Gas compressor

Abstract

A gas compressor (1) according to one embodiment includes a cylinder (3A) and a hydraulic cylinder (4A). The air cylinder (3A) comprises an air cylinder pipe (31), an air cover (32) and an air piston (33). A compression chamber (3a) is formed between the gas piston (33) and the gas cover (32). The hydraulic cylinder (4A) comprises a hydraulic cylinder pipe (41), a first hydraulic cover (42), a second hydraulic cover (43) and a hydraulic piston (44). The hydraulic piston (44) forms a first drive chamber (4a) and a second drive chamber (4b) between the hydraulic piston (44) and the first hydraulic cover (42) and the second hydraulic cover (43). Furthermore, the gas compressor (1) is provided with: a rod (51) that passes through the first hydraulic cover (42) and connects the gas piston (33) and the hydraulic piston (44); and a position detector (8A) that is attached to the second hydraulic cover (43) and detects the position of the hydraulic piston (44).

Description

Technical Field

[0001] The present disclosure relates to a hydraulically driven gas compressor. Background Art

[0002] Conventionally, a hydraulically driven gas compressor is known, and is used, for example, as a large gas compressor.

[0003] For example, a gas compressor including an air cylinder and a hydraulic cylinder is disclosed in Patent Document 1. Specifically, in the gas compressor of Patent Document 1, the air cylinder includes an air cylinder tube, an air cover, and a air piston, and the hydraulic cylinder includes a hydraulic cylinder tube, a pair of hydraulic covers, and a hydraulic piston.

[0004] The air cylinder and hydraulic cylinder are coaxially arranged. An air cap is located on the side of the cylinder tube opposite the hydraulic cylinder. A gas piston is positioned within the cylinder tube, forming a compression chamber between the gas cap and the air cap. Furthermore, a pair of hydraulic caps are located on either side of the cylinder tube. The hydraulic piston is positioned within the tube, forming a pair of drive chambers between the hydraulic caps and the gas piston. The gas piston and hydraulic piston are connected by a rod that passes through the hydraulic cap on the air cylinder side.

[0005] Furthermore, in the gas compressor of Patent Document 1, a position sensor for measuring the position of the hydraulic piston is attached to the cylinder tube.

[0006] Prior art literature: Patent Literature: Patent Document 1: Japanese Patent Application Publication No. 2021-522446. Summary of the Invention

[0007] Problems to be solved by the invention: However, when a position sensor is attached to the cylinder tube as in the gas compressor of Patent Document 1, it is only possible to detect whether the hydraulic piston is at the same position as that of the position sensor.

[0008] Therefore, an object of the present disclosure is to provide a gas compressor capable of detecting the stroke of a hydraulic piston.

[0009] Means of solving the problem: The present disclosure provides a gas compressor comprising: a cylinder comprising a cylinder tube, a gas cover located on one side of the cylinder tube, and a gas piston arranged in the cylinder tube to form a compression chamber between the gas cover; a hydraulic cylinder comprising a hydraulic cylinder tube, a first hydraulic cover and a second hydraulic cover located on both sides of the hydraulic cylinder tube, and a hydraulic piston arranged in the hydraulic cylinder tube to form a first drive chamber between the first hydraulic cover and a second drive chamber between the second hydraulic cover; a rod passing through the first hydraulic cover to connect the gas piston and the hydraulic piston; and a position detector installed on the second hydraulic cover to detect the position of the hydraulic piston.

[0010] Effects of the invention: According to the present disclosure, a gas compressor capable of detecting the stroke of a hydraulic piston is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic structural diagram of a gas compressor according to one embodiment. DETAILED DESCRIPTION

[0012] Figure 1 1 shows a gas compressor 1 according to one embodiment. In this embodiment, the gas compressor 1 includes a first gas booster 2A and a second gas booster 2B, and compresses gas in two stages. The gas to be compressed is not particularly limited, and is, for example, hydrogen.

