Uniaxial eccentric screw pump

Abstract

[Problem] To provide a uniaxial eccentric screw pump with which an interference or a clearance between a rotor and a stator can be easily adjusted, and which can be automated. [Solution] This uniaxial eccentric screw pump 1 comprises an input shaft 60 rotated by the power of a drive machine, a rotor 5 connected to the input shaft 60 in an eccentrically rotatable manner, a joint section 9 that connects the input shaft 60 and the rotor 5 directly or indirectly via a joint shaft 7, and a stator 12 into which the rotor 5 can be inserted. The outer diameter of the rotor 5 and / or the inner diameter of an inner hole 12a of the stator 12 can be formed so as to decrease from one end toward the other end, and / or the amount of eccentricity of the rotor can be changed. The input shaft 60, the joint shaft 7, and / or the joint section 9 is provided with an expansion / contraction mechanism 50 that causes the rotor 5 to move toward and away from the stator 12 by expanding and contracting in the axial direction.

Description

Uniaxial Eccentric Screw Pump

[0001] The present invention relates to a uniaxial eccentric screw pump. More specifically, for example, it relates to a uniaxial eccentric screw pump capable of adjusting the tightening allowance or clearance between a rotor and a stator according to the volume change due to the temperature change of a stator or according to the wear of the stator.

[0002] Conventionally, a uniaxial eccentric screw pump is known in which a male screw type rotor is inserted into the inner hole of a female screw type stator, and the fluid sucked in from the suction port is discharged from the discharge port when the rotor rotates (for example, Patent Document 1).

[0003] The uniaxial eccentric screw pump described in Patent Document 1 is formed such that the outer diameter of the rotor decreases and the inner diameter of the inner hole of the stator decreases as it goes from one corresponding end portion of the rotor and the stator to the other end portion. It is provided with a moving mechanism for relatively moving the stator in the direction of the central axis of the inner hole with respect to the rotor. Further, the moving mechanism constituting the uniaxial eccentric screw pump described in Patent Document 1 includes a moving casing provided with the stator, a fixed casing provided with the rotor, and a screw portion connecting the moving casing and the fixed casing to each other. By rotating the moving casing in the screw direction of the screw portion, the stator is relatively moved in the direction of the central axis of the inner hole with respect to the rotor. Thereby, the invention described in Patent Document 1 above is supposed to adjust the tightening allowance or clearance (simply, also collectively referred to as tightening allowance, etc. for both) between the rotor and the stator...

[0004] Japanese Patent No. 5320849

[0005] By the way, in recent years, in the uniaxial eccentric screw pump as described in Patent Document 1 above, there are demands for simply adjusting the tightening allowance or the like between the rotor and the stator and for automation in the adjustment of the tightening allowance or the like. However, the uniaxial eccentric screw pump described in Patent Document 1 cannot fully satisfy these demands.

[0006] Therefore, the present invention aims to provide a single-screw eccentric pump that allows for simple adjustment of the overlap or gap between the rotor and stator, and also enables automation.

[0007] (1) The single-screw eccentric pump of the present invention, provided to solve the above-mentioned problems, comprises an input shaft that rotates by the power of a drive machine, a rotor that is eccentrically rotatable with respect to the input shaft and is composed of a male screw-type shaft body, a joint portion that connects the input shaft and the rotor directly or indirectly via a joint shaft, and a stator formed in the shape of a female screw through which the rotor can be inserted, wherein either or both of the outer diameter of the rotor and the inner diameter of the inner bore of the stator can be formed to decrease from one end to the other, or the amount of eccentricity of the rotor can be changed, and at least one of the input shaft, the joint shaft, and the joint portion is provided with an extension / retraction mechanism that moves the rotor closer to and further away from the stator by extending or retracting in the axial direction.

[0008] The single-screw eccentric pump of the present invention is designed so that either the outer diameter of the rotor and / or the inner diameter of the inner bore of the stator are formed to decrease from one end to the other, or the eccentricity of the rotor is changed, or both. Therefore, the single-screw eccentric pump of the present invention does not require the rotor or stator to be replaced even if the rotor and stator change in volume due to temperature changes or wear occurs, and the overlap or gap (collectively referred to as overlap, etc.) of the rotor and stator can be easily adjusted.

[0009] Furthermore, the single-screw pump of the present invention, through its telescopic mechanism, allows the rotor to move closer to and further away from the stator by extending or retracting at least one of the input shaft, joint shaft, and joint portion (hereinafter also referred to as the input shaft, etc.), thus facilitating adjustments such as the overlap between the rotor and stator. In addition, the single-screw pump of the present invention, through its telescopic mechanism, allows the rotor to move closer to and further away from the stator, so that adjustments such as the overlap between the rotor and stator can be easily made without changing the position of the fluid intake port or discharge piping.

[0010] (2) In the single-screw eccentric pump of the present invention as described above, the input shaft or the joint shaft, or both thereof, comprises an outer shaft having a hollow hole formed along the axial direction and an inner shaft inserted through the hollow hole and movable relative to the outer shaft along the axial direction, and the telescopic mechanism comprises an adjustment member that changes the relative positional relationship of the inner shaft and the outer shaft in the axial direction, and the input shaft or the joint shaft, or both thereof, is telescopically extended or retracted by moving the inner shaft and the outer shaft relative to each other via the adjustment member.

[0011] The single-screw pump of the present invention, by having such a configuration, allows the input shaft and the like to be configured as a nested structure (also referred to as a double-cylinder structure) of an inner shaft and an outer shaft. Therefore, the single-screw pump of the present invention allows the inner shaft to be moved relative to the outer shaft. Furthermore, since the single-screw pump of the present invention is equipped with an adjustment member that changes the relative positional relationship between the inner shaft and the outer shaft, the input shaft and the like can be easily extended and retracted by moving the inner shaft and the outer shaft relative to each other in the axial direction using the adjustment member.

[0012] (3) The single-screw eccentric pump of the present invention described above is preferably characterized in that it is provided with a locking mechanism that allows the relative positional relationship between the inner shaft and the outer shaft to be changed when the lock is released, and that fixes the inner shaft and the outer shaft so that they cannot move relative to each other when the lock is released.

[0013] The single-screw pump of the present invention, with this configuration, can fix the inner shaft and outer shaft, which have been moved relative to each other by the adjustment member, in a predetermined position. Therefore, the single-screw pump of the present invention can maintain a state in which the tightening allowance of the rotor and stator, etc., is adjusted, and thus can stably discharge liquid.

[0014] (4) In the single-screw eccentric pump of the present invention as described above, the adjustment member is preferably disposed between the inner shaft and the outer shaft, suppresses relative movement of the inner shaft and the outer shaft along the axial direction, and is detachably provided on at least one of the inner shaft and the outer shaft, so that the amount of relative movement of the inner shaft and the outer shaft in the axial direction can be changed by attaching or detaching the adjustment member.

[0015] The single-screw pump of the present invention has an adjustment member positioned between the inner shaft and the outer shaft, which suppresses the relative movement of the inner shaft and the outer shaft along the axial direction. Furthermore, the single-screw pump of the present invention has the adjustment member detachably provided on at least one of the inner shaft and the outer shaft. Therefore, the single-screw pump of the present invention allows the distance between the inner shaft and the outer shaft to be adjusted by attaching or detaching the adjustment member, thereby changing the relative movement of the inner shaft and the outer shaft. As a result, the single-screw pump of the present invention allows for easy adjustment of the rotor and stator tension, etc.

