Rotating machinery

Abstract

To provide a rotating machine that structurally suppresses vibration and wear, is capable of operating efficiently over a wide range of rotational speeds and torques, reduces torque fluctuations (pulsations), and achieves smooth rotation. [Solution] The air motor (rotating machine) 1 comprises a shaft 3, an inner rotor 4 having p convex portions formed along the circumferential direction on its outer circumference, an outer drum 5 having p+1 recesses formed along the circumferential direction on its inner circumference, and a synchronization mechanism 6 connected to the inner rotor 4 and outer drum 5, configured to rotate synchronously around a first axis and around a second axis. The convex portions 7 and recesses 8 maintain their relative positions and are not in physical contact due to the synchronous rotation. The convex portions 7 and recesses 8 form a plurality of volume fluctuation spaces 13 whose volume periodically expands and contracts as they rotate synchronously. The plurality of volume fluctuation spaces 13 are configured to discharge fluid supplied from an intake port 14 to an exhaust port 15.

Description

Technical Field

[0001] The present invention relates to a rotating machine.

Background Art

[0002] Generally, an air motor is known as a device that converts the pressure energy of compressed air into rotational energy. Examples of air motors include vane-type air motors, turbine-type air motors, piston-type air motors, and the like.

[0003] In addition, Patent Document 1 below discloses a technology related to a rotary engine. A rotor is provided inside a housing, and the rotor performs a planetary motion with respect to the housing, and a plurality of variable volume working chambers are set between the inner contour of the housing and the outer contour of the rotor. In this technology, when the rotor rotates, there is a problem that the parts wear at the contact portion because the inner contour of the housing and the outer contour of the rotor directly contact each other.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a vane-type air motor, a plurality of vanes are slidably mounted on a rotor, and the rotor has a structure that rotates with respect to a casing while these vanes are constantly pressed against the inner wall of the casing. For this reason, friction occurs between the vanes and the casing, and there is a problem that wear due to long-term operation causes a decrease in output torque and deterioration in efficiency.

[0006] Turbine-type air motors have a nozzle that injects compressed air and turbine blades that rotate using the compressed air injected from the nozzle. Because the rotating parts are lightweight and have little friction, relatively high rotational speeds can be achieved. On the other hand, they have the disadvantage of low torque (rotational force), and even if the airflow rate is increased, the increase in torque is limited, making them unsuitable for low-speed operation or high-torque applications.

[0007] A piston-type air motor uses the expansion force of compressed air to reciprocate a piston inside a cylinder, and this reciprocating motion is converted into rotational motion by a crank mechanism or similar device. It has the characteristic of generating high torque even at low speeds. However, it has the disadvantage of being composed of multiple parts, resulting in a complex structure and increased weight. Furthermore, it is prone to torque fluctuations (pulsations) due to the intermittent expansion stroke.

[0008] Conventional technology includes internal gear motors (including internal gear pumps, also commonly referred to as Gerotors). Internal gear motors have a structure in which an internal rotor and an external rotor physically mesh, and volume fluctuations are generated depending on tooth surface contact. As a result, friction losses are large, and there are limitations in terms of durability and efficiency. Furthermore, the outer shell member (housing) is fixed, and there is no mechanism to actively recover the reaction torque generated by the pressure of the working fluid as power. As described above, conventional air motors have problems with energy efficiency, durability, and performance degradation due to wear.

[0009] The present invention has been made in view of these circumstances, and aims to provide a rotating machine that can suppress vibration and wear structurally, operate efficiently over a wide range of rotational speeds and torques, reduce torque fluctuations (pulsations), and achieve smooth rotation. [Means for solving the problem]

[0010] To solve the above problems, the rotating machine of the present invention employs the following means. In other words, the rotating machine according to the present invention comprises a shaft whose axis is set to coincide with a first axis, an inner rotor whose axis is set to coincide with the first axis, is rotatable about the first axis, and has p (2≦p) protrusions formed along the circumferential direction on its outer circumference, an outer drum whose axis is set to coincide with a second axis that is parallel to the first axis and located away from the first axis, is rotatable about the second axis, and has p+1 recesses formed along the circumferential direction on its inner circumference, and a synchronization mechanism connected to the inner rotor and the outer drum, respectively, and configured to rotate synchronously around the first axis and around the second axis, wherein the relative positions of the protrusions and recesses are maintained by the synchronous rotation and they are physically non-contact, and the protrusions and recesses form a plurality of volume fluctuation spaces whose volume periodically expands and contracts by the synchronous rotation, the plurality of volume fluctuation spaces are formed such that fluid supplied from the intake port is discharged to the exhaust port, and when fluid is supplied to at least one of the volume fluctuation spaces, the remaining at least one of the volume fluctuation spaces discharges the fluid.

[0011] In the above invention, the inner rotor has a first space and a second space inside, the shaft is a fixed shaft with an intake port and an exhaust port formed inside, fluid can be supplied from the intake port to the volume-variable space through the first space, and fluid can be exhausted from the volume-variable space to the exhaust port through the second space, the inner rotor has a plurality of openings connecting either the first space or the second space to the outer circumferential surface of the inner rotor when it rotates, and the plurality of openings may be formed in the inner rotor such that when at least one of the openings is located on the first space side, at least one of the remaining openings is located on the second space side.