[0013] The first gas booster 2A includes a cylinder 3A, a hydraulic cylinder 4A, a rod 51, and a position detector 8A, while the second gas booster 2B includes a cylinder 3B, a hydraulic cylinder 4B, a rod 53, and a position detector 8B. The main difference between the first gas booster 2A and the second gas booster 2B is the size of the cylinders 3A and 3B. Specifically, the diameter of the gas piston 37, described later, is smaller than the diameter of the gas piston 33, described later. For example, the area of ​​the gas piston 33 is at least twice and at most ten times the area of ​​the gas piston 37. Furthermore, the volumes within the cylinder tubes 31 and 35, described later, may differ depending on factors other than the diameters of the gas pistons 33 and 37.

[0014] The air cylinder 3A and hydraulic cylinder 4A of the first gas booster 2A are coaxially arranged, while the cylinder 3B and hydraulic cylinder 4B of the second gas booster 2B are coaxially arranged. In this embodiment, the axial directions of the cylinders 3A, 3B, and hydraulic cylinders 4A, 4B are vertical. The axial directions of the cylinders 3A, 3B, and hydraulic cylinders 4A, 4B may be parallel to the vertical direction or slightly inclined relative to the vertical direction, for example, within 20 degrees. Furthermore, in this embodiment, the hydraulic cylinder 4A is positioned below the air cylinder 3A, and the hydraulic cylinder 4B is positioned below the air cylinder 3B.

[0015] Regarding the first gas booster 2A, the cylinder 3A includes a cylinder tube 31, a gas cap 32, and a gas piston 33. The cylinder tube 31 is cylindrical and extends in the vertical direction. The gas cap 32 is located on the side of the cylinder tube 31 opposite the hydraulic cylinder 4A, and closes the opening at the top of the cylinder tube 31. The gas piston 33 is disposed within the cylinder tube 31, forming a compression chamber 3a between the gas piston 33 and the gas cap 32. A seal such as an O-ring is attached to the outer circumference of the gas piston 33.

[0016] The cylinder 3A also includes a cylindrical jacket 34 that houses the cylinder tube 31 and extends from the gas cover 32 to the first hydraulic cover 42, described later. An annular cooling chamber is formed between the cylinder tube 31 and the jacket 34, into which coolant is supplied and discharged. However, depending on the temperature of the gas after the first stage of compression, the jacket 34 may be omitted.

[0017] The gas cap 32 is, for example, disc-shaped. In this embodiment, the gas cap 32 has an inlet port 6a and an outlet port 6b on its radially outward end surface. However, one or both of the inlet port 6a and the outlet port 6b may be on the upper surface of the gas cap 32.

[0018] The gas cap 32 is formed with a first gas flow path 61 extending from the intake port 6a to the discharge port 6b and a second gas flow path 64 connecting the first gas flow path 61 with the compression chamber 3a. In this embodiment, a check valve 62 is provided in the portion of the first gas flow path 61 between the intake port 6a and the second gas flow path 64, and a check valve 63 is provided in the portion of the first gas flow path 61 between the second gas flow path 64 and the discharge port 6b.

[0019] However, the check valve 62 may be provided in the gas supply path 11 (described later), and the check valve 63 may be provided in the gas communication path 12 (described later). In this case, the intake port 6a and the discharge port 6b may be provided in the upper portion of the cylinder tube 31, and the first gas flow path 61 and the second gas flow path 64 may be omitted. Alternatively, when the intake port 6a and the discharge port 6b are provided in the cylinder tube 31, the piping through-jacket 34 constituting the gas supply path 11 may be connected to the intake port 6a, and the piping through-jacket 34 constituting the gas communication path 12 may be connected to the discharge port 6b.

[0020] Hydraulic cylinder 4A includes a hydraulic cylinder tube 41, a first hydraulic cover 42, a second hydraulic cover 43, and a hydraulic piston 44. The hydraulic cylinder tube 41 is cylindrical and extends in the vertical direction. The first and second hydraulic covers 42, 43 are located on either side of the hydraulic cylinder tube 41. The first hydraulic cover 42 blocks the top opening of the hydraulic cylinder tube 41, while the second hydraulic cover 43 blocks the bottom opening of the hydraulic cylinder tube 41.

[0021] The hydraulic piston 44 is positioned within the hydraulic cylinder tube 41, forming a first drive chamber 4a between it and the first hydraulic cover 42 and a second drive chamber 4b between it and the second hydraulic cover 43. A seal, such as an O-ring, is attached to the outer circumference of the hydraulic piston 44. In this embodiment, the hydraulic piston 44 is comprised of a single component, but it can also be comprised of multiple components. For example, the hydraulic piston 44 can consist of two plates with a rod between them. In this case, hydraulic oil can also be supplied between the two plates.

