Single-axis eccentric screw pump

Abstract

To provide a uniaxial eccentric screw pump capable of coupling a coupling shaft to at least one shaft body of a rotor and a driving machine while suppressing the deviation of an axis position, and capable of smoothly releasing the coupling.SOLUTION: In a uniaxial eccentric screw pump 10, at least either one of a drive side coupling portion 100 and a rotor side coupling portion 200 are disassemblably coupled with each other while fitting structures 180 and 280 are formed by first shaft coupling portions 110 and 210 provided on a first shaft forming one of two shafts to be connected, and second coupling portions 150 and 250 provided on a second shaft forming the other. The uniaxial eccentric screw pump 10 is equipped with a coupling bolt 170 for releasing the fitting structures 180 and 280, and a non-fastening screw hole 118b for providing the coupling bolt 170.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a single-shaft eccentric screw pump. [Background technology]

[0002] Conventionally, in a single-shaft eccentric screw pump or the like disclosed in Patent Document 1 below, rotational power output from the output shaft of a driver can be transmitted to a rotor via a connecting shaft such as a flexible rod. The connecting portion (connecting structure) with the shaft body (drive shaft in Patent Document 1) connected to the connecting shaft is connected by inserting one into the other and then bonding them together.

[0003] In a single-shaft eccentric screw pump disclosed in Patent Document 2 below, a threaded shaft portion at the tip of a flexible rod is inserted into a shaft insertion hole provided in the rotor or drive shaft, and the shafts are joined by screwing them together. Furthermore, the end of the flexible rod serves as a flange portion that is in surface contact with the end face of the rotor or drive shaft. Joining the shafts in this manner allows the two shafts to be joined without rattle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3629100 [Patent Document 2] Patent No. 5724096 Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors have studied ways to connect a flexible connecting shaft (first shaft) such as a flexible rod to another shaft (second shaft) such as an output shaft or rotor that rotates upon receiving output from a driver, so that the connection can be disassembled even when the pump is large, and so that misalignment of the axial center is unlikely to occur.As a result, they have discovered that by connecting the flexible connecting shaft (first shaft) and the second shaft connected to it by attaching bolts to the flanges in a state where they form a fitting structure, it is possible to connect even large pumps so that the connection can be disassembled and so that misalignment of the axial center is unlikely to occur.

[0006] On the other hand, we have come to the realization that if the connecting shaft (first shaft) and a second shaft such as a rotor or output shaft are connected with the above-described fitting structure formed, it may be difficult to disassemble them into the first and second shafts for maintenance, etc. Specifically, if a heavy connecting shaft must be used, for example, because the single-shaft eccentric screw pump is large, the connecting shaft may tilt due to its own weight when disassembling the connection between the connecting shaft and the rotor. If the connecting shaft (first shaft) tilts in this way, it may get caught in the connection portion, making it difficult to disassemble them into the connecting shaft (first shaft) and the second shaft.

[0007] Therefore, the present invention aims to provide a single-shaft eccentric screw pump that can connect a connecting shaft to at least one of the shaft bodies of the rotor and the driver in a manner that is less likely to cause misalignment of the axial center position, and can also be smoothly disconnected. [Means for solving the problem]

[0008] (1) The uniaxial eccentric screw pump of the present invention, which is provided to solve the above-mentioned problems, comprises a flexible connecting shaft, a rotor constituted by a male-threaded shaft body, and a stator into which the rotor can be inserted and whose inner peripheral surface is formed with a female thread. The pump comprises a drive-side connecting portion that directly or indirectly connects the connecting shaft to an output shaft that rotates in response to the output of the drive machine, and a rotor-side connecting portion that directly or indirectly connects the connecting shaft to the rotor, so that the rotational power output from the drive machine can be transmitted to the stator via the connecting shaft to drive it. At least one of the drive-side connecting portion and the rotor-side connecting portion is disassemblably connected in a state where a fitting structure is formed by a first shaft connecting portion provided on a first shaft that is one of the two shafts to be connected, and a second shaft connecting portion provided on a second shaft that is the other of the two shafts to be connected, and the pump is characterized in that it comprises at least one of a fitting-release member for releasing the fitting structure and a fitting-release member installation portion for installing the fitting-release member.

[0009] In the single-shaft eccentric screw pump of the present invention, one of the first shaft and the second shaft serves as a connecting shaft, and the other serves as a rotor or an output shaft. Furthermore, in the single-shaft eccentric screw pump of the present invention, at least one of the drive-side connecting portion and the rotor-side connecting portion does not simply connect to the first-shaft connecting portion and the second-shaft connecting portion provided on the first and second shafts to be connected, but rather forms a fitting structure and is connected in a manner that allows for disassembly. Therefore, in the single-shaft eccentric screw pump of the present invention, the connecting shaft can be connected to the rotor or the output shaft in a manner that is less likely to cause misalignment of the axial centers. Furthermore, in the single-shaft eccentric screw pump of the present invention, because the first-shaft connecting portion and the second-shaft connecting portion are connected to each other by forming a fitting structure, misalignment of the axial centers of the first and second shafts is less likely to occur during disassembly.

[0010] Furthermore, the single-shaft eccentric screw pump of the present invention includes at least one of a disengagement member for disengaging the fitting structure and a disengagement member installation portion for providing the disengagement member. Therefore, when disassembling the single-shaft eccentric screw pump of the present invention into the first shaft and the second shaft, the disengagement member can be used to smoothly disengage the fitting structure formed by the first shaft connecting portion and the second shaft connecting portion. Therefore, the single-shaft eccentric screw pump of the present invention can be easily disassembled as well as connected to the connecting shaft.

[0011] (2) The single-shaft eccentric screw pump of the present invention described above may be characterized in that the engagement release member has a screw shaft, and the engagement release member installation portion has a screw receiving portion having a screw that screws onto the screw shaft.

[0012] With this configuration, the single-shaft eccentric screw pump of the present invention can firmly install a member equipped with the threaded shaft that forms the disengaging member by the screw-receiving portion that forms the disengaging member mounting portion due to the screw-engaging force generated between the member and the threaded receiving portion that forms the disengaging member mounting portion. Furthermore, by threading the threaded shaft that forms the disengaging member into the threaded receiving portion that forms the disengaging member mounting portion and rotating the threaded shaft, the threaded shaft can be advanced and retreated in the axial direction, and the force generated thereby can be utilized to release the fitting structure. Therefore, with the single-shaft eccentric screw pump of the present invention, the force required to release the fitting in the fitting structure can be fully applied by threading the threaded shaft that forms the disengaging member into the threaded receiving portion that forms the disengaging member mounting portion.

[0013] (3) The single-shaft eccentric screw pump of the present invention described above may be characterized in that the fitting structure can be disengaged by a release operation that involves a separation operation that separates the first shaft connecting portion and the second shaft connecting portion in a direction along the axial direction of the connecting shaft, and the screw receiving portion is provided so that the screw shaft can be advanced and retreated in the axial direction of the connecting shaft, and the separation operation can be performed by advancing the screw shaft.

[0014] With this configuration, the single-shaft eccentric screw pump of the present invention can perform a separating operation to separate the first shaft coupling portion and the second shaft coupling portion by advancing the screw shaft attached to the screw receiving portion in the axial direction of the connecting shaft. Therefore, the single-shaft eccentric screw pump of the present invention can utilize the force generated by rotating the screw shaft to advance it, to release the fitting structure.

[0015] (4) The above-described single-shaft eccentric screw pump of the present invention may be characterized in that the screw receiving portion is provided on one of the first shaft connecting portion and the second shaft connecting portion, and the first shaft connecting portion and the second shaft connecting portion can be moved relatively in a direction to release the fitting structure by advancing the screw shaft attached to the screw receiving portion in contact with the other of the first shaft connecting portion and the second shaft connecting portion.

[0016] With this configuration, the single-shaft eccentric screw pump of the present invention can apply a force generated by advancing the screw shaft attached to the screw receiving portion provided in one of the first and second shaft connecting portions to the other connecting portion, thereby enabling the single-shaft eccentric screw pump of the present invention to release the fitting structure by utilizing the force generated by rotating the screw shaft to advance it.

[0017] (5) In the above-described uniaxial eccentric screw pump, the fitting structure may be configured by a clearance fit.

[0018] By configuring the uniaxial eccentric screw pump of the present invention as described above, it is possible to easily disassemble and assemble the fitting structure formed by the first shaft connecting portion and the second shaft connecting portion.

[0019] (6) The above-described single-shaft eccentric screw pump of the present invention may be characterized in that the connecting shaft is a first shaft, and a flange portion extending in a direction intersecting the axial direction of the connecting shaft is provided on the connecting shaft as part or all of the first shaft connecting portion, and at least one of the drive-side connecting portion and the rotor-side connecting portion is configured to connect the first shaft connecting portion and the second shaft connecting portion by fitting a bolt across the flange portion and the second shaft connecting portion while bringing the flange portion into surface contact with the second shaft connecting portion provided on the second shaft connected to the connecting shaft.

