compressor

Abstract

To provide a compressor which is downsized and simply constructed, and excellent in versatility.SOLUTION: A compressor 1 for compression includes an input shaft 10 extending in the axial direction and having an external tooth gear 11 on the axial periphery, a rotor 20 having an approximately triangular shape in plan view from the axial direction, having an internal tooth gear 22 engaging with the external tooth gear 11, and adapted to be turned to revolve around the input shaft 10 with the axial rotation of the input shaft 10, and a rotor housing 30 rotatably storing the rotor 20 and forming an operation chamber 32 between the rotor 20 and itself, the rotor 20 being provided with a seal member 24 having slide contact with an inner peripheral face 31 of the rotor housing 30 at each of three angular parts 23, and an elastic member 25 pushing the seal member 24 against the inner peripheral face 31, the rotor housing 30 being provided with suction holes 33a, 33b for sucking air into the operation chamber 32, and discharge holes 34a, 34b for discharging air compressed in the operation chamber 32.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a compressor.

Background Art

[0002] As conventional general compressors, screw-type compressors and reciprocating compressors are known. A screw-type compressor, for example, as described in Patent Document 1 below, integrally rotates a pair of screw rotors, a male rotor and a female rotor, to cause the male rotor and to continuously compress fluid between the female rotor to increase the pressure of the fluid. A reciprocating compressor, for example, as described in Patent Document 2 below, is configured to reciprocate a piston in a cylinder via a piston rod to compress fluid and increase the pressure thereof.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problem to be Solved by the Invention

[0004] Screw-type compressors are suitable for use in large-scale equipment because they have a large discharge capacity, but are not suitable for use in small-scale equipment that does not require such high performance. Therefore, for small-scale equipment, a reciprocating compressor with a low discharge capacity can be used. Although reciprocating compressors have the advantage of being smaller in size than screw-type compressors, they have the problem of having a large number of parts and a complicated structure. Furthermore, since reciprocating compressors are independently designed according to the required discharge capacity, the discharge capacity cannot be changed in accordance with the work content and environment where high-pressure fluid is used, which is disadvantageous in terms of low versatility.

[0005] This invention has been made in view of the above problems, and aims to provide a compressor that is small, has a simple structure, and is highly versatile. [Means for solving the problem]

[0006] One aspect of the present invention is, A compressor for compressing fluids, An input shaft that extends axially and has an external gear on its circumference, A rotor has a roughly triangular shape in plan view from the axial direction and has an internal gear that engages with the external gear, and revolves around the input shaft in conjunction with the rotation of the input shaft. A rotor housing that houses the rotor and forms an operating chamber between itself and the rotor, Equipped with, The rotor is provided with a sealing member that slides against the inner circumferential surface of the rotor housing at each of the three corners, and an elastic member that presses the sealing member against the inner circumferential surface. The rotor housing is provided with an intake port for drawing the fluid into the working chamber and an exhaust port for discharging the fluid compressed in the working chamber. 、 The rotor has an introduction passage that communicates with the working chamber, and is configured such that the pressure of the fluid in the introduction passage is used to press the sealing member against the inner circumferential surface of the rotor housing. The rotor has a connecting passage for connecting the introduction passage to a low-pressure region in the working chamber, where the pressure is lower than the high-pressure region which is the source of the fluid, during the compression stage of the fluid, and an on / off valve for opening and closing the connecting passage according to the pressure of the introduction passage. The above-mentioned inlet passage is through which the above-mentioned fluid flows. A person skilled in the art, Downstream, it branches into a housing space for housing the sealing member, a housing space for housing the on / off valve, and the connecting passage. Compressor, It is located there. [Effects of the Invention]

[0007] In the compressor according to the above-described embodiment, when the input shaft rotates due to external power, a substantially triangular rotor having an internal gear that engages with the external gear of the input shaft revolves around the input shaft. As the rotor revolves, the three corners of the rotor slide against the inner surface of the rotor housing via a sealing member. At this time, the fluid is drawn into the working chamber through the intake hole of the rotor housing, compressed, and then discharged to the outside of the rotor housing through the discharge hole of the rotor housing.

