Oxygen concentrator

Abstract

To provide an oxygen concentrator capable of satisfactorily generating high concentration oxygen when a plurality of compressors are mounted.SOLUTION: An oxygen concentrator of the present disclosure includes a sieve bed, at least first and second compressors that supply air to the sieve bed, a common base to which the first and second compressors are fixed, and a vibration isolator provided between the common base and a base portion.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present disclosure relates to oxygen concentrators used in medical and home oxygen therapy (HOT). [Background technology]

[0002] A conventional oxygen concentrator of this type is described in, for example, Patent Document 1. The oxygen concentrator has a compressor and a sieve bed (adsorption tower). In the oxygen concentrator, the compressor sends air to the sieve bed, which then adsorbs nitrogen. This allows for the production of highly concentrated oxygen. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-147105 Summary of the Invention [Problem to be solved by the invention]

[0004] By the way, oxygen concentrators are generally equipped with one compressor.

[0005] Conventional oxygen concentrators were not designed to be equipped with multiple compressors, and no consideration was given to the placement of multiple compressors when installed in an oxygen concentrator.

[0006] The present disclosure provides an oxygen concentrator that can effectively generate high-concentration oxygen when equipped with multiple compressors. [Means for solving the problem]

[0007] One aspect of the oxygen concentrator of the present disclosure is Sheave bed and at least first and second compressors supplying air to the sieve bed; a common base to which the first and second compressors are fixed; a vibration-isolating portion provided between the common base and the base portion; Equipped with. [Effects of the Invention]

[0008] According to the present disclosure, even if the distance between the first and second compressors is reduced, the compressors can be prevented from colliding with each other during vibration. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing the appearance of an oxygen concentrator according to an embodiment; [Figure 2] FIG. 1 is a diagram showing a configuration of a main part of an oxygen concentrator according to an embodiment. [Figure 3] A diagram showing the schematic configuration of the control system for an oxygen concentrator. [Figure 4] 4A is a chart showing the change in pressure in the product tank; FIG. 4B is a chart showing the open / close states of the pressure equalizing valve and the on-off valve; and FIG. 4D is a chart showing the on / off state of the compressor. [Figure 5] FIG. 10 is a diagram showing another example of an operation chart of the oxygen concentrator according to the embodiment. [Figure 6] FIG. 10 is a diagram showing another example of an operation chart of the oxygen concentrator according to the embodiment. [Figure 7] FIG. 10 is a diagram showing another example of an operation chart of the oxygen concentrator according to the embodiment. [Figure 8] FIG. 1 is a perspective view showing an internal configuration of an oxygen concentrator according to an embodiment. [Figure 9] A perspective view showing the configuration of a compressor [Figure 10] FIG. 1 is a perspective view showing an arrangement of two compressors according to an embodiment. [Figure 11] A perspective view showing a support structure for a compressor [Figure 12] A perspective view showing another arrangement of two compressors. [Figure 13]A perspective view showing another arrangement of two compressors. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0011] <1> Overall configuration of oxygen concentrator 1 is a perspective view showing the appearance of an oxygen concentrator 1 according to an embodiment of the present disclosure. Here, in this embodiment, for convenience, the left-right direction of oxygen concentrator 1 is defined as the X-axis direction, the front-rear direction as the Y-axis direction, and the up-down direction as the Z-axis direction.

[0012] Oxygen concentrator 1 has a housing 2, inside which the various components described below are housed. Casters 3 are provided on the bottom of housing 2, allowing oxygen concentrator 1 to be movable. An operation unit 4 and a display unit 5 are provided on the top surface of housing 2. An oxygen outlet 6 is also provided on the top surface of housing 2.

[0013] A humidification bottle 7 is provided on the front side of the housing 2 of the oxygen concentrator 1. The humidification bottle 7 is provided on the oxygen concentrator 1 so as to be detachable.

[0014] Fig. 2 is a diagram showing the configuration of the main components of the oxygen concentrator 1. The oxygen concentrator 1 is a pressure swing adsorption (PSA) type oxygen concentrator that generates highly concentrated oxygen by changing the pressure inside two sieve beds. Fig. 2 mainly shows the main components of the flow system of the oxygen concentrator 1. The oxygen concentrator 1 includes an air intake section 10, an air compression section 100, a PSA section 200, an oxygen storage section 20, and an oxygen supply section 30.

[0015] Air intake section 10 is a section that takes in outside air, which will become raw air, into the housing, and is equipped with intake filter 11, air filter 12, etc. Intake filter 11 removes airborne particles such as dirt and dust from the raw air introduced through air intake port 13 provided in housing 2. Air filter 12 removes fine particles that were not removed by intake filter 11. As air filter 12, for example, a HEPA (High Efficiency Particulate Air Filter) filter can be used.

[0016] In this embodiment, the air compression unit 100 has two compressors 100-1 and 100-2. The compressors 100-1 and 100-2 compress the raw air introduced through the air intake unit 10 to generate compressed air. Specifically, the compressors 100-1 and 100-2 have motors as their driving sources. The compressors 100-1 and 100-2 compress air with a force corresponding to the motor rotation speed to obtain compressed air.

[0017] It is preferable to provide an expansion type silencer (silencer) upstream of the compressors 100-1 and 100-2 (downstream of the air filter 12) to reduce the noise generated by the compressors 100-1 and 100-2.

[0018] The PSA unit 200 functions as a high-concentration oxygen generator that generates high-concentration oxygen by the pressure swing adsorption (PSA) method. The PSA unit 200 separates nitrogen and moisture from the compressed air generated by the compressors 100-1 and 100-2 to generate high-concentration oxygen, which is then sent to the oxygen storage unit 20. The PSA unit 200 includes a flow path switching unit 201, an exhaust silencer 202, sieve beds (adsorption towers) 200-1 and 200-2, a purge orifice 203, a pressure equalizing valve 204, a check valve 205, and the like.