[0012] In the above invention, the outer drum has a helical structure in which the recess extends more than one rotation (360°) along the axial direction, the inner rotor has a helical structure in which the protrusion extends along the axial direction, the twist angle of the protrusion of the inner rotor is (p+1) / p times the twist angle of the recess of the outer drum, the shaft has an intake port formed inside that communicates with a first space, the outer drum has an exhaust port formed at its longitudinal end that communicates with a second space, fluid can be supplied from the intake port through the first space to one end of the plurality of volume variation spaces and to the plurality of volume variation spaces, and fluid can be exhausted from the other end of the plurality of volume variation spaces towards the exhaust port through the second space.

[0013] In the above invention, when the fluid flowing through the intake port is sent to at least one of the volume-changing spaces, the inner rotor and the outer drum act to expand the volume-changing space due to the pressure of the fluid, and the fluid in the remaining at least one of the volume-changing spaces may be discharged to the exhaust port.

[0014] In the above invention, when an external rotational force acts on the outer drum, the inner rotor acts, and the fluid that has flowed through the intake port is sent to the expanded volume-changing space, while the fluid in the remaining volume-changing space is discharged to the exhaust port. [Effects of the Invention]

[0015] According to the present invention, vibration and wear are structurally suppressed, and operation can be performed efficiently over a wide range of rotational speeds and torques. Furthermore, torque fluctuations (pulsations) are reduced, resulting in smooth rotation. [Brief explanation of the drawing]

[0016] [Figure 1] This is a perspective view showing an air motor according to the first embodiment of the present invention. [Figure 2]It is a longitudinal sectional view showing an air motor according to a first embodiment of the present invention. [Figure 3] It is a cross-sectional view showing an air motor according to a first embodiment of the present invention, and is a view taken in the direction of the arrow III-III in FIG. 2. [Figure 4] It is a cross-sectional view showing an air motor according to a first embodiment of the present invention, and is a view taken in the direction of the arrow IV-IV in FIG. 2. [Figure 5] It is an exploded perspective view showing an air motor according to a first embodiment of the present invention. [Figure 6] It is an explanatory view showing the operation of an air motor according to a first embodiment of the present invention. [Figure 7] It is an explanatory view showing a modified example of an air motor according to a first embodiment of the present invention. [Figure 8] It is an explanatory view showing a modified example of an air motor according to a first embodiment of the present invention. [Figure 9] It is a perspective view showing a helical turbine according to a second embodiment of the present invention. [Figure 10] It is a longitudinal sectional view showing a helical turbine according to a second embodiment of the present invention. [Figure 11] It is a cross-sectional view showing a helical turbine according to a second embodiment of the present invention, and is a view taken in the direction of the arrow XI-XI in FIG. 10. [Figure 12] It is a cross-sectional view showing a helical turbine according to a second embodiment of the present invention, and is a view taken in the direction of the arrow XII-XII in FIG. 10. [Figure 13] It is an exploded perspective view showing a helical turbine according to a second embodiment of the present invention. [Figure 14] It is an explanatory view showing the operation of a helical turbine according to a second embodiment of the present invention.

Mode for Carrying Out the Invention

[0017] [First Embodiment] Hereinafter, the air motor 1 according to the first embodiment of the present invention will be described with reference to the drawings.

[0018] As shown in Figures 1 to 5, the air motor 1 according to the first embodiment of the present invention comprises a shaft 3, an inner rotor 4, an outer drum 5, and a synchronization mechanism 6. The air motor 1 is a rotating machine that rotates using the pressure of compressed air. The air motor 1 is just one example of a rotating machine, and the following description will focus on an example where the circulating fluid is air, but the present invention is not limited to this example. That is, the fluid circulating in the rotating machine according to the present invention may be a gas other than air, such as water vapor, or a liquid such as water or oil.

[0019] As shown in Figures 3 and 5, the shaft 3 is an axial member that supports the inner rotor 4 and the outer drum 5, and has a portion centered on the first shaft S1 and a portion centered on the second shaft S2. The portion of the shaft 3 centered on the first shaft S1 supports the inner rotor 4, and the portion centered on the second shaft S2 supports the outer drum 5.

[0020] Multiple bearings 31, 32, 33, 34, and 35 are interposed on the shaft 3, and as shown in Figures 2 and 5, the bearings 31, 32, 33, 34, and 35 are arranged in the order of the second shaft S2, the first shaft S1, the first shaft S1, the second shaft S2, and the second shaft S2 on the axis of the second shaft S2. Bearing 31 is interposed between the shaft 3 and the outer drum 5, bearing 32 is interposed between the shaft 3 and the inner rotor 4, bearing 33 is interposed between the shaft 3 and the synchronous mechanism 6 connected to the inner rotor 4, bearing 34 is interposed between the shaft 3 and the outer drum 5, and bearing 35 is interposed between the outer drum 5 and the base 21.

[0021] A bulkhead 16 is installed on the shaft 3. The bulkhead 16 is provided on the upper and lower parts of the portion of the shaft 3 centered on the first axis S1, such that the wall surfaces of the bulkhead 16 are parallel to the axial direction of the shaft 3. The portion of the shaft 3 centered on the first axis S1 supports the inner rotor 4. Both ends of the shaft 3 are supported by a base 21.

[0022] The base 21 provides fixed support to one axial end of the shaft 3. The intake port 14 and exhaust port 15 formed on the shaft 3 are fixed and do not rotate. At the other axial end of the shaft 3 on the base 21, the output shaft 20 formed on the outer drum 5, which rotates around its axis, is supported by the base 21 via a bearing.