[0008] With the compressor configuration described above, fluid can be ejected twice during one rotation of the input shaft. Therefore, it can eject twice the amount of fluid per cylinder compared to a reciprocating compressor, allowing the compressor itself to be made smaller. In addition, such a compressor has fewer components and a simpler structure. Furthermore, because the rotor and rotor housing set is assembled to the input shaft, the number of rotor and rotor housing sets can be changed as needed while using the same input shaft. In this case, the versatility of the compressor can be increased by changing the number of rotor and rotor housing sets according to the required ejection capacity to suit the work content and environment in which high-pressure fluid is used.

[0009] As described above, according to the above-described embodiment, it is possible to provide a compressor that is small, has a simple structure, and is highly versatile. [Brief explanation of the drawing]

[0010] [Figure 1] An exploded perspective view of the compressor of Embodiment 1. [Figure 2] Cross-sectional view of the compressor shown in Figure 1. [Figure 3] Figure 2 is a cross-sectional view showing an enlarged view of the peripheral structure around the corner of the rotor in the compressor. [Figure 4] This diagram schematically shows the operation process of the compressor of Embodiment 1 in the first operating stage, where the input shaft is in the first rotation position. [Figure 5] Figure 4 schematically shows the operation process during the second operation stage, when the input shaft has rotated from the first rotation position to the second rotation position. [Figure 6] Figure 5 schematically shows the operation process of the third operation stage, in which the input shaft has rotated from the second rotation position to the third rotation position. [Figure 7] Figure 6 schematically shows the operation process of the fourth stage, when the input shaft has rotated from the third rotation position to the fourth rotation position. [Figure 8]A diagram schematically showing the operation process of the fifth operation stage in which the input shaft rotates from the fourth rotational position to the fifth rotational position in FIG. 7 [Figure 9] A diagram schematically showing the operation process of the sixth operation stage in which the input shaft rotates from the fifth rotational position to the sixth rotational position in FIG. 8 [Figure 10] An enlarged view showing the peripheral structure of a corner portion of the rotor in the compressor of FIG. 2, showing a state where the on-off valve is in a closed state [Figure 11] A graph showing that air pressure and seal pressure change as the process progresses [Figure 12] A diagram showing a state when the on-off valve switches from the closed state to the open state in FIG. 10 [Figure 13] An exploded perspective view of a compressor according to a modified example of the compressor of FIG. 1 [Figure 14] An enlarged cross-sectional view showing the peripheral structure of a corner portion of the rotor in the compressor according to Embodiment 2 DESCRIPTION OF EMBODIMENTS

[0011] Preferred embodiments of the above aspect will be described below

[0012] In the compressor according to the above aspect, it is preferable that the rotor has an introduction passage communicating with the working chamber, and the pressure of the fluid in the introduction passage is configured to be used for the pressing force of the sealing member against the inner circumferential surface of the rotor housing

[0013] In this compressor, the pressing force of the sealing member against the inner surface of the rotor housing is the sum of the elastic biasing force of the elastic member and the fluid pressure in the intake passage. At this time, the pressure in the intake passage changes according to the pressure in the working chamber. The pressure in the region of the working chamber during the fluid compression stage is relatively high, and high sealing performance is required in this region. In contrast, the pressure in the region of the working chamber during the fluid intake stage is relatively low, and high sealing performance is not required in this region. Therefore, by utilizing the fluid pressure in the intake passage for the pressing force of the sealing member, it is possible to increase the sealing pressure only of the sealing member involved in the fluid compression stage and decrease the sealing pressure of the other sealing members. In other words, the sealing pressure can be optimized according to the progress of the process while ensuring the necessary sealing performance. As a result, energy loss due to friction between the inner surface of the rotor housing and the sealing member can be kept low compared to when the sealing pressure of each sealing member is always constant in accordance with the fluid compression stage.

[0014] In the compressor according to the above-described embodiment, it is preferable that the rotor has a connecting passage for connecting the introduction passage to a low-pressure region in the working chamber where the pressure is lower than the high-pressure region which is the source of the fluid introduction, during the fluid compression stage, and an on / off valve for opening and closing the connecting passage according to the pressure of the introduction passage.

[0015] This compressor, by providing an on-off valve that opens and closes the connecting passage according to the pressure in the inlet passage, allows the connecting passage to be opened by the on-off valve to release some of the fluid from the high-pressure area to the low-pressure area if the pressure in the high-pressure region of the working chamber rises above the standard control value during the fluid compression stage. This prevents the working chamber from becoming overpressurized beyond the standard control value. Furthermore, the fluid that flows from the high-pressure region to the low-pressure region is used in the compression stage as the process progresses, thus preventing fluid waste.