[0019] The flow path switching unit 201 is composed of a manifold (multi-pipe) equipped with four on-off valves SV1 to SV4, and alternately sends compressed air generated by compressors 100-1 and 100-2 to sieve beds 200-1 and 200-2, and alternately opens sieve beds 200-1 and 200-2 to atmospheric pressure to discharge the nitrogen-enriched air in sieve beds 200-1 and 200-2.

[0020] Specifically, in flow path switching unit 201, on-off valve SV1 is "open" and on-off valve SV2 is "closed," thereby opening the flow paths from compressors 100-1 and 100-2 to sieve bed 200-1, while closing the flow path from sieve bed 200-1 to exhaust silencer 202. At the same time, on-off valve SV3 is "closed" and on-off valve SV4 is "open," thereby closing the flow paths from compressors 100-1 and 100-2 to sieve bed 200-2, while opening the flow path from sieve bed 200-2 to exhaust silencer 202. In this case, compressed air generated by compressors 100-1 and 100-2 is sent to sieve bed 200-1, and nitrogen-enriched air is released from sieve bed 200-2 and exhausted via exhaust silencer 202.

[0021] Furthermore, when the on-off valves SV1 to SV4 are in the opposite state to that described above, i.e., when on-off valve SV1 is "closed," on-off valve SV2 is "open," on-off valve SV3 is "open," and on-off valve SV4 is "closed," compressed air generated by compressors 100-1 and 100-2 is sent to sieve bed 200-2, and nitrogen-enriched air is released from sieve bed 200-1 and exhausted through exhaust silencer 202. The on-off states of on-off valves SV1 to SV4 are switched, for example, at 10-second intervals.

[0022] The exhaust silencer 202 is connected to an exhaust port (not shown) provided in the housing 2 of the oxygen concentrator 1, and silences the exhaust noise when the nitrogen-enriched air released from the sieve beds 200-1 and 200-2 is discharged outside the housing.

[0023] The sieve beds 200-1 and 200-2 are filled with an adsorbent such as zeolite, which has the property of adsorbing more nitrogen than oxygen. The sieve beds 200-1 and 200-2 separate nitrogen and moisture from the compressed air sent through the flow path switching unit 201, and produce highly concentrated oxygen.

[0024] When the flow path from the air compressor 100 is opened by the flow path switching unit 201, the sieve beds 200-1 and 200-2 are pressurized by the compressed air being fed in. At this time, the sieve beds 200-1 and 200-2 adsorb nitrogen and moisture to generate highly concentrated oxygen (adsorption process).

[0025] The concentration of the high-concentration oxygen produced in the sieve beds 200-1 and 200-2 is adjusted to, for example, about 90%. Furthermore, since zeolite adsorbs not only nitrogen but also moisture, the high-concentration oxygen produced in the sieve beds 200-1 and 200-2 is in an extremely dry state (for example, humidity of 0.1 to 0.2%).

[0026] On the other hand, when the flow path to the exhaust silencer 202 is opened by the flow path switching unit 201, the sieve beds 200-1 and 200-2 are opened to atmospheric pressure and placed in a reduced pressure state. At this time, the nitrogen and moisture adsorbed in the zeolite are desorbed from the zeolite, and nitrogen-enriched air is released from the sieve beds 200-1 and 200-2 and exhausted through the exhaust silencer 202. This regenerates the adsorption capacity of the sieve beds 200-1 and 200-2 (regeneration process).

[0027] The sieve beds 200-1 and 200-2 are connected to the product tank 21 of the oxygen storage unit 20 via check valves 205. The check valves 205 prevent the highly concentrated oxygen stored in the product tank 21 from flowing back into the sieve beds 200-1 and 200-2.

[0028] The downstream sides of the sieve beds 200-1 and 200-2 are connected by a pipe having a purge orifice 203. High-concentration oxygen generated in one sieve bed 200-1 (or 200-2) is sent to the oxygen storage section 20 via check valves 205, 205, and is also sent to the other sieve bed 200-2 (or 200-1) via the purge orifice 203. By sending a portion of the generated high-concentration oxygen to the other sieve bed 200-2 (or 200-1), the regeneration process of the sieve bed 200-2 (or 200-1) is efficiently carried out. The flow rate of high-concentration oxygen in each flow path is controlled by the orifice diameter of the purge orifice 203.

[0029] The downstream sides of the sieve beds 200-1 and 200-2 are connected by a pipe having a pressure equalizing valve 204. When switching the sieve beds 200-1 and 200-2 in the regeneration process to the adsorption process, if compressed air is introduced under reduced pressure (atmospheric pressure), the nitrogen adsorption efficiency will be poor. Therefore, the pressure equalizing valve 204 is opened during the switching process to equalize the pressures in the sieve beds 200-1 and 200-2.

[0030] The oxygen storage unit 20 is a unit that temporarily stores the high-concentration oxygen generated in the PSA unit 200. The oxygen storage unit 20 includes a product tank 21, a pressure adjustment unit (pressure regulator) 22, an oxygen sensor 23, a pressure sensor 24, and the like.

[0031] Product tank 21 is a container for storing the high-concentration oxygen generated by sieve beds 200-1 and 200-2. By temporarily storing the high-concentration oxygen delivered from sieve beds 200-1 and 200-2 in product tank 21, fluctuations in the concentration and pressure of the high-concentration oxygen are suppressed, allowing high-concentration oxygen to be supplied to the patient at a stable concentration and flow rate.