[0016] Here, the adjustment member may be, for example, a spacer member that can be positioned between the inner shaft and the outer shaft. Furthermore, by preparing adjustment members (spacer members) of multiple lengths along the axial direction of the input shaft, for example, the relative position of the inner shaft and the outer shaft can be selectively changed according to the length of the adjustment member. In addition, the adjustment member can be attached in various ways, such as by clamping (gripping) it from the outer circumference, or by fixing the locking part described above, so that the adjustment member is sandwiched from both sides by the inner shaft and the outer shaft along the axial direction.

[0017] (5) The single-screw eccentric pump of the present invention described above is preferably characterized in that the adjustment member is made of an elastic material.

[0018] The single-screw pump of the present invention, with this configuration, allows the adjustment member to be elastically expanded and contracted, making it easy to adjust the overlap between the rotor and stator. Here, a spring or the like can be preferably used as the elastic member. In this way, by using a spring or the like as the elastic member, the single-screw pump of the present invention can automatically change the relative position of the rotor and stator, thus enabling the automation of adjustments such as the overlap between the rotor and stator. Furthermore, for example, if either or both of the rotor and stator wear down, the rotor is pushed into the stator by the elastic extension of the elastic member, so the reduction in the overlap due to wear can be automatically compensated for.

[0019] (6) In the single-screw eccentric pump of the present invention as described above, the outer shaft is characterized in that a threaded portion is formed on the inner surface of the hollow hole at a position corresponding to the adjustment member, the adjustment member has a bolt, the bolt is screwed into the threaded portion, and the relative amount of movement of the inner shaft and the outer shaft can be changed by adjusting the screwing position of the bolt.

[0020] The single-screw pump of the present invention has the following configuration, so the relative position of the inner shaft and outer shaft (rotor and stator) can be easily changed by adjusting the screwing position of the bolt on the adjustment member relative to the threaded portion of the outer shaft. As a result, the single-screw pump of the present invention can easily adjust the tightening allowance of the rotor and stator. Here, the threaded portion may be located, for example, within a bearing housing that houses a bearing that rotatably supports the input shaft, etc. With this configuration, the single-screw pump of the present invention can share the maintenance work location for the shaft seal, etc., with the operating location of the extension / retraction mechanism (adjustment member), thus improving maintainability and operability. The threaded portion is not limited to being located within the bearing housing; it can also be located in various areas, such as an area with an externally accessible maintenance hole. The adjustment member may also be provided with a nut or the like to fix the screwing position of the bolt. Furthermore, the single-screw pump of the present invention can be expected to automate the adjustment of the tightening allowance of the rotor and stator by automatically screwing the bolt on the adjustment member with an actuator or the like.

[0021] (7) The single-screw eccentric pump of the present invention described above is characterized in that the adjustment member is a clamp member capable of gripping the inner shaft, the clamp member allows relative movement between the inner shaft and the outer shaft when the inner shaft is not gripped, and prevents relative movement between the inner shaft and the outer shaft when the inner shaft is gripped.

[0022] The single-screw pump of the present invention has the above configuration, so that the relative positions of the inner shaft and the outer shaft (rotor and stator) can be easily changed by changing the gripping position of the clamp member. As a result, the single-screw pump of the present invention can be easily adjusted for the overlap between the rotor and stator. Furthermore, by making the gripping position of the clamp member automatically changed by an actuator or the like, the adjustment of the overlap between the rotor and stator can be automated. The gripping of the inner shaft by the clamp member can be performed by tightening with an appropriate fastening member or engaging with an engaging member. The clamp member can be placed in various areas of the pump casing or bearing housing, such as an area with an externally accessible maintenance hole.

[0023] (8) In the single-screw eccentric pump of the present invention as described above, the inner shaft is provided with an elongated hole formed longitudinally along the axial direction, or a plurality of shaft-side locking holes formed at intervals along the axial direction of the input shaft, and the clamp member is provided with a clamp-side locking hole corresponding to at least one of the elongated hole or the shaft-side locking hole, and the inner shaft and the outer shaft are locked so as not to rotate relative to each other by inserting the shaft member through the clamp-side locking hole into the shaft-side locking hole.

[0024] The single-screw pump of the present invention, with this configuration, can receive torque from the input shaft and the like through the shaft member. Therefore, the single-screw pump of the present invention can appropriately transmit rotation from the drive unit to the rotor via the input shaft and the like.

[0025] (9) In the single-screw eccentric pump of the present invention as described above, either one or both of the input shaft or the joint shaft are divided and formed into at least a first shaft and a second shaft along the axial direction, the extension mechanism comprises a plurality of adjustment members of different lengths to which the first shaft and the second shaft can be connected, and the input shaft or the joint shaft is extended or retracted in the axial direction by connecting the first shaft and the second shaft via at least one selected from the plurality of adjustment members.

[0026] The single-screw eccentric pump of the present invention allows the distance between the first and second shafts to be changed by arranging at least one of a plurality of adjustment members of different lengths between the divided input shafts, etc. (first shaft and second shaft). Therefore, the single-screw eccentric pump of the present invention allows the length of the input shaft, etc. to be easily changed by replacing the initially installed adjustment member with another adjustment member of a different length. This allows the single-screw eccentric pump of the present invention to easily adjust the tightening allowance of the rotor and stator, etc. Here, the adjustment member can be arranged in various areas of the pump casing, bearing housing, etc., such as areas where maintenance holes accessible from the outside are provided.

[0027] (10) In the single-screw eccentric pump of the present invention as described above, either one or both of the input shaft or the joint shaft are divided into at least a first shaft and a second shaft along the axial direction, the extension mechanism includes an adjustment member to which the first shaft and the second shaft can be connected, the adjustment member is configured to change the connection position along the axial direction with respect to at least one or both of the first shaft and the second shaft, and by changing the connection position, either one or both of the input shaft or the joint shaft can be extended or retracted.

[0028] The single-screw eccentric pump of the present invention allows for adjustment of the distance between the first and second shafts by enabling the adjustment member to change the connection position along the axial direction with respect to at least one or both of the first and second shafts. As a result, the single-screw eccentric pump of the present invention allows for adjustment of the distance between the first and second shafts without attaching or detaching the adjustment member, making it easy to adjust the tightening allowance of the rotor and stator. The adjustment member can be, for example, one that can change the connection position by sliding along the axial direction with respect to either one or both of the first and second shafts. Alternatively, the adjustment member can be a clamp member capable of gripping (clamping) the first or second shaft. The adjustment member can be placed in various areas of the pump casing or bearing housing, such as areas with externally accessible maintenance holes.

[0029] (11) The single-screw eccentric pump of the present invention described above is characterized in that at least a portion of the first shaft and the second shaft are made of a flexible material, the connecting ends of the first shaft and the second shaft form a first shaft side connecting portion and a second shaft side connecting portion, and the first shaft side connecting portion and the second shaft side connecting portion are connected via the adjustment member.

[0030] The single-screw pump of the present invention, with this configuration, allows the input shaft, joint shaft, or both (referred to as the input shaft, etc.) to be extended or retracted via the adjustment member, even if they are flexible rods made of a flexible material. In other words, the single-screw pump of the present invention, with the configuration described in (11) above, allows adjustment of the tightening allowance of the rotor and stator via the adjustment member, even if the input shaft, etc. is made of a flexible rod. Here, the joint shaft should be appropriately widened in the intermediate section that does not contribute to eccentricity in order to ensure a thickness suitable for providing the adjustment member (extension mechanism). This makes it easier to mount the extension mechanism and also ensures rigidity, so the effects of preventing twisting and buckling can be expected.

