JP7822601B2 - Single-axis eccentric screw pump - Google Patents

Description

The present invention relates to a single-shaft eccentric screw pump.

Conventionally, in a single-shaft eccentric screw pump such as that disclosed in Patent Document 1 below, the rotational power output from the output shaft of the driver can be transmitted to the rotor via a connecting shaft such as a flexible rod. The connecting portion (connecting structure) between 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.

In a single-shaft eccentric screw pump, such as that disclosed in Patent Document 2 below, the threaded shaft at the tip of the flexible rod is inserted into and screwed into a shaft insertion hole in the rotor or drive shaft. Furthermore, the end of the flexible rod serves as a flange that makes surface contact with the end face of the rotor or drive shaft. By joining the two shafts in this way, it is possible to join the two shafts without any rattle.

Patent No. 3629100 Patent No. 5724096

The inventors therefore investigated 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 the drive unit, in a manner that allows for disassembly even when the pump is large, and that minimizes misalignment of the axial center. As a result, they discovered that by connecting the flexible connecting shaft (first shaft) and the connected second shaft by attaching bolts to the flanges while forming an interlocking structure, even large pumps can be connected in a manner that allows for disassembly and minimizes misalignment of the axial center.

However, we have come to the realization that if the connecting shaft (first shaft) is connected to a second shaft such as a rotor or output shaft while the above-mentioned fitting structure is formed, it may be difficult to disassemble 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, there is a possibility that 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) becomes tilted in this way, it may get caught in the connection portion, making it difficult to disassemble the connecting shaft (first shaft) and the second shaft.

The present invention aims to provide a single-shaft eccentric screw pump that can connect the connecting shaft to the shaft of at least one of the rotor and driver without causing misalignment of the axial center, and that can be smoothly disconnected.

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

In the single-shaft eccentric screw pump of the present invention, one of the first and second shafts is used as the connecting shaft, and the other is used as the rotor or 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 output shaft in a manner that is less likely to cause misalignment of the axial center. 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 form a fitting structure, misalignment of the axial center of the first and second shafts is less likely to occur even when disassembling.

Furthermore, the single-shaft eccentric screw pump of the present invention is equipped with at least one of a disengagement member for disengaging the engagement 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 and second shafts, the disengagement member can be used to smoothly disengage the engagement 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 easily connected to the connecting shaft.

(2) The above-described uniaxial eccentric screw pump of the present invention may be characterized in that the engagement release member has a threaded shaft, and the engagement release member installation portion has a screw receiving portion with a screw that threads onto the threaded shaft.

With this configuration, the single-shaft eccentric screw pump of the present invention can firmly install a member equipped with a threaded shaft that forms the disengagement member due to the threading force generated between the member and the threaded receiving portion that forms the disengagement member installation portion. Furthermore, by threading the threaded shaft that forms the disengagement member into the threaded receiving portion that forms the disengagement member installation 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 engagement structure. Therefore, the single-shaft eccentric screw pump of the present invention can fully apply the force required to release the engagement in the engagement structure by threading the threaded shaft that forms the disengagement member into the threaded receiving portion that forms the disengagement member installation portion.

(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.

With this configuration, the single-shaft eccentric screw pump of the present invention can perform a separation operation to separate the first shaft connecting portion and the second shaft connecting 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 and advancing the screw shaft to release the fitting structure.

(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 while in contact with the other of the first shaft connecting portion and the second shaft connecting portion.

By adopting this configuration, the single-shaft eccentric screw pump of the present invention can apply the force generated by advancing the screw shaft attached to the screw receiving portion provided on one of the first and second shaft connecting portions to the other connecting portion. This allows 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.

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

By adopting this configuration, the single-shaft eccentric screw pump of the present invention can easily disassemble and assemble the fitting structure formed by the first shaft connecting portion and the second shaft connecting portion.

(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, 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 connected to the first 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.

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 using bolts while the flange portion provided on the connecting shaft, which is the first shaft and constitutes the first shaft connecting portion, is 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, the surface contact portion between the flange portion of the first shaft connecting portion and the second shaft connecting portion can withstand moments acting in the axial and axial rotational directions due to eccentric rotation. Therefore, in the single-shaft eccentric screw pump of the present invention, rattle is less likely 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 when the connecting shaft rotates eccentrically as the pump is driven, fretting wear and damage due to stress concentration are less likely to occur at the connection portion between the first shaft connecting portion and the second shaft connecting portion.

(7) The above-described 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.

Because the single-shaft eccentric screw pump of the present invention is configured in this way, it is easy to insert a disengagement member into the gap between the first shaft connecting portion and the second shaft connecting portion to disengage the engagement structure.