[0032] Pressure adjustment unit 22 adjusts the pressure of the high-concentration oxygen to a constant pressure suitable for use in order to control the flow rate of the high-concentration oxygen being supplied. The pressure of the high-concentration oxygen stored in product tank 21 will fluctuate to some extent as long as there is flow into or out of product tank 21. In this case, accurate flow rate control becomes difficult, and accurate concentration measurement by oxygen sensor 23 becomes difficult. Taking this into consideration, pressure adjustment unit 22 adjusts the high-concentration oxygen to a constant pressure.

[0033] The oxygen sensor 23 detects the concentration of the high-concentration oxygen sent from the pressure adjusting unit 22 at predetermined intervals (for example, every 20 minutes) or continuously. A zirconia-type or ultrasonic sensor, for example, is suitable for the oxygen sensor 23. Since accurate measurement becomes difficult if the pressure of the high-concentration oxygen to be measured fluctuates, the oxygen sensor 23 is generally connected downstream of the pressure adjusting unit 22 via a flow-restricting orifice 25.

[0034] Pressure sensor 24 detects the pressure of the high-concentration oxygen stored in product tank 21. Based on the detection result by pressure sensor 24, it can be confirmed whether the pressure of the high-concentration oxygen stored in product tank 21 is maintained within a normal range.

[0035] The oxygen supply unit 30 synchronizes the highly concentrated oxygen delivered from the oxygen reservoir 20 with the patient's breathing, humidifies the oxygen, and releases it from the oxygen outlet 6. The oxygen supply unit 30 includes a bacterial filter 31, a synchronization valve 32, a pressure sensor 33, and a humidifying bottle 7.

[0036] The bacterial filter 31 captures and sterilizes bacteria contained in the high-concentration oxygen in order to supply clean high-concentration oxygen to the patient.

[0037] The tuning valve 32 is a three-way valve with ports P1 to P3, and switches the flow path that opens depending on the patient's breathing, and controls the flow rate of high-concentration oxygen supplied to the patient by adjusting the opening degree of the flow path. A bacterial filter 31 is connected to port P1 of the tuning valve 32, a humidification bottle 7 and an oxygen outlet 6 are connected to port P2, and a pressure sensor 33 is connected to port P3.

[0038] For example, when the tuning valve 32 is opened, the flow path (first flow path) connecting the ports P1 and P2 is opened, and high-concentration oxygen is released from the oxygen outlet 6 via the humidifier bottle 7. On the other hand, when the tuning valve 32 is closed, the flow path (second flow path) connecting the ports P2 and P3 is opened, and pressure fluctuations caused by the patient's breathing can be detected by the pressure sensor 33.

[0039] Pressure sensor 33 is a sensor for detecting the patient's breathing, and is connected to port P3 of tuning valve 32, and is also connected downstream of tuning valve 32 (the flow path connecting port P2 and oxygen outlet 6) via flow restriction orifice 34. Therefore, when tuning valve 32 is in the "closed" state (the second flow path is open), it can detect pressure that changes with the patient's breathing, and when tuning valve 32 is in the "open" state (the first flow path is open), it can detect pressure that changes with oxygen supply.

[0040] In oxygen concentrator 1, the open / close state of tuning valve 32 is controlled based on the detection result from pressure sensor 33. Specifically, when tuning valve 32 is in the "closed" state and pressure sensor 33 detects negative pressure, tuning valve 32 is instantly "opened" to start the supply of high-concentration oxygen. Then, after a predetermined time has elapsed, tuning valve 32 is "closed" to release a predetermined amount of high-concentration oxygen. The high-concentration oxygen released from oxygen supply unit 30 is supplied to the patient via a nasal cannula or oxygen mask connected to oxygen outlet 6.

[0041] Since the high-concentration oxygen stored in the oxygen storage unit 20 is in an extremely dry state, a humidification bottle 7 is provided upstream of the oxygen outlet 6. By supplying the high-concentration oxygen after passing through the humidification bottle 7, humidified high-concentration oxygen can be output from the oxygen outlet 6.

[0042] FIG. 3 is a diagram showing a schematic configuration of a control system of oxygen concentrator 1 according to this embodiment.

[0043] 3, the control unit 50 of the oxygen concentrator 1 includes a CPU (Central Processing Unit) 51, a RAM (Random Access Memory) 52, and a ROM (Read Only Memory) 53. The CPU 51 reads a program corresponding to the processing content from the ROM 53, loads it into the RAM 52, and controls the operation of each block of the oxygen concentrator 1 in cooperation with the loaded program.

[0044] Specifically, detection signals from various sensors, such as oxygen sensor 23 in oxygen storage unit 20, pressure sensor 24 in product tank 21, pressure sensor 33 in oxygen supply unit 30, and temperature sensor 61 that measures the temperature inside housing 2, are input to control unit 50. In addition, when the supply flow rate is set by the patient, for example, in operation unit 4, control unit 50 receives an operation signal instructing the set flow rate.

[0045] Based on these input signals, the control unit 50 controls the rotation speed of the motors of the compressors 100-1 and 100-2, and controls the open / close state and opening degree of the on-off valves SV1 to SV4 of the flow path switching unit 201 and the synchronization valve 32. Through such control, the oxygen concentrator 1 outputs high-concentration oxygen in an amount corresponding to the set flow rate.

[0046] The control unit 50 also controls the display on the display unit 5, which is made up of a liquid crystal display (LCD) and a light emitting diode (LED), and controls the audio output from the speaker 62. The display unit 5 and the speaker 62 are used to notify the patient of various types of information.