[0020] In the single-shaft eccentric screw pump of the present invention, the first shaft connecting portion and the second shaft connecting portion can be connected by using bolts to connect a flange portion provided on the connecting shaft, which is the first shaft, as a first shaft connecting portion, in surface contact with the second shaft connecting portion of the second shaft connected to the connecting shaft. Therefore, in the single-shaft eccentric screw pump of the present invention, moments acting in the axial direction and in the axial rotation direction due to eccentric rotation can be absorbed by the surface contact portion between the flange portion of the first shaft connecting portion and the second shaft connecting portion. Therefore, in the single-shaft eccentric screw pump of the present invention, rattle is unlikely to occur at the connection portion between the first shaft connecting portion and the second shaft connecting portion. Furthermore, in the single-shaft eccentric screw pump of the present invention, even if the connecting shaft rotates eccentrically due to drive, fretting wear and damage due to stress concentration are unlikely to occur at the connection portion between the first shaft connecting portion and the second shaft connecting portion.

[0021] (7) The above-mentioned single-shaft eccentric screw pump of the present invention may be characterized in that the fitting release member installation portion accepts insertion of the fitting release member into the gap between the first shaft connecting portion and the second shaft connecting portion.

[0022] Because the single-shaft eccentric screw pump of the present invention has this configuration, it is easy to insert the engagement release member into the gap between the first shaft connecting portion and the second shaft connecting portion to release the engagement structure.

[0023] (8) The above-mentioned single-shaft eccentric screw pump of the present invention may be characterized in that the fitting release member installation portion forms a groove between the first shaft connecting portion and the second shaft connecting portion.

[0024] By configuring the single-shaft eccentric screw pump of the present invention in this manner, the engagement structure formed by the first shaft connecting portion and the second shaft connecting portion can be released using the engagement release member by inserting the engagement release member into the groove that constitutes the engagement release member installation portion. [Effects of the Invention]

[0025] According to the present invention, it is possible to provide a single-shaft eccentric screw pump in which the connecting shaft can be connected to the shaft body of at least one of the rotor and the driver in a state where misalignment of the axial center position is unlikely to occur, and the connection can be smoothly released. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a cross-sectional view of a single-shaft eccentric screw pump according to an embodiment of the present invention. [Figure 2] 2 is an enlarged view of the vicinity of a drive-side coupling portion of the uniaxial eccentric screw pump shown in FIG. 1. FIG. [Figure 3] 2 is an exploded perspective view showing a state in which a drive-side connecting portion of the uniaxial eccentric screw pump shown in FIG. 1 is disassembled. FIG. [Figure 4] 2 is an exploded perspective view showing a drive shaft and a first shaft connecting portion of the uniaxial eccentric screw pump shown in FIG. 1. FIG. [Figure 5] 2 is an exploded perspective view showing a state in which a drive-side connecting portion of the uniaxial eccentric screw pump shown in FIG. 1 is disassembled. FIG. [Figure 6] FIG. 2 is a front view of the adapter viewed from the positioning end face side. [Figure 7] FIG. 10 is a diagram showing a front view of a component body constituting a first connecting portion. [Figure 8] 2 is an enlarged view of the vicinity of a rotor-side connecting portion of the uniaxial eccentric screw pump shown in FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0027] Next, a uniaxial eccentric screw pump 10 according to one embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the overall structure of the uniaxial eccentric screw pump 10 will be first described, and then the drive-side connecting portion 100 and the rotor-side connecting portion 200 will be described in more detail.

[0028] <Overall structure of the single-shaft eccentric screw pump 10> As shown in Fig. 1, the uniaxial eccentric screw pump 10 is a so-called rotary positive displacement pump, and as shown in Fig. 1, a stator 20, a rotor 30, a power transmission mechanism 50, and the like are housed inside a casing 12. The casing 12 is a cylindrical metal member, and a first opening 14a is provided in a disk-shaped end stud 12a attached to one longitudinal end. A second opening 14b is provided on the outer periphery of the casing 12. The second opening 14b communicates with the interior space of the casing 12 at an intermediate portion 12d located in the longitudinal middle of the casing 12.

[0029] The first opening 14a and the second opening 14b function as the suction port and the discharge port, respectively, of the uniaxial eccentric screw pump 10. In the uniaxial eccentric screw pump 10 of this embodiment, by rotating the rotor 30 in the forward direction, the first opening 14a functions as the discharge port and the second opening 14b functions as the suction port, thereby pumping out a fluid. In addition, by rotating the rotor 30 in the reverse direction, the uniaxial eccentric screw pump 10 can pump out a fluid so that the first opening 14a functions as the suction port and the second opening 14b functions as the discharge port. Unless otherwise specified, the uniaxial eccentric screw pump 10 will be described below as operating so that the first opening 14a functions as the discharge port and the second opening 14b functions as the suction port.

[0030] The stator 20 is a component having a cylindrical external shape. The stator 20 is made of, for example, an elastic body, resin, metal, or ceramic. The material of the stator 20 is appropriately selected depending on the type and properties of the transported material (fluid) to be transported using the uniaxial eccentric screw pump 10. The stator 20 is housed inside a stator mounting portion 12b located adjacent to the first opening 14a of the casing 12. The outer diameter of the stator 20 is approximately the same as the inner diameter of the stator mounting portion 12b. Therefore, the stator 20 is mounted with its outer peripheral surface in close contact with the inner peripheral surface of the stator mounting portion 12b. The stator 20 is fixed by clamping a flange portion 20a on one end side between end studs 12a at the end of the casing 12 and attaching and tightening stay bolts 16 between the end studs 12a and the main body of the casing 12. Therefore, the stator 20 does not shift position within the stator mounting portion 12b of the casing 12. The inner peripheral surface 24 of the stator 20 has an n-thread, single-stage or multi-stage female thread shape. In this embodiment, the inner peripheral surface 24 has a two-thread, multi-stage shape as shown in Figures 1 and 2.

[0031] The rotor 30 is configured as a male-screw shaft. The rotor 30 is formed of a material such as metal or ceramic. The material of the rotor 30 is appropriately selected depending on the type and properties of the transported object (fluid). The rotor 30 has an n-1-thread single-stage or multi-stage female thread. In this embodiment, the rotor 30 has a single-thread multi-stage. The rotor 30 is a shaft (connected shaft) to which a connecting shaft 70, which will be described in detail later, is connected. The rotor 30 is connected to the connecting shaft 70 (connecting shaft) via a rotor-side connecting portion 200. The rotor 30 rotates eccentrically by power transmitted via the connecting shaft 70. The rotor 30 is formed so that its cross-sectional shape is approximately circular when viewed in cross section at any position in the longitudinal direction. The rotor 30 is inserted into the through-hole 22 formed in the stator 20 described above and is free to eccentrically rotate within the through-hole 22.

[0032] When the rotor 30 is inserted into the stator 20, the outer peripheral surface 32 of the rotor 30 and the inner peripheral surface 24 of the stator 20 come into contact at their tangent lines (seal lines). As a result, a series of independent sealed spaces called cavities 34 are formed between the inner peripheral surface 24 of the stator 20, which forms the through-holes 22, and the outer peripheral surface of the rotor 30. The cavities 34 constitute fluid transport paths 40 for transporting fluid, which is not a transport object. When the lead length L of the stator 20 or rotor 30 described above is taken as a reference length S, the fluid transport path 40 is a multi-stage (d-stage) flow path having a length d times the reference lead length S in the axial direction of the stator 20 or rotor 30.

[0033] The fluid transport path 40 extends spirally in the longitudinal direction of the stator 20 and the rotor 30. Furthermore, when the rotor 30 is rotated within the through-hole 22 of the stator 20, the fluid transport path 40 advances in the longitudinal direction of the stator 20 while rotating within the stator 20. Therefore, when the rotor 30 is rotated, a fluid is drawn into the fluid transport path 40 from one end of the stator 20, and the fluid is transported toward the other end of the stator 20 while being confined within the fluid transport path 40, and then discharged from the other end of the stator 20. That is, when the rotor 30 is rotated in the forward direction, the fluid drawn in through the second opening 14b can be pumped and discharged from the first opening 14a. Furthermore, when the rotor 30 is rotated in the reverse direction, the fluid drawn in through the first opening 14a can be discharged from the second opening 14b.

[0034] The power transmission mechanism 50 is provided to transmit power from a driver 55, such as a motor, provided outside the casing 12 to the rotor 30. The power transmission mechanism 50 has a power connection portion 52 and an eccentric rotation portion 54. The power connection portion 52 is provided in a shaft accommodating portion 12c provided at one end of the casing 12 in the longitudinal direction, more specifically, on the opposite side to where the end studs 12a and the stator mounting portion 12b are provided (hereinafter also simply referred to as the "base end side"). The eccentric rotation portion 54 is provided in an intermediate portion 12d formed between the shaft accommodating portion 12c and the stator mounting portion 12b.