(8) The above-described 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.

With this configuration, the single-shaft eccentric screw pump of the present invention can release the engagement structure formed by the first shaft connecting portion and the second shaft connecting portion by inserting the engagement release member into the groove that forms the engagement release member installation portion.

This invention provides a single-shaft eccentric screw pump that can connect the connecting shaft to the shaft of at least one of the rotor and driver without causing misalignment of the axial center, and can also be smoothly disconnected.

1 is a cross-sectional view of a single-shaft eccentric screw pump according to an embodiment of the present invention. 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. FIG. 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. 2 is an exploded perspective view showing a drive shaft and a first shaft coupling portion of the uniaxial eccentric screw pump shown in FIG. 1 . FIG. 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. 2 is a front view of the adapter viewed from the positioning end face side. FIG. 10 is a diagram showing a front view of a component body constituting a first connecting portion. 2 is an enlarged view of the rotor-side coupling portion and its vicinity of the uniaxial eccentric screw pump shown in FIG. 1 . FIG.

Next, a single-shaft 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 explanation, the overall structure of the single-shaft eccentric screw pump 10 will first be described, and then the drive-side connecting portion 100 and the rotor-side connecting portion 200 will be described in more detail.

<<Overall structure of the uniaxial eccentric screw pump 10>>
As shown in Fig. 1, the uniaxial eccentric screw pump 10 is a so-called rotary 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.

The first opening 14a and the second opening 14b function as the suction port and discharge port, respectively, of the eccentric screw pump 10. In this embodiment, the eccentric screw pump 10 is capable of pumping fluid by rotating the rotor 30 in the forward direction, with the first opening 14a functioning as the discharge port and the second opening 14b functioning as the suction port. Furthermore, the eccentric screw pump 10 is capable of pumping fluid by rotating the rotor 30 in the reverse direction, with the first opening 14a functioning as the suction port and the second opening 14b functioning as the discharge port. Hereinafter, unless otherwise specified, the eccentric screw pump 10 will be described as operating with the first opening 14a functioning as the discharge port and the second opening 14b functioning as the suction port.

The stator 20 is a cylindrical component. It is made of, for example, an elastic material, resin, metal, or ceramic. The material of the stator 20 is selected appropriately depending on the type and properties of the transported material (fluid) being transported using the eccentric screw pump 10. The stator 20 is housed inside the stator mounting portion 12b, which is 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 secured by clamping the flange portion 20a on one end of the casing 12 between the end stud 12a and the main body of the casing 12, and then fastening the stay bolt 16 between the end stud 12a and the main body of the casing 12. As a result, 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, it has a two-thread, multi-stage shape as shown in Figures 1 and 2.

The rotor 30 is composed of a male-threaded shaft. The rotor 30 is made of materials 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 the connecting shaft 70, described in detail below, is connected. The rotor 30 is connected to the connecting shaft 70 (connecting shaft) via the rotor-side connecting portion 200. The rotor 30 rotates eccentrically due to the power transmitted via the connecting shaft 70. The rotor 30 is formed so that its cross-sectional shape is approximately circular when viewed 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.

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). This creates a series of independent, sealed spaces called cavities 34 between the inner peripheral surface 24 of the stator 20, which defines the through-holes 22, and the outer peripheral surface of the rotor 30. The cavities 34 form a fluid transport path 40 for transporting fluids, which are not transported objects. When the lead length L of the stator 20 or rotor 30 described above is taken as the reference length S, the fluid transport path 40 is a multi-stage (d-stage) flow path with a length d times the reference lead length S in the axial direction of the stator 20 or rotor 30.

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 moves in the longitudinal direction of the stator 20 while rotating within the stator 20. Therefore, when the rotor 30 is rotated, fluid is drawn into the fluid transport path 40 from one end of the stator 20, and this fluid is then transported toward the other end of the stator 20 while confined within the fluid transport path 40, where it is discharged from the other end of the stator 20. In other words, 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.

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 longitudinal end of the casing 12, more specifically, on the opposite side from where the end stud 12a and stator mounting portion 12b are provided (hereinafter also referred to simply as the "base end"). 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.

The power connection section 52 has a drive shaft 56. The drive shaft 56 is rotatably supported by two bearings 56a and 56b. The drive shaft 56 extends to the outside from the closed portion at the base end of the casing 12. The drive shaft 56 is connected to the 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.

A shaft seal member 60 is provided between the shaft accommodating section 12c, where the power connection section 52 is provided, and the intermediate section 12d. The shaft seal member 60 is provided to ensure that the fluid being transported does not leak from the intermediate section 12d side to the shaft accommodating section 12c side. The shaft seal member 60 can be composed of, for example, 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).