[0047] Although not shown, oxygen concentrator 1 may be provided with an interface that can be connected to a communication network such as a wireless LAN (Local Area Network) or Bluetooth (registered trademark), so that various data can be transmitted and received between oxygen concentrator 1 and external devices.

[0048] <2> Compressor and on-off valve control Next, the control of the compressors 100-1 and 100-2 and the on-off valves SV1 to SV4 according to this embodiment will be described.

[0049] Oxygen concentrator 1 of this embodiment has two compressors 100-1 and 100-2.

[0050] In this embodiment, the maximum discharge rate of each of the compressors 100-1 and 100-2 is 5 L / min. Therefore, the total discharge rate of the two compressors 100-1 and 100-2 is 5 L / min + 5 L / min = 10 L / min.

[0051] The control unit 50 controls the motor rotation speeds of the compressors 100-1 and 100-2 in accordance with the target oxygen output flow rate set by operating the operation unit 4, thereby controlling the discharge rates from the compressors 100-1 and 100-2.

[0052] For example, if the total discharge rate is 5 L / min, the control unit 50 can control the motor rotation speeds of the compressors 100-1 and 100-2 so that the discharge rate of the compressor 100-1 is 2.5 L / min and the discharge rate of the compressor 100-2 is 2.5 L / min. The control unit 50 may also control the motor rotation speeds of the compressors 100-1 and 100-2 so that the discharge rate of the compressor 100-1 is 5 L / min and the discharge rate of the compressor 100-2 is 0 L / min. In short, the motor rotation speeds of the two compressors 100-1 and 100-2 may be controlled so that the total discharge rate becomes the target value.

[0053] Furthermore, for example, when the total discharge rate is 1 [L / min], the control unit 50 can control the motor rotation speeds of the compressors 100-1 and 100-2 so that the discharge rate of the compressor 100-1 is 0.5 [L / min] and the discharge rate of the compressor 100-2 is 0.5 [L / min]. Furthermore, the control unit 50 may control the motor rotation speeds of the compressors 100-1 and 100-2 so that the discharge rate of the compressor 100-1 is 1 [L / min] and the discharge rate of the compressor 100-2 is 0 [L / min].

[0054] As described above, the oxygen concentrator 1 of this embodiment has two compressors 100-1 and 100-2, and the two compressors 100-1 and 100-2 cooperate to control the total discharge rate to a target value. Therefore, for example, if both compressors 100-1 and 100-2 are operated to obtain a total discharge rate of 1, the motor rotation speed per compressor can be reduced compared to when only one compressor is operated to obtain a discharge rate of 1. As a result, the life of the compressors can be extended. Furthermore, for example, if one compressor is operated and the other compressor is stopped, the life of the other compressor can be extended. Furthermore, for example, the other compressor can be used as a spare in case one compressor breaks down.

[0055] However, in a configuration in which the discharge ports of two compressors 100-1 and 100-2 are connected to each other and compressed air is sent to sieve beds 200-1 and 200-2, as in the present embodiment, one compressor may act as a load on the other compressor. For example, when one compressor is operating and the other compressor is stopped, pressure is applied to the discharge port of the other compressor when the other compressor starts operating. Therefore, in order to start the other compressor, a large drive current must be applied to the other compressor, and in some cases, the other compressor may not be able to start operating.

[0056] Therefore, we focused on the fact that sieve beds 200-1, 200-2 and on-off valves SV1 to SV4 are located downstream of compressors 100-1, 100-2, and discovered a configuration that effectively utilizes these sieve beds 200-1, 200-2 and on-off valves SV1 to SV4 to operate the two compressors 100-1, 100-2 smoothly.

[0057] One feature of this embodiment is that the control unit 50 controls the increase in the motor rotation speed of the compressors 100-1 and 100-2 in synchronization with the opening and closing of the on-off valves SV1 to SV4. This allows the sieve beds 200-1 and 200-2 to be used as pressure buffers, reducing the pressure load caused by the compressor with a higher motor rotation speed when increasing the motor rotation speed of the compressor with a lower motor rotation speed. As a result, the motor rotation speed of the compressor with a lower motor rotation speed can be increased smoothly.

[0058] FIG. 4 is a diagram showing an operation chart of the oxygen concentrator 1 of the present embodiment.

[0059] Fig. 4A is a chart showing changes in pressure in product tank 21. Fig. 4B is a chart showing the open / close states of pressure equalizing valve 204 and on-off valves SV1 to SV4. Fig. 4C is a chart showing changes in pressure in sieve beds 200-1 and 200-2. Fig. 4D is a chart showing the ON / OFF states of compressors 100-1 and 100-2.

[0060] In the example of FIG. 4, a case will be described in which the compressor 100-2 is controlled to be in an ON state from a state in which the compressor 100-1 is ON and the compressor 100-2 is OFF.

[0061] In the period before time t1 in Figure 4, air is sent from compressor 100-1 to sieve bed 200-1, and the highly concentrated oxygen obtained in sieve bed 200-1 is sent to product tank 21, and as a result, the pressure in product tank 21 increases over time.

[0062] When the pressure in product tank 21 eventually reaches the threshold value at time t1, control unit 50 controls pressure equalizing valve 204 to the open state. Control unit 50 controls pressure equalizing valve 204 to the open state during the period from time t1 to time t3.