[0022] In this embodiment, the lower opening of the cylinder tube 31 is blocked by the first hydraulic cover 42. The rod 51 passes through the first hydraulic cover 42, connecting the gas piston 33 and the hydraulic piston 44. However, similar to the gas compressor disclosed in Patent Document 1, the lower opening of the cylinder tube 31 may be blocked by an intermediate cover, and an intermediate pipe may be provided between the intermediate cover and the first hydraulic cover 42 to surround the space around the rod 51.

[0023] The first hydraulic cover 42 and the second hydraulic cover 43 are, for example, disc-shaped. In this embodiment, the first hydraulic cover 42 has a first supply and discharge port 7a on its radially outward end surface, and the second hydraulic cover 43 has a second supply and discharge port 7b on its radially outward end surface. However, the positions of the first supply and discharge port 7a and the second supply and discharge port 7b are not limited to this. For example, the first supply and discharge port 7a may be provided at the upper portion of the hydraulic cylinder tube 41, omitting the first hydraulic flow path 71 described later. Alternatively, the second supply and discharge port 7b may be provided at the lower portion of the hydraulic cylinder tube 41, omitting the second hydraulic flow path 72 described later.

[0024] A first hydraulic flow path 71 is formed in the first hydraulic cover 42 to connect the first supply and discharge port 7a with the first drive chamber 4a, and a second hydraulic flow path 72 is formed in the second hydraulic cover 43 to connect the second supply and discharge port 7b with the second drive chamber 4b.

[0025] Regarding the second gas booster 2B, the cylinder 3B includes a cylinder tube 35, a gas cap 36, and a gas piston 37. The cylinder tube 35 is cylindrical and extends in the vertical direction. The gas cap 36 is located on the side of the cylinder tube 35 opposite the hydraulic cylinder 4B, and closes the opening at the top of the cylinder tube 35. The gas piston 37 is disposed within the cylinder tube 35, forming a compression chamber 3b between the gas piston 37 and the gas cap 36. A seal such as an O-ring is attached to the outer circumference of the gas piston 37.

[0026] Cylinder 3B further includes a cylindrical jacket 38 that houses cylinder tube 35 and extends from gas cap 36 to first hydraulic cover 46, described later. An annular cooling chamber is formed between cylinder tube 35 and jacket 38, into which coolant is supplied and discharged. However, jacket 38 may be omitted depending on the temperature of the gas after the second-stage compression.

[0027] The gas cap 36 is, for example, disc-shaped. In this embodiment, the gas cap 36 has an inlet port 6c and an outlet port 6d on its radially outward end surface. However, one or both of the inlet port 6c and the outlet port 6d may be on the upper surface of the gas cap 36.

[0028] The gas cap 36 is formed with a first gas flow path 65 extending from the intake port 6c to the discharge port 6d, and a second gas flow path 68 connecting the first gas flow path 65 with the compression chamber 3b. In this embodiment, a check valve 66 is provided in the portion of the first gas flow path 65 between the intake port 6c and the second gas flow path 68, and a check valve 67 is provided in the portion of the first gas flow path 65 between the second gas flow path 68 and the discharge port 6d.

[0029] However, the check valve 66 may be provided in the gas communication passage 12 (described later), and the check valve 67 may be provided in the gas exhaust passage 13 (described later). In this case, the intake port 6c and the discharge port 6d may be provided in the upper portion of the cylinder tube 35, and the first gas flow passage 65 and the second gas flow passage 68 may be omitted. Alternatively, when the intake port 6c and the discharge port 6d are provided in the cylinder tube 35, the piping through-jacket 38 constituting the gas communication passage 12 may be connected to the intake port 6c, and the piping through-jacket 38 constituting the gas exhaust passage 13 may be connected to the discharge port 6d.

[0030] Hydraulic cylinder 4B includes a hydraulic cylinder tube 45, a first hydraulic cover 46, a second hydraulic cover 47, and a hydraulic piston 48. The hydraulic cylinder tube 45 is cylindrical and extends in the vertical direction. The first and second hydraulic covers 46, 47 are located on either side of the hydraulic cylinder tube 45. The first hydraulic cover 46 closes the top opening of the hydraulic cylinder tube 45, while the second hydraulic cover 47 closes the bottom opening of the hydraulic cylinder tube 45.