The eccentric rotation unit 54 connects the drive shaft 56 and the rotor 30 so that power can be transmitted between them. The eccentric rotation unit 54 has a connecting shaft 70. The connecting shaft 70 is configured as a flexible shaft. In this embodiment, the connecting shaft 70 is configured as 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.

<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 serves as a first shaft and the drive shaft 56 serves as a second shaft, and these shafts are directly or indirectly connected so as to be 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) of the connecting shaft 70 and a second shaft coupling part 150 at the end (tip end) of the drive shaft 56 in a state in which a fitting structure 180 is formed.

As shown in Figures 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. However, 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.

The component body 114 is a cylindrical portion that connects 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 end of the connecting shaft 70 can be inserted into the insertion portion 122 with almost no gap.

The flange portion 116 is a flange-shaped portion that extends 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 extend radially outward.

The screw hole 118 is a hole with a thread on its inner surface that screws into the connecting bolt 170, which will be described later. The screw hole 118 is formed so as to pass through the flange portion 116 in the axial direction. As shown in Figures 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 screw holes 118 are provided at positions that correspond to the 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 the screw holes 162c (hereinafter also referred to as "non-fastening screw holes 118b").

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. Multiple fastening screw holes 118a (eight in this embodiment) are provided at approximately equal intervals around the axis of the component body 114.

The non-fastening screw hole 118b serves as a disengagement member installation portion for installing a disengagement member for disengaging the engagement structure formed by the first shaft coupling portion 110 and the second shaft coupling portion 150. In this embodiment, as described below, the connecting bolt 170 is utilized as the disengagement member. Therefore, like the fastening screw hole 118a, the non-fastening screw hole 118b has a thread on its inner surface that can be threaded onto the screw shaft 170s of the connecting bolt 170. The non-fastening screw hole 118b is located offset from the fastening screw hole 118a in the direction around the axis of the component body 114. Multiple non-fastening screw holes 118b (two in this embodiment) are provided at positions symmetrical 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 cover the hole except during disassembly.

The sealing portion 120 seals the gap between the insertion portion 122 provided in the component body 114 and the connecting shaft 70 to prevent fluid leakage. As shown in Figures 2 and 3, the sealing portion 120 includes a sealing member 126 and a lid member 128.

The sealing member 126 is formed, for example, from an O-ring or a gasket. In this embodiment, an O-ring with a diameter larger than the opening diameter of the insertion portion 122 is provided as the sealing member 126. The sealing member 126 is arranged to surround the circular opening area that forms the insertion portion 122.

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. This secures the lid member 128 so that it fits along the end face of the component body 114 via the seal member 126. Attaching the lid member 128 in this manner provides a seal portion 120 in which the seal member 126 is sandwiched between the end face of the component body 114 and the lid member 128, while the opening area of the insertion portion 122 is surrounded by the seal member 126.

The first shaft coupling part 110 is provided with the aforementioned component body 114 at the end of the connecting shaft 70, and is provided with a convex part 140 where 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.

As shown in Figures 2, 3, and 5, the second shaft coupling portion 150 is provided on the drive shaft 56, which forms 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, forming a fitting structure.

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

The connecting portion 162 is a portion used for connecting 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.

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 ( eight in this embodiment) screw holes 162c that open into the connection end surface 162a and are equally spaced around the axis of the adapter 160. The screw holes 162c are provided at positions that correspond to the fastening screw holes 118a provided in the flange portion 116 of the first shaft coupling portion 110.

The positioning end surface 162b is the surface that faces the shaft seal member 60 attached to the drive shaft 56 when the drive-side coupling 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 based on the positioning end surface 162b.

The recess 164 is a concave portion that receives at least a portion of the first shaft coupling portion 110 described above. In this embodiment, the recess 164 is configured 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 in the axial direction from the connection end surface 162a) is set to be equal to or greater than the protrusion amount of the protrusion 140 on 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. Because of 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 in surface contact with the flange portion 116, while the recess 164 and the convex portion 140 are fitted together with a clearance fit to form a spigot structure.

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 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.

The partition wall 164b is a wall surface that separates the recess 164 from the shaft fitting portion 166, which is located offset from the recess 164 in the axial direction of the adapter 160. As shown in FIG. 6, the partition wall 164b has a bolt insertion hole 164d. The bolt insertion hole 164d is a hole for inserting an adapter fixing bolt 168 (fixing member) that fixes the adapter 160 to the drive shaft 56. The bolt insertion hole 164d extends in the axial direction of the adapter 160, extending from the recess 164 to the shaft fitting portion 166. The bolt insertion hole 164d is located at a position corresponding to the bolt hole 56x located in the drive shaft 56.