[0035] The power connection portion 52 has a drive shaft 56. The drive shaft 56 is rotatably supported by two bearings 56a, 56b. The drive shaft 56 is taken out from a closed portion on the base end side of the casing 12. The drive shaft 56 is connected to a driver 55. Therefore, the drive shaft 56 can be rotated by operating the driver 55. In other words, the drive shaft 56 is a shaft that functions as an output shaft that rotates upon receiving the output of the driver 55.

[0036] A shaft seal member 60 is provided between the shaft accommodating portion 12c, where the power connection portion 52 is provided, and the intermediate portion 12d. The shaft seal member 60 is provided to provide a structure that prevents the fluid, which is the transported object, from leaking from the intermediate portion 12d side to the shaft accommodating portion 12c side. The shaft seal member 60 can be configured, for example, by a mechanical seal or a gland packing. In this embodiment, a mechanical seal is used as the shaft seal member 60. The shaft seal member 60 is attached to the drive shaft 56 (output shaft).

[0037] The eccentric rotation unit 54 is a part that connects the drive shaft 56 and the rotor 30 so as to be able to transmit power. The eccentric rotation unit 54 has a connecting shaft 70. The connecting shaft 70 is configured by a flexible shaft body. In this embodiment, the connecting shaft 70 is configured by a flexible rod. The connecting shaft 70 is connected to the drive shaft 56 at one longitudinal end (base end) via a drive-side connecting unit 100. The connecting shaft 70 is also connected to the rotor 30 at the other longitudinal end (tip end) via a rotor-side connecting unit 200. With this configuration, the eccentric rotation unit 54 can transmit the rotational power transmitted from the driver 55 via the drive shaft 56 to the rotor 30, causing the rotor 30 to rotate eccentrically.

[0038] <<Regarding the drive-side connecting portion 100>> Next, the drive-side coupling part 100 will be described. As shown in Figures 1 and 2, the drive-side coupling part 100 is a part in which the connecting shaft 70 is the first shaft and the drive shaft 56 is the second shaft, and these shafts are directly or indirectly connected so that they are connected in the axial direction. The drive-side coupling part 100 is formed by disassembling a first shaft coupling part 110 at one end (base end side) of the connecting shaft 70 and a second shaft coupling part 150 at the end (tip end side) of the drive shaft 56 in a state in which a fitting structure 180 is formed.

[0039] 2 to 4, the first shaft coupling portion 110 can be formed integrally as part of the connecting shaft 70 by processing the end of the connecting shaft 70, but in this embodiment it is formed by attaching a coupling portion constituent 112 formed separately from the connecting shaft 70 to the connecting shaft 70. The coupling portion constituent 112 includes a constituent body 114, a flange portion 116, a screw hole 118, and a seal portion 120.

[0040] The component body 114 is a cylindrical portion connected to the end of the connecting shaft 70. An insertion portion 122 is provided at the axial center of the component body 114. The insertion portion 122 is configured as a hole into which the end of the connecting shaft 70 can be inserted. The insertion portion 122 allows the end of the connecting shaft 70 to be inserted with almost no gap.

[0041] The flange portion 116 is a flange-shaped portion that expands in a direction intersecting the axial direction of the connecting shaft 70 inserted into the insertion portion 122. The flange portion 116 is provided around the entire circumference of the component body 114. The flange portion 116 is provided in the axially intermediate portion of the component body 114 so as to expand radially outward.

[0042] The screw holes 118 are holes having threads on their inner circumferential surfaces that screw into connecting bolts 170, which will be described later. The screw holes 118 are formed so as to penetrate through the flange portion 116 in the axial direction. As shown in FIGS. 4 and 8, a plurality of screw holes 118 are provided in the direction around the axis of the component main body 114. Some of the plurality of screw holes 118 are provided at positions that correspond to screw holes 162c provided in the second shaft connecting portion 150, which will be described later (hereinafter also referred to as "fastening screw holes 118a"), and the remaining ones are provided at positions that do not correspond to screw holes 162c (hereinafter also referred to as "non-fastening screw holes 118b").

[0043] The fastening screw holes 118a are used when connecting the first shaft connecting portion 110 and the second shaft connecting portion 150 with the connecting bolt 170. A plurality of fastening screw holes 118a (eight in this embodiment) are provided at approximately equal intervals around the axis of the component body 114.

[0044] The non-fastening screw hole 118b serves as a fitting release member installation portion for installing a fitting release member for releasing the fitting structure formed by the first shaft coupling portion 110 and the second shaft coupling portion 150. In this embodiment, as will be described later, the connecting bolt 170 is used as the fitting release member. Therefore, like the fastening screw hole 118a, the non-fastening screw hole 118b has a thread on its inner circumferential surface that can be threaded onto the screw shaft 170s of the connecting bolt 170. The non-fastening screw hole 118b is located at a position offset from the fastening screw hole 118a in the direction around the axis of the component body 114. In addition, multiple non-fastening screw holes 118b (two in this embodiment) are located symmetrically about the axis of the component body 114. In this embodiment, a dummy bolt 171 is inserted into the non-fastening screw hole 118b to close the hole except during disassembly.

[0045] The seal portion 120 seals the fluid so that it does not leak through the gap between the connecting shaft 70 and the insertion portion 122 provided in the component body 114. As shown in Figures 2 and 3, the seal portion 120 includes a seal member 126 and a cover member 128.

[0046] The seal member 126 is configured by, for example, an O-ring, a gasket, etc. In this embodiment, an O-ring having a diameter larger than the opening diameter of the insertion portion 122 is provided as the seal member 126. The seal member 126 is disposed so as to surround the circular opening region that forms the insertion portion 122.

[0047] The lid member 128 is a member that sandwiches the seal member 126 between itself and the end face of the component body 114. The lid member 128 is a plate-shaped member that is larger than the opening area of ​​the insertion portion 122 provided in the component body 114, and is attached so as to cover the entire opening area of ​​the insertion portion 122. The lid member 128 is fixed to the end of the connecting shaft 70 inserted into the insertion portion 122 using a lid fixing bolt 130, with the seal member 126 disposed between itself and the end face of the component body 114. As a result, the lid member 128 is fixed so as to fit along the end face of the component body 114 via the seal member 126. By attaching the lid member 128 in this manner, the opening area of ​​the insertion portion 122 is surrounded by the seal member 126, and a seal portion 120 is provided in which the seal member 126 is sandwiched between the end face of the component body 114 and the lid member 128.

[0048] The first shaft coupling part 110 is provided with the above-described component body 114 at the end of the connecting shaft 70, and is provided with a convex part 140 in which the component body 114 protrudes in the axial direction of the connecting shaft 70 from the flange part 116 toward the tip side. The convex part 140 forms a fitting structure 180 in combination with a concave part 164 of the second shaft coupling part 150, which will be described later. The convex part 140 is cylindrical in shape.

[0049] 2, 3, and 5, the second shaft coupling portion 150 is provided on the drive shaft 56, which constitutes the second shaft, in the drive-side coupling portion 100. The second shaft coupling portion 150 can be formed integrally as part of the drive shaft 56 by processing the end of the drive shaft 56, but in this embodiment, the drive shaft 56 is attached to an adapter 160 formed separately from the drive shaft 56, with a fitting structure formed between the adapter 160 and the drive shaft 56.

[0050] 1 and 2, the adapter 160 is detachably attached to the shaft sealing member 60 attached to the drive shaft 56 at a position offset toward the axial end of the drive shaft 56. As shown in FIGS. 2, 5, and 6, the adapter 160 includes a connecting portion 162, a recess 164, and a shaft fitting portion 166.

[0051] The connecting portion 162 is a portion used for connection to the flange portion 116 of the first shaft coupling portion 110. In this embodiment, the connecting portion 162 also constitutes an expanded diameter portion (adapter expanded diameter portion 162x) that expands more than the drive shaft 56 in a direction intersecting the axial direction of the drive shaft 56 (hereinafter also referred to as the "radial direction") when attached to the drive shaft 56. The connecting portion 162 has a radial size equivalent to that of the flange portion 116 of the first shaft coupling portion 110 described above. The connecting portion 162 has a connecting end surface 162a located on one axial side of the adapter 160 and a positioning end surface 162b located on the other axial side.

[0052] The connection end surface 162a is a portion that comes into surface contact with the flange portion 116 of the first shaft coupling portion 110 when the drive side coupling portion 100 is configured. The connection portion 162 has a plurality of openings (in this embodiment, 8 ) are provided at equal intervals around the axis of the adapter 160. The screw holes 162c are provided at positions corresponding to the fastening screw holes 118a provided in the flange portion 116 of the first shaft coupling portion 110.

[0053] The positioning end surface 162b is a surface that faces the shaft seal member 60 provided on the drive shaft 56 when the drive-side connecting portion 100 is configured. The shaft seal member 60 abuts against the positioning end surface 162b, and is attached in a state where it is positioned with reference to the positioning end surface 162b.