[0031] The hydraulic piston 48 is positioned within the hydraulic cylinder tube 45, forming a first drive chamber 4c between it and the first hydraulic cover 46 and a second drive chamber 4d between it and the second hydraulic cover 47. A seal, such as an O-ring, is attached to the outer circumference of the hydraulic piston 48. In this embodiment, the hydraulic piston 48 is constructed from a single component, but it can also be constructed from multiple components. For example, the hydraulic piston 48 can consist of two plates with a rod between them. In this case, hydraulic oil can also be supplied between the two plates.

[0032] In this embodiment, the lower opening of the cylinder tube 35 is blocked by the first hydraulic cover 46. The rod 53 passes through the first hydraulic cover 46, connecting the gas piston 37 and the hydraulic piston 48. However, similar to the gas compressor disclosed in Patent Document 1, the lower opening of the cylinder tube 35 may be blocked by an intermediate cover, and an intermediate tube may be provided between the intermediate cover and the first hydraulic cover 46 to surround the space around the rod 53.

[0033] The first hydraulic cover 46 and the second hydraulic cover 47 are, for example, disc-shaped. In this embodiment, the first hydraulic cover 46 has a first supply and discharge port 7c on its radially outward end surface, and the second hydraulic cover 47 has a second supply and discharge port 7d on its radially outward end surface. However, the positions of the first supply and discharge ports 7c and the second supply and discharge ports 7d are not limited to this. For example, the first supply and discharge port 7c may be provided at the upper portion of the hydraulic cylinder tube 45, omitting the first hydraulic flow path 73, described later. Alternatively, the second supply and discharge port 7d may be provided at the lower portion of the hydraulic cylinder tube 45, omitting the second hydraulic flow path 74, described later.

[0034] A first hydraulic flow path 73 is formed in the first hydraulic cover 46 to connect the first supply and discharge port 7c with the first drive chamber 4c, and a second hydraulic flow path 74 is formed in the second hydraulic cover 47 to connect the second supply and discharge port 7d with the second drive chamber 4d.

[0035] The intake port 6a of the first gas booster 2A is connected to a gas supply path 11, and the discharge port 6d of the second gas booster 2B is connected to a gas exhaust path 13. Furthermore, the discharge port 6b of the first gas booster 2A and the intake port 6c of the second gas booster 2B are connected to each other via a gas communication path 12.

[0036] The gas piston 33 and the gas piston 37 move alternately. When the gas piston 33 descends, gas is supplied from the gas supply path 11 to the compression chamber 3a through the upstream portion of the first gas flow path 61 and the second gas flow path 64. When the gas piston 33 ascends and the gas piston 37 descends, gas is supplied from the compression chamber 3a to the compression chamber 3b through the second gas flow path 64, the downstream portion of the first gas flow path 61, the gas communication path 12, the upstream portion of the first gas flow path 65, and the second gas flow path 68. At this time, the gas is compressed due to the difference in area between the compression chambers 3a and 3b. When the gas piston 37 ascends, the gas in the compression chamber 3b is compressed to at least the pressure downstream of the check valve 67. The compressed gas is then discharged through the second gas flow path 68, the downstream portion of the first gas flow path 65, and the gas discharge path 13.

[0037] Supply and discharge passages 14 and 16 are connected to the first supply and discharge port 7a of the first gas booster 2A and the first supply and discharge port 7c of the second gas booster 2B, respectively. Furthermore, the second supply and discharge port 7b of the first gas booster 2A and the second supply and discharge port 7d of the second gas booster 2B are connected to each other via a hydraulic communication passage 15. In other words, the second drive chamber 4b of the first gas booster 2A and the second drive chamber 4d of the second gas booster 2B are connected via the hydraulic communication passage 15.