As shown in Figures 2 and 5, the bolt holes 56x are holes that open at 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 bolt holes 56x (six in this embodiment) are provided at approximately equal intervals around the axis of the drive shaft 56. A plurality of bolt insertion holes 164d (six in this embodiment) are provided at equal intervals around the axis at positions corresponding to the bolt holes 56x thus provided on the drive shaft 56.

As shown in FIG. 6 , the partition wall 164b is provided with a recessed threaded hole 164e (adapter release member mounting portion) in addition to the bolt insertion hole 164d. Like the bolt insertion hole 164d, the recessed threaded hole 164e extends in the axial direction of the adapter 160 and is formed to extend from the recess 164 to the shaft fitting portion 166. The inner surface of the recessed threaded hole 164e is threadedly formed with threads that engage with the screw shaft 168s of the 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.

As shown in FIG. 2, the shaft fitting portion 166 is provided on the opposite side (the other axial side) of the adapter 160 from the recess 164 on one axial side thereof, via the partition wall 164b described above. 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 designed to allow the drive shaft 56 to be inserted so as to form a spigot structure.

The second shaft coupling portion 150 is configured by inserting the drive shaft 56 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 secured 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. The adapter fixing bolt 168 is inserted from the recess 164 into the bolt insertion hole 164d and fastened to the bolt hole 56x via a washer 167 and a circular plate 169 having a hole corresponding to the bolt insertion hole 164d. By attaching the adapter 160 to the drive shaft 56 in this manner, the shaft seal member 60 attached to the drive shaft 56 abuts against the positioning end surface 162b of the connecting portion 162 that constitutes 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, using 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 by being pressed against each other with an appropriate biasing force that maintains sliding surface pressure.

In addition, with the adapter fixing bolt 168 of the second shaft coupling portion 150 removed from the bolt insertion hole 164d and the bolt hole 56x and replaced with the recessed threaded hole 164e, the adapter fixing bolt 168 can be rotated to advance toward the shaft fitting portion 166. This causes the adapter fixing bolt 168 to apply a pressing force in the axial direction to the drive shaft 56, moving the adapter 160 and the drive shaft 56 relative to each other in a direction that releases the fitting structure 190 between them. 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 to release the fit between the adapter 160 and the drive shaft 56.

The drive-side connecting portion 100 is constructed by fitting and connecting the first shaft connecting portion 110 and the second shaft connecting portion 150 described above. 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 first shaft connecting portion 110 and the second shaft connecting portion 150 can be connected by placing the flange portion 116 in surface contact with the connecting portion 162 and inserting and threading the threaded shaft 170s of the connecting bolt 170 through the fastening screw hole 118a provided in the flange portion 116 and the threaded hole 162c provided in the connecting portion 162.

When disassembling the connecting shaft 70 and drive shaft 56, the connecting bolt 170 is removed from the fastening threaded hole 118a and the threaded hole 162c in the drive-side connecting portion 100. 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 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, eventually disengaging the fitting structure 180 formed by the convex portion 140 and the concave portion 164. 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.

<Regarding the rotor-side connecting portion 200>
Next, the rotor-side coupling part 200 will be described. The rotor-side coupling part 200 shares the same commonality with the drive-side coupling part 100 described above 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 directly or indirectly connects the connecting shaft 70 and the rotor 30 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 to form a fitting structure 280. 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.

As shown in Figures 4 and 8, the first shaft coupling portion 210 has a configuration substantially similar to the first shaft coupling portion 110 provided at one end (base end) 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 formed 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 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 body 114, flange portion 116, and 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.

As shown in FIG. 8 , the second shaft coupling portion 250 is provided on the rotor 30, which forms the second shaft of the rotor-side coupling portion 200. Like the second shaft coupling portion 150 provided on the drive-side coupling portion 100 described above, the second shaft coupling portion 250 can be configured as an adapter formed separately from the rotor 30, which forms the second shaft. However, in this embodiment, the second shaft coupling portion 250 is formed as part of the rotor 30 by machining the end of the rotor 30. The second shaft coupling portion 250 has a connection portion 262 and a recess 264.

The connection portion 262 is a portion used for connecting to the flange portion 116 that constitutes the first shaft coupling portion 210. The connection portion 262 has a radial size equivalent to that of the flange portion 116 of the first shaft coupling portion 210. The connection 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 connection portion 262 has multiple (eight in this embodiment) screw holes 262c that open into the connection end surface 262a and are equally spaced around the axis. The screw holes 262c are located at positions that correspond to the fastening screw holes 118a located in the flange portion 116 of the first shaft coupling portion 210.