[0054] The recess 164 is a concave portion that receives at least a portion of the above-described first shaft coupling portion 110. In this embodiment, the recess 164 is configured to be able to receive and fit the protrusion 140 of the first shaft coupling portion 110. Specifically, the inner diameter of the recess 164 is approximately the same as the outer diameter of the protrusion 140, and the recess 164 has a concave shape that is recessed in the axial direction from the connection end surface 162a of the connection portion 162. The depth of the recess 164 (the length from the connection end surface 162a in the axial direction) is set to be equal to or greater than the protrusion amount of the protrusion 140 of the first shaft coupling portion 110 (the protrusion length in the axial direction from the flange portion 116). In this embodiment, taking into consideration the protrusion amount of the bolt head 168h of the adapter fixing bolt 168 that fixes the adapter 160 to the drive shaft 56 and the bolt head 130h of the lid fixing bolt 130 in the first shaft coupling portion 110, the depth of the recess 164 is set to be greater than the protrusion amount of the bolt heads 168h, 130h than the protrusion amount of the convex portion 140. With this configuration, the drive-side coupling portion 100 can couple the connecting shaft 70 to the drive shaft 56 with the connecting end surface 162a of the connecting portion 162 and the flange portion 116 in surface contact, while the recess 164 and the convex portion 140 are fitted together with a clearance fit to form a spigot structure.

[0055] The recess 164 has an inner circumferential surface 164a and a partition wall 164b that intersects with the inner circumferential surface 164a. A recess seal member 164c is provided on the inner circumferential surface 164a. The recess seal member 164c is a member that seals between the outer circumferential surface of the protrusion 140 of the first shaft coupling part 110 and the inner circumferential surface 164a when the protrusion 140 is inserted into the recess 164. The recess seal member 164c is formed by an O-ring.

[0056] The partition wall 164b is a wall surface that separates the recessed portion 164 from a shaft fitting portion 166 that is provided at a position offset from the recessed portion 164 in the axial direction of the adapter 160. As shown in FIG. 6, a bolt insertion hole 164d is provided in the partition wall 164b. The bolt insertion hole 164d is a hole for inserting an adapter fixing bolt 168 (fixing member) for fixing the adapter 160 to the drive shaft 56. The bolt insertion hole 164d extends in the axial direction of the adapter 160 and is formed so as to reach the shaft fitting portion 166 from the recessed portion 164. The bolt insertion hole 164d is provided at a position corresponding to a bolt hole 56x provided in the drive shaft 56.

[0057] 2 and 5, the bolt holes 56x are holes that open in the end face of the drive shaft 56, extend in the axial direction, and have threads formed on the inner peripheral surface. A plurality of (six in this embodiment) bolt holes 56x are provided at approximately equal intervals around the axis of the drive shaft 56. A plurality of (six in this embodiment) bolt insertion holes 164d are provided at equal intervals around the axis at positions corresponding to the bolt holes 56x thus provided in the drive shaft 56.

[0058] 6, the partition wall 164b is provided with a recessed threaded hole 164e (adapter releasing member installation portion) in addition to the bolt insertion hole 164d. The recessed threaded hole 164e extends in the axial direction of the adapter 160, similar to the bolt insertion hole 164d, and is formed so as to reach the shaft fitting portion 166 from the recess 164. A thread is formed on the inner circumferential surface of the recessed threaded hole 164e to threadably engage with the screw shaft 168s of an adapter fixing bolt 168 used to fix the adapter 160. Therefore, by inserting the adapter fixing bolt 168 into the recessed threaded hole 164e from the recess 164 side and rotating the adapter fixing bolt 168 with the screw shaft 168s threadedly engaged, the screw shaft 168s can be advanced or retreated toward the shaft fitting portion 166.

[0059] 2, the shaft fitting portion 166 is provided on the opposite side (the other axial side) of the recess 164 on one axial side of the adapter 160, with the partition wall 164b interposed therebetween. The shaft fitting portion 166 has a recessed shape in the axial direction of the adapter 160, into which the drive shaft 56 can be inserted and fitted. The shaft fitting portion 166 is configured so that the drive shaft 56 can be inserted to form a spigot structure.

[0060] The second shaft coupling portion 150 is configured in a state in which the drive shaft 56 is inserted into the shaft fitting portion 166 of the adapter 160 described above via a seal member (O-ring 163 in this embodiment) to form a fitting structure 190. The adapter 160 is fixed to the end of the drive shaft 56 by aligning the bolt insertion hole 164d with the bolt hole 56x of the drive shaft 56, and then fastening an adapter fixing bolt 168 inserted from the recess 164 into the bolt insertion hole 164d to the bolt hole 56x via a washer 167 and a circular plate 169 having a hole at a position corresponding to the bolt insertion hole 164d. By attaching the adapter 160 to the drive shaft 56 in this manner, the shaft sealing member 60 attached to the drive shaft 56 comes into contact with the positioning end surface 162b of the connecting portion 162 constituting the adapter 160. As a result, the shaft seal member 60 is fixed in a state where it is positioned in the axial direction of the drive shaft 56, with the positioning end surface 162b as a reference. In this embodiment, a mechanical seal is used, so the fixed ring and rotating ring of the mechanical seal can be positioned with being pressed against each other with an appropriate biasing force that can maintain the sliding surface pressure.

[0061] Furthermore, with the adapter fixing bolt 168 removed from the bolt insertion hole 164d and the bolt hole 56x and replaced with the recessed threaded hole 164e, the second shaft coupling portion 150 can be advanced toward the shaft fitting portion 166 by rotating the adapter fixing bolt 168. This causes the adapter fixing bolt 168 to apply a pressing force in the axial direction to the drive shaft 56, allowing the adapter 160 and the drive shaft 56 to move relative to each other in a direction that releases the fitting structure 190 between the adapter 160 and the drive shaft 56. In other words, in this embodiment, the adapter fixing bolt 168 used to secure the adapter 160 can be used as an adapter release member for releasing the fitting between the adapter 160 and the drive shaft 56.

[0062] The drive-side connecting portion 100 is configured by connecting and fitting together the above-described first shaft connecting portion 110 and second shaft connecting portion 150. Specifically, when connecting the connecting shaft 70 and the drive shaft 56, the convex portion 140 of the first shaft connecting portion 110 is inserted into the concave portion 164 of the second shaft connecting portion 150 to form a fitting structure 180. Furthermore, the flange portion 116 is placed in surface contact with the connecting portion 162, and the threaded shaft 170s of the connecting bolt 170 is inserted through and screwed into the fastening screw hole 118a provided in the flange portion 116 and the threaded hole 162c provided in the connecting portion 162, thereby connecting the first shaft connecting portion 110 and the second shaft connecting portion 150.

[0063] Furthermore, when disassembling the connecting shaft 70 and the drive shaft 56, the connecting bolt 170 is removed from the fastening screw hole 118a and the screw hole 162c in the drive-side connecting portion 100. The removed connecting bolt 170 is then fastened into the non-fastening screw hole 118b provided in the flange portion 116 of the first shaft connecting portion 110. When the connecting bolt 170 is further rotated in this state, the threaded shaft 170s of the connecting bolt 170 protrudes toward the connection portion 162 of the second shaft connecting portion 150. As a result, the threaded shaft 170s presses against the connection end surface 162a, causing the first shaft connecting portion 110 and the second shaft connecting portion 150 to move relative to each other in the axial direction so as to move away from each other, and eventually the fitting structure 180 formed by the convex portion 140 and the concave portion 164 is released. In this way, the connection and fitting structure 180 between the first shaft connection portion 110 and the second shaft connection portion 150 is released, and the drive-side connection portion 100 is disassembled into the connection shaft 70 and the drive shaft 56.

[0064] <Regarding the rotor-side connecting portion 200> Next, the rotor-side coupling part 200 will be described. The rotor-side coupling part 200 has the same commonality as the drive-side coupling part 100 in that the connecting shaft 70 serves as the first axis, as in the drive-side coupling part 100 described above, but differs in that the rotor 30 serves as the second axis. As shown in FIG. 8 , the rotor-side coupling part 200 is a part that directly or indirectly connects the connecting shaft 70 and the rotor 30 so that they are connected in the axial direction. The rotor-side coupling part 200 is formed by disassembling a first shaft coupling part 210 at the other end (tip side) of the connecting shaft 70 and a second shaft coupling part 250 at the end (tip side) of the rotor 30 in a state where a fitting structure 280 is formed. Note that in the following description, components common to the drive-side coupling part 100 described above are denoted by the same reference numerals, and detailed description thereof will be omitted. In the following description, the configuration of each part constituting the rotor-side coupling part 200 will be described while appropriately comparing it with that of the drive-side coupling part 100.