[0038] Therefore, when hydraulic oil is supplied from the pump to the first drive chamber 4a through the supply and discharge line 14 and the first hydraulic flowpath 71, the hydraulic piston 44 descends, and hydraulic oil is supplied from the second drive chamber 4b to the second drive chamber 4d through the second hydraulic flowpath 72, the hydraulic communication line 15, and the second hydraulic flowpath 74. When hydraulic oil is supplied to the second drive chamber 4d, the hydraulic piston 48 ascends, and hydraulic oil is discharged from the first drive chamber 4c through the first hydraulic flowpath 73 and the supply and discharge line 16.

[0039] Conversely, when hydraulic oil is supplied from the pump to the first drive chamber 4c via the supply / discharge line 16 and the first hydraulic flowpath 73, the hydraulic piston 48 descends, and hydraulic oil is supplied from the second drive chamber 4d to the second drive chamber 4b via the second hydraulic flowpath 74, the hydraulic communication line 15, and the second hydraulic flowpath 72. When hydraulic oil is supplied to the second drive chamber 4b, the hydraulic piston 44 ascends, and hydraulic oil is discharged from the first drive chamber 4a via the first hydraulic flowpath 71 and the supply / discharge line 14.

[0040] The diameter of the hydraulic piston 44 of the first gas booster 2A is equal to the diameter of the hydraulic piston 48 of the second gas booster 2B. Therefore, the strokes of the hydraulic piston 44 and the gas piston 33 are equal to the strokes of the hydraulic piston 48 and the gas piston 37. However, the diameters of the hydraulic piston 44 and the hydraulic piston 48 may be different, and the strokes of the hydraulic piston 44 and the gas piston 33 may be different from the strokes of the hydraulic piston 48 and the gas piston 37.

[0041] A pressure sensor 91 for detecting the pressure in the first drive chamber 4a is provided on the supply and exhaust line 14, and a pressure sensor 93 for detecting the pressure in the first drive chamber 4c is provided on the supply and exhaust line 16. Alternatively, pressure sensor 91 may be provided on the hydraulic cylinder tube 41 or the first hydraulic cover 42, while pressure sensor 93 may be provided on the hydraulic cylinder tube 45 or the first hydraulic cover 46. A pressure sensor 92 for detecting the pressure in the second drive chambers 4b and 4d is provided on the hydraulic communication line 15. Alternatively, pressure sensor 92 may be provided on one of the hydraulic cylinder tubes 41 and 45 or on one of the second hydraulic covers 43 and 47.

[0042] The position detectors 8A and 8B are respectively mounted on the second hydraulic covers 43 and 47. The position detector 8A detects the position of the hydraulic piston 44, and the position detector 8B detects the position of the hydraulic piston 48.

[0043] Position detectors 8A and 8B have the same structure. In this embodiment, position detectors 8A and 8B are magnetostrictive linear sensors. However, position detectors 8A and 8B may be other types of sensors, such as laser or infrared sensors.

[0044] Specifically, position detector 8A comprises a probe 81 mounted on second hydraulic cover 43 and extending through hydraulic piston 44, and a magnet 84 mounted on hydraulic piston 44. Probe 81 includes a head 82 located outside second hydraulic cover 43 and a sensor rod 83 extending from head 82. In this embodiment, magnet 84 is annular and penetrates sensor rod 83. Holes 52 are provided in hydraulic piston 44 and rod 51 to prevent interference with sensor rod 83.

[0045] Similarly, position detector 8B includes a probe 81 mounted on second hydraulic cover 47 and extending through hydraulic piston 48, and a magnet 84 mounted on hydraulic piston 48. Probe 81 includes a head 82 located outside second hydraulic cover 43 and a sensor rod 83 extending from head 82. In this embodiment, magnet 84 is annular and penetrates sensor rod 83. Holes 54 are provided in hydraulic piston 48 and rod 53 to prevent interference with sensor rod 83.

[0046] As described above, in the gas compressor 1 of this embodiment, the position detectors 8A and 8B are attached to the second hydraulic covers 43 and 47 that face the hydraulic pistons 44 and 48. Therefore, the positions of the hydraulic pistons 44 and 48 can be detected regardless of the positions of the hydraulic pistons 44 and 48. Therefore, the position detectors 8A and 8B can be used as stroke sensors to detect the stroke of the hydraulic pistons 44 and 48.

[0047] Furthermore, by comprehensively controlling the flow rate of gas, the flow rate of hydraulic oil, the stroke of the hydraulic pistons 44 and 48 , etc. using a control device (not shown), a stable supply of compressed gas can be achieved.