The recess 264 is a concave portion that receives at least a portion of the first shaft coupling portion 210. In this 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 axially 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 on the first shaft coupling portion 210. Because of 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 mated to form a spigot structure, and with the connection end surface 262a of the connection portion 262 in surface contact with the flange portion 116.

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

To disassemble the connecting shaft 70 and 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 installed in the fastening threaded hole 118a is 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 separate from each other, eventually disengaging the fitting structure 280 formed by the convex portion 140 and the concave portion 264. In this way, the connection and fitting structure 280 between 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 connecting shaft 70 and the rotor 30.

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

(a) The single-shaft eccentric screw pump 10 of this embodiment comprises a flexible connecting shaft 70, a rotor 30 constructed from a male-threaded shaft body, and a stator 20 into which the rotor 30 can be inserted and whose inner surface is formed with a female thread.By forming a drive side connecting portion 100 that directly or indirectly connects the connecting shaft 70 to a drive shaft 56 that rotates in response to the output of the driver 55, and a rotor side connecting portion 200 that directly or indirectly connects the connecting shaft 70 to the rotor 30, the rotational power output from the driver 55 can be transmitted to the stator 20 via the connecting shaft 70 to drive it. 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 a first shaft coupling portion 110, 210 provided on a first shaft (connecting shaft 70 in this embodiment), which constitutes one of the two shafts to be connected, and a second shaft coupling portion 150, 250 provided on the drive shaft 56 or rotor 30, which constitutes the other second shaft, in a state where they form a fitting structure 180, 280. In this way, 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 the fitting structure 180, 280 and then dismountably coupled. 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 misalignment of the axial centers of the first and second shafts is unlikely to occur even when disassembling.

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 and second shafts, the operation of disengaging the engagement structures 180, 280 formed by the first shaft connecting portions 110, 210 and the second shaft connecting 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 connected to the connecting shaft 70.

In the single-shaft eccentric screw pump 10 of this embodiment, both the drive-side connecting portion 100 and the rotor-side connecting portion 200 are connected in a disassemblable manner with fitting structures 180, 280 formed thereon, but the present invention is not limited to this. The single-shaft eccentric screw pump 10 may also be configured so that either the drive-side connecting portion 100 or the rotor-side connecting portion 200 is connected without forming the fitting structure 180, 280.

Furthermore, while the uniaxial eccentric screw pump 10 of this embodiment is equipped with both a disengagement member for releasing the engagement structures 180, 280 and a disengagement member installation portion for mounting 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 engagement structures 180, 280 or the disengagement member installation portion for mounting 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 part of the uniaxial eccentric screw pump 10 and that is prepared separately from the connecting bolt 170, or other parts or tools, etc., can also be attached to the non-fastening screw hole 118b as the disengagement member.

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

(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 with a screw that threads onto 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 due to the threading force generated between it 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, the uniaxial eccentric screw pump 10 can fully apply the force required to release the engagement between the engagement structures 180 and 280 by threading the screw shaft 170s and the non-fastening screw hole 118b.

Note that while the single-shaft eccentric screw pump 10 of this embodiment has the configuration shown in (b) above, the present invention is not limited to this, and it is also possible for the pump to not have the configuration shown in (b) above. Furthermore, while the single-shaft eccentric screw pump 10 of this embodiment has the screw receiving portion forming the disengaging member installation portion formed by a hole equipped with a screw that threads onto the screw shaft 170s, the present invention is not limited to this. For example, the single-shaft eccentric screw pump 10 may have the screw receiving portion forming the disengaging member installation portion formed by a recess formed by a non-through hole or recess that threads onto the screw shaft 170s. In this case, the screw receiving portion is used to secure a disengaging member other than the screw shaft 170s, as described below.

In the single-shaft eccentric screw pump 10 of this embodiment, the connecting bolt 170, which has a head in addition to the screw shaft 170s, serves as the engagement release member, but the present invention is not limited to this. For example, the single-shaft eccentric screw pump 10 could also be configured with a shaft body that has a screw shaft 170s but no head.

(c) In the single-shaft eccentric screw pump 10 of this embodiment, the fitting structures 180, 280 can be disengaged by a release operation that involves a separation operation that separates the first shaft coupling portions 110, 210 and the second shaft coupling portions 150, 250 in 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 portions 150, 250 in a direction away from the first shaft coupling portions 110, 210, causing the first shaft coupling portions 110, 210 and the second shaft coupling portions 150, 250 to move apart relatively, thereby disengaging the fitting structure.