[0065] As shown in FIGS. 4 and 8 , the first shaft coupling portion 210 has substantially the same configuration as the first shaft coupling portion 110 provided on one end side (base end side) of the connecting shaft 70 described above. Specifically, the first shaft coupling portion 210 can be formed integrally as part of the connecting shaft 70 by processing the end of the connecting shaft 70; however, in this embodiment, the first shaft coupling portion 210 is configured by attaching a coupling portion constituent 212 formed separately from the connecting shaft 70 to the connecting shaft 70. Here, the coupling portion constituent 212 has the same configuration as the coupling portion constituent 112 described above in that it includes a constituent main body 114, a flange portion 116, and a screw hole 118. On the other hand, the coupling portion constituent 212 differs in configuration from the first shaft coupling portion 110 described above in that it does not include a seal portion 120. The constituent main body 114, the flange portion 116, and the screw hole 118 that constitute the coupling portion constituent 212 are the same as those of the first shaft coupling portion 110 described above, and therefore detailed description thereof will be omitted.

[0066] 8, the second shaft coupling part 250 is provided on the rotor 30 that forms the second shaft in the rotor-side coupling part 200. Like the second shaft coupling part 150 provided in the drive-side coupling part 100 described above, the second shaft coupling part 250 can be configured as an adapter or the like that is formed separately from the rotor 30 that forms the second shaft. However, in this embodiment, the second shaft coupling part 250 is formed as part of the rotor 30 by processing the end part of the rotor 30. The second shaft coupling part 250 has a connection part 262 and a recess part 264.

[0067] The connecting portion 262 is a portion used for connection to the flange portion 116 that constitutes the first shaft coupling portion 210. The connecting portion 262 has a radial size equivalent to that of the flange portion 116 of the first shaft coupling portion 210. The connecting portion 262 has a connection end surface 262a that comes into surface contact with the flange portion 116 of the first shaft coupling portion 210 when the rotor-side coupling portion 200 is configured. The connecting portion 262 has a plurality of (eight in this embodiment) screw holes 262c that are open to the connection end surface 262a and are equally spaced around the axis. The screw holes 262c are provided at positions corresponding to the fastening screw holes 118a provided in the flange portion 116 of the first shaft coupling portion 210.

[0068] The recess 264 is a concave portion that receives at least a portion of the first shaft coupling portion 210. In the present embodiment, the recess 264 is configured to receive and fit the protrusion 140 of the first shaft coupling portion 210. Specifically, the inner diameter of the recess 264 is approximately the same as the outer diameter of the protrusion 140, and the recess 264 has a concave shape that is recessed in the axial direction from the connection end surface 262a of the connection portion 262. The depth of the recess 264 (the length in the axial direction from the connection end surface 262a) is equal to or greater than the protrusion amount of the protrusion 140 at the first shaft coupling portion 210. With this configuration, the rotor-side coupling portion 200 can couple the connecting shaft 70 to the rotor 30 with the recess 264 and the protrusion 140 engaged to form a spigot structure, and with the connection end surface 262a of the connection portion 262 and the flange portion 116 in surface contact.

[0069] The rotor-side coupling portion 200 is configured by coupling and fitting the above-described first shaft coupling portion 210 and second shaft coupling portion 250. Specifically, when coupling the coupling shaft 70 and the rotor 30, the convex portion 140 of the first shaft coupling portion 210 is inserted into the concave portion 264 of the second shaft coupling portion 250 to form a fitting structure 280. Furthermore, the flange portion 116 of the first shaft coupling portion 210 is placed in surface contact with the connection portion 262 of the second shaft coupling portion 250, and the threaded shaft 170s of the connecting bolt 170 is inserted through and screwed into the fastening screw hole 118a and the threaded hole 262c provided in the connection portion 262, thereby coupling the first shaft coupling portion 210 and the second shaft coupling portion 250.

[0070] Furthermore, when disassembling the connecting shaft 70 and the rotor 30, the connecting bolt 170 is removed from the threaded hole 262c in the rotor-side connecting portion 200, and the dummy bolt 171 attached to the fastening threaded hole 118a is also removed. The removed connecting bolt 170 is then fastened to the non-fastening threaded hole 118b provided in the flange portion 116 of the first shaft connecting portion 210. When the connecting bolt 170 is further rotated in this state, the threaded shaft 170s protrudes toward the connection portion 262 of the second shaft connecting portion 250. As a result, the threaded shaft 170s presses against the connection end surface 262a, causing the first shaft connecting portion 210 and the second shaft connecting portion 250 to move relative to each other in the axial direction so as to move away from each other, and eventually the fitting structure 280 formed by the convex portion 140 and the concave portion 264 is released. In this way, the connection and fitting structure 280 of the first shaft connection portion 210 and the second shaft connection portion 250 is released, and the rotor-side connection portion 200 is disassembled into the connection shaft 70 and the rotor 30 (f).

[0071] The uniaxial eccentric screw pump 10 of this embodiment has the characteristic configuration as described above, and therefore can achieve the following effects.

[0072] (a) The uniaxial eccentric screw pump 10 of this embodiment comprises a flexible connecting shaft 70, a rotor 30 formed by a male-threaded shaft, and a stator 20 into which the rotor 30 can be inserted and whose inner circumferential surface is formed with a female thread. By forming a drive-side connecting section 100 that directly or indirectly connects the connecting shaft 70 to a drive shaft 56 that rotates in response to the output of a driving machine 55, and a rotor-side connecting section 200 that directly or indirectly connects the connecting shaft 70 to the rotor 30, the rotational power output from the driving machine 55 can be transmitted to the stator 20 via the connecting shaft 70 to drive the stator 20. Furthermore, in the single-shaft eccentric screw pump 10, the drive-side coupling portion 100 and the rotor-side coupling portion 200 are dismountably coupled to each other in a state where fitting structures 180, 280 are formed by first shaft coupling portions 110, 210 provided on a first shaft (the connecting shaft 70 in this embodiment), which constitutes one of the two shafts to be connected, and second shaft coupling portions 150, 250 provided on the drive shaft 56 or the rotor 30, which constitute the other second shaft. In this manner, in the single-shaft eccentric screw pump 10, the drive-side coupling portion 100 and the rotor-side coupling portion 200 do not simply connect the first shaft coupling portions 110, 210 and the second shaft coupling portions 150, 250 provided on the first and second shafts to be connected, but rather form fitting structures 180, 280 and are dismountably coupled to each other. Therefore, in the single-shaft eccentric screw pump 10 of this embodiment, the connecting shaft 70 can be coupled to the rotor 30 or the drive shaft 56 in a state where misalignment of the axial center is unlikely to occur. Furthermore, in the single-shaft eccentric screw pump 10 of this embodiment, the first shaft connecting portions 110, 210 and the second shaft connecting portions 150, 250 are connected after forming the fitting structures 180, 280, so that the axial positions of the first shaft and the second shaft are less likely to shift even when disassembling.

[0073] Furthermore, the uniaxial eccentric screw pump 10 is equipped with a disengagement member (connecting bolt 170 in this embodiment) for disengaging the engagement structures 180, 280, and a disengagement member installation portion (non-fastening screw hole 118b in this embodiment) for accommodating the connecting bolt 170. Therefore, when disassembling the uniaxial eccentric screw pump 10 of this embodiment into the first shaft and the second shaft, the operation of disengaging the engagement structures 180, 280 formed by the first shaft coupling portions 110, 210 and the second shaft coupling portions 150, 250 can be smoothly performed using the connecting bolt 170. Therefore, the uniaxial eccentric screw pump 10 of this embodiment can be easily disassembled as well as easily connected to the connecting shaft 70.

[0074] In the uniaxial eccentric screw pump 10 of this embodiment, both the drive-side coupling portion 100 and the rotor-side coupling portion 200 are connected in a disassemblable manner after forming the fitting structures 180, 280, but the present invention is not limited to this. The uniaxial eccentric screw pump 10 may be configured such that either the drive-side coupling portion 100 or the rotor-side coupling portion 200 is connected without forming the fitting structure 180, 280.

[0075] Furthermore, although the uniaxial eccentric screw pump 10 of this embodiment is equipped with both a disengagement member for releasing the fitting structures 180, 280 and a disengagement member installation portion for receiving the connecting bolt 170, the present invention is not limited to this. The uniaxial eccentric screw pump 10 may also be configured without either the disengagement member for releasing the fitting structures 180, 280 or the disengagement member installation portion for receiving the connecting bolt 170. For example, in this embodiment, the uniaxial eccentric screw pump 10 is configured to include a disengagement member by utilizing the connecting bolt 170 as the disengagement member. However, a bolt that is not a component of the uniaxial eccentric screw pump 10 and that is prepared separately from the connecting bolt 170, or another part or tool, can also be attached to the non-fastening screw hole 118b as the disengagement member.

[0076] In addition, in this embodiment, an example has been shown in which the connecting shaft 70 is the first shaft in the present invention, and the drive shaft 56 or the rotor 30 is the second shaft, but a configuration may also be used in which the connecting shaft 70 is the second shaft, and the drive shaft 56 or the rotor 30 is the first shaft. Furthermore, in this embodiment, the configuration exemplified as being provided on the first shaft and the configuration exemplified as being provided on the second shaft may be interchanged.