[0063] Furthermore, at time t1, the control unit 50 controls the on-off valve SV1 from open to closed, the on-off valve SV2 from closed to open, the on-off valve SV3 from closed to open, and the on-off valve SV4 from open to closed. As a result, the sieve bed 200-1 is placed in the regeneration process, and the sieve bed 200-2 is placed in the adsorption process. Specifically, the nitrogen and moisture adsorbed in the sieve bed 200-1 are discharged to the outside via the on-off valve SV2 and the exhaust silencer 202. Meanwhile, air is sent from the compressor 100-1 to the sieve bed 200-2, and the highly concentrated oxygen obtained in the sieve bed 200-2 is sent to the product tank 21.

[0064] The pressure in product tank 21 decreases during the period from immediately after time t1 to time t4 because, during this period, the outflow of high-concentration oxygen from product tank 21 to oxygen supply unit 30 is greater than the inflow of high-concentration oxygen into product tank 21. During the period from time t4 to time t5, the inflow of high-concentration oxygen from sieve bed 200-2 into product tank 21 is greater than the outflow of high-concentration oxygen from product tank 21 to oxygen supply unit 30, so the pressure in product tank 21 increases.

[0065] When the pressure in product tank 21 eventually reaches the threshold value at time t5, control unit 50 controls pressure equalizing valve 204 to the open state. Control unit 50 controls pressure equalizing valve 204 to the open state during the period from time t5 to time t6.

[0066] Furthermore, at time t5, the control unit 50 controls the on-off valve SV1 from closed to open, the on-off valve SV2 from open to closed, the on-off valve SV3 from open to closed, and the on-off valve SV4 from closed to open. As a result, the sieve bed 200-2 is placed in the regeneration process, and the sieve bed 200-1 is placed in the adsorption process. Specifically, the nitrogen and moisture adsorbed in the sieve bed 200-2 are discharged to the outside via the on-off valve SV4 and the exhaust silencer 202. Meanwhile, air is sent from the compressors 100-1 and 100-2 to the sieve bed 200-1, and the highly concentrated oxygen obtained in the sieve bed 200-1 is sent to the product tank 21.

[0067] In this way, the oxygen concentrator 1 controls the open / close states of the on-off valves SV1 to SV4 of the flow path switching unit 201 so that the sieve beds 200-1 and 200-2 alternately repeat the adsorption process and the regeneration process.

[0068] In addition to this control, the oxygen concentrator 1 of this embodiment is configured to start the operation of compressor 100-2 in addition to compressor 100-1 during high-concentration oxygen generation operation. The start of operation of compressor 100-2 is triggered, for example, by a change in the oxygen output flow rate target value by the user. Specifically, when the user changes the oxygen output flow rate target value via the operation unit 4 and the control unit 50 determines that the oxygen output flow rate target value cannot be achieved by compressor 100-1 alone, the control unit 50 operates compressor 100-2.

[0069] Here, the flow path on the discharge port side of compressor 100-1 and the flow path on the discharge port side of compressor 100-2 are connected. In this configuration, if compressor 100-2 is to be operated when compressor 100-1 is already operating, a large pressure is applied to the discharge port side of compressor 100-2, and this pressure acts as a load, which may prevent compressor 100-2 from operating.

[0070] In consideration of this, in this embodiment, the timing for starting the operation of the compressor 100-2 is devised. Specifically, the control unit 50 starts the operation of the compressor 100-2 at a timing synchronized with the timing for switching between the adsorption process and the regeneration process of the sieve beds 200-1 and 200-2, in other words, at a timing synchronized with the timing for switching between pressurization and depressurization of the sieve beds 200-1 and 200-2.

[0071] In the example of Fig. 4D, the operation of compressor 100-2 begins at time t2, immediately after time t1, which is the timing for switching between the adsorption process and the regeneration process of sieve beds 200-1 and 200-2. Here, as can be seen from Fig. 4C, immediately after time t1, the pressure in sieve bed 200-2, which had been reduced until then, is low. Because the air from compressors 100-1 and 100-2 flows into this sieve bed 200-2, the pressure on the discharge sides of compressors 100-1 and 100-2 is low, and the pressure on the discharge sides of compressors 100-1 and 100-2 also increases slowly.

[0072] In this embodiment, immediately after time t1, when the adsorption process and the regeneration process of the sieve beds 200-1 and 200-2 are switched, the sieve bed 200-2 can function as a pressure buffer. Therefore, at time t2, immediately after time t1, when the adsorption process and the regeneration process are switched, the operation of the compressor 100-2, which had been stopped until then, is started (i.e., the rotation of the motor of the compressor 100-2 is started). This allows the operation of the compressor 100-2 to be started when the load on the compressor 100-2 is small, thereby preventing a situation in which the compressor 100-2 cannot be started.

[0073] 4D, the compressor 100-2 starts operating at time t2, which is immediately after time t1, which is the timing for switching between the adsorption process and the regeneration process. However, the timing for starting the operation of the compressor 100-2 is not limited to this. For example, the compressor 100-2 may start operating at the same time as time t1. In short, the compressor 100-2 only needs to start operating before the pressure in the sieve beds 200-1 and 200-2 reaches a predetermined threshold (e.g., half the maximum pressure during the adsorption process).

[0074] FIG. 5 shows another example of an operation chart of the oxygen concentrator 1 according to the embodiment. In FIG. 5, FIG. 5A is a chart showing changes in the pressure in the product tank 21, FIG. 5B is a chart showing the open / close states of the pressure equalizing valve 204 and the on-off valves SV1 to SV4, and FIG. 5C is a chart showing changes in the pressure in the sieve beds 200-1 and 200-2. These FIGS. 5A, 5B, and 5C are similar to FIGS. 4A, 4B, and 4C. FIG. 5D is a chart showing the ON / OFF states of the compressors 100-1 and 100-2. The ON timing of the compressor 100-2 is different from the ON timing of the compressor 100-2 in FIG. 4D. As shown in FIG. 5D, the operation of the compressor 100-2 can be started within a period Δt1 during which the pressure in the sieve bed 200-2 is less than a predetermined value th1, starting from the time t1 when the adsorption process and the regeneration process are switched.