Note that, although the single-shaft eccentric screw pump 10 of this embodiment has the configuration as described in (c) above, the present invention is not limited to this, and it is also possible for the pump 10 not to have the configuration as described in (c) above. Furthermore, in this embodiment, the mating structures 180, 280 can be disengaged simply by a separating action in the direction along the axial direction of the connecting shaft 70, but the present invention is not limited to this. For example, the mating 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 direction along the axial direction of the connecting shaft 70.

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

In this embodiment, an example is shown in which the mating 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 mating structures 180, 280 may be fitted by a method other than a clearance fit.

(e) In the single-shaft eccentric screw pump 10 of this embodiment, a non-fastening screw hole 118b is provided in the first shaft connecting portion 110, 210, and the screw shaft 170s attached to the non-fastening screw hole 118b can be advanced in contact with the second shaft connecting portion 150, 250 to move the first shaft connecting portion 110, 210 and the second shaft connecting portion 150, 250 relative to each other in a direction that releases the fitting structure 180, 280. As a result, the single-shaft 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 this force to release the fitting structure 180, 280.

While 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). The uniaxial eccentric screw pump 10 illustrated in this embodiment is configured to convert the rotational force around the axis of the screw shaft 170s by the action of the screw into a thrust force in the axial direction of the screw shaft 170s, thereby outputting a force for disengagement and disengaging the engagement structures 180, 280. However, the present invention is not limited thereto. For example, a shaft without threads or another member having a shaft-like portion may be used as the engagement release member instead of the screw shaft 170s, and the non-fastening screw hole 118b may also be a through-hole without threads. With this configuration, the uniaxial eccentric screw pump 10 can release the fitting structures 180, 280 by inserting a shaft or the like used as the engagement release member in place of the screw shaft 170s into the through-hole used as the engagement release member installation portion in place of the non-fastening screw hole 118b, and applying a pressing force in the axial direction to the shaft in this state.

(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 connect the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250 by attaching a connecting bolt 170 across the flange portion 116 and the second shaft coupling portion 150, 250 while bringing the flange portion 116 into surface contact with 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 connecting portion 110, 210 and the second shaft connecting 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 connecting portion 110, 210 and the second shaft connecting portion 150, 250 is less likely to experience damage due to fretting wear or stress concentration.

While the single-shaft eccentric screw pump 10 of this embodiment has the configuration described in (f) above, the present invention is not limited thereto, and the pump may not have the configuration described in (f) above. Furthermore, while the single-shaft eccentric screw pump 10 of this embodiment has been illustrated as having the connecting shaft 70 as the first shaft and the flange portion 116 as constituting the first shaft coupling portion 110, 210, 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, while the single-shaft eccentric screw pump 10 of this embodiment has been illustrated as having the flange portion 116 as constituting the first shaft coupling portion 110, 210, and the flange portion 116 is connected to the end face of the second shaft coupling portion 150, 250 in surface contact with the second shaft coupling portion 150, 250, the present invention is not limited thereto. The single-shaft eccentric screw pump 10 can also have a flange 116 similar to the flange 116 provided on the second shaft connecting portion 150, 250, with the flange 116 being connected to this by surface contact. Also, in this embodiment, the flange 116 is provided as part of the first shaft connecting portion 110, 210, but the single-shaft eccentric screw pump 10 can also be configured without the flange 116, for example by providing another structure to avoid fretting wear and stress concentration.

(g) As described above, the single-shaft eccentric screw pump 10 of this embodiment comprises a flexible connecting shaft 70, a rotor 30 constructed from a male-threaded shaft body, and a stator 20 into which the rotor 30 can be inserted and whose inner surface is formed into a female-threaded shape, and 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 a drive shaft 56 that rotates in response to the output of 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 a detachable adapter 160 to the drive shaft 56 at a position offset toward the axial end of the drive shaft 56 from the shaft seal member 60, and the adapter 160 has an adapter enlarged diameter portion 162x that bulges out more than the drive shaft 56 in a direction intersecting the axial direction of the drive shaft 56.

Since the uniaxial eccentric screw pump 10 is configured as described above in (g), 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, the uniaxial eccentric screw pump 10 allows the connecting shaft 70 and drive shaft 56 to be connected via the adapter 160 at the drive-side connecting portion 100, and maintenance of the seal member 60 can be easily performed.

While the single-shaft eccentric screw pump 10 of this embodiment has the configuration described above in (g), the present invention is not limited to this, and the pump may be configured without the configuration described above in (g). In addition, the single-shaft eccentric screw pump 10 has been described as having the second shaft coupling 150 formed by attaching the adapter 160 described above to the drive shaft 56, while the second shaft coupling 250 is configured without the adapter 160. However, the present invention is not limited to this. Instead of or in addition to the second shaft coupling 150, the second shaft coupling 250 may also be configured with an adapter 160, similar to the second shaft coupling 150 described above. Furthermore, similar to the adapter enlarged diameter portion 162x of the second shaft coupling 150, the second shaft coupling 250 may also be configured with an enlarged diameter portion that bulges outward from the rotor 30 in a direction intersecting the axial direction of the rotor 30.