[0031] (12) In the single-screw eccentric pump of the present invention described above, the outer shaft has an outer shaft side threaded portion formed on its outer circumference, the inner shaft has an inner shaft side threaded portion formed on the outer circumference of the exposed portion not inserted into the hollow hole, the inner shaft side threaded portion has threads cut in the opposite direction to the outer shaft side threaded portion, the adjustment member has a first threaded portion and a second threaded portion whose screwing directions are opposite to each other, the first threaded portion and the outer shaft side threaded portion, and the second threaded portion and the inner shaft side threaded portion are screwed together, and the relative position of the inner shaft and the outer shaft is changed by moving the screwing position of the first threaded portion and the second threaded portion along the axial direction.

[0032] The single-screw eccentric pump of the present invention has a first screw portion and a second screw portion constituting an adjustment member, which are formed as opposite threads to each other. By moving the screwing position of the first screw portion and the second screw portion along the axial direction, the relative position of the inner shaft and the outer shaft can be changed. This allows the single-screw eccentric pump of the present invention to easily adjust the tightening allowance of the rotor and stator. Preferably, the adjustment member is provided with a lock nut to fix the screwing position of the first screw portion and the second screw portion. Furthermore, either the inner shaft or the outer shaft, or both, may be provided with a stopper (engaging portion) that suppresses at least one of the extension or contraction of the inner shaft or the outer shaft in the axial direction. The first screw portion and the second screw portion can be arranged in various areas of the pump casing or bearing housing, such as areas where maintenance holes accessible from the outside are provided.

[0033] (13) In the single-screw eccentric pump of the present invention described above, the telescopic mechanism is preferably characterized in that the drive mechanism comprises a drive unit housed in the hollow hole and moving the inner shaft relative to the outer shaft, a generator housed in the hollow hole and generating electricity in conjunction with the rotation of the outer shaft, a control unit housed in the hollow hole and controlling the drive of at least the drive unit, and a battery housed in the hollow hole and supplying power to at least the drive unit and the control unit, and storing the power generated by the generator, and the relative positions of the inner shaft and the outer shaft in the axial direction are changed by the drive of the drive unit.

[0034] The single-screw pump of the present invention, with this configuration, can automatically change the relative position of the inner and outer shafts using electricity generated by a generator housed in a hollow hole in the outer shaft. Furthermore, since the drive unit, generator, control unit, and battery are housed in the aforementioned hollow hole, the relative position of the inner and outer shafts can be changed within the outer shaft (hollow hole). Therefore, the single-screw pump of the present invention can be miniaturized. Here, for example, a generator that generates electricity by the relative rotation of the generator body and a weight can be used. For example, the generator body can be fixed in the hollow hole so as not to rotate relative to it, and the generator body can rotate with the rotation of the outer shaft relative to the weight. Note that the generator is not limited to the above, but various types can be used, such as those that generate electricity using vibration, acceleration, etc., or those that use MEMS (micro-electromechanical systems), etc.

[0035] (14) In the single-screw eccentric pump of the present invention as described above, the adjustment member is preferably characterized in that it comprises a screw shaft that is rotationally driven by the drive unit, and a nut member that is screwed onto the screw shaft and is movable along the axial direction of the screw shaft by rotationally driving the screw shaft, wherein the nut member is attached to the inner shaft so as not to rotate relative to it and is movable integrally with the inner shaft.

[0036] The single-screw pump of the present invention has the above configuration, so that the relative position of the inner shaft and the outer shaft can be automatically changed by rotating the screw shaft with the drive unit. Therefore, the single-screw pump of the present invention can automatically adjust the tightening allowance of the rotor and stator, etc.

[0037] (15) In the single-screw eccentric pump of the present invention described above, the telescopic mechanism comprises a screw shaft that is rotationally driven by power, a nut member that is screwed onto the screw shaft and can move along the axial direction of the screw shaft by rotationally driving the screw shaft, a link shaft provided in a direction intersecting the screw shaft, a rotation direction conversion unit that converts the rotation direction of the link shaft to the rotation direction of the screw shaft, and an opening that opens in the outer shaft and allows the link shaft to be rotated from the outside of the outer shaft, wherein the nut member is attached to the inner shaft so as not to rotate relative to it and is movable integrally with the inner shaft, and the screw shaft is rotated by rotating the link shaft through the opening, thereby changing the relative position of the inner shaft and the outer shaft in the axial direction.

[0038] The single-screw pump of the present invention, with this configuration, allows the relative position of the inner and outer shafts to be changed by operating the link shaft from outside the outer shaft through an opening in the outer shaft. As a result, the single-screw pump of the present invention allows adjustment of the rotor and stator tension by operating from outside the outer shaft, dramatically improving the operability of such adjustments and facilitating automation.

[0039] (16) In the single-screw eccentric pump of the present invention described above, the adjustment member is preferably characterized in that it comprises a cylinder constituting the outer shaft and a piston constituting the inner shaft and capable of moving back and forth in the hollow hole provided in the cylinder, and the cylinder and the piston can move relative to each other in the axial direction by drawing in or discharging liquid or gas into the cylinder chamber formed by the cylinder and the piston.

[0040] The single-screw eccentric pump of the present invention allows the piston to move back and forth in a hollow hole by drawing liquid or gas into and out of the cylinder, thereby changing the relative position of the inner shaft and the outer shaft through the movement of the piston. Therefore, the single-screw eccentric pump of the present invention allows for easy adjustment of the rotor and stator engagement by controlling the pressure applied to the cylinder. Furthermore, since the rotor and stator engagement can be adjusted by controlling the pressure of the cylinder, the single-screw eccentric pump of the present invention can be easily automated.

[0041] (17) In the single-screw eccentric pump of the present invention as described above, the telescopic mechanism has an adjustment member in the joint portion, and the adjustment member comprises an outer member connected to either the rotor side or the input shaft side and formed along the axial direction of the input shaft, and an inner member connected to either the rotor side or the input shaft side and movable relative to the outer member in the axial direction, and the relative position of the outer member and the inner member is changed.

[0042] The single-screw pump of the present invention, by having such a configuration, allows the relative positions of the outer member and the inner member to be changed. This makes it easy to adjust the overlap of the rotor and stator in the single-screw pump of the present invention. Here, either the outer member or the inner member has, for example, a plurality of locking holes formed at predetermined intervals along the axial direction of the input shaft, and the other of the outer member or the inner member is provided with another locking hole corresponding to at least one of the aforementioned locking holes, and a shaft member (locking pin) that can engage with both locking holes. Therefore, the extension mechanism (adjustment member) can change the relative positions of the outer member and the inner member by engaging the shaft member with either of the locking holes. This makes it easy to adjust the overlap of the rotor and stator in the single-screw pump of the present invention. Here, the joint (adjustment member) can be placed in various areas of the pump casing, such as an area where an externally accessible maintenance hole is provided.

[0043] (18) In the uniaxial eccentric screw pump of the present invention described above, the expansion and contraction mechanism has an adjustment member at the joint portion. The adjustment member includes a plurality of first engagement members having different lengths in the axial direction, and a second engagement member that slidably engages with one of the plurality of first engagement members selected therefrom. By engaging at least one selected from the plurality of first engagement members with the second engagement member, either one or both of the input shaft and the joint shaft are expanded and contracted in the axial direction. It is preferable to be characterized by this.