[0023] In this embodiment, an example is shown where the shaft 3 is fixed (fixed shaft), but the present invention is not limited to this. The shaft 3 itself may rotate as long as relative rotation with respect to the inner rotor 4 and the outer drum 5 is ensured and fluid supply and discharge are possible.

[0024] The inner rotor 4 is, for example, a cylindrical member, and as shown in Figure 3, its axis is positioned to coincide with the first axis S1, and it is rotatable about the first axis S1. The inner rotor 4 has a plurality of protrusions 7 formed on its outer circumference along the circumferential direction. The number p of the protrusions 7 can be set to, for example, two or more (2≦p). The number p of the protrusions 7 is set according to the performance that the air motor 1 is intended to achieve. In Figure 3, the number p of the protrusions 7 is shown as 4.

[0025] The outer drum 5 is, for example, a cylindrical member, and as shown in Figure 3, its axis is positioned to coincide with the second axis S2, and it is rotatable about the second axis S2. The second axis S2 is parallel to the first axis S1 and is located away from the first axis S1. The outer drum 5 has a plurality of recesses 8 formed on its inner surface along the circumferential direction. The number of recesses 8, q, is p+1, which is one more than the number of protrusions 7, and can be set to, for example, 3 or more (3≦q). The number of recesses 8, q, is set according to the performance of the air motor 1. In Figure 3, the number of recesses 8, q, is shown as 5.

[0026] By setting the number of protrusions 7 and recesses 8 to p and p+1, respectively, the volume fluctuation space 13 continuously expands with each half rotation of the outer drum 5, and then continuously contracts in the subsequent half rotation. Thus, a periodic and continuous cycle of increase and decrease in the volume fluctuation space 13 occurs during one rotation of the outer drum 5. On the other hand, if the numbers are p and p+2 or more, the volume fluctuation space 13 geometrically breaks down during rotation, the space does not continuously expand or contract, and the cycle of increase and decrease in the volume fluctuation space 13 does not occur.

[0027] Figures 7 and 8 show variations of the air motor 1 when the number of protrusions 7 p and the number of recesses 8 q are changed. Figure 7 shows variations when the size (cross-sectional area) of the first space 17 and the second space 18 is changed, and Figure 8 shows variations when the size (cross-sectional area) of the volume variation space 13 is changed. The number of protrusions 7 p, the number of recesses 8 q, the size of the first space 17 or the second space 18, or the size of the volume variation space 13 are set according to the performance of the air motor 1, etc.

[0028] As shown in Figure 2, the synchronous mechanism 6 is installed at the axial ends of the inner rotor 4 and the outer drum 5. As shown in Figure 4, the synchronous mechanism 6 has a spur gear 11 with teeth formed on its outer circumference and an internal gear 12 that meshes with the spur gear 11 and has teeth formed on its inner circumference. The spur gear 11 is connected to the inner rotor 4, and its axis is positioned to coincide with the first axis S1. The internal gear 12 is connected to the outer drum 5, and its axis is positioned to coincide with the second axis S2. The tooth ratio of the spur gear 11 and the internal gear 12 is set to p:(p+1).

[0029] Since the synchronous mechanism 6 is connected to both the inner rotor 4 and the outer drum 5, it maintains the relative position of the axis of the outer drum 5 with respect to the axis of the inner rotor 4. The synchronous mechanism 6 maintains a constant phase difference between the inner rotor 4 and the outer drum 5, thus maintaining a non-contact state. When both the inner rotor 4 and the outer drum 5 are rotating, the synchronous mechanism 6 enables synchronous rotation of the inner rotor 4 and the outer drum 5.

[0030] The synchronization mechanism 6 allows the inner rotor 4 and outer drum 5 to rotate without contact with each other. In other words, power is not transmitted in a way that would cause the inner rotor 4 and outer drum 5 to directly mesh. Because they are in a non-contact state, the inner rotor 4 and outer drum 5 rotate without physical contact, maintaining a distance from each other and forming a gap.

[0031] However, in the air motor 1 according to this embodiment, the inner rotor 4 and the outer drum 5 are basically kept in a non-contact state. Specifically, a minute gap is formed between the cylindrical outer surface of the inner rotor 4 having the protrusion 7 and the cylindrical inner surface of the outer drum 5 having the recess 8. If the distance of this gap is set to 0 (zero), the members will come into contact with each other, causing friction and wear, so it is set to a value greater than 0. On the other hand, since fluid leakage occurs if a gap exists, it is desirable to make the distance of the gap as close to 0 as possible. Therefore, the distance of this gap is set to a value that can minimize leakage while maintaining a non-contact state, taking into consideration the viscosity and pressure of the fluid used, or the material and machining precision of the components constituting the rotating machine. In exceptional cases, such as when the amount of leakage is large depending on the type of fluid or pressure conditions, a sealing member may be provided between the inner rotor 4 and the outer drum 5 (for example, at both axial ends or on the opposing surfaces of the protrusion 7 and the recess 8) to ensure airtightness.