[0077] (b) In the uniaxial eccentric screw pump 10 of the above-described embodiment, the connecting bolt 170 has a threaded shaft 170s, and the non-fastening screw hole 118b is configured as a hole provided with a screw that screws into the threaded shaft 170s. Because the uniaxial eccentric screw pump 10 has this configuration, the connecting bolt 170, which constitutes the engagement release member, can be firmly installed by the threading force generated between the connecting bolt 170 and the non-fastening screw hole 118b, which constitutes the engagement release member installation portion. Furthermore, by rotating the threaded shaft 170s, which constitutes the engagement release member, while threading the threaded shaft 170s into the non-fastening screw hole 118b, which constitutes the engagement release member installation portion, the threaded shaft 170s can be advanced and retreated in the axial direction, and the force generated thereby can be utilized to release the engagement structures 180, 280. Therefore, in the uniaxial eccentric screw pump 10, the force required to release the fitting at the fitting structures 180, 280 can be sufficiently exerted by threading the screw shaft 170s into the non-fastening screw hole 118b.

[0078] Although the uniaxial eccentric screw pump 10 of this embodiment has the configuration as described in (b) above, the present invention is not limited thereto, and the uniaxial eccentric screw pump 10 may not have the configuration as described in (b) above. Furthermore, although the uniaxial eccentric screw pump 10 of this embodiment has the screw-receiving portion forming the fitting release member installation portion configured as a hole provided with a screw thread that threadably engages with the screw shaft 170s, the present invention is not limited thereto. For example, the uniaxial eccentric screw pump 10 may have the screw-receiving portion forming the fitting release member installation portion configured as a recessed portion formed by a non-through hole or recess provided with a screw thread that threadably engages with the screw shaft 170s. In this case, the screw-receiving portion is used to fix a fitting release member other than the screw shaft 170s, which will be described later.

[0079] In the uniaxial eccentric screw pump 10 of this embodiment, the connecting bolt 170 having a head in addition to the screw shaft 170s is used as the engagement release member, but the present invention is not limited to this. For example, the uniaxial eccentric screw pump 10 can also be configured with a shaft body having the screw shaft 170s but no head.

[0080] (c) In the single-shaft eccentric screw pump 10 of this embodiment, the fitting structures 180, 280 can be released by a release operation that involves a separating operation that separates the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250 in a direction along the axial direction of the connecting shaft 70. Furthermore, the non-fastening screw hole 118b is provided so that the screw shaft 170s can advance and retreat in the axial direction of the connecting shaft 70. Therefore, in the single-shaft eccentric screw pump 10, by advancing the screw shaft 170s, a pressing force is applied to the second shaft coupling portion 150, 250 in a direction away from the first shaft coupling portion 110, 210, causing the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250 to move apart relatively, thereby releasing the fitting structure.

[0081] Although the uniaxial eccentric screw pump 10 of this embodiment has the configuration as described in (c) above, the present invention is not limited thereto, and the pump may be configured without the configuration as described in (c). Furthermore, although the fitting structures 180, 280 of this embodiment can be disengaged only by a separating action in the axial direction of the connecting shaft 70, the present invention is not limited thereto. For example, the fitting structures 180, 280 can be disengaged by a rotational action around the axis of the connecting shaft 70 or a movement in a direction intersecting the axis of the connecting shaft 70, in addition to or instead of a separating action in the axial direction of the connecting shaft 70.

[0082] (d) In the above-described uniaxial eccentric screw pump 10, the fitting structures 180, 280 are configured by a clearance fit. This allows the fitting structures 180, 280 of the uniaxial eccentric screw pump 10 to be easily disassembled and assembled.

[0083] In this embodiment, the fitting structures 180, 280 are configured by a clearance fit, but the present invention is not limited to this. For example, either or both of the fitting structures 180, 280 may be fitted by a method other than a clearance fit.

[0084] (e) In the uniaxial eccentric screw pump 10 of this embodiment, the first shaft coupling portion 110, 210 is provided with a non-fastening screw hole 118b, and by advancing the screw shaft 170s attached to the non-fastening screw hole 118b while in contact with the second shaft coupling portion 150, 250, the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250 can be moved relatively in the direction of releasing the fitting structure 180, 280. As a result, the uniaxial eccentric screw pump 10 can convert the rotational force that rotates the screw shaft 170s into a force in the axial direction of the connecting shaft 70 and utilize it to release the fitting structure 180, 280.

[0085] Although the uniaxial eccentric screw pump 10 of this embodiment has the configuration described in (e) above, the present invention is not limited thereto, and the pump may be configured without the configuration described in (e) above. Furthermore, the uniaxial eccentric screw pump 10 illustrated in this embodiment has a configuration in which the rotational force around the axis of the screw shaft 170s is converted by the action of the screw into a thrust force in the axial direction of the screw shaft 170s, thereby outputting a force for disengaging the engagement and disengaging the engagement structures 180, 280. However, the present invention is not limited thereto. For example, instead of the screw shaft 170s, a shaft body without threads or another member having a shaft-like portion may be used as the engagement release member, and the non-fastening screw hole 118b may also be a through-hole without threads. In such a configuration, the uniaxial eccentric screw pump 10 can release the engagement structures 180, 280 by inserting a shaft body or the like used as an engagement release member instead of the screw shaft 170s into the through hole used as an engagement release member installation portion instead of the non-fastening screw hole 118b, and in this state applying a pressing force in the axial direction to the aforementioned shaft body.

[0086] (f) In the single-shaft eccentric screw pump 10 of this embodiment, a flange portion 116 extending in a direction intersecting the axial direction of the connecting shaft 70 is provided on the connecting shaft 70 as part of the first shaft coupling portion 110, 210, and the drive-side coupling portion 100 and the rotor-side coupling portion 200 have the flange portion 116 in surface contact with the second shaft coupling portion 150, 250, and connecting bolts 170 are attached across the flange portion 116 and the second shaft coupling portion 150, 250, thereby coupling the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250. As a result, the single-shaft eccentric screw pump 10 can withstand moments acting in the axial and axial rotational directions due to eccentric rotation at the surface contact portions between the flange portion 116 constituting the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250. Therefore, the single-shaft eccentric screw pump 10 is less likely to experience rattle at the connection between the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250. Furthermore, even if the connecting shaft 70 rotates eccentrically as the single-shaft eccentric screw pump 10 is driven, the connection between the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250 is less likely to experience breakage due to fretting wear or stress concentration.

[0087] Although the single-shaft eccentric screw pump 10 of this embodiment has the configuration as described above in (f), the present invention is not limited thereto, and the pump may not have the configuration as described above in (f). Furthermore, the single-shaft eccentric screw pump 10 of this embodiment has been described as having the connecting shaft 70 as the first shaft and the flange portion 116 as the first shaft coupling portion 110, 210, but the present invention is not limited thereto. The single-shaft eccentric screw pump 10 may have the drive shaft 56 or the rotor 30 as the first shaft, with one or both of them being provided with a flange portion 116. Furthermore, the single-shaft eccentric screw pump 10 of this embodiment has been described as having the flange portion 116 as the first shaft coupling portion 110, 210, and the flange portion 116 is coupled to the end face of the second shaft coupling portion 150, 250 in surface contact with the end face of the second shaft coupling portion 150, 250, but the present invention is not limited thereto. The single-shaft eccentric screw pump 10 can also be provided with a flange 116 similar to the flange 116 on the second shaft coupling parts 150, 250, and the flange 116 can be coupled to the second shaft coupling parts 150, 250 by making surface contact with the flange 116. Furthermore, although the present embodiment illustrates an example in which the flange 116 is provided as part of the first shaft coupling parts 110, 210, the single-shaft eccentric screw pump 10 can also be configured without the flange 116, by providing, for example, another configuration for avoiding fretting wear and stress concentration.

[0088] (g) As described above, the uniaxial eccentric screw pump 10 of this embodiment includes a flexible connecting shaft 70, a rotor 30 formed by a male-threaded shaft body, and a stator 20 into which the rotor 30 can be inserted and whose inner circumferential surface is formed with a female thread. The uniaxial eccentric screw pump 10 has a drive-side connecting portion 100 formed by directly or indirectly connecting a first shaft connecting portion 110, 210 provided on the connecting shaft 70 to a second shaft connecting portion 150, 250 provided on the drive shaft 56 that rotates upon receiving output from the driving machine 55. The uniaxial eccentric screw pump 10 is also characterized in that a shaft seal member 60 is provided on the drive shaft 56, and the second shaft connecting portion 150 is configured by attaching an adapter 160 that is detachable from the drive shaft 56 to the drive shaft 56 at a position that is offset toward the axial end of the drive shaft 56 from the shaft seal member 60, and the adapter 160 has an adapter enlarged portion 162x that bulges out more than the drive shaft 56 in a direction intersecting the axial direction of the drive shaft 56.