[0044] By adopting such a configuration, the uniaxial eccentric screw pump of the present invention can change the connection length in the axial direction of the input shaft by appropriately selecting a first engagement member having an appropriate length from a plurality of first engagement members having different lengths. As a result, the uniaxial eccentric screw pump of the present invention can adjust the tightening allowance between the rotor and the stator and the like. Here, the first engagement member can be formed of, for example, a female disk (male disk) as an Oldham joint, and the second engagement member can be formed of a male disk (female disk) that can engage with the corresponding female disk (male disk).

[0045] (19) The uniaxial eccentric screw pump of the present invention described above is characterized in that it includes a pump casing that houses the expansion and contraction mechanism, and the pump casing has an access area that is accessible to at least a part of the expansion and contraction mechanism.

[0046] By adopting such a configuration, the uniaxial eccentric screw pump of the present invention has a pump casing in which the expansion and contraction mechanism is housed and has an accessible access area, so that the expansion and contraction mechanism can be accessed through the access area. Therefore, the uniaxial eccentric screw pump of the present invention can easily perform the expansion and contraction operation and maintenance of the expansion and contraction mechanism through the access area. Here, the access area is preferably formed, for example, by providing an openable / closable or detachable lid on the pump casing. When the above-described lid is used as the access area, it is desirable that the space between the pump casing and the lid is sealed by a seal or the like.

[0047] According to the present invention, it is possible to provide a uniaxial eccentric screw pump that can easily adjust the tightening allowance or clearance between the rotor and the stator and can also be automated.

[0048] (a) is a front-direction cross-sectional view showing the state before adjustment of the tightening allowance or the like of the uniaxial eccentric screw pump according to an embodiment of the present invention, and (b) is a front-direction cross-sectional view showing the state after adjustment of the tightening allowance or the like of the uniaxial eccentric screw pump of (a). (a) is a front-direction cross-sectional view showing the state before adjustment of the tightening allowance or the like of the uniaxial eccentric screw pump according to the first modification example of the present invention, and (b) is a front-direction cross-sectional view showing the state after adjustment of the tightening allowance or the like of the uniaxial eccentric screw pump of (a). (a) is an explanatory view of a clamp member (adjusting member) in the uniaxial eccentric screw pump according to the second modification example of the present invention, and (b) is an explanatory view of the clamp member according to another embodiment of (a). It is a front-direction cross-sectional view of the uniaxial eccentric screw pump according to the third modification example of the present invention. (a) to (c) are explanatory views of adjusting members with different lengths in the uniaxial eccentric screw pump according to the third modification example of the present invention, and (d) is a front view of the adjusting member of (c) in the removed state. (a) to (c) are explanatory views when changing the connection position of the adjusting member in the uniaxial eccentric screw pump according to the fourth modification example of the present invention. It is a front view of the expansion and contraction mechanism (flexible material) in the uniaxial eccentric screw pump in which a part of the fourth modification example of FIG. 6 is changed. (a) is an explanatory view showing the extended state of the expansion and contraction mechanism (adjusting member) in the uniaxial eccentric screw pump according to the fifth modification example of the present invention, and (b) is an explanatory view showing the contracted state of the expansion and contraction mechanism of (a). It is a front-direction cross-sectional view of the expansion and contraction mechanism in the uniaxial eccentric screw pump according to the sixth modification example of the present invention. It is a front-direction cross-sectional view of the expansion and contraction mechanism in the uniaxial eccentric screw pump according to the seventh modification example of the present invention. It is a front-direction cross-sectional view of the expansion and contraction mechanism in the uniaxial eccentric screw pump according to the eighth modification example of the present invention. (a) is an explanatory view showing the contracted state of the expansion and contraction mechanism (adjusting member) in the uniaxial eccentric screw pump according to the ninth modification example of the present invention, and (b) is an explanatory view showing the extended state of the expansion and contraction mechanism of (a). It is an explanatory view showing another embodiment of the expansion and contraction mechanism of FIG. 12. (a) is an explanatory view showing the contracted state of the expansion and contraction mechanism (adjusting member) in the uniaxial eccentric screw pump according to the tenth modification example of the present invention, and (b) is an explanatory view showing the extended state of the expansion and contraction mechanism of (a).

[0049] The following describes in detail a single-screw eccentric pump 1 according to one embodiment of the present invention, with reference to the drawings. Note that the figures are schematic representations for ease of understanding and may differ from the actual shape, size, and arrangement of components. Also note that hatching in the cross-section may be omitted in some figures. Furthermore, in Figure 1, the left side may be described as the front side and the right side as the rear side. Unless otherwise specified, the axial direction of the input shaft 60 may simply be referred to as the axial direction.

[0050] As shown in Figures 1(a) and 1(b), the single-screw eccentric pump 1 includes an input shaft 60 that transmits the driving force of a drive unit (not shown), a joint shaft 7 (also referred to as a connecting shaft 7), and a joint section 9. The single-screw eccentric pump 1 also includes a male screw-type rotor 5 (also referred to as rotor 5), a female screw-type stator 12 (also referred to as stator 12), and an extension mechanism 50. In addition to the above, the single-screw eccentric pump 1 also includes a stator casing 10, a pump casing 20, a bearing housing 30, a bearing 32 that rotatably supports the input shaft 60, and a shaft seal casing 40, etc.

[0051] The single-screw eccentric pump 1 is a rotary positive displacement pump. The single-screw eccentric pump 1 can transfer or fill any fluid, from low viscosity to high viscosity, with high precision by having a rotor 5 inserted through the inner bore 12a of the stator 12 rotate relative to the stator 12. Here, the fluid includes liquids, gases, and fluids such as slurries and granular materials.

[0052] The rotor 5 is composed of a male screw-type shaft body with n (in this embodiment, n=1) threads (leaves), and its longitudinal cross-sectional shape is formed to be approximately circular. The pitch of the helical shape is set to 1 / 2 of the lead of the inner hole 12a of the stator 12. The rotor 5 is made of a metal such as stainless steel and is inserted through the inner hole 12a of the stator 12. A joint shaft 7 (also referred to as a connecting shaft 7) is integrally provided at the base end (rear end) of the rotor 5. The joint shaft 7 is connected to the input shaft 60 via a joint part 9 (also referred to as a connecting part 9), such as a pin joint, universal joint, gear joint, Oldham joint, or flexible rod. The rotor 5 (joint shaft 7) can rotate eccentrically with respect to the input shaft 60. Multiple joint parts 9 may be provided as needed.

[0053] Furthermore, both the outer diameter of the rotor 5 and the inner diameter of the stator 12, which will be described later, are formed to decrease in size from one end to the other. In this embodiment, both the outer diameter of the rotor 5 and the inner diameter of the inner bore 12a of the stator 12 are formed to decrease in size from one end of the rotor 5 on the joint shaft 7 side (right side in the figure) to the other end of the rotor 5 on the tip side (left side in the figure). Note that the direction in which the outer diameter of the rotor 5 and the inner diameter of the inner bore 12a of the stator 12 decrease can be changed depending on the usage conditions. Also, it is sufficient if either or both of the outer diameter of the rotor 5 and the inner diameter of the inner bore 12a of the stator 12 change in size from one end to the other.

[0054] Furthermore, in the single-screw eccentric pump 1 according to this embodiment, the eccentricity of the rotor 5 can be changed instead of, or in conjunction with, the changes to the outer diameter of the rotor 5 and the inner diameter of the stator 12.