[0032] In this embodiment, an example in which the synchronization mechanism 6 is implemented by a gear having multiple teeth has been described. However, the synchronization mechanism according to the present invention is not limited to this example, and an equivalent mechanism that performs the same function as the synchronization mechanism 6 may also be used. For example, instead of gears, a synchronization mechanism implemented by a timing belt, magnetic coupling, or electronically controlled synchronization may be used. This makes the overall mechanism more compact and lighter than the synchronization mechanism 6 composed of gears. In this case as well, physical non-contact and balance between the inner rotor 4 and the outer drum 5 are taken into consideration.

[0033] Inside the outer drum 5, multiple volume-varying spaces 13 are formed by convex portions 7 and concave portions 8. The volume of the volume-varying spaces 13 periodically expands and contracts as the convex portions 7 and concave portions 8 rotate due to the rotation of the inner rotor 4 and outer drum 5. Figure 6 shows the rotational operation of the inner rotor 4 and outer drum 5 in an air motor 1 with four p-numbered convex portions 7 and five q-numbered concave portions 8. In Figure 6, the changes in the inner rotor 4 and outer drum 5 are shown at 9° intervals of the inner rotor 4's rotation angle. The volume-varying spaces 13 are spaces that fluctuate as the inner rotor 4 and outer drum 5 rotate relative to each other while maintaining a non-contact state.

[0034] An output shaft 20 formed on the outer drum 5 is provided at one end of the outer drum 5. Torque is generated in the outer drum 5 by the reaction force generated by the rotating outer drum 5, and power is obtained by transmitting this torque to the outside via the output shaft 20. At the same time, torque is also generated in the inner rotor 4 and transmitted to the output shaft 20 via the synchronization mechanism 6.

[0035] A fluid flows within the volume-changing space 13. As shown in Figures 1 and 2, an intake port 14 and an exhaust port 15 are provided inside the shaft 3. The inlet of the intake port 14 and the outlet of the exhaust port 15 are on the same side with respect to the axial direction of the first shaft S1 and are located on one end of the inner rotor 4. The side on which the inlet of the intake port 14 and the outlet of the exhaust port 15 are provided is opposite to the side on which the output shaft 20 formed in the outer drum 5 is provided.

[0036] A cylindrical space is formed inside the inner rotor 4. As shown in Figures 2 and 3, the inner rotor 4 has a plurality of openings 19. The plurality of openings 19 are formed in a direction perpendicular to the first axis S1. The openings 19 may be flow paths connecting the apex of the protrusion 7 to the internal space of the inner rotor 4, or they may be flow paths connecting the space between the two protrusions 7 (valley-shaped portion) to the internal space of the inner rotor 4.

[0037] As shown in Figures 2 and 3, the cylindrical space formed inside the inner rotor 4 is divided into two spaces, a first space 17 and a second space 18, by a partition wall 16 provided on the shaft 3. The opening 19 connects either the first space 17 or the second space 18 to the outer circumferential surface of the inner rotor 4. Fluid supplied through the intake port 14 is supplied towards the first space 17 and then taken into the volume variation space 13 through the opening 19. The volume variation space 13 discharges the taken-in fluid from the second space 18 through the opening 19 towards the exhaust port 15.

[0038] The volume fluctuation space 13 is a space into which fluid is supplied, which is temporarily stored, and which is also used to discharge the stored fluid.

[0039] As shown in Figure 6, the shape of the volume fluctuation space 13 is formed such that when fluid is supplied to at least one volume fluctuation space 13, the remaining at least one volume fluctuation space 13 discharges the fluid.

[0040] In the air motor 1 having the above configuration, when the fluid flowing through the intake port 14 is sent to at least one volume fluctuation space 13, the inner rotor 4 and outer drum 5 act to expand the volume fluctuation space 13 by the pressure of the fluid. Then, the fluid in the remaining at least one volume fluctuation space 13 is discharged to the exhaust port 15.

[0041] While the outer drum 5 rotates once, the volume-changing space 13 repeatedly expands and contracts. Specifically, during the first half of the outer drum 5's rotation, the volume of the space expands, and during the second half, the volume of the space contracts.

[0042] During the first half of one rotation of the outer drum 5, in the process of expanding the volumetric space 13, the intake port 14 coincides with the opening 19 of the inner rotor 4. During this time, a fluid such as compressed air flows into the volumetric space 13. The volumetric space 13, into which the fluid has flowed, expands due to the pressure of the fluid. As a result, the fluid pressure acts on both the inner rotor 4 and the outer drum 5 in a direction that expands the volumetric space 13. This becomes the source of the rotational torque of the air motor 1.

[0043] After the volume fluctuation space 13 reaches its maximum, in the latter half of one rotation of the outer drum 5, the volume fluctuation space 13 begins to shrink due to the rotation (synchronous rotation) occurring in both the inner rotor 4 and the outer drum 5. At this time, the exhaust port 15 coincides with the opening 19 of the inner rotor 4. During this time, fluid is discharged from the volume fluctuation space 13 and flows into the exhaust port 15.

[0044] In this way, each volume fluctuation space 13 repeatedly expands and contracts, resulting in continuous volume fluctuations and thus stable continuous rotation. Furthermore, as described above, the synchronization mechanism 6 allows the air motor 1 to realize the periodic changes in the volume fluctuation spaces 13 in a non-contact structure, enabling it to convert the fluid pressure energy into rotational torque with high efficiency.