[0016] In the compressor according to the above-described embodiment, the rotor has an elastic member that elastically biases the on-off valve in the closing direction, the on-off valve is provided to constantly receive the pressure of the fluid in the inlet passage, and is preferably configured to close the connection passage according to the elastic biasing force of the elastic member when the pressure is below a control standard value, and to open the connection passage against the elastic biasing force of the elastic member when the pressure exceeds the control standard value.

[0017] According to this compressor, the structure for operating the on-off valve can be simplified by using an elastic member that elastically biases the on-off valve in the closing direction.

[0018] The compressor according to the above-described embodiment comprises a plurality of rotors and rotor housings, wherein the input shaft is provided with a plurality of external gears spaced apart from each other in the axial direction, and it is preferable that the internal gears of each of the plurality of rotors are configured to engage with each of the plurality of external gears.

[0019] This compressor allows for increased fluid ejection capacity compared to a system with only one rotor and rotor housing set relative to the input shaft.

[0020] (Embodiment 1) The compressor of Embodiment 1 will be described below with reference to Figures 1 to 13.

[0021] In the diagrams used for this explanation, unless otherwise specified, the axial direction of the input shaft constituting the compressor is indicated by arrow X, and the axial rotation direction of this input shaft is indicated by arrow D.

[0022] 1. Overall structure of compressor 1 A compressor 1 of Embodiment 1 is shown in Figure 1. This compressor 1 is an air compressor that compresses air. Air is a compressible fluid whose volume changes when compressed or expanded. This compressor 1 comprises side housings 2 and 3, an input shaft 10, a rotor 20, and a rotor housing 30. This compressor 1 is also called a "rotary compressor" or a "Wankel compressor".

[0023] The input shaft 10 extends in the axial direction X and has an external gear 11 around its circumference. The input shaft 10 is connected to a power source (not shown), such as an electric motor, and is configured to rotate axially in the axial rotation direction D when driven by the power of this power source. The input shaft 10 is also provided with an eccentric portion (not shown) that serves to revolve the rotor 20.

[0024] The rotor 20 has a roughly triangular shape when viewed from the axial direction X. The rotor 20 has three corners 23, each of which serves as a vertex. The rotor 20 has an internal gear 22 on the inner circumference side of a through hole 21 that penetrates the center in the axial direction X, which engages with the external gear 11 of the input shaft 10. The rotor 20 is configured to revolve around the input shaft 10 as the input shaft 10 rotates.

[0025] The rotor housing 30 houses the rotor 20 so that it can revolve. When the rotor 20 is housed in the rotor housing 30, all three corners 23 of the rotor 20 slide against the inner circumferential surface 31 of the rotor housing 30 at the sealing member 24. At this time, the rotor housing 30 forms an operating chamber 32 between its inner circumferential surface 31 and the outer surface of the rotor 20.

[0026] The side housings 2 and 3 are positioned on either side of the rotor housing 30 in the axial direction X. The input shaft 10 is supported so as to be rotatable on its axis, with one end inserted through a support hole 2a that penetrates the side housing 2 in the axial direction X, and the other end inserted through a support hole 3a that penetrates the side housing 3 in the axial direction X.

[0027] 2. Structure of the rotor housing 30 As shown in Figure 2, the inner circumferential surface 31 of the rotor housing 30 is a trochoidal surface formed by a trochoidal curve. The rotor housing 30 is provided with intake holes 33a and 33b for drawing in air, which is a compressible fluid G, into the working chamber 32, and exhaust holes 34a and 34b for discharging the air compressed in the working chamber 32. In other words, this embodiment exemplifies a case where the rotor housing 30 is provided with two intake holes and two exhaust holes. The number of intake holes and exhaust holes may be changed as needed. Note that in this embodiment, when the fluid to be compressed is air, "intake" can also be called "intake" and "discharge" can also be called "exhaust."

[0028] 3. Structure of Rotor 20 As shown in Figure 2, the rotor 20 has a roughly triangular shape, composed of three internal envelopes that are inscribed within the inner circumferential surface 31 of the rotor housing 30. This shape of the rotor 20 is also called a "Reuleaux triangle". When the input shaft 10 rotates in the axial rotation direction D, the rotor 20 revolves so that its three corners 23 trace the inner circumferential surface 31 of the rotor housing 30 due to the function of the eccentric part described above. Air is drawn in, compressed, and ejected from the rotor 20 as it revolves. As will be described in detail later, in this embodiment, the rotor 20 is configured to revolve once for every three axial rotations of the input shaft 10.