[0055] The input shaft 60 is formed of a metal shaft and, in this embodiment, extends from the rear end of the bearing housing 30 (described later) to the inside of the pump casing 20. The input shaft 60 is rotatably supported by a pair of bearings 32, 32 (bearings 32, 32) spaced apart within the bearing housing 30, and the drive shaft of a drive unit (not shown) can be connected to its rear end (right side in the figure) via a connecting part such as a key or coupling. Therefore, the input shaft 60 can be rotationally driven by the power of the drive unit. Here, the drive unit is an electric motor such as a stepping motor or a servo motor. In this embodiment, the connecting part is a key. Note that the connection between the drive shaft of the drive unit and the input shaft 60 can also be made by rail or spline in addition to a key or coupling.

[0056] The input shaft 60 is connected to a joint shaft 7 via a joint portion 9 (also referred to as a connecting portion 9) formed by a pin joint or the like at its front end (left side in the figure). In this embodiment, the joint shaft 7 is connected via the joint portion 9 so as to be able to rotate eccentrically with respect to the input shaft 60. That is, the rotor 5 is connected so as to be able to rotate eccentrically with respect to the input shaft 60. The input shaft 60 is also formed to extend along the axial direction. In this embodiment, the input shaft 60 has a double cylindrical nested structure and has an outer shaft 61 and an inner shaft 65. The outer shaft 61 and the inner shaft 65 constitute part of the telescopic mechanism 50 which will be described later.

[0057] The outer shaft 61 is formed in a cylindrical shape, and a circular hollow hole 62 is formed along its axial direction. The hollow hole 62 is formed up to a certain point along the axial direction of the outer shaft 61.

[0058] The inner shaft 65 is formed in a cylindrical shape along its axial direction and is slidably inserted into the hollow hole 62 via a key, spline, rail, etc. Therefore, the inner shaft 65 is movable relative to the outer shaft 61 along its axial direction. The rear end of the inner shaft 65 is formed to extend to the connection part with the drive mechanism. A stopper 66 (also referred to as an engaging part 66) is formed on the outer circumference of the portion of the inner shaft 65 that is exposed from the hollow hole 62. A locking part 70 is also provided on the rear end of the inner shaft 65.

[0059] The locking portion 70 comprises a screw groove (not shown) provided on the outer circumference of the rear end of the input shaft 60, and a nut member 71 screwed into the screw groove. By tightening the nut member 71, the locking portion 70 comes into contact with the outer circumference of the inner shaft 65, fixing the input shaft 60 so that it cannot move relative to it (corresponding to a locked state).

[0060] On the other hand, the locking part 70 can be opened by loosening the nut member 71, thereby releasing the lock and allowing the outer shaft 61 to move relative to the inner shaft 67. In other words, the locking part 70 can be opened to change the relative positional relationship between the inner shaft 65 and the outer shaft 61.

[0061] The stopper 66 abuts against the outer peripheral edge of the rear end side (right side in the figure) of the outer shaft 61, and is designed to suppress relative movement of the outer shaft 61 with respect to the inner shaft 65 by more than a predetermined amount. The stopper 66 also functions as a retainer to prevent the inner shaft 65 from coming out of the bearings 32, 32.

[0062] The joint section 9 is configured to connect the input shaft 60 and the rotor 5 directly or indirectly via the joint shaft 7. In this embodiment, the joint section 9 connects the front end of the input shaft 60 (outer shaft 61) to the rear end of the joint shaft 7. As described above, the joint section 9 is composed of a pin joint or the like, and the joint shaft 7 can be connected eccentrically with respect to the axis of the input shaft 60.

[0063] The stator casing 10 is designed to house the stator 12 so that it cannot rotate relative to the stator. In this embodiment, the stator casing 10 and the stator 12 are integrated by adhesive bonding. However, the stator casing 10 and the stator 12 may be integrated by means other than adhesive bonding (for example, engagement). The stator casing 10 is formed in a cylindrical shape from a metal such as stainless steel. An end stud 11 is provided at the tip side (front end side) of the stator casing 10. The end stud 11 has a fluid discharge port 16 opening at its tip side. The end stud 11 may be formed integrally with the stator casing 10. The rear end of the stator casing 10 is connected to a pump casing 20, which will be described later.

[0064] The stator 12 is formed in a female thread shape through which the rotor 5 can be inserted. The stator 12 is mounted in a sealed state within the stator casing 10 so as not to rotate relative to it. The stator 12 has, for example, a two-groove female threaded inner bore 12a and is formed in a substantially cylindrical shape. The inner bore 12a has an oval shape in its longitudinal cross-section. The inner bore 12a is twisted in the direction of its central axis 3a with a lead twice that of the rotor 5.

[0065] The stator 12 can be formed from synthetic resins, including, for example, synthetic rubber, Teflon (registered trademark), polyacetal, and engineering plastics such as cast nylon. By forming the stator 12 from synthetic rubber or synthetic resin, the liquid-tightness (sealing) of the space 14 formed by the outer surface of the rotor 5 and the inner surface of the inner bore 12a of the stator 12 can be ensured.

[0066] The pump casing 20 is positioned between the stator casing 10 and the bearing housing 30, which will be described later. The pump casing 20 is formed in a substantially cylindrical shape using a material such as metal (stainless steel, etc.). The pump casing 20 is connected to the stator casing 10 on the side opposite to the discharge port 16 (the rear end side). In other words, the pump casing 20 is provided along the axial direction of the input shaft 60. In this embodiment, the pump casing 20 is positioned adjacent to the bearing housing 30. The pump casing 20 may be positioned adjacent to the bearing housing 30, or a portion of it may overlap with it. In addition, other components may be interposed between the pump casing 20 and the bearing housing 30.

[0067] The pump casing 20 has a supply port 22 (suction port 22) for drawing in fluid formed on a part of its outer circumference. In this embodiment, the area around the suction port 22 is formed to protrude cylindrically radially outward from the pump casing 20, and a flange 22a for connecting piping or the like is formed at the protruding end. One end portion of the input shaft 60, the joint portion 9, and the joint shaft 7 are rotatably inserted inside the pump casing 20. Furthermore, a bearing housing 30 is connected to the rear end side of the pump casing 20 (opposite the stator casing 10) via a shaft seal casing 40, along the axial direction of the input shaft 60.

[0068] As shown in Figure 1(a), the pump casing 20 has a bearing housing 30 connected to its rear end. As the rotor 5 rotates, the pump casing 20 can deliver (transfer) the fluid drawn in from the suction port 22 toward the inner bore 12a of the stator 12. The fluid delivered to the stator 12 is discharged from the discharge port 16 as the rotor 5 rotates. The pump casing 20 houses an extension mechanism 50, which will be described later.

[0069] The bearing housing 30 is connected to the pump casing 20 via a shaft seal casing 40. The bearing housing 30 is formed in a substantially cylindrical shape using a material such as metal (stainless steel, etc.). The bearing housing 30 can house a pair of bearings 32, 32 arranged at a predetermined distance apart, so as not to rotate relative to each other. An input shaft 60 is inserted through the bearing housing 30, and the input shaft 60 is rotatably supported by the bearings 32, 32. In other words, the input shaft 60 is rotatably supported by the bearing housing 30. The shaft seal casing 40 is connected to the front end of the bearing housing 30 (pump casing 20 side) so as not to rotate relative to the bearing housing 30. A portion of the input shaft 60 protrudes axially from the rear end of the bearing housing 30.

[0070] The bearing housing 30 is provided with a support portion 36 on its lower end for support on a machine base (not shown). The support portion 36 can be fixed to the machine base with bolts or the like.