[0045] Furthermore, in the configuration according to this embodiment, multiple volume fluctuation spaces 13 are geometrically arranged so as to be continuously connected to the intake port 14 or exhaust port 15. This arrangement structurally smooths out volume fluctuations and reduces torque fluctuations (pulsations) during rotation. In particular, since the multiple volume fluctuation spaces 13 are connected to the intake port 14 or exhaust port 15 with a phase difference from each other, smoother rotation can be obtained compared to conventional reciprocating mechanisms or uneven-speed rotation mechanisms.

[0046] Unlike this embodiment, if there is no synchronization mechanism 6, the inner rotor 4 and the outer drum 5 will come into direct contact, causing friction and reducing rotational torque. In contrast, the air motor 1 can significantly suppress the occurrence of wear.

[0047] In the air motor 1 according to this embodiment, the inner rotor 4 rotates around the first axis S1, and the outer drum 5 rotates around the second axis S2. The inner rotor 4 and the outer drum 5 rotate symmetrically and non-contact while maintaining a constant phase relationship by the synchronization mechanism 6. Therefore, even during rotation, the masses of the inner rotor 4 and the outer drum 5 are evenly distributed and do not become unbalanced. As a result, vibrations to the shaft 3 are suppressed. Compared to conventional piston-type air motors, vibrations due to periodic mass transfer do not occur, and vibrations are reduced even at high speeds. Therefore, the air motor 1 is suitable for high-speed rotation.

[0048] Furthermore, in conventional vane-type air motors and other structures with eccentric shafts, a fixed casing structure is common. Due to fluid pressure, a reaction force equivalent to the action acting on the rotor rotating inside the casing is generated on the casing side. However, this reaction torque is not utilized as energy, and energy loss occurs as a load on bearings and structures (base). In contrast, the air motor 1 recovers the torque (reaction torque) generated by the reaction force on the rotating outer drum 5, thereby significantly improving torque efficiency. In addition, because it has a configuration that recovers the reaction torque associated with fluid pressure as power in the outer drum 5, it can utilize the energy that was lost due to the fixed structure of the outer shell member (housing) of the internal gear motor, unlike conventional internal gear motors.

[0049] Furthermore, in the air motor 1, the inlet of the intake port 14 and the inlet of the exhaust port 15 are located on the same side with respect to the axial direction of the first shaft S1, so that the flow path is concentrated on one side, and the opposite side is sealed and the output shaft 20 is supported by a bearing. This reduces the number of parts required for fluid sealing, and as a result the structure of the air motor 1 is simplified and made lighter.

[0050] It should be noted that the rotating machine according to the present invention is not limited to the air motor 1 according to this embodiment, which performs the operation of converting the pressure energy of a fluid into rotational energy. The rotating machine according to the present invention has the same configuration as the air motor 1, but unlike the air motor 1, it can also function as a compressor or pump by being subjected to rotational force from an external source.

[0051] When functioning as a compressor or pump, the outer drum 5 is forcibly rotated by applying an external rotational force to the output shaft 20. This causes the inner rotor 4 to rotate synchronously via the synchronization mechanism 6. In this case, during the stroke in which the volume fluctuation space 13 expands, fluid is drawn in from the intake port 14. Subsequently, during the stroke in which the volume fluctuation space 13 contracts, the confined fluid is pressurized and discharged from the exhaust port 15 at increased pressure. Thus, the structure of the air motor 1 described above is reversible, and by controlling the direction of rotation and the direction of fluid flow, it can be used not only as a power machine (motor, turbine, etc.) but also as a fluid machine (compressor, pump, etc.).

[0052] [Second Embodiment] Next, a helical turbine 2 according to a second embodiment of the present invention will be described with reference to the drawings.

[0053] As shown in Figures 9 to 12, the helical turbine 2 according to the second embodiment of the present invention comprises a shaft 3, an inner rotor 4, an outer drum 5, and a synchronization mechanism 6. In the first embodiment (air motor 1), a plurality of openings 19 were formed in the radial direction of the inner rotor 4, whereas in the second embodiment (helical turbine 2), no openings are provided in the radial direction of the inner rotor 4, but openings are provided in the axial front and rear directions. Therefore, as shown in Figure 10, fluid is supplied from the first space 17 through the intake port 14, passing through the front opening to the volume fluctuation space 13, and the fluid that has acted in the volume fluctuation space 13 passes through the rear opening, through the second space 18, and is discharged to the outside from the exhaust port 15.

[0054] The helical turbine 2 according to this embodiment is consistent with the first embodiment in that a volume fluctuation space 13 is formed between the inner rotor 4 and the outer drum 5. As will be described later, the volume fluctuation space 13 of the helical turbine 2 is a helical space formed between a convex portion 7 and a concave portion 8 having a helical structure, and the fluid always flows from one axial end to the other axial end of the volume fluctuation space 13.

[0055] As shown in Figures 10 and 13, the shaft 3 is an axial member that supports the inner rotor 4 and the outer drum 5, and has a portion centered on the first shaft S1 and a portion centered on the second shaft S2. The portion of the shaft 3 centered on the first shaft S1 supports the inner rotor 4, and the portion centered on the second shaft S2 supports the outer drum 5.

[0056] Multiple bearings 31, 32, 33, 34, and 35 are interposed on the shaft 3, and as shown in Figures 10 and 13, the bearings 31, 32, 33, 34, and 35 are arranged in the order of the second shaft S2, the first shaft S1, the first shaft S1, the second shaft S2, and the second shaft S2 on the axis of the second shaft S2. Bearing 31 is interposed between the shaft 3 and the outer drum 5, bearing 32 is interposed between the shaft 3 and the inner rotor 4, bearing 33 is interposed between the shaft 3 and the synchronous mechanism 6 connected to the inner rotor 4, bearing 34 is interposed between the shaft 3 and the outer drum 5, and bearing 35 is interposed between the outer drum 5 and the base 21. Both ends of the shaft 3 are supported by the base 21. An intake port 14 is formed inside the shaft 3.