(h) In the single-shaft eccentric screw pump 10 of this embodiment, the shaft seal 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. Because of this configuration, the single-shaft eccentric screw pump 10 can accurately position the shaft seal 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 seal member 60, such as using a dedicated positioning jig when installing the shaft seal member 60, making assembly easier.

Note that while the uniaxial eccentric screw pump 10 of this embodiment has the configuration described in (h) above, the present invention is not limited to this, and it is also possible for the pump to not have the configuration described in (h) above. For example, the uniaxial eccentric screw pump 10 can be configured so that the shaft seal member 60 can be positioned using another member instead of the adapter enlarged diameter portion 162x.

(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, forming a fitting structure 190. The second shaft coupling portion 150 is equipped 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 mounting the adapter fixing bolt 168. Because of this configuration, the uniaxial eccentric screw pump 10 can be connected 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 is equipped with the adapter fixing bolt 168 and the recessed threaded hole 164e, the operation of releasing the fitting structure 190 between 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 disassembled as well as connected to the adapter 160 and the drive shaft 56.

Note that while the uniaxial eccentric screw pump 10 of this embodiment has the configuration 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 described in (i) above. The uniaxial eccentric screw pump 10 is equipped with both 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. However, the present invention is not limited to this, and for example, it is also possible for the pump to not have an adapter fixing bolt 168, and instead to attach another bolt that is not part of the uniaxial eccentric screw pump 10 to the recessed threaded hole 164e as an adapter release member to release the fitting structure 190.

(j) In the uniaxial eccentric screw pump 10 of the present embodiment described above, the adapter fixing bolt 168 is equipped with a threaded shaft 168s, and the recessed threaded hole 164e is equipped with 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 force generated thereby can be utilized to release the fitting structure 190. Therefore, the uniaxial eccentric screw pump 10 is able to fully apply the force required to release the fitting structure 190 by threading the threaded shaft 168s into the recessed threaded hole 164e.

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

(k) In the single-shaft eccentric screw pump 10 of the present embodiment described above, 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 so that the recess 164, which is provided to receive the first shaft coupling portion 110, can also be used as space to accommodate the adapter fixing bolt 168, thereby minimizing the components of the adapter 160 that are exposed to the outside.

Note that, although the uniaxial eccentric screw pump 10 of this embodiment has the configuration described in (k) above, the present invention is not limited to this, and it is also possible for the pump to not have the configuration 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.

(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, forming a fitting structure 190. The adapter fixing bolt 168 removed from the fixed point between the adapter 160 and the drive shaft 56 can be used as an adapter release member for releasing the fitting structure 190 in the second shaft coupling portion 150. By configuring the uniaxial eccentric screw pump 10 in this manner, when disassembling the adapter 160 and the drive shaft 56, the adapter fixing bolt 168 removed from the fixed point 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 result in, for example, a reduction in the number of parts, resulting in cost savings and improved workability.

Note that while the uniaxial eccentric screw pump 10 of this embodiment has the configuration described in (l) above, the present invention is not limited to this, and it is also possible for the pump to not have the configuration described in (l) above. In other words, rather than using the adapter fixing bolt 168 as the adapter release member, the uniaxial eccentric screw pump 10 can be configured with a bolt or other member different from the adapter fixing bolt 168 as the adapter release member.

(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 threads onto the threaded shaft 168s. By threading the adapter fixing bolt 168, which has been removed from the fixed 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 in 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.

Note that the uniaxial eccentric screw pump 10 of this embodiment has the configuration described in (m) above, but the present invention is not limited to this, and it is also possible for the pump to not have the configuration described in (m) above.

(n) The uniaxial eccentric screw pump 10 of the present embodiment described above is configured so that the interior of the recess 164 is liquid-tight. This prevents the uniaxial eccentric screw pump 10 from having fluid flow into the interior of the recess 164, causing deterioration within the interior of the recess 164, or from having components arranged within the interior of the recess 164 corroded by the fluid.

Note that while the uniaxial eccentric screw pump 10 of this embodiment has the configuration described in (n) above, the present invention is not limited to this, and it is also possible for the pump to not have the configuration described in (n) above. That is, the uniaxial eccentric screw pump 10 may have a configuration in which the recess 164 is not liquid-tight, but rather allows fluid to flow in and out. In this case, it is preferable for the uniaxial eccentric screw pump 10 to be configured so that the recess 164 is easy to clean, or so that fluid that has flowed into the recess 164 is smoothly discharged from the recess 164, thereby making it less likely for fluid to stagnate inside the recess 164.