[0071] As shown in Figures 1(a) and 1(b), a pair of bearings 32, 32 are housed in the bearing housing 30 at a predetermined distance apart. The input shaft 60 is rotatably inserted through the bearing housing 30 via the bearings 32, 32.

[0072] The shaft seal casing 40 is provided between the bearing housing 30 and the pump casing 20. The shaft seal casing 40 is formed in a cylindrical shape using a material such as metal (such as stainless steel). The shaft seal casing 40 has an inner diameter that is approximately the same as or slightly larger than the outer diameter of the input shaft 60, allowing the input shaft 60 to be inserted through it. The shaft seal casing 40 is provided with a shaft seal 42 on its inner circumference, which keeps the space between the input shaft 60 and the shaft seal casing 40 (around the input shaft 60) sealed when the input shaft 60 is inserted through it. Here, for example, a gland packing is used for the shaft seal 42. In addition to gland packing, various sealing members such as lip seals (lip packings) and mechanical seals can be used for the shaft seal 42. The rear end of the shaft seal casing 40 is coupled to the inner circumference of the front end of the bearing housing 30.

[0073] The front end of the shaft seal casing 40 is fitted onto the rear end of the pump casing 20. In other words, the shaft seal casing 40 is designed to overlap with the pump casing 20 in at least a portion. The space between the shaft seal casing 40 and the pump casing 20 is sealed by a sealing member 44 such as an O-ring, which prevents liquid from leaking out of the pump casing 20.

[0074] The telescopic mechanism 50 is designed to move the rotor 5 closer to and further away from the stator 12 by extending or retracting the input shaft 60. In this embodiment, the telescopic mechanism 50 includes an adjustment member 51 that changes the relative positional relationship between the inner shaft 65 and the outer shaft 61.

[0075] As shown in Figure 1(a), the adjustment member 51 is positioned between the stopper 66 on the inner shaft 65 and the outer shaft 61. In this embodiment, the adjustment member 51 is formed as a spacer that can be attached to and removed from the outer circumference of the inner shaft 65. The adjustment member 51 is formed in a cylindrical shape and is divided into two parts in the radial direction. After the adjustment member 51 is attached to the outer circumference of the inner shaft 65, it is fixed to the inner shaft 65 by, for example, tightening it from the outer circumference with a tightening member 52. As a result, the inner shaft 65 and the outer shaft 61 are fixed in a state where the distance between them is maintained by the adjustment member 51 (corresponding to the extended state) and are unable to move relative to each other.

[0076] As shown in Figure 1(b), the adjustment member 51 can be removed from the inner shaft 65, thereby causing the inner shaft 65 and the outer shaft 61 to move relative to each other and be retracted. In other words, by removing the adjustment member 51 from the inner shaft 65, the outer shaft 61 can be moved axially toward the inner shaft 65. To put it another way, the inner shaft 65 can be moved in the retraction direction relative to the outer shaft 61 by the length of the adjustment member 51 in the axial direction. Here, since the input shaft 60 is integrated with the outer shaft 61, it can be extended or retracted by the length of the adjustment member 51 in the axial direction by attaching or detaching the adjustment member 51.

[0077] When the relative positional relationship between the inner shaft 65 and the outer shaft 61 is changed by the adjustment member 51, the locking part 70 described above is switched from the unlocked state to the locked state, thereby fixing the inner shaft 65 and the outer shaft 61 in a predetermined relative position so that they cannot move relative to each other (relative movement is suppressed).

[0078] In this way, the single-screw eccentric pump 1 can move the rotor 5 closer to or further away from the stator 12 by extending or retracting the input shaft 60. This allows the single-screw eccentric pump 1 to adjust the tension and gap (hereinafter, both together will be referred to as tension, etc.) between the rotor 5 and the stator 12. To extend or retract the input shaft 60, when transitioning from the state shown in Figure 1(a) to the state shown in Figure 1(b), the adjustment member 51 is removed, and the nut 70 is tightened to pull the input shaft 60. Conversely, when transitioning from the state shown in Figure 1(b) to the state shown in Figure 1(a), the nut 70 is loosened, the input shaft 60 is tapped in with a hammer or the like to push it in, and then the nut 70 is tightened to fix it in place.

[0079] The above describes the configuration of the single-screw eccentric pump 1 according to one embodiment of the present invention. Next, the effects and advantages exhibited by the configuration of the single-screw eccentric pump 1 of the present invention will be described below.

[0080] (a) The single-screw eccentric pump 1 of the present invention comprises an input shaft 60 that rotates by the power of a drive machine, a rotor 5 that is eccentrically rotatable with respect to the input shaft 60 and is composed of a male screw-type shaft body, a joint portion 9 that directly or indirectly connects the input shaft 60 and the rotor 5 via a joint shaft 7, and a stator 12 formed in the shape of a female screw through which the rotor 5 can be inserted, wherein either or both of the outer diameter of the rotor 5 and the inner diameter of the inner bore 12a of the stator 12 are formed to decrease from one end to the other, or the amount of eccentricity of the rotor 5 is changed, and at least one of the input shaft 60, the joint shaft 7, and the joint portion 9 is equipped with an extension / retraction mechanism 50 that moves the rotor 5 closer to and further away from the stator 12 by extending or retracting in the axial direction.

[0081] The single-screw eccentric pump 1 of the present invention allows either the outer diameter of the rotor 5 and / or the inner diameter of the inner bore 12a of the stator 12 to decrease from one end to the other, or to change the eccentricity of the rotor 5, or both. Therefore, the single-screw eccentric pump 1 of the present invention does not require replacement of the rotor 5 or stator 12 even if the rotor 5 and stator 12 change in volume due to temperature changes or wear out, and the overlap or gap (collectively referred to as overlap, etc.) of the rotor 5 and stator 12 can be easily adjusted.

[0082] Furthermore, the single-screw pump 1 of the present invention, through the extension and retraction mechanism 50, allows at least one of the input shaft 60, joint shaft 7, and joint portion 9 (hereinafter also referred to as the input shaft 60, etc.) to move the rotor 5 closer to and further away from the stator 12, making it easy to adjust the tension of the rotor 5 and stator 12.

[0083] (b) In the single-screw eccentric pump 1 of the present invention, either one or both of the input shaft 60 or the joint shaft 7 comprises an outer shaft 61 having a hollow hole 62 formed along the axial direction and an inner shaft 65 inserted through the hollow hole 62 and movable relative to the outer shaft 61 along the axial direction, and the telescopic mechanism 50 comprises an adjustment member 51 that changes the relative positional relationship of the inner shaft 65 and the outer shaft 61 in the axial direction, and is characterized in that either one or both of the input shaft 60 or the joint shaft 7 are telescopically extended or retracted by moving the inner shaft 65 and the outer shaft 61 relative to each other via the adjustment member 51.

[0084] The single-screw pump 1 of the present invention, by having the configuration described in (b) above, can be configured with the input shaft 60 etc. as a nested structure (also referred to as a double-cylinder structure) of an inner shaft 65 and an outer shaft 61. Therefore, the single-screw pump 1 of the present invention can move the inner shaft 65 relative to the outer shaft 61. Furthermore, since the single-screw pump 1 of the present invention is equipped with an adjustment member 51 that changes the relative positional relationship between the inner shaft 65 and the outer shaft 61, the input shaft 60 etc. can be easily extended and retracted by moving the inner shaft 65 and the outer shaft 61 relative to each other in the axial direction using the adjustment member 51.