[0048] Furthermore, since pressure sensors 91, 92, and 93 are used in this embodiment, the pressure in compression chamber 3a can be estimated based on the detection values ​​of pressure sensors 91 and 92, and the pressure in compression chamber 3b can be estimated based on the detection values ​​of pressure sensors 93 and 92. Therefore, the pressures in compression chambers 3a and 3b can be determined without using special pressure sensors that are resistant to high temperatures and high pressures, as is the case when directly detecting the pressures in compression chambers 3a and 3b.

[0049] Modifications The present disclosure is not limited to the contents of the above-described embodiment, and various modifications can be made without departing from the gist of the present disclosure.

[0050] For example, the axial directions of the air cylinders 3A, 3B and the hydraulic cylinders 4A, 4B may be lateral rather than vertical. However, as in the above-described embodiment, if the axial directions of the air cylinders 3A, 3B and the hydraulic cylinders 4A, 4B are vertical, the installation area of ​​the gas compressor 1 can be reduced compared to a case where the axial directions of the air cylinders 3A, 3B and the hydraulic cylinders 4A, 4B are lateral. Furthermore, since the area above the air cylinders 3A, 3B can be used as maintenance space, the gaps between the first gas booster 2A, which includes the air cylinders 3A and 4A, and surrounding structures, and the gaps between the second gas booster 2B, which includes the air cylinders 3B and 4B, and surrounding structures can be reduced. Furthermore, since the air cylinders 3A, 3B are located above the hydraulic cylinders 4A, 4B, the air pistons 33, 37 can be lifted from above, improving maintainability.

[0051] Alternatively, contrary to the above embodiment, the first supply and discharge port 7a of the first gas booster 2A and the first supply and discharge port 7c of the second gas booster 2B may be connected to each other via a hydraulic communication passage 15, while the second supply and discharge port 7b of the first gas booster 2A and the second supply and discharge port 7d of the second gas booster 7B may be connected to supply and discharge passages 14 and 16, respectively. In other words, the first drive chamber 4a of the first gas booster 2A and the first drive chamber 4c of the second gas booster 2B may also be connected via the hydraulic communication passage 15. In this case, the pressure sensor 92 provided in the hydraulic communication passage 15 detects the pressures in the first drive chambers 4a and 4c, the pressure sensor 91 provided in the supply and discharge passage 14 detects the pressure in the second drive chamber 4b, and the pressure sensor 93 provided in the supply and discharge passage 16 detects the pressure in the second drive chamber 4d.

[0052] Alternatively, the gas compressor 1 may include only the first gas booster 2A, compressing gas in a single stage. In this case, hydraulic oil is alternately supplied from a pump to the first drive chamber 4a and the second drive chamber 4b of the first gas booster 2A. With this configuration, as in the above-described embodiment, the pressure of the gas introduced into the compression chamber 3a or 3b of one of the first and second gas boosters 2A, 2B, can be used to compress the gas in the other.

[0053] Summary As a first embodiment, the present disclosure provides a gas compressor comprising: a cylinder comprising a cylinder tube, a gas cover located on one side of the cylinder tube, and a gas piston arranged in the cylinder tube to form a compression chamber between the gas cover; a hydraulic cylinder comprising a hydraulic cylinder tube, a first hydraulic cover and a second hydraulic cover located on both sides of the hydraulic cylinder tube, and a hydraulic piston arranged in the hydraulic cylinder tube to form a first drive chamber between the first hydraulic cover and a second drive chamber between the second hydraulic cover; a rod passing through the first hydraulic cover to connect the gas piston and the hydraulic piston; and a position detector installed on the second hydraulic cover to detect the position of the hydraulic piston.

[0054] According to the above structure, since the position detector is mounted on the second hydraulic cover facing the hydraulic piston, the position of the hydraulic piston can be detected regardless of the position of the hydraulic piston. Therefore, the position detector can be used as a stroke sensor to detect the stroke of the hydraulic piston.