[0075] 4D, the compressors 100-1 and 100-2 are controlled to be ON / OFF, but if the control to increase the motor rotation speeds of the compressors 100-1 and 100-2 is performed in synchronization with the opening and closing of the on-off valves SV1 to SV4, the same effects as those of the above-described embodiment can be obtained. Note that the control to switch the compressors 100-1 and 100-2 from OFF to ON is an example of the control to increase the motor rotation speeds of the compressors 100-1 and 100-2, and is included in the control to increase the motor rotation speed.

[0076] FIG. 6 shows another example of an operation chart of the oxygen concentrator 1 according to the embodiment. FIGS. 6A, 6B, and 6C are similar to FIGS. 4A, 4B, and 4C. FIG. 6D is a chart showing the motor rotation speeds of the compressors 100-1 and 100-2, with the motor rotation speeds shown in the range of 0 to 100%. As shown in FIG. 6D, the rotation speed of the compressor 100-2 is increased from time t1, when the adsorption process and the regeneration process are switched, during the period Δt2 during which the pressure in the sieve bed 200-2 is less than the predetermined value th2. In other words, the rotation speed of the compressor 100-2 is increased in synchronization with the opening and closing of the on-off valves SV1 to SV4, and during the period Δt2 during which the pressure in the sieve beds 200-1 and 200-2 reaches the threshold value th2. This allows the motor rotation speed of the compressor 100-2 to be increased when the load on the compressor 100-2 is small, thereby preventing a situation in which the rotation speed of the compressor 100-2 cannot be increased.

[0077] FIG. 7 shows another example of an operation chart of the oxygen concentrator 1 according to the embodiment. FIGS. 7A, 7B, and 7C are similar to FIGS. 4A, 4B, and 4C. FIG. 7D is a chart showing the motor rotation speeds of compressors 100-1 and 100-2, with the motor rotation speeds shown in the range of 0 to 100%. As shown in FIG. 7D, the rotation speed of compressor 100-2 is increased immediately after time t1, when the adsorption process and the regeneration process are switched over. Furthermore, the motor rotation speed of compressor 100-1, which has a higher motor rotation speed, is decreased during at least a portion of the period during which the motor rotation speed of compressor 100-2, which has a lower motor rotation speed, is increased. This reduces the pressure at the discharge port of compressor 100-1, which is connected to the discharge port of compressor 100-1. As a result, the motor rotation speed of the compressor 100-2 can be increased when the load on the compressor 100-2 is smaller, so that it is possible to more reliably prevent a situation in which the rotation speed of the compressor 100-2 cannot be increased.

[0078] As described above, this embodiment employs the following configuration.

[0079] (1) One aspect of the oxygen concentrator of this embodiment includes sieve beds 200-1, 200-2, at least first and second compressors 100-1, 100-2 that supply air to the sieve beds 200-1, 200-2, one or more on-off valves SV1 to SV4 provided in a flow path connecting the sieve beds 200-1, 200-2 and the first and second compressors 100-1, 100-2, and a control unit 50 that controls the first and second compressors 100-1, 100-2 and the on-off valves SV1 to SV4, and the control unit 50 controls the increase in the motor rotation speed of the first or second compressor 100-1, 100-2 in synchronization with the opening and closing operation of the on-off valves SV1 to SV4.

[0080] (2) One aspect of the oxygen concentrator of this embodiment is that in (1) above, when the control unit 50 controls to increase the motor rotation speed of the second compressor 100-2, which has a lower motor rotation speed than the first compressor 100-1, the control unit 50 controls to increase the motor rotation speed of the second compressor 100-2 in synchronization with the timing of controlling the on-off valves SV1 to SV4 so that the sieve bed 200-1 in the adsorption process and the sieve bed 200-2 in the regeneration process are switched.

[0081] (3) In one aspect of the oxygen concentrator of this embodiment, in the above (2), the control unit 50 may further control the motor rotation speed of the first compressor 100-1, which has a high motor rotation speed, to decrease during a period in which the motor rotation speed of the second compressor 100-2, which has a low motor rotation speed, is controlled to increase.

[0082] (4) One aspect of the oxygen concentrator of this embodiment is that, in (1) above, when the control unit 50 transitions from a state in which the motor of the first compressor 100-1 is rotating and the motor of the second compressor 100-2 is stopped to a state in which the motor of the second compressor 100-2 is rotating, it starts rotating the motor of the second compressor 100-2 in synchronization with the timing of controlling the on-off valves SV1 to SV4 so that the sieve bed 200-1 in the adsorption process and the sieve bed 200-2 in the regeneration process are switched.

[0083] (5) In one aspect of the oxygen concentrator of this embodiment, in the above (4), the control unit 50 may further control the motor rotation speed of the first compressor 100-1 to be reduced in synchronization with the start of rotation of the motor of the second compressor 100-2.

[0084] (6) One aspect of the oxygen concentrator of this embodiment is that in any of the above (1) to (5), the control unit 50 controls the increase in the motor rotation speed of the compressors 100-1 and 100-2 when the target value of the oxygen output flow rate of the oxygen concentrator 1 is changed.

[0085] <3> Compressor installation structure Next, the arrangement of the compressors 100-1 and 100-2 according to this embodiment will be described.