[0085] (c) The single-screw eccentric pump 1 of the present invention is characterized in that it is provided with a locking part 70 that allows the relative positional relationship between the inner shaft 65 and the outer shaft 61 to be changed when the lock is released and unlocked, and fixes the inner shaft 65 and the outer shaft 61 so that they cannot move relative to each other when locked.

[0086] The single-screw eccentric pump 1 of the present invention, by having the configuration described in (c) above, can fix the inner shaft 65 and outer shaft 61, which have been moved relative to each other by the adjustment member 51, in a predetermined position. Therefore, the single-screw eccentric pump 1 of the present invention can maintain a state in which the tightening allowance of the rotor 5 and stator 12 is adjusted, and thus can stably discharge liquid.

[0087] (d) In the single-screw eccentric pump 1 of the present invention, the adjustment member 51 is disposed between the inner shaft 65 and the outer shaft 61, suppresses the relative movement of the inner shaft 65 and the outer shaft 61 along the axial direction, and is detachably provided on at least one of the inner shaft 65 and the outer shaft 61, and the amount of relative movement of the inner shaft 65 and the outer shaft 61 in the axial direction can be changed by attaching or detaching the adjustment member 51.

[0088] The single-screw pump 1 of the present invention has an adjustment member 51 positioned between the inner shaft 65 and the outer shaft 61, which suppresses the relative movement of the inner shaft 65 and the outer shaft 61 along the axial direction. Furthermore, the single-screw pump 1 of the present invention has the adjustment member 51 detachably attached to at least one of the inner shaft 65 and the outer shaft 61. Therefore, the single-screw pump 1 of the present invention allows the distance between the inner shaft 65 and the outer shaft 61 to be adjusted by attaching or detaching the adjustment member 51, thereby changing the relative amount of movement of the inner shaft 65 and the outer shaft 61. As a result, the single-screw pump 1 of the present invention allows for easy adjustment of the tightening allowance of the rotor 5 and the stator 12.

[0089] Here, the adjustment member 51 may be, for example, a spacer member that can be positioned between the inner shaft 65 and the outer shaft 61. Furthermore, by preparing multiple lengths of the adjustment member 51 (spacer member) along the axial direction of the input shaft 60, for example, the relative position of the inner shaft 65 and the outer shaft 61 can be selectively changed according to the length of the adjustment member 51. In addition, the adjustment member 51 can be attached in various ways, such as by clamping (gripping) the adjustment member 51 from the outer circumference, or by fixing the locking part 70 described above, thereby clamping the adjustment member 51 from both sides along the axial direction by the inner shaft 65 and the outer shaft 61.

[0090] The above describes the configuration and operation and effects of the single-screw eccentric pump 1 according to one embodiment of the present invention. Next, the single-screw eccentric pump 100 according to the first modified example of the present invention will be described below with reference to Figure 2. Note that the single-screw eccentric pump 100 according to the first modified example has the same configuration as the single-screw eccentric pump 1, except that a part of the adjustment member 51 in the telescopic mechanism 50 has been changed, so the description of the same parts will be omitted. Also, note that the same reference numerals are used for the same components.

[0091] <First Modification> In the first modification, the single-screw eccentric pump 100, as shown in Figure 2(a), has a telescopic mechanism 50 (adjustment member 51) in the single-screw eccentric pump 1 that, instead of a spacer, is equipped with a bolt 153 (also referred to as adjustment member 153) and a nut member 151 as a telescopic mechanism 150.

[0092] In the single-screw eccentric pump 100, a screw groove 152 (also referred to as a threaded portion 152) is formed on the inner circumferential surface of the hollow hole 62 in the outer shaft 61. The nut member 151 is positioned on the outer circumference of the inner shaft 65 and is screwed into a screw groove (not shown) on the outer circumference of the bolt 153. The nut member 151 can be fixed to a predetermined screwing position on the bolt 153.

[0093] As shown in Figure 2(a), the outer shaft 61 is screwed onto the tip of the bolt 153, allowing the outer shaft 61 to be extended relative to the inner shaft 65. That is, the input shaft 60 is extended, and the rotor 5 approaches the stator 12. The bolt 153 is connected to the head with a key, which allows it to rotate around its axis while suppressing movement in the axial direction.

[0094] On the other hand, as shown in Figure 2(b), the outer shaft 61 can be brought closer to the inner shaft 65, thereby shortening the outer shaft 61 relative to the inner shaft 65. That is, the input shaft 60 is shortened, and the rotor 5 is separated from the stator 12. Thus, the single-shaft eccentric screw pump 100 according to the first modified example is configured so that the input shaft 60 is extended or retracted according to the screwing position of the adjustment member 153. Furthermore, there is a spline between the input shaft 60 and the outer shaft 61, so that the input shaft 60 and the outer shaft 61 rotate together as a single unit. The screwing position of the bolt 153 can be changed by using a maintenance hole that allows access from the outside to the inside of the single-shaft eccentric screw pump 100, or by providing an actuator or the like to automatically rotate the bolt 153. If an access area is not provided, the single-shaft eccentric screw pump 100 can be disassembled and serviced as appropriate.

[0095] A single-screw eccentric pump 100 according to a first modified example of the present invention can be configured as follows, for example, and this configuration can produce the following unique effects.

[0096] (f) In the single-screw eccentric pump 100 of the present invention, the outer shaft 61 has a threaded portion 152 formed at a position corresponding to the adjustment member 51 on the inner surface of the hollow hole 62, the adjustment member 51 has a bolt 153, and the bolt 153 is screwed into the threaded portion 152, and the relative amount of movement of the inner shaft 65 and the outer shaft 61 can be changed by adjusting the screwing position of the bolt 153.

[0097] The single-screw eccentric pump 100 of the present invention has the configuration described in (f) above, so the relative position of the inner shaft 65 and the outer shaft 61 (rotor 5 and stator 12) can be easily changed by adjusting the screwing position of the bolt 153 on the adjustment member with respect to the threaded portion 152 of the outer shaft 61. As a result, the single-screw eccentric pump 100 of the present invention can easily adjust the tightening allowance of the rotor 5 and stator 12. Here, the threaded portion 152 is preferably located in a bearing housing 30 that houses a bearing 32 that rotatably supports the input shaft 60, for example. With this configuration, the single-screw eccentric pump 100 of the present invention can share the maintenance work position for the shaft seal and the operating position of the telescopic mechanism 150 (adjustment member 153), so improvements in maintainability and operability can be expected. Note that the threaded portion 152 is not limited to being located in the bearing housing 30, but can be located in various areas, such as an area with an externally accessible maintenance hole. Furthermore, a nut member 151 or the like may be provided to fix the screwing position of the bolt 153. In addition, the single-axis eccentric screw pump 100 of the present invention can be expected to automate the adjustment of the tightening allowance of the rotor 5 and stator 12 by automatically screwing the bolt 153 (adjustment member 153) with an actuator or the like.

[0098] Although not shown in the diagram, in the first modified example, the single-axis eccentric screw pump 100 may use an elastic member such as a spring instead of the adjustment member 153 as the adjustment member 51 or adjustment member 153. In this configuration, the elastic member as the adjustment member 51 should be placed between the inner shaft 65 and the outer shaft 61.

[0099] Thus, the single-screw eccentric pump 100 according to the first modified example of the present invention can be configured as shown in (e) below, thereby achieving the following unique effects.

[0100] (e) The single-screw eccentric pump 100 of the present invention is characterized in that the adjustment member 153 is made of an elastic material.

