation. Therefore, in some embodiments, the axial rigidity of the second auxiliary spring portion 70 may be smaller than the axial rigidity of the first auxiliary spring portion 68.

  In some embodiments, the linear compressor may include a piston fixed to the compressor container and a cylinder that moves axially relative to the piston. In this case, the leaf spring unit may elastically support the cylinder on the compressor container so that the cylinder can reciprocate in the axial direction.

  In an embodiment, an additional elastic member that elastically supports the movable body of the linear compressor may be provided separately from the leaf spring unit. The elastic member may be provided between the movable body and the compressor container so as to bias the movable body in the axial direction toward the low pressure chamber (or the high pressure chamber).

  FIG. 4 is a schematic diagram showing a cryogenic refrigerator 100 according to an embodiment of the present invention. The cryogenic refrigerator 100 includes a linear compressor 10 and an expander 102. A discharge pipe 30 of the linear compressor 10 is connected to the expander 102 through a high-pressure pipe 104. Further, the suction pipe 32 of the linear compressor 10 is connected to the expander 102 through the low-pressure pipe 106. The expander 102 is, for example, a Gifford McMahon expander. The expander 102 may incorporate a valve unit for selectively connecting the internal expansion chamber to one of the discharge pipe 30 and the suction pipe 32 of the linear compressor 10. The high pressure working gas 36 is supplied from the linear compressor 10 to the expander 102 through the high pressure pipe 104. The low pressure working gas 34 is recovered from the expander 102 to the linear compressor 10 through the low pressure pipe 106.

  A heat exchanger 108 for cooling the high-pressure working gas 36 discharged from the linear compressor 10 (for example, to room temperature) may be provided outside the expander 102. The heat exchanger 108 may be provided in the middle of the high-pressure pipe 104, for example. Thus, the working gas whose temperature is appropriately adjusted may be supplied to the expander 102.

  DESCRIPTION OF SYMBOLS 10 Linear compressor, 14 Compressor container, 22 Leaf spring unit, 23 Leaf spring part, 26 High pressure chamber, 28 Low pressure chamber, 42 Intake valve, 44 Discharge valve, 68 1st auxiliary spring part, 69 1st auxiliary spring, 70 A second auxiliary spring portion, 71 a second auxiliary spring, 100 a cryogenic refrigerator.

Claims (10)

A movable body support structure in a linear compressor,
A movable body that partitions a high-pressure chamber and a low-pressure chamber of working gas inside a compressor container, wherein the one in the axial reciprocation that periodically repeats one-way movement and reverse movement in a predetermined axial movement range. A movable body that compresses the working gas in the high-pressure chamber by directional movement;
A plurality of leaf springs arranged in the axial direction, each of the leaf springs elastically supporting the movable body on the compressor container so that the movable body can reciprocate in the axial direction. A leaf spring,
A plurality of first auxiliary spring portions arranged in the axial direction, each first auxiliary spring portion has a first axial rigidity, and each first auxiliary spring portion corresponds to the plurality of leaf spring portions. A plurality of first auxiliary spring portions disposed adjacent to one side of the leaf spring portion;
A plurality of second auxiliary spring portions arranged in the axial direction, each second auxiliary spring portion having a second axial rigidity, and each second auxiliary spring portion being opposite to the corresponding leaf spring portion A plurality of second auxiliary spring portions disposed adjacent to the side,
The second axial rigidity corrects a deviation of an actual axial movable range of the movable body from the predetermined axial movable range caused by a pressure difference between the high pressure chamber and the low pressure chamber acting on the movable body. Thus, the movable body support structure is different from the first axial rigidity. The predetermined axial range of motion is determined so that the center position of the periodic axial elastic deformation of the leaf spring portion in the axial reciprocation of the movable body matches the neutral position of the leaf spring portion,
2. The movable according to claim 1, wherein the second axial rigidity is different from the first axial rigidity so as to correct an axial displacement of the center position from a neutral position of a leaf spring portion. Body support structure. Each first auxiliary spring portion is adjacent to one direction side of the leaf spring portion so as to follow the elastic deformation by contact with the leaf spring portion due to elastic deformation of the corresponding leaf spring portion in one direction. ,
Each second auxiliary spring part is adjacent to the opposite side of the leaf spring part so as to follow the elastic deformation by contact with the leaf spring part accompanying the elastic deformation of the corresponding leaf spring part in the opposite direction. The movable body support structure according to claim 1 or 2, wherein Each first auxiliary spring portion includes one or more first auxiliary springs arranged in an axial direction between two leaf spring portions adjacent in the axial direction,
Each second auxiliary spring part includes one or more second auxiliary springs arranged in an axial direction between two leaf spring parts adjacent in the axial direction,
The movable body support structure according to claim 1, wherein the number of the first auxiliary springs is different from the number of the second auxiliary springs.   The movable body support structure according to claim 4, wherein the first auxiliary spring has the same dimensions as the second auxiliary spring and is formed of the same material.   The first auxiliary spring part has a size different from that of the second auxiliary spring part, and / or the first auxiliary spring part is formed of a material different from that of the second auxiliary spring part. The movable body support structure according to any one of claims 1 to 4. Before Stories second axial stiffness, the movable body supporting structure according to any one of claims 1 to 6, characterized in that greater than the first axial stiffness. A movable body support structure in a linear compressor,
A movable body that partitions a high-pressure chamber and a low-pressure chamber of working gas inside a compressor container, and the operation of the high-pressure chamber is performed by the one-way movement in an axial reciprocating motion that periodically repeats one-way movement and reverse movement. A movable body that compresses gas ;
A plurality of leaf springs arranged in the axial direction, each of the leaf springs elastically supporting the movable body on the compressor container so that the movable body can reciprocate in the axial direction. A leaf spring,
A plurality of first auxiliary spring portions arranged in the axial direction, each first auxiliary spring portion has a first axial rigidity, and each first auxiliary spring portion corresponds to the plurality of leaf spring portions. A plurality of first auxiliary spring portions disposed adjacent to one side of the leaf spring portion;
A plurality of second auxiliary spring portions arranged in the axial direction, wherein each second auxiliary spring portion has a second axial rigidity larger than the first axial rigidity, and each second auxiliary spring portion is A movable body support structure comprising: a plurality of second auxiliary spring portions arranged adjacent to the opposite side of the corresponding leaf spring portion.   A linear compressor comprising the movable body support structure according to claim 1.   A cryogenic refrigerator comprising the linear compressor according to claim 9.

Images