[0057] The base 21 provides fixed support to one axial end of the shaft 3. The intake port 14 formed on the shaft 3 remains fixed and does not rotate. At the other axial end of the shaft 3 on the base 21, the output shaft 20 formed on the outer drum 5, which rotates around its axis, is supported by the base 21 via a bearing.

[0058] The inner rotor 4 is, for example, a cylindrical member, and its axis is positioned to coincide with the first axis S1, and it is rotatable about the first axis S1. The inner rotor 4 has a plurality of protrusions 7 formed on its outer circumference along the circumferential direction. The number p of the protrusions 7 can be set to, for example, two or more (2≦p). The number p of the protrusions 7 is set according to the performance that the helical turbine 2 is intended to achieve. In Figures 10 and 11, the number p of the protrusions 7 is shown as 2.

[0059] The outer drum 5 is, for example, a cylindrical member, and its axis is positioned to coincide with the second axis S2, and it is rotatable about the second axis S2. The second axis S2 is parallel to the first axis S1 and is located at a distance from the first axis S1. The outer drum 5 has a plurality of recesses 8 formed on its inner surface along the circumferential direction. The number of recesses 8, q, is p+1, which is one more than the number of protrusions 7, and can be set to, for example, 3 or more (3≦q). The number of recesses 8, q, is set according to the performance of the helical turbine 2. In Figures 10 and 11, the number of recesses 8, q, is shown as 3.

[0060] The recess 8 has a helical structure on the inner circumferential surface of the outer drum 5 that extends more than one rotation (360°) along the axial direction. The protrusion 7 has a helical structure on the outer circumferential surface of the inner rotor 4 that extends along the axial direction. The twist angle of the protrusion 7 of the inner rotor 4 is (p+1) / p times the twist angle of the recess 8 of the outer drum 5. In Figures 10 and 14(A) to 14(D), the number p of the protrusions 7 on the inner rotor 4 is shown as 2. Since it is a helical structure twisted 1.5 rotations (540°) along the axial direction, three protrusions 7 can be seen.

[0061] The synchronous mechanism 6 is installed at the axial ends of the inner rotor 4 and the outer drum 5. The synchronous mechanism 6 has a spur gear 11 with teeth formed on its outer circumference and an internal gear 12 that meshes with the spur gear 11 and has teeth formed on its inner circumference. The spur gear 11 is connected to the inner rotor 4, and its axis is positioned to coincide with the first axis S1. The internal gear 12 is connected to the outer drum 5, and its axis is positioned to coincide with the second axis S2.

[0062] Since the synchronous mechanism 6 is connected to both the inner rotor 4 and the outer drum 5, it maintains the relative position of the axis of the outer drum 5 with respect to the axis of the inner rotor 4. The synchronous mechanism 6 maintains a constant phase difference between the inner rotor 4 and the outer drum 5, thus maintaining a non-contact state. When both the inner rotor 4 and the outer drum 5 are rotating, the synchronous mechanism 6 enables synchronous rotation of the inner rotor 4 and the outer drum 5.

[0063] The synchronous mechanism 6 allows the inner rotor 4 and outer drum 5 to rotate without contact with each other. In other words, power is not transmitted in a way that would cause the inner rotor 4 and outer drum 5 to directly mesh. Because they are in a non-contact state, the inner rotor 4 and outer drum 5 rotate without physical contact, maintaining a distance from each other and forming a gap. The presence of a gap leads to fluid leakage, but eliminating the gap would result in frictional losses, so the gap distance is approached as close to zero as possible, but is not zero.

[0064] In this embodiment, an example in which the synchronization mechanism 6 is implemented by a gear having multiple teeth has been described. However, the synchronization mechanism according to the present invention is not limited to this example, and may be an equivalent mechanism that performs the same function as the synchronization mechanism 6.

[0065] Inside the outer drum 5, multiple volume-varying spaces 13 are formed by convex portions 7 and concave portions 8. The volume of the volume-varying spaces 13 periodically expands and contracts due to the synchronous rotation of the inner rotor 4 and the outer drum 5, causing the volume between the convex portions 7 and concave portions 8 to expand and contract. Figures 14(A) to 14(D) show the rotational operation of the inner rotor 4 and outer drum 5 in the helical turbine 2. The volume-varying spaces 13 are spaces that fluctuate as the inner rotor 4 and outer drum 5 rotate relative to each other while maintaining a non-contact state. With each rotation of the outer drum 5, the volume-varying spaces 13 expand by half a rotation in the axial direction from the first space 17 on the intake side to the second space 18 on the exhaust side, and contract by the remaining half rotation.

[0066] A fluid flows within the volume-changing space 13. An intake port 14 is provided inside the shaft 3. The intake port 14 is a cylindrical space formed inside the shaft 3. An exhaust port 15 is provided at the longitudinal end of the outer drum 5. The exhaust port 15 is a through hole formed in the disc member at the end of the outer drum 5. The inlet of the intake port 14 and the outlet of the exhaust port 15 are on the same side with respect to the axial direction of the first shaft S1. The side on which the inlet of the intake port 14 and the outlet of the exhaust port 15 are provided is opposite to the side on which the output shaft 20 formed in the outer drum 5 is provided.