[0086] Fig. 8 is a perspective view showing the internal configuration of oxygen concentrator 1 of the present embodiment. Fig. 8 shows the internal configuration of oxygen concentrator 1, particularly the arrangement of compressors 100-1 and 100-2 and sieve beds 200-1 and 200-2.

[0087] 9 is a perspective view showing the configuration of compressors 100-1 and 100-2. Note that the configuration of compressor 100-1 is shown in FIG. 9. The configuration of compressor 100-2 is similar to the configuration of compressor 100-1 shown in FIG.

[0088] The compressor 100-1 is a so-called reciprocating compressor, and includes a motor unit 101 and pressure cylinders 102 and 103. The pressure cylinders 102 and 103 are connected by a connecting pipe 104.

[0089] A motor is built into the motor unit 101, and pistons are built into the pressure cylinders 102 and 103. Inside the motor unit 101, the motor rotates in the direction of arrow a in the figure. The rotational force of this motor is transmitted to the pistons, causing the pistons inside the pressure cylinders 102 and 103 to reciprocate in the ±Z directions.

[0090] When the motor of the compressor 100-1 rotates, air is sucked into the pressure cylinders 102 and 103, and the compressed air obtained in the compression cylinders 102 and 103 is discharged from a discharge port 106 provided in the pressure cylinder 103.

[0091] FIG. 10 is a perspective view showing the arrangement of two compressors 100-1 and 100-2 according to the embodiment.

[0092] Compressor 100-2 is disposed rotated 180° about the Z axis relative to compressor 100-1. In other words, compressors 100-1 and 100-2 are disposed rotated 180° relative to each other about a direction perpendicular to the mounting surface (the Z axis in the example of FIG. 10). As a result, discharge port 106-1 of compressor 101-1 faces in the -Y direction, whereas discharge port 106-2 of compressor 101-2 faces in the +Y direction.

[0093] Furthermore, the rotation direction of the motor of compressor 101-1 is clockwise as indicated by arrow a1 when viewed from the +X direction, whereas the rotation direction of the motor of compressor 101-2 is counterclockwise as indicated by arrow a2 when viewed from the +X direction.

[0094] An intake pipe 105 is connected to the pressure cylinders of the compressors 100-1 and 100-2. The other end of the intake pipe 105 is connected to the air intake unit 10 (FIG. 2). The discharge ports 106-1 and 106-2 are connected by a connecting pipe 107. Furthermore, the connecting pipe 107 is connected to the PSA unit 200 (FIG. 2).

[0095] Fig. 11 is a perspective view showing a support structure that supports the compressors 100-1 and 100-2. Note that Fig. 11 is a view obtained by omitting the compressors 100-1 and 100-2 from Fig. 10.

[0096] The compressors 100-1 and 100-2 are fixed to a base plate 111 via supports 112.

[0097] Although base plate 111 may be formed from a single large plate, in the present embodiment base plate 111 is made up of divided base plate 111a and divided base plate 111b. This allows base plate 111 to be lighter by the amount of the gap between two divided base plates 111a and 111b.

[0098] Four supports 112 (112a to 112d) are fixed onto the base plate 111. Each of the supports 112a to 112d is a U-shaped member with an open top. The supports 112 are made of metal. The supports 112 may also be made of a material that easily absorbs vibrations, such as hard rubber.

[0099] Both end portions of the motor unit 101 (FIG. 9) of the compressors 100-1 and 100-2 are fitted into the support 112. Specifically, four support members 112a to 112d are fixed onto the base plate 111, and both end portions of the motor unit 101 (FIG. 9) of the compressors 100-1 and 100-2 are inserted into the support members 112a to 112d from above the support members 112a to 112d and fixed with screws 114. Alternatively, the support members 112a to 112d may be fixed to both end portions of the motor unit 101 (FIG. 9) of the compressors 100-1 and 100-2 first, and then the support members 112a to 112d may be fixed to the base plate 111.

[0100] In this way, by fixing compressors 100-1 and 100-2 via U-shaped supports 112a to 112d, the force in the rotational direction of the motor can be firmly absorbed by U-shaped support 112, and rattling of compressors 100-1 and 100-2 due to the rotation of the motor can be suppressed.

[0101] Furthermore, the motor units 101 of the compressors 100-1 and 100-2 are fixed to the support body 112 by screws 114 (114a to 114c) (see FIG. 11) arranged so as to surround the rotation center of the motor. This makes it possible to more reliably suppress rattle of the compressors 100-1 and 100-2 in the direction of motor rotation.

[0102] The base plate 111 is connected to the bottom surface of the main body of the oxygen concentrator 1 via a coil damper 113 as a vibration-isolating part. As a result, vibrations of the compressors 100-1 and 100-2 are absorbed by the coil damper 113, reducing the transmission of vibrations to the main body of the oxygen concentrator 1. Note that the vibration-isolating part is not limited to the coil damper 113, and other materials such as rubber may also be used.

[0103] A distinctive feature of the compressor installation structure of this embodiment is that the two compressors 100-1 and 100-2 are fixed to a common base plate 111 (divided base plates 111a and 111b). This makes it possible to prevent the compressors 100-1 and 100-2 from colliding with each other when vibrations occur in the compressors 100-1 and 100-2, compared to when the compressors 100-1 and 100-2 are fixed to individual base plates (when the compressor 100-1 is fixed to the base plate for the compressor 100-1 and the compressor 100-2 is fixed to the base plate for the compressor 100-2).