(o) The single-shaft eccentric screw pump 10 of this embodiment has a connection part constituent 112, 212 provided at the end of the connecting shaft 70. 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 the insertion part 122 provided on the connection part constituent 112, 212. The connection part constituent 112 is also provided with a seal part 120 that seals the gap between the insertion part 122 and the connecting shaft 70 inside the recess 164. By configuring the single-shaft eccentric screw pump 10 in this manner, it is possible to prevent fluid from flowing into the inside of the recess 164 through the gap formed between the insertion part 122 provided on the connection part constituent 112 and the connecting shaft 70. This makes it possible for the single-shaft eccentric screw pump 10 to prevent deterioration of the fluid inside the recess 164 and corrosion of the components arranged inside the recess 164 by the fluid.

While the single-shaft eccentric screw pump 10 of this embodiment has the configuration described in (o) above, the present invention is not limited to this, and the pump may not have the configuration described in (o) above. In other words, while the single-shaft eccentric screw pump 10 has been described as having a seal 120 on the connection component 112 that constitutes the first shaft connection 110, the present invention is not limited to this, and the pump may be configured without the seal 120. With this configuration, the absence of the seal 120 increases the likelihood of fluid flowing into the recess 164. Therefore, if the seal 120 is not provided, the single-shaft eccentric screw pump 10 should be configured to make the recess 164 easy to clean, or to allow fluid that has flowed into the recess 164 to be smoothly discharged from the recess 164, thereby preventing fluid from accumulating within the recess 164.

(p) The above-described single-shaft eccentric screw pump 10 is merely an example of 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 equipped with a disengagement member installation portion that accepts insertion of a disengagement member into the gap between the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250.

(q) More specifically, the single-shaft eccentric screw pump 10 may be configured so that a groove is provided between the first shaft connecting portion 110, 210 and the second shaft connecting portion 150, 250 as an installation portion for the disengagement member.

By configuring the uniaxial eccentric screw pump 10 as described above in (p) and (q), it becomes possible to insert a disengagement member into the gap between the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250 to release the engagement structure 180, 280. For example, as described above in (q), a disengagement member installation portion for installing a disengagement member can 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 the engagement structure 180, 280 formed by the first shaft coupling portion 110, 210 and the second shaft coupling portion 150, 250 can be released by inserting a flat-tipped tool such as a crowbar or flathead screwdriver into this groove as a disengagement member. In addition, the fitting structures 180, 280 formed by the first shaft connecting portions 110, 210 and the second shaft connecting portions 150, 250 can be released using a tool configured to expand the gap between the pair of working pieces by applying an external force, such as by turning a screw, or a tool configured similar to a gear puller.

In addition, in this embodiment, the connecting bolt 170 serves as the engagement release member, and the non-fastening screw hole 118b that screws into the connecting bolt 170 serves as the engagement release member installation portion. The engagement structures 180, 280 can be released using the thrust of the connecting bolt 170 generated by rotating the connecting bolt 170 while the two are threaded together. However, the present invention is not limited to this. For example, a screw receiving portion consisting of a recess such as a threaded 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 engagement structures 180, 280 may be released by inserting an eyebolt into the screw receiving portion and pulling it with a chain block, for example.

The present invention is not limited to the above-described embodiments and variations, and other embodiments may be possible within the scope of the claims, based on the teachings and spirit of the invention. 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 that embodies any component described in the Summary of the Invention. We intend to obtain rights to these as well through amendments to this application or divisional applications, etc.

The present invention can be suitably used in all fluid discharge systems for pumping and discharging fluids.

DESCRIPTION OF SYMBOLS 10: Uniaxial eccentric screw pump 20: Stator 30: Rotor 55: Driver 56: Drive shaft 60: Shaft seal member 70: Connecting shaft 100: Drive side connecting portion 110: First shaft connecting portion 112: Connecting portion constituent body 116: Flange portion 118b: Non-fastening screw hole (fitting release member installation portion)
120: Sealing portion 122: Insertion portion 150: Second shaft connecting portion 160: Adapter 162x: Adapter enlarged diameter portion 164: Recess 164e: Recessed screw hole (adapter release member installation portion)
168: Adapter fixing bolt (adapter release member)
168s: screw shaft 170: connecting bolt (disengagement member)
170s: screw shaft 180: fitting structure 190: fitting structure 200: rotor side connecting portion 210: first shaft connecting portion 212: connecting portion constituent body 250: second shaft connecting portion 280: fitting structure

Claims (6)

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