[0067] A cylindrical space is formed inside the inner rotor 4, and the shaft 3 is housed within it. Fluid can be supplied to the first space 17 via the intake port 14, and to the multiple volume-variable spaces 13 from one end of the first space 17. Fluid can also flow from the other end of the multiple volume-variable spaces 13 to the second space 18 and be exhausted to the outside via the exhaust port 15.

[0068] The volume fluctuation space 13 is a helical space formed along the helical structure of the convex portion 7 and the helical structure of the concave portion 8. The volume fluctuation space 13 is a space in which fluid is supplied from the first space 17, the fluid is temporarily stored, and the fluid stored in the second space 18 is discharged.

[0069] Fluid is supplied from an opening formed in the first space 17 of the volume fluctuation space 13, and the fluid is discharged from an opening formed in the second space 18 of the volume fluctuation space 13. Multiple openings are formed at one end of the volume fluctuation space 13 connected to the first space 17 and the other end connected to the second space 18, and each of them opens and closes repeatedly in a continuous manner. Therefore, in the helical turbine 2, at least the number of openings p, which are the number of protrusions 7, are always formed as openings into which fluid is taken in.

[0070] The shape of the volume fluctuation space 13 is such that when fluid is supplied to at least one volume fluctuation space 13, the remaining at least one volume fluctuation space 13 discharges the fluid.

[0071] In the helical turbine 2 having the above configuration, when the fluid that has flowed through the intake port 14 and the first space 17 is sent to at least one volume fluctuation space 13, the fluid pressure acts on both the inner rotor 4 and the outer drum 5 to expand the volume fluctuation space 13, generating rotational power. Then, the fluid in the remaining at least one volume fluctuation space 13 flows through the second space 18 and is discharged to the exhaust port 15.

[0072] While the outer drum 5 rotates once, the volume-varying space 13 repeatedly expands and contracts from the first space 17 to the second space 18 while moving in the axial direction. Specifically, during the first half of the outer drum 5's rotation (from 0° to 180°), the volume of the space expands, and during the second half (from 180° to 360°), the volume of the space contracts.

[0073] The volume-fluctuating space 13 into which the fluid flows expands due to the fluid pressure. As a result, the fluid pressure acts on both the inner rotor 4 and the outer drum 5 in a direction that expands the volume-fluctuating space 13. This becomes the source of the rotational torque of the helical turbine 2.

[0074] After the volume fluctuation space 13 reaches its maximum, in the latter half of one rotation of the outer drum 5, the rotation (synchronous rotation) occurring in both the inner rotor 4 and the outer drum 5 causes the volume fluctuation space 13 to shrink. As a result, the fluid is discharged from the volume fluctuation space 13 and flows into the exhaust port 15.

[0075] In this way, each volume fluctuation space 13 repeatedly expands and contracts, resulting in continuous volume fluctuations and thus stable continuous rotation. Furthermore, as described above, the synchronization mechanism 6 allows the helical turbine 2 to realize the periodic changes in the volume fluctuation spaces 13 in a non-contact structure, enabling it to convert the fluid pressure energy into rotational torque with high efficiency.

[0076] Unlike this embodiment, if there is no synchronization mechanism 6, the inner rotor 4 and the outer drum 5 will come into direct contact, causing friction and reducing rotational torque. In contrast, the helical turbine 2 can significantly suppress the occurrence of wear.

[0077] In the helical turbine 2 according to this embodiment, the inner rotor 4 rotates around the first axis S1, and the outer drum 5 rotates around the second axis S2. The inner rotor 4 and the outer drum 5 rotate symmetrically and non-contact while maintaining a constant phase relationship by the synchronization mechanism 6. Therefore, even during rotation, the masses of the inner rotor 4 and the outer drum 5 are evenly distributed and do not become unbalanced. As a result, vibrations to the shaft 3 are suppressed. Compared to conventional piston-type air motors, vibrations due to periodic mass transfer do not occur, and vibrations are reduced even at high speeds. Therefore, the helical turbine 2 is suitable for high-speed rotation.

[0078] In conventional vane-type air motors and other structures with eccentric shafts, the casing is typically fixed. Due to fluid pressure, a reaction force equivalent to the action acting on the rotor rotating inside the casing is generated on the casing side. However, this reaction torque is not utilized as energy, resulting in energy loss as a load on bearings and structures (bases). In contrast, the helical turbine 2 recovers the torque (reaction torque) generated by the reaction force on the rotating outer drum 5, significantly improving torque efficiency. Furthermore, because it has a configuration that recovers the reaction torque associated with fluid pressure as power in the outer drum 5, it can utilize the energy that was lost due to the fixed structure of the outer shell member (housing) of the internal gear motor, unlike conventional internal gear motors.

[0079] Furthermore, in the helical turbine 2, the inlet of the intake port 14 and the inlet of the exhaust port 15 are located on the same side with respect to the axial direction of the first shaft S1, so that the flow path is concentrated on one side, and the opposite side is sealed and the output shaft 20 is supported by a bearing. This reduces the number of parts required for fluid sealing, and as a result the structure of the helical turbine 2 is simplified and made lighter.