[0029] 4. Seal structure The seal structure of the compressor 1 in this embodiment includes a sealing member 24 and an elastic member 25. The sealing member 24 and the elastic member 25 are provided at each of the three corners 23 (first corner 23A, second corner 23B, and third corner 23C) of the rotor 20. Each elastic member 25 performs the function of pressing the corresponding sealing member 24 against the inner circumferential surface 31 of the rotor housing 30 by utilizing its elastic biasing force. In this embodiment, an example is given in which the elastic member 25 is composed of a spring member.

[0030] As shown in Figure 3, the first corner 23A of the rotor 20 is provided with an introduction passage 26 communicating with the working chamber 32, a connecting passage 27, and an on-off valve 28. Downstream of the introduction passage 26, it branches into a housing space 24a, a housing space 28a, and a connecting passage 27. The sealing member 24 and the elastic member 25 are housed in the housing space 24a. When air is introduced into the housing space 24a from the introduction passage 26, the pressure of the air is used to press the sealing member 24 against the inner circumferential surface 31 of the rotor housing 30. As a result, the sealing member 24 is pressed against the inner circumferential surface 31 of the rotor housing 30 with a force equal to the elastic biasing force of the elastic member 25 plus the air pressure.

[0031] The connecting passage 27 is an air passage that connects the introduction passage 26 to a low-pressure region in the working chamber 32, where the pressure is lower than the high-pressure region, which is the air source, during the air compression phase by the rotor 20. The on-off valve 28 and the elastic member 29 are housed in the housing space 28a. The housing space 28a is a stepped passage with a larger diameter than the introduction passage 26. Therefore, the on-off valve 28 is prevented from entering the introduction passage 26 by a stepped portion formed at the boundary with the introduction passage 26. The on-off valve 28 has the function of opening and closing the connecting passage 27 by utilizing the pressure change of the air in the introduction passage 26. The elastic member 29 elastically biases the on-off valve 28 in the closing direction, that is, toward the introduction passage 26. In this embodiment, the case in which the elastic member 29 is composed of a spring member is illustrated.

[0032] Under normal load conditions, when the pressure in the high-pressure region of the working chamber 32 is below the control standard value, the on-off valve 28 is held in the closed position according to the elastic biasing force of the elastic member 29. That is, the elastic biasing force that the elastic member 29 applies to the on-off valve 28 exceeds the force of the air pressure acting on the on-off valve 28. The closed position of the on-off valve 28 at this time is determined by the on-off valve 28 contacting the stop portion. When the on-off valve 28 is in the closed position, the on-off valve 28 closes the connecting passage 27. That is, the connecting passage 27 is separated from the inlet passage 26.

[0033] In contrast, when the pressure in the high-pressure region of the working chamber 32 exceeds the control standard value during an overload, the force of the air pressure acting on the on-off valve 28 exceeds the elastic biasing force applied to the on-off valve 28 by the elastic member 29. Therefore, the on-off valve 28 moves from the closed position to the open position against the elastic biasing force of the elastic member 29. As a result, the connecting passage 27 is connected to the inlet passage 26, and some of the air in the working chamber 32 can be released from the high-pressure region to the low-pressure region. Subsequently, as the pressure in the high-pressure region decreases, the on-off valve 28 moves back to the closed position.

[0034] Note that the structures of the second corner 23B and the third corner 23C are the same as those of the first corner 23A, so their explanation will be omitted.

[0035] As described above, the seal structure of this embodiment has a self-sealing pressure adjustment function that allows the sealing pressure by the sealing member 24 to be adjusted according to the pressure of the introduction passage 26.

[0036] 5. Operation of Compressor 1 Next, the operation of the compressor 1 with the above configuration will be explained with reference to Figures 4 to 11. In these drawings, an arrow is added to the input shaft 10 to indicate its reference position in order to clarify its rotational position.

[0037] 5-1. Operation process of the first operating stage As shown in Figure 4, we will first explain the operation process of the first operating stage, in which the input shaft 10 is at the first rotational position P1. In this first operating stage, the rotor 20 operates as follows: the first corner 23A is "inhaled", the second corner 23B is "exhaled", and the third corner 23C is "inhaled".