[0089] Because the uniaxial eccentric screw pump 10 is configured as described in (g) above, the seal member 60 can be positioned relative to the drive shaft 56 by attaching the adapter 160 to the drive shaft 56. Furthermore, by removing the adapter 160 from the drive shaft 56, the seal member 60 can be removed from the drive shaft 56 and maintenance can be performed without the need for extensive work such as removing the drive shaft 56 from the driver 55. Therefore, in the uniaxial eccentric screw pump 10, the connecting shaft 70 and the drive shaft 56 can be connected via the adapter 160 at the drive-side connecting portion 100, and maintenance of the seal member 60 can be easily performed.

[0090] Although the single-shaft eccentric screw pump 10 of this embodiment has the configuration as described above in (g), the present invention is not limited thereto, and the pump may be configured without the configuration as described above in (g). In addition, the single-shaft eccentric screw pump 10 has been described as having the second shaft coupling portion 150, 250, in which the second shaft coupling portion 150 is configured by attaching the adapter 160 having the above-described configuration to the drive shaft 56, and the second shaft coupling portion 250 is configured without the adapter 160. However, the present invention is not limited thereto. Instead of or in addition to the second shaft coupling portion 150, the second shaft coupling portion 250 may also be configured with an adapter 160, similar to the second shaft coupling portion 150 described above. Furthermore, similar to the adapter expanded diameter portion 162x of the second shaft coupling portion 150, the second shaft coupling portion 250 may also be configured with an expanded diameter portion that expands more than the rotor 30 in a direction intersecting the axial direction of the rotor 30.

[0091] (h) In the single-shaft eccentric screw pump 10 of this embodiment, the shaft sealing member 60 is positioned in the axial direction of the drive shaft 56 by abutting against the adapter enlarged diameter portion 162x at the second shaft coupling portion 150. With this configuration, the single-shaft eccentric screw pump 10 can accurately position the shaft sealing member 60 using the adapter enlarged diameter portion 162x as a reference. As a result, the single-shaft eccentric screw pump 10 of this embodiment does not require measures to position the shaft sealing member 60, such as using a dedicated positioning jig when installing the shaft sealing member 60, making assembly easier.

[0092] Although the uniaxial eccentric screw pump 10 of this embodiment has the configuration as described in (h) above, the present invention is not limited to this, and the uniaxial eccentric screw pump 10 may not have the configuration as described in (h) above. For example, the uniaxial eccentric screw pump 10 may be configured so that the shaft sealing member 60 can be positioned by another member instead of the adapter enlarged diameter portion 162x.

[0093] (i) In the uniaxial eccentric screw pump 10 of the present embodiment described above, the second shaft coupling portion 150, 250 couples the adapter 160 and the drive shaft 56 together while forming the fitting structure 190. The second shaft coupling portion 150 is provided with an adapter fixing bolt 168 as an adapter release member that releases the fitting structure 190, and a recessed threaded hole 164e as an adapter release member installation portion for accommodating the adapter fixing bolt 168. Because of this configuration, the uniaxial eccentric screw pump 10 can be coupled and disassembled without causing misalignment of the axial positions of the adapter 160 and the drive shaft 56. Furthermore, because the uniaxial eccentric screw pump 10 includes the adapter fixing bolt 168 and the recessed threaded hole 164e, the coupling and disassembly of the adapter 160 and the drive shaft 56 can be performed smoothly. Therefore, the uniaxial eccentric screw pump 10 of the present embodiment can be easily coupled to and disassembled from the adapter 160 and the drive shaft 56.

[0094] Although the uniaxial eccentric screw pump 10 of this embodiment has the configuration as described in (i) above, the present invention is not limited to this, and it is also possible for the pump to not have the configuration as described in (i) above. The uniaxial eccentric screw pump 10 has both the adapter fixing bolt 168 as an adapter release member that releases the fitting structure 190, and the recessed threaded hole 164e as an adapter release member installation portion for accommodating the adapter fixing bolt 168, but the present invention is not limited to this, and for example, it is also possible for the pump to not have the adapter fixing bolt 168, and for the fitting structure 190 to be released by attaching another bolt that is not part of the uniaxial eccentric screw pump 10 to the recessed threaded hole 164e as an adapter release member.

[0095] (j) In the uniaxial eccentric screw pump 10 of the above-described embodiment, the adapter fixing bolt 168 includes a threaded shaft 168s, and the recessed threaded hole 164e includes a thread that threadably engages with the threaded shaft 168s. Because the uniaxial eccentric screw pump 10 is configured in this manner, the adapter fixing bolt 168 can be firmly installed due to the threading force generated between the adapter fixing bolt 168 and the recessed threaded hole 164e. Furthermore, by rotating the threaded shaft 168s while threading it into the recessed threaded hole 164e, the threaded shaft 168s can be advanced and retreated in the axial direction, and the resulting force can be utilized to release the fitting structure 190. Therefore, in the uniaxial eccentric screw pump 10, the threaded engagement between the threaded shaft 168s and the recessed threaded hole 164e can fully exert the force required to release the fitting structure 190.

[0096] Although the uniaxial eccentric screw pump 10 of this embodiment has the configuration described in (j) above, the present invention is not limited thereto, and the uniaxial eccentric screw pump 10 may also be configured without the configuration described in (j) above. For example, the uniaxial eccentric screw pump 10 may employ an unthreaded shaft or another member having a shaft-like portion as the adapter releasing member instead of the threaded shaft 168s, and an unthreaded through-hole may serve as the adapter releasing member installation portion instead of the recessed threaded hole 164e. In such a configuration, the uniaxial eccentric screw pump 10 can release the fitting structure 190 by inserting a shaft or the like used as the adapter releasing member into the through-hole used as the adapter releasing member installation portion and applying a pressing force axially to the shaft in this state.

[0097] (k) In the single-shaft eccentric screw pump 10 of the above-described embodiment, the adapter 160 has a recess 164 that receives at least a portion of the first shaft coupling portion 110, and an adapter fixing bolt 168 that fixes the adapter 160 to the drive shaft 56 is provided inside the recess 164. The single-shaft eccentric screw pump 10 is configured in this way so that the recess 164, which is provided to receive the first shaft coupling portion 110, can also be used as a space for accommodating the adapter fixing bolt 168, and therefore the components of the adapter 160 that are exposed to the outside can be kept to a minimum.

[0098] Although the uniaxial eccentric screw pump 10 of this embodiment has the configuration as described in (k) above, the present invention is not limited to this, and the uniaxial eccentric screw pump 10 may not have the configuration as described in (k) above. For example, the uniaxial eccentric screw pump 10 may have a configuration in which the adapter fixing bolt 168 is disposed outside the recess 164, rather than inside the recess 164.

[0099] (l) In the uniaxial eccentric screw pump 10 of the present embodiment described above, the second shaft coupling portion 150 couples the adapter 160 and the drive shaft 56 together while forming a fitting structure 190, and the adapter fixing bolt 168 removed from the fixed portion between the adapter 160 and the drive shaft 56 can be used as an adapter release member for releasing the fitting structure 190 at the second shaft coupling portion 150. With this configuration, when disassembling the adapter 160 and the drive shaft 56, the adapter fixing bolt 168 removed from the fixed portion can be used as an adapter release member for releasing the fitting structure 190. Therefore, the uniaxial eccentric screw pump 10 does not require an adapter release member separate from the adapter fixing bolt 168, which can be expected to reduce the number of parts, resulting in cost savings and improved workability.

[0100] Although the uniaxial eccentric screw pump 10 of this embodiment has the configuration as described above in (l), the present invention is not limited to this, and it is also possible for the pump to not have the configuration as described above in (l). That is, instead of using the adapter fixing bolt 168 as the adapter release member, the uniaxial eccentric screw pump 10 can be provided with a member such as a bolt different from the adapter fixing bolt 168 as the adapter release member.

[0101] (m) In the uniaxial eccentric screw pump 10 of this embodiment, the adapter fixing bolt 168 has a threaded shaft 168s, and the adapter 160 has a recessed threaded hole 164e that threadably engages with the threaded shaft 168s. By threading the adapter fixing bolt 168, which has been removed from the fixing point between the adapter 160 and the drive shaft 56, into the recessed threaded hole 164e and advancing it toward the drive shaft 56, the threaded shaft 168s comes into direct contact with the drive shaft 56, and the adapter 160 and the drive shaft 56 can be moved relative to each other in a direction that releases the fitting structure 190 at the second shaft coupling portion 150. Because the uniaxial eccentric screw pump 10 is configured in this manner, the force generated by rotating and advancing the threaded shaft 168s can be utilized to release the fitting structure 190.

[0102] Although the uniaxial eccentric screw pump 10 of this embodiment has the configuration as described in (m) above, the present invention is not limited to this, and it is also possible for the pump to not have the configuration as described in (m) above.

[0103] (n) The uniaxial eccentric screw pump 10 of the present embodiment described above is configured so that the inside of the recess 164 is liquid-tight. This prevents the uniaxial eccentric screw pump 10 from deteriorating the inside of the recess 164 due to the fluid flowing into the inside of the recess 164, or from corroding the components disposed inside the recess 164 due to the fluid.