[0055] As a second embodiment, in the first embodiment, the axial directions of the air cylinder and the hydraulic cylinder are vertical, and the hydraulic cylinder is positioned below the air cylinder. This configuration reduces the installation area of ​​the gas compressor compared to a case where the axial directions of the air cylinder and the hydraulic cylinder are horizontal. Furthermore, since the area above the air cylinder can be used as maintenance space, the clearance between the gas booster, which includes the air cylinder and the hydraulic cylinder, and surrounding structures can be reduced. Furthermore, since the air cylinder is positioned above the hydraulic cylinder, the gas piston can be lifted from above, improving maintainability.

[0056] As a third aspect, in the first or second aspect, for example, the position detector is a magnetostrictive linear sensor including a probe attached to the second hydraulic cover and extending through the hydraulic piston, and a magnet attached to the hydraulic piston.

[0057] As a fourth aspect, in any of the first to third aspects, the gas compressor may further include: a pressure sensor for detecting the pressure in the first drive chamber; and a pressure sensor for detecting the pressure in the second drive chamber. This configuration allows the pressure in the compression chamber to be estimated based on the values ​​detected by the pressure sensors. Therefore, the pressure in the compression chamber can be determined without using a special pressure sensor that is resistant to high temperatures and high pressures, as is the case when directly detecting the pressure in the compression chamber.

[0058] As a fifth aspect, in any one of the first to fourth aspects, the gas compressor may include a first gas booster and a second gas booster, each of the first gas booster and the second gas booster including the air cylinder, the hydraulic cylinder, the rod, and the position detector, gas being supplied from the compression chamber of the first gas booster to the compression chamber of the second gas booster via a gas communication passage, and the first drive chambers or the second drive chambers of the first and second gas boosters being connected to each other via a hydraulic communication passage. With this configuration, the pressure of the gas introduced into the compression chamber of one of the first and second gas boosters can be used to compress the gas of the other.

[0059] Explanation of symbols: 1: Gas compressor; 12: Gas communication path; 15: Hydraulic communication line; 2A: First gas booster; 2B: Second gas booster; 3A, 3B: cylinder; 31, 35: cylinder tube; 32, 36: gas cap; 33, 37: gas piston; 3a, 3b: compression chamber; 4A, 4B: hydraulic cylinder; 41, 45: hydraulic cylinder tube; 42, 46: first hydraulic cover; 43, 47: second hydraulic cover; 44, 48: hydraulic piston; 4a, 4c: first drive chamber; 4b, 4d: second drive chamber; 51, 53: rod; 8A, 8B: position detector; 81: probe; 84: magnet; 91, 92, 93: Pressure sensors.

Claims

1. A gas compressor, characterized in that: have: A cylinder comprising a cylinder tube, a gas cap located on one side of the cylinder tube, and a gas piston disposed in the cylinder tube to form a compression chamber between the gas cap and the gas piston; A hydraulic cylinder comprising a hydraulic cylinder tube, a first hydraulic cover and a second hydraulic cover located on both sides of the hydraulic cylinder tube, and a hydraulic piston disposed in the hydraulic cylinder tube to form a first drive chamber between the hydraulic cover and the first hydraulic cover and a second drive chamber between the hydraulic piston and the second hydraulic cover; a rod passing through the first hydraulic cover and connecting the gas piston and the hydraulic piston; and A position detector is mounted on the second hydraulic cover and detects a position of the hydraulic piston.

2. The gas compressor according to claim 1, characterized in that The axial directions of the air cylinder and the hydraulic cylinder are vertical directions, and the hydraulic cylinder is arranged below the air cylinder.

3. The gas compressor according to claim 1 or 2, characterized in that: The position detector is a magnetostrictive linear sensor including a probe mounted on the second hydraulic cover and extending through the hydraulic piston, and a magnet mounted on the hydraulic piston.

4. The gas compressor according to claim 1 or 2, characterized in that: Also features: a pressure sensor for detecting the pressure of the first driving chamber; and A pressure sensor detects the pressure of the second driving chamber.

5. The gas compressor according to claim 1 or 2, characterized in that: A first gas booster and a second gas booster are provided, The first gas booster and the second gas booster respectively include the air cylinder, the hydraulic cylinder, the rod, and the position detector. Gas is supplied from the compression chamber of the first gas booster to the compression chamber of the second gas booster via a gas communication passage. The first drive chambers of the first gas booster and the second gas booster are in communication with each other or the second drive chambers are in communication with each other via a hydraulic communication passage.

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