[0038] The compressed air in the first operating stage is released into the working chamber 32 Of these, the waste is discharged through the discharge hole 34a from the region (hereinafter referred to as the "discharge region") defined by the outer surface of the rotor 20 from the first corner 23A to the second corner 23B. In parallel with this, the working chamber 32Air is drawn in through the intake hole 33b into the region (hereinafter referred to as the "intake region") defined by the outer surface of the rotor 20 from the second corner 23B to the third corner 23C. In parallel with this, the working chamber 32 Of these, the region demarcated by the outer surface from the third corner 23C to the first corner 23A of the rotor 20 (hereinafter referred to as the "compression region") transitions to the air compression stage. In this embodiment, the working chamber 32 In this configuration, an intake region is formed behind the discharge region in the axial rotation direction D, and a compression region is formed behind the intake region in the axial rotation direction D.

[0039] 5-2. Operation process of the second operating stage As shown in Figure 5, in the second operating stage, the input shaft 10 rotates 180 degrees in the axial rotation direction D from the first rotation position P1 (see Figure 4) to the second rotation position P2. In this second operating stage, as the rotor 20 revolves, the operating process of the first corner 23A becomes "exhaust," the operating process of the second corner 23B becomes "intake," and the operating process of the third corner 23C becomes "intake."

[0040] The compressed air in the second operating stage is released into the working chamber. 32 Of these, the waste is discharged through the discharge hole 34b from the discharge region defined by the outer surface of the rotor 20 from the third corner 23C to the first corner 23A. In parallel with this, the working chamber 32 Air is drawn in through the intake hole 33a into the intake region partitioned by the outer surface of the rotor 20 from the first corner 23A to the second corner 23B. In parallel with this, the working chamber 32 Of these, the compression region demarcated by the outer surface from the second corner 23B to the third corner 23C of the rotor 20 transitions to the air compression stage.

[0041] 5-3. Operation process of the third operating stage As shown in Figure 6, in the operation process of the third operating stage, the input shaft 10 rotates 180 degrees in the axial rotation direction D from the second rotation position P2 (see Figure 5) to the third rotation position P3. In other words, the input shaft 10 has rotated one full turn compared to the first operating stage. In this third operating stage, as the rotor 20 revolves, the operation process of the first corner 23A becomes "intake", the operation process of the second corner 23B becomes "intake", and the operation process of the third corner 23C becomes "exhaust".

[0042] In the third operating stage, the compressed air is released into the working chamber. 32 Of these, the waste is discharged through the discharge hole 34a from the discharge region demarcated by the outer surface of the rotor 20 from the second corner 23B to the third corner 23C. In parallel with this, the working chamber 32 Air is drawn in through the intake hole 33b into the intake region, which is defined by the outer surface of the rotor 20 from the third corner 23C to the first corner 23A. In parallel with this, the working chamber 32 Of these, the compression region demarcated by the outer surface from the first corner 23A to the second corner 23B of the rotor 20 transitions to the air compression stage.

[0043] Thus, during the one rotation of the input shaft 10 from the first to the third operating stage, air is ejected from the discharge port 34a twice. The same applies to the ejection of air from the discharge port 34b. Therefore, with this configuration, twice the amount of air can be ejected per cylinder compared to a reciprocating compressor, and the air ejection efficiency is doubled.

[0044] 5-4. Operation process of the fourth operating stage As shown in Figure 7, in the fourth operating stage, the input shaft 10 rotates 180 degrees in the axial rotation direction D from the third rotation position P3 (see Figure 6) to the fourth rotation position P4. In this fourth operating stage, as the rotor 20 revolves, the operating process of the first corner 23A becomes "intake," the operating process of the second corner 23B becomes "exhaust," and the operating process of the third corner 23C becomes "intake."

[0045] In the fourth operating stage, the compressed air is released into the working chamber.32 Of these, the waste is discharged through the discharge hole 34b from the discharge region demarcated by the outer surface of the rotor 20 from the first corner 23A to the second corner 23B. In parallel with this, the working chamber 32 Air is drawn in through the intake hole 33a into the intake region partitioned by the outer surface of the rotor 20 from the second corner 23B to the third corner 23C. In parallel with this, the working chamber 32 Of these, the compression region demarcated by the outer surface from the third corner 23C to the first corner 23A of the rotor 20 transitions to the air compression stage.