[0104] Although the uniaxial eccentric screw pump 10 of this embodiment has the configuration as described above in (n), the present invention is not limited to this, and the uniaxial eccentric screw pump 10 may not have the configuration as described above in (n). That is, the uniaxial eccentric screw pump 10 may have a configuration in which the recess 164 is not liquid-tight but allows fluid to flow in and out. In this case, it is preferable that the uniaxial eccentric screw pump 10 is configured so that the recess 164 is easy to clean or so that the fluid that flows into the recess 164 is smoothly discharged from the recess 164, thereby preventing the fluid from accumulating inside the recess 164.

[0105] (o) The uniaxial eccentric screw pump 10 of this embodiment has a connection part constituent 112, 212 provided at the end of the connecting shaft 70, and the first shaft connection part 110, 210 is formed by fixing the connection part constituent 112, 212 to the connecting shaft 70 in a state where the end of the connecting shaft 70 is inserted into an insertion part 122 provided in the connection part constituent 112, 212. Furthermore, the connection part constituent 112 is provided with a seal part 120 that seals a gap between the insertion part 122 and the connecting shaft 70 inside the recess 164. By configuring the uniaxial eccentric screw pump 10 in this way, it is possible to prevent the fluid from flowing into the inside of the recess 164 through a gap formed between the insertion part 122 provided in the connection part constituent 112 and the connecting shaft 70. As a result, the uniaxial eccentric screw pump 10 can prevent the fluid from deteriorating inside the recess 164 and the components arranged inside the recess 164 from being corroded by the fluid.

[0106] Although the single-shaft eccentric screw pump 10 of this embodiment has the configuration as described above in (o), the present invention is not limited thereto, and the single-shaft eccentric screw pump 10 may not have the configuration as described above in (o). That is, while the single-shaft eccentric screw pump 10 has been described as having the seal unit 120 provided on the connection unit constituent 112 that constitutes the first shaft connection unit 110, the present invention is not limited thereto, and the single-shaft eccentric screw pump 10 may have a configuration without the seal unit 120. Note that, in the case of such a configuration, the absence of the seal unit 120 increases the likelihood of fluid flowing into the recess 164. Therefore, if the seal unit 120 is not provided, the single-shaft eccentric screw pump 10 may be configured to make the recess 164 easy to clean or to smoothly discharge fluid that has flowed into the recess 164 from the recess 164, thereby preventing fluid from accumulating therein.

[0107] (p) The above-described single-shaft eccentric screw pump 10 merely illustrates one embodiment of the present invention, and the configuration can be modified as appropriate without departing from the spirit of the present invention. For example, instead of the non-fastening screw hole 118b, or in addition to the non-fastening screw hole 118b, the single-shaft eccentric screw pump 10 can be provided with a disengagement member installation portion that accepts insertion of a disengagement member into the gap between the first shaft coupling portions 110, 210 and the second shaft coupling portions 150, 250.

[0108] (q) More specifically, the uniaxial eccentric screw pump 10 may be configured such that a groove is provided between the first shaft connecting portions 110, 210 and the second shaft connecting portions 150, 250 as a fitting release member installation portion.

[0109] By configuring the uniaxial eccentric screw pump 10 as described above in (p) or (q), it becomes possible to insert a disengaging member into the gap between the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250 to release the fitting structures 180, 280. For example, as described above in (q), a disengaging member installation portion for installing a disengaging member may be provided between the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250 using a groove or the like, and a tool with a flat tip such as a crowbar or flat-head screwdriver may be inserted into this groove as a disengaging member, thereby making it possible to release the fitting structures 180, 280 formed by the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250. In addition, the fitting structure 180, 280 formed by the first shaft connecting portion 110, 210 and the second shaft connecting portion 150, 250 can be made disengageable using a tool that is configured to have a pair of operating pieces that can be inserted between the first shaft connecting portion 110, 210 and the second shaft connecting portion 150, 250 as an engagement release member, and that can expand the gap between the pair of operating pieces by applying an external force by turning a screw, etc., or a tool that has a configuration similar to a gear puller.

[0110] Furthermore, in this embodiment, the connecting bolt 170 is used as the engagement release member, the non-fastening screw hole 118b that screws into the connecting bolt 170 is used as the engagement release member installation portion, and the engaging structures 180, 280 can be released by rotating the connecting bolt 170 while the two are screwed together, using the driving force of the connecting bolt 170. However, the present invention is not limited to this. For example, a screw-receiving portion formed of a recess such as a screw hole or a hole with a screw, similar to the non-fastening screw hole 118b, may be provided as the engagement release member installation portion, and the engaging structures 180, 280 may be released by inserting an eyebolt into the screw-receiving portion and pulling it with a chain block, for example.

[0111] The present invention is not limited to the above-described embodiments and variations thereof, and other embodiments may be possible within the scope of the claims. The components of the above-described embodiments may be arbitrarily selected and combined. Furthermore, any component of the embodiments may be arbitrarily combined with any component described in the Summary of the Invention or any component embodying any component described in the Summary of the Invention. The present invention intends to obtain rights to these as well through amendments to this application or divisional applications, etc. [Industrial Applicability]

[0112] The present invention can be suitably used in all fluid discharge systems for pumping and discharging fluid. [Explanation of symbols]

[0113] 10: Single-shaft eccentric screw pump 20: Stator 30: Rotor 55: Drive unit 56: Drive shaft 60: Shaft seal material 70:Connection shaft 100: Drive side connection part 110: First shaft connection part 112:Connection component 116: Flange part 118b: Non-fastening screw hole (unfastening member installation portion) 120: Seal part 122: Insertion part 150:Second shaft connection part 160: Adapter 162x: Enlarged adapter part 164: Recess 164e: Recessed screw hole (adapter release member installation part) 168: Adapter fixing bolt (adapter release part) 168s: screw shaft 170: Connecting bolt (uncoupling member) 170s: screw shaft 180: Interlocking structure 190: Interlocking structure 200: Rotor side connection part 210: First shaft connection part 212:Connection component 250:Second shaft connection part 280: Interlocking structure

Claims

1. a flexible connecting shaft; a rotor formed by a male-threaded shaft; a stator into which the rotor can be inserted and whose inner circumferential surface is formed with a female screw; It is equipped with a drive mechanism, By forming a drive-side coupling section that directly or indirectly couples the connecting shaft to an output shaft that rotates upon receiving the output of the drive machine, and a rotor-side coupling section that directly or indirectly couples the connecting shaft to the rotor, the rotational power output from the drive machine can be transmitted to the rotor via the connecting shaft to drive the rotor, At least one of the drive-side connecting portion and the rotor-side connecting portion is disassemblably connected in a state where a fitting structure is formed by a first shaft connecting portion provided on a first shaft that is one of the two shafts to be connected and a second shaft connecting portion provided on a second shaft that is the other of the two shafts to be connected, a disengaging member for disengaging the engagement structure, and a disengaging member installation portion for installing the disengaging member, The engagement release member has a threaded shaft, the fitting release member installation portion is provided with a screw receiving portion formed of a hole or a recess provided with a screw that threads onto the screw shaft, the screw receiving portion is provided in one of the first shaft connecting portion and the second shaft connecting portion, a screw shaft attached to the screw receiving portion that is in contact with the other of the first shaft connecting portion and the second shaft connecting portion, and that is advanced in such a state that the first shaft connecting portion and the second shaft connecting portion can be moved relatively in a direction to release the fitting structure.

2. the fitting structure can be released from the fitting state by a release operation that involves a separation operation that separates the first shaft connecting portion and the second shaft connecting portion in a direction along the axial direction of the connecting shaft, The screw receiving portion is provided so that the screw shaft can advance and retreat in the axial direction of the connecting shaft, 2. The uniaxial eccentric screw pump according to claim 1, wherein the separating operation is performed by advancing the screw shaft.

3. 3. The uniaxial eccentric screw pump according to claim 1, wherein the fitting structure is a clearance fit.

4. the connecting shaft is a first shaft, and a flange portion extending in a direction intersecting the axial direction of the connecting shaft is provided on the connecting shaft as part or all of the first shaft connecting portion, 4. The uniaxial eccentric screw pump according to claim 1, wherein at least one of the drive-side connecting portion and the rotor-side connecting portion connects the first shaft connecting portion and the second shaft connecting portion by abutting the flange portion against the second shaft connecting portion provided on the second shaft connected to the connecting shaft and attaching a bolt across the flange portion and the second shaft connecting portion.

5. 5. The uniaxial eccentric screw pump according to claim 1, wherein the fitting release member installation portion accepts insertion of the fitting release member into the gap between the first shaft connecting portion and the second shaft connecting portion.

6. 5. The uniaxial eccentric screw pump according to claim 4, wherein the disengagement member installation portion forms a groove between the first shaft connecting portion and the second shaft connecting portion.

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