[0104] This will be explained in more detail. In order to achieve compactness in the oxygen concentrator 1, the distance between the two compressors 100-1 and 100-2 is made small. Therefore, if each compressor 100-1 and 100-2 were fixed to an individual base plate and the individual base plates were connected to the bottom of the main body of the oxygen concentrator 1 via a coil damper, there is a possibility that each base plate would swing freely. As a result, there is a risk that the compressors 100-1 and 100-2 arranged nearby may collide with each other, which may result in a collision noise. Incidentally, if the distance between the compressors 100-1 and 100-2 were increased to prevent the compressors 100-1 and 100-2 from colliding with each other, this would naturally result in the disadvantage of increasing the product size of the oxygen concentrator 1.

[0105] Taking this into consideration, in this embodiment, two compressors 100-1 and 100-2 are fixed to a common base plate 111 and are connected to the bottom surface of the main body of oxygen concentrator 1 via coil damper 113. As a result, even if base 111 shakes, two compressors 100-1 and 100-2 will shake in the same direction and will not collide with each other.

[0106] In the above-described embodiment, the two compressors 100-1 and 100-2 are arranged in parallel. However, the compressors 100-1 and 100-2 may be arranged in series as shown in FIG. 12, or the compressors 100-1 and 100-2 may be arranged vertically as shown in FIG. 13.

[0107] 12 and 13, compressors 100-1 and 100-2 are fixed to a common base plate 111. Also, in the cases of Figures 12 and 13, compressors 100-1 and 100-2 are arranged rotated 180° relative to each other about a direction perpendicular to the mounting surface. Also, in the cases of Figures 12 and 13, compressors 100-1 and 100-2 are fixed to a common base (base plate 111) via a U-shaped support 112.

[0108] As described above, this embodiment employs the following configuration.

[0109] (1) One aspect of the oxygen concentrator of this embodiment includes sieve beds 200-1 and 200-2, at least first and second compressors 100-1 and 100-2 that supply air to sieve beds 200-1 and 200-2, a common base (base plate 111) to which first and second compressors 100-1 and 100-2 are fixed, and a vibration-isolating unit (coil damper 113) provided between the common base (base plate 111) and a base unit (a bottom surface of the main body of oxygen concentrator 1). This prevents the compressors 100-1 and 100-2 from colliding with each other during vibration, even if the distance between the two compressors 100-1 and 100-2 is small.

[0110] (2) In one aspect of the oxygen concentrator of this embodiment, in (1) above, the first and second compressors 100-1 and 100-2 are arranged rotated 180 degrees relative to each other about the direction (Z-axis direction) perpendicular to the mounting surface. This prevents vibrations and heat from concentrating locally, and allows for a well-balanced compressor installation structure.

[0111] (3) In one aspect of the oxygen concentrator of this embodiment, in (2) above, first and second compressors 100-1 and 100-2 are fixed to a common base (base plate 111) so that the rotation direction of the motor of first compressor 100-1 and the rotation direction of the motor of second compressor 100-2 are opposite to each other. This causes the inertial forces caused by the rotation of the motors of the first and second compressors to cancel each other out, thereby further suppressing vibrations caused by compressors 100-1 and 100-2.

[0112] (4) One aspect of the oxygen concentrator of this embodiment is that, in the above (1), it further includes a support 112 that fits into the motor section 101 of the first and second compressors 100-1 and 100-2, and the first and second compressors 100-1 and 100-2 are fixed to a common base (base plate 111) via the support 112.

[0113] (5) In one aspect of the oxygen concentrator of this embodiment, in the above (4), support 112 is U-shaped. This allows U-shaped support 112 to firmly receive the force in the rotational direction of the motor, thereby suppressing rattles of compressors 100-1 and 100-2 caused by the rotation of the motor.

[0114] (6) In one aspect of the oxygen concentrator of this embodiment, in the above (3) or (4), motor units 101 of first and second compressors 100-1 and 100-2 are fixed to support body 112 by screws arranged to surround the rotation center of the motor. This makes it possible to more reliably suppress rattle of compressors 100-1 and 100-2 in the motor rotation direction.

[0115] The above-described embodiments are merely examples of specific embodiments of the present invention, and the technical scope of the present invention should not be construed as being limited by these embodiments. In other words, the present invention can be embodied in various forms without departing from the gist or main characteristics thereof. [Industrial Applicability]

[0116] The present disclosure is generally applicable to oxygen concentrators having compressors. [Explanation of symbols]

[0117] 1. Oxygen concentrator 10 Air intake 20 Oxygen reservoir 30 Oxygen supply unit 50 control section 100 Air Compressor 100-1, 100-2 compressor 101 Motor section 102, 103 Pressure cylinder 104, 104-1, 104-2, 107 Connecting pipe 105 Intake pipe 106, 106-1, 106-2 outlet 111 Base plate 112 Support 113 Coil damper 114 screws 200 PSA Department 200-1, 200-2 sieve bed 201 Flow path switching unit SV1~SV4 On-off valves

Claims

1. Sheave bed and at least first and second compressors supplying air to the sieve bed; a common base to which the first and second compressors are fixed; a vibration-isolating portion provided between the common base and the base portion; An oxygen concentrator comprising:

2. The first and second compressors are arranged in a state rotated 180° from each other about a direction perpendicular to the mounting surface.

10. The oxygen concentrator of claim 1.

3. The first and second compressors the first compressor and the second compressor are fixed to the common base so that their motors rotate in opposite directions.

3. The oxygen concentrator of claim 2.

4. a support body that fits onto the motor portions of the first and second compressors; the first and second compressors are fixed to the common base via the support; 10. The oxygen concentrator of claim 1.

5. The support is U-shaped.

5. The oxygen concentrator of claim 4.

6. the motor units of the first and second compressors are fixed to the support by screws arranged to surround the rotation centers of the motors; 5. The oxygen concentrator according to claim 3 or 4.

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