[0046] 5-5. Operation process of the fifth operating stage As shown in Figure 8, in the fifth operating stage, the input shaft 10 rotates 180 degrees in the axial rotation direction D from the fourth rotation position P4 (see Figure 7) to the fifth rotation position P5. In other words, the input shaft 10 rotates twice compared to the first operating stage. In this fifth operating stage, as the rotor 20 revolves, the operating process of the first corner 23A becomes "exhaust," the operating process of the second corner 23B becomes "intake," and the operating process of the third corner 23C becomes "intake."

[0047] In the fifth operating stage, the compressed air is released into the working chamber. 32 Of these, the waste is discharged through the discharge hole 34a from the discharge region defined by the outer surface of the rotor 20 from the third corner 23C to the first corner 23A. In parallel with this, the working chamber 32 Air is drawn in through the intake hole 33b into the intake region partitioned by the outer surface of the rotor 20 from the first corner 23A to the second corner 23B. In parallel with this, the working chamber 32 Of these, the compression region demarcated by the outer surface from the second corner 23B to the third corner 23C of the rotor 20 transitions to the air compression stage.

[0048] 5-6. Operation process of the sixth operating stage As shown in Figure 9, in the sixth operating stage, the input shaft 10 rotates 180 degrees in the axial rotation direction D from the fifth rotation position P5 (see Figure 8) to the sixth rotation position P6. In this sixth operating stage, as the rotor 20 revolves, the operating process of the first corner 23A becomes "intake," the operating process of the second corner 23B becomes "intake," and the operating process of the third corner 23C becomes "exhaust."

[0049] The compressed air in the sixth operating stage is released into the working chamber 32 Of these, the waste is discharged through the discharge hole 34b from the discharge region demarcated by the outer surface of the rotor 20 from the second corner 23B to the third corner 23C. In parallel with this, the working chamber 32 Air is drawn in through the intake hole 33a into the intake region, which is defined by the outer surface of the rotor 20 from the third corner 23C to the first corner 23A. In parallel with this, the working chamber 32 Of these, the compression region demarcated by the outer surface from the first corner 23A to the second corner 23B of the rotor 20 transitions to the air compression stage.

[0050] After the sixth operating stage, the input shaft 10 rotates 180 degrees in the axial rotation direction D, returning to the state shown in Figure 4. That is, the rotor 20 revolves once while the input shaft 10 rotates three times compared to the first operating stage.

[0051] Here, with reference to Figures 10 to 12, the aforementioned "self-sealing pressure adjustment function" provided by the sealing member 24 will be explained in detail.

[0052] As shown in Figure 10, for example, when the input shaft 10 is in the second position P2 (see Figure 5), the sealing member 24 seals the space between the discharge region 32a and the suction region 32b within the working chamber 32. The discharge region 32a is a high-pressure region with a higher pressure than the suction region 32b, and the suction region 32b is a low-pressure region with a lower pressure than the discharge region 32a.

[0053] Air from the discharge region 32a of the working chamber 32 is introduced into the introduction passage 26 of the rotor 20. In this embodiment, the elastic biasing force of the elastic member 29 is set so that the on-off valve 28 does not operate until the pressure in the working chamber 32 exceeds the control standard value. Therefore, when the pressure in the working chamber 32 is below the control standard value, the on-off valve 28 is always kept closed. In this case, the air introduced from the discharge region 32a of the working chamber 32 into the introduction passage 26 is used to adjust the sealing pressure of the sealing member 24 housed in the containment space 24a.

[0054] As shown in Figure 11, the sealing pressure from the sealing member 24 is generated by adding the air pressure in the introduction passage 26 to a constant elastic biasing force from the elastic member 25. In other words, the difference between the sealing pressure and the air pressure corresponds to the elastic biasing force. Therefore, if the elastic member 25 is designed to exert the minimum necessary elastic biasing force during the intake phase, and the structure of the introduction passage 26 is designed so that the desired sealing pressure is generated at maximum compression, then the sealing pressure will automatically adjust to the desired value as the process (time) progresses from the intake phase and the air pressure rises to the maximum compression level. The sealing pressure can be increased only when it is desired. This prevents the sealing pressure from becoming excessively high at times other than maximum compression, and reduces energy loss due to friction between the inner circumferential surface 31 of the rotor housing 30 and the sealing member 24. Moreover, it becomes possible to adjust the sealing pressure using only mechanical structure without using complex control.