[0080] It should be noted that the rotating machine according to the present invention is not limited to the helical turbine 2 according to this embodiment, which performs the operation of converting the pressure energy of a fluid into rotational energy. The rotating machine according to the present invention may have the same configuration as the helical turbine 2, but unlike the helical turbine 2, it can also function as a compressor or pump by having rotational force applied from an external source.

[0081] When functioning as a compressor or pump, the outer drum 5 is forcibly rotated by applying an external rotational force to the output shaft 20. This causes the inner rotor 4 to rotate synchronously via the synchronization mechanism 6. In this case, during the stroke in which the volume fluctuation space 13 expands while moving axially, fluid is drawn in from one end of the volume fluctuation space 13 via the intake port 14 and the first space 17. Subsequently, during the stroke in which the volume fluctuation space 13 contracts, the fluid is pressurized and pushed axially, and discharged from the other end of the volume fluctuation space 13 to the exhaust port 15 via the second space 18. Because the volume fluctuation space 13 has a helical structure, the fluid is continuously transported along the axial direction, resulting in smooth discharge characteristics with minimal pulsation. Thus, the structure of the helical turbine 2 described above is reversible, and by controlling the direction of rotation and the direction of fluid flow, it can be used not only as a power machine (motor, turbine, etc.) but also as a fluid machine (compressor, pump, etc.). [Industrial applicability]

[0082] The present invention can be effectively applied not only as a drive motor for various devices and equipment, but also to experimental equipment for educational and research purposes, wind power generation and tidal power generation systems that utilize renewable energy, and even to thermal energy conversion devices such as Stirling engines or heat pumps. [Explanation of Symbols]

[0083] 1: Air motor (rotating machinery) 2: Helical turbine (rotating machinery) 3: Shaft 4: Inner rotor 5: Outer drum 6:Synchronization mechanism 7: Convex part 8: Recess 11: Spur gear 12: Internal gear 13: Volume-varying space 14: Intake port 15: Exhaust port 16: Bulkhead 17: 1st space 18:Second space 19: Opening 20: Output shaft 21: Pedestal 31, 32, 33, 34, 35: Bearings

Claims

1. A shaft whose axis is positioned to coincide with the first axis, An inner rotor whose axis is positioned to coincide with the first axis, which is rotatable about the first axis, and which has p (2 ≤ p) protrusions formed along the circumferential direction on its outer surface, An outer drum having an axis positioned parallel to the first axis and coinciding with a second axis located away from the first axis, rotatable about the second axis, and having p+1 recesses formed along the circumferential direction on its inner surface, A synchronization mechanism connected to the inner rotor and the outer drum, respectively, and configured to rotate synchronously around the first axis and around the second axis, Equipped with, When the inner rotor rotates 1 / p due to the aforementioned synchronous rotation, the outer drum rotates 1 / (p+1) times. Due to the aforementioned synchronous rotation, the convex portion and the concave portion maintain their relative positions and are not in physical contact. The convex portion and the concave portion form a plurality of volume fluctuation spaces in which the volume periodically expands and contracts when they rotate synchronously. The aforementioned multiple volume-fluctuating spaces discharge the fluid supplied from the intake port to the exhaust port. The plurality of volume-varying spaces are formed such that when fluid is supplied to at least one of the volume-varying spaces, the remaining at least one of the volume-varying spaces discharges the fluid. A rotating machine in which the volume fluctuation space continuously expands during half a rotation of the outer drum, and the volume fluctuation space continuously contracts during the next half rotation of the outer drum after the volume fluctuation space has been continuously expanded.

2. The inner rotor has a first space and a second space inside, The shaft is a fixed shaft in which the intake port and the exhaust port are formed inside. Fluid can be supplied from the intake port to the volume-changing space via the first space, and fluid can be exhausted from the volume-changing space to the exhaust port via the second space. The inner rotor has a plurality of openings that connect either the first space or the second space to the outer circumferential surface of the inner rotor when it rotates. The rotating machine according to claim 1, wherein the plurality of openings are formed in the inner rotor such that when at least one of the openings is located on the first space side, the remaining at least one of the openings is located on the second space side.

3. The outer drum has a helical structure in which the recess extends more than one rotation (360°) along the axial direction, the inner rotor has a helical structure in which the protrusion extends along the axial direction, and the twist angle of the protrusion of the inner rotor is (p+1) / p times the twist angle of the recess of the outer drum. The shaft has the intake port formed inside, which communicates with the first space. The outer drum has the exhaust port, which communicates with the second space, formed at its longitudinal end. The rotating machine according to claim 1, wherein fluid can be supplied from the intake port through the first space to one end of the plurality of volume variation spaces to the plurality of volume variation spaces, and fluid can be exhausted from the other end of the plurality of volume variation spaces toward the exhaust port through the second space.

4. The rotating machine according to any one of claims 1 to 3, wherein when the fluid that has flowed through the intake port is sent to at least one of the volume-changing spaces, the inner rotor and the outer drum act to expand the volume-changing space by the pressure of the fluid, and the fluid in the remaining at least one of the volume-changing spaces is discharged to the exhaust port.

5. The rotating machine according to any one of claims 1 to 3, wherein when an external rotational force is applied to the outer drum, the inner rotor acts while the fluid that has flowed through the intake port is sent to the expanded at least one of the volume-changing spaces, and the fluid in the remaining at least one of the volume-changing spaces that has been reduced is discharged to the exhaust port.

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