[0055] As shown in Figure 12, when the pressure in the discharge region 32a of the working chamber 32 exceeds the control standard value, the state of the on-off valve 28 switches from a closed state with the connecting passage 27 closed to an open state with the connecting passage 27 open. In this case, a portion of the air in the discharge region 32a flows to the intake region 32b through the introduction passage 26 and the connecting passage 27. This prevents the air pressure and seal pressure from rising excessively. The air that flows from the discharge region 32a to the intake region 32b is used when the intake region 32b enters the compression stage as the process progresses.

[0056] 6. Effects According to Embodiment 1 described above, the following effects and advantages can be obtained.

[0057] In the compressor 1 of Embodiment 1, when the input shaft 10 rotates due to external power, a substantially triangular rotor 20 having an internal gear 22 that engages with the external gear 11 of the input shaft 10 revolves around the input shaft 10. When the rotor 20 revolves, the three corners 23 of the rotor 20 seal members 24 The air slides along the inner circumferential surface 31 of the rotor housing 30 via the air intake holes 33a and 33b of the rotor housing 30, is compressed, and then discharged to the outside of the rotor housing 30 through the discharge holes 34a and 34b of the rotor housing 30.

[0058] With the compressor 1 configured as described above, air can be ejected twice during one rotation of the input shaft 10. Compared to a reciprocating compressor, it can eject twice the amount of air per cylinder, allowing the compressor 1 itself to be made smaller. Furthermore, such a compressor 1 has fewer components and a simpler structure.

[0059] In addition, since the structure involves assembling a set of rotors 20 and rotor housings 30 onto an input shaft 10, the same input shaft 10 can be used while appropriately changing only the number of rotor 20 and rotor housing 30 sets. In this case, the versatility of the compressor 1 can be increased by changing the number of rotor 20 and rotor housing 30 sets according to the required ejection capacity to suit the work content and environment in which high-pressure air is used. For example, instead of the one shown in Figure 1, the compressor 1 shown in Figure 13 can be constructed. This compressor 1 has two sets of rotors 20 and rotor housings 30 arranged in series. An intermediate housing 4 having a through hole 4a through which the input shaft 10 is inserted is interposed between the two rotor housings 30. This makes it possible to increase the air ejection capacity with a simple structural change.

[0060] As described above, the embodiment 1 described above makes it possible to provide a compressor 1 that is compact, has a simple structure, and is highly versatile.

[0061] In the compressor 1 of Embodiment 1, the pressing force of the sealing member 24 against the inner circumferential surface 31 of the rotor housing 30 is the sum of the elastic biasing force of the elastic member 25 and the air pressure in the introduction passage 26. At this time, the pressure in the introduction passage 26 changes according to the pressure in the working chamber 32. The pressure in the region of the working chamber 32 during the air compression stage is relatively high, and high sealing performance is required in this region. In contrast, the pressure in the region of the working chamber 32 during the air intake stage is relatively low, and high sealing performance is not required in this region. Therefore, by utilizing the air pressure in the introduction passage 26 for the pressing force of the sealing member 24, it is possible to increase the sealing pressure only of the sealing member 24 involved in the air compression stage and decrease the sealing pressure of the other sealing members 24. In other words, the sealing pressure can be optimized according to the progress of the process while ensuring the necessary sealing performance. As a result, energy loss due to friction between the inner circumferential surface 31 of the rotor housing 30 and the sealing member 24 can be kept low compared to the case where the sealing pressure of each sealing member 24 is always constant in accordance with the air compression stage.

[0062] According to the compressor of Embodiment 1, by providing an on-off valve 28 that opens and closes the connecting passage 27 in accordance with the pressure in the inlet passage 26, if the pressure in the high-pressure region of the working chamber 32 rises above the standard control value during the air compression stage, the on-off valve 28 can open the connecting passage 27, allowing some of the air to escape from the high-pressure region to the low-pressure region. This prevents the working chamber 32 from becoming overpressurized and exceeding the standard control value. Furthermore, the air that flows from the high-pressure region to the low-pressure region is used in the compression stage as the process progresses, thus preventing wasted air.

[0063] According to the compressor 1 of Embodiment 1, the structure for performing the opening and closing operation of the on-off valve 28 can be simplified by using an elastic member 29 that elastically biases the on-off valve 28 in the closing direction.

[0064] The compressor 1 of Embodiment 1 is suitable for use in small-scale equipment that does not require the high performance of a screw-type compressor. Furthermore, the compressor 1 has the advantage of being able to suppress air pulsation, vibration, and operating noise to a lower level compared to a reciprocating compressor.

[0065] Next, other embodiments related to Embodiment 1 described above will be explained with reference to the drawings. In the other embodiments, elements identical to those in Embodiment 1 are denoted by the same reference numerals, and the explanation of such identical elements will be omitted.

[0066] (Embodiment 2) As shown in Figure 14, the compressor 1A of Embodiment 2 differs from the compressor 1 of Embodiment 1 in that the connecting passages 27 and on-off valves 28 are not provided at each corner 23 of the rotor 20. The other configurations of the compressor 1A are the same as those of the compressor 1 of Embodiment 1.

[0067] According to Embodiment 2, the structure of compressor 1A can be simplified compared to that of compressor 1 in Embodiment 1. Furthermore, it provides the same advantages and benefits as in Embodiment 1.

[0068] The present invention is not limited to the typical embodiments described above, and various applications and modifications are conceivable as long as they do not depart from the purpose of the invention. For example, the following embodiments can be implemented by applying the embodiments described above.

[0069] In the above-described embodiment, the example shown was the use of spring members as elastic members 25 and 29, but other means besides spring members can be used as elastic members 25 and 29 as long as they have a similar function.

[0070] In the above-described embodiment, the example was given of compressing air, which is a type of fluid. However, the fluid is not limited to air, and other fluids (for example, gases or liquids other than air that are compressible) may be compressed as needed. [Explanation of Symbols]

[0071] 1,1A…Compressor, 10…Input shaft, 11…External gear, 20…Rotor, 22…Internal gear, 23,23A,23B,23C…Corner section, 24…Seal member, 25…Elastic member, 26…Inlet passage, 27…Connecting passage, 28…On / off valve, 29…Elastic member, 30…Rotor housing, 31…Inner circumferential surface, 32…Operating chamber, 33a,33b…Intake port, 34a,34b…Discharge port, G…Air (fluid), X…Axial direction

Claims

1. A compressor for compressing fluids, An input shaft that extends axially and has an external gear on its circumference, A rotor has a roughly triangular shape in plan view from the axial direction and has an internal gear that engages with the external gear, and revolves around the input shaft in conjunction with the rotation of the input shaft. A rotor housing that houses the rotor and forms an operating chamber between itself and the rotor, Equipped with, The rotor is provided with a sealing member that slides against the inner circumferential surface of the rotor housing at each of the three corners, and an elastic member that presses the sealing member against the inner circumferential surface. The rotor housing is provided with an intake port for drawing the fluid into the working chamber and an exhaust port for discharging the fluid compressed in the working chamber. The rotor has an introduction passage that communicates with the working chamber, and is configured such that the pressure of the fluid in the introduction passage is used to press the sealing member against the inner circumferential surface of the rotor housing. The rotor has a connecting passage for connecting the introduction passage to a low-pressure region in the working chamber, where the pressure is lower than the high-pressure region which is the source of the fluid, during the compression stage of the fluid, and an on / off valve for opening and closing the connecting passage according to the pressure of the introduction passage. The above-mentioned inlet passage branches downstream of the fluid through which the above-mentioned fluid flows into a housing space for housing the sealing member, a housing space for housing the on / off valve, and the above-mentioned connecting passage. Compressor.

2. The compressor according to claim 1, wherein the rotor has an elastic member that elastically biases the on-off valve in the closing direction, the on-off valve is provided to constantly receive the pressure of the fluid in the inlet passage, and is configured to close the connection passage according to the elastic biasing force of the elastic member when the pressure is below a control standard value, and to open the connection passage against the elastic biasing force of the elastic member when the pressure exceeds the control standard value.

3. The compressor according to claim 1 or 2, comprising a plurality of rotors and rotor housings, wherein the input shaft is provided with a plurality of external gears spaced apart from each other in the axial direction, and each internal gear of the plurality of rotors is configured to engage with each of the plurality of external gears.

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