[0101] The single-screw eccentric pump 100 of the present invention, by having the configuration described in (e) above, allows the adjustment member 153 to be elastically expanded and contracted, making it easy to adjust the tightening allowance of the rotor 5 and stator 12. Here, a spring or the like can be preferably used as the elastic member. In this way, by using a spring or the like as the elastic member, the single-screw eccentric pump 100 of the present invention can automatically change the relative position of the rotor 5 and stator 12, so the automation of adjusting the tightening allowance of the rotor 5 and stator 12 can be expected. Furthermore, for example, if either or both of the rotor 5 and stator 12 wear out, the rotor 5 is pushed into the stator 12 by the elastic extension of the elastic member, so the reduction in the tightening allowance due to wear can be automatically compensated for.

[0102] The above describes the configuration and operation and effects of the single-screw eccentric pump 100 according to the first modified example of the present invention. Next, an embodiment of the single-screw eccentric pump 100 according to the second modified example of the present invention will be described below with reference to Figure 3.

[0103] ≪Second Modification≫ The single-screw pump 200 according to the second modification has the same configuration as the single-screw pump 100 according to the first modification, except that the configuration of the telescopic mechanism 150 is changed to a telescopic mechanism 250. Therefore, a description of the configuration similar to that of the above-described embodiment will be omitted. Also, please note that the same reference numerals are used for the same components as in the above-described embodiment of the single-screw pump 1. Also, please note that in Figures 3(a) and 3(b), only the main parts related to the telescopic mechanism 250 are shown, and other parts are omitted.

[0104] As shown in Figure 3(a), the single-screw eccentric pump 200 has a telescopic mechanism 250 instead of the telescopic mechanism 50 (adjustment member 51) in the single-screw eccentric pump 100. The telescopic mechanism 250 includes a clamp member 251 (also referred to as the adjustment member 251) attached to the outer circumference of the inner shaft 65. In this embodiment, the clamp member 251 is integrally formed with the outer shaft 61. The inner shaft 65 also has an elongated hole 266a formed so as to be longitudinal along the axial direction. Note that the clamp member 251 can be of various forms, such as being integrally formed with the outer shaft 61 or being configured as a separate component from the outer shaft 61.

[0105] The clamp member 251 can be attached to the inner shaft 65 by gripping the inner shaft 65. The clamp member 251 also has a circular clamp-side locking hole 252 at a position corresponding to the elongated hole 266a. The clamp member 251 is designed to lock the inner shaft 65 and the outer shaft 61 so that they cannot move relative to each other. Therefore, the telescopic mechanism 250 can extend or retract the input shaft 60 by changing the gripping position of the clamp member 251 in the axial direction. This allows the single-axis eccentric screw pump 200 to easily adjust the tightening allowance of the rotor 5 and stator 12.

[0106] Furthermore, the shaft member 253 (also referred to as the locking pin 253) is inserted through the elongated hole 266a via the clamp-side locking hole 252, thereby fixing the inner shaft 65 and the outer shaft 61 so that they cannot rotate relative to each other. As a result, the torque applied to the inner shaft 65 and the outer shaft 61 is absorbed by the shaft member 253 and the clamp member 251. The outer diameter of the shaft member 253 should be approximately the same diameter as the clamp-side locking hole 252, or slightly smaller, so that it can be inserted into the clamp-side locking hole 252.

[0107] In the second modified example of the single-screw eccentric pump 200, as shown in Figure 3(b), instead of the elongated hole 266a provided in the inner shaft 65, a plurality of shaft-side locking holes 266b can be provided at predetermined intervals along the axial direction of the input shaft 60. In this configuration, the inner shaft 65 and the outer shaft 61 can be fixed so as not to rotate relative to each other by inserting the shaft member 253 (also referred to as a locking pin 253) through the shaft-side locking hole 266b via the clamp-side locking hole 252.

[0108] As described above, when multiple shaft-side locking holes 266b are provided, the gripping position of the inner shaft 65 by the clamp member 251 can be moved axially according to each shaft-side locking hole 266b. That is, the relative positional relationship between the inner shaft 65 and the outer shaft 61 is changed, and the input shaft 60 extends and retracts. This allows the single-axis eccentric screw pump 200 to easily adjust the tightening allowance of the rotor 5 and the stator 12. In the second modified example, the single-axis eccentric screw pump 200 may eliminate the elongated hole 266a, the shaft-side locking hole 266b, and the clamp-side locking hole 252, and fix the inner shaft 65 and the outer shaft 61 so that they cannot rotate relative to each other by gripping the inner shaft 65 with the clamp member 251 alone. In this case, the clamp member 251 should be configured to receive the rotational torque of the input shaft 60.

[0109] A single-screw eccentric pump 200 according to a second modified example of the present invention can be configured as follows, for example, and this configuration can produce the following unique effects.

[0110] (g) The single-screw eccentric pump 200 of the present invention is characterized in that the adjustment member 251 is a clamp member 251 capable of gripping the inner shaft 65, the clamp member 251 allows relative movement of the inner shaft 65 and the outer shaft 61 when the inner shaft 65 is not gripped, and prevents relative movement of the inner shaft 65 and the outer shaft 61 when the inner shaft 65 is gripped.

[0111] The single-screw eccentric pump 200 of the present invention has the configuration described in (g) above, so that the relative positions of the inner shaft 65 and the outer shaft 61 (rotor 5 and stator 12) can be easily changed by changing the gripping position of the clamp member 251. As a result, the single-screw eccentric pump 200 of the present invention can easily adjust the tightening allowance of the rotor 5 and stator 12. Furthermore, by making the gripping position of the clamp member 251 automatically changed by an actuator or the like, the adjustment of the tightening allowance of the rotor 5 and stator 12 can be automated. The gripping of the inner shaft 65 by the clamp member 251 can be performed by tightening with an appropriate fastening member or engaging with an engaging member. Here, the clamp member 251 can be placed in various areas of the pump casing 20 or bearing housing 30, such as an area where an externally accessible maintenance hole is provided.

[0112] (h) In the single-screw eccentric pump 200 of the present invention, the inner shaft 65 is provided with an elongated hole 266a formed longitudinally along the axial direction, or a plurality of shaft-side locking holes 266b formed at intervals along the axial direction of the input shaft 60, and the clamp member 251 is provided with a clamp-side locking hole 252 corresponding to at least one of the elongated hole 266a or the shaft-side locking hole 266b, and the inner shaft 65 and the outer shaft 61 are locked so as not to rotate relative to each other by inserting the shaft member 253 through the shaft-side locking hole 266b via the clamp-side locking hole 252.

[0113] The single-screw pump 200 of the present invention, by having the configuration described in (h) above, can receive torque from the input shaft 60, etc., with the shaft member 253. Therefore, the single-screw pump 1 of the present invention can appropriately transmit rotation from the drive unit to the rotor 5 via the input shaft 60, etc.

[0114] The above describes the configuration and operation and effects of the single-screw eccentric pump 200 according to the second modified example of the present invention. Next, an embodiment of the single-screw eccentric pump 300 according to the third modified example of the present invention will be described below with reference to Figures 4 and 5. Note that Figure 5 shows only the main parts, and the components of the pump body and other parts are not shown.

[0115] ≪Third Modification≫ The single-screw pump 300 according to the third modification has the same configuration as the single-screw pump 100 according to the first modification, except that the configuration of the telescopic mechanism 150 is changed to a telescopic mechanism 350. Therefore, a description of the configuration similar to that of the above-described embodiment will be omitted. Also, please note that the same reference numerals are used for the same components as in the embodiment of the single-screw pump 100 according to the first modification described above.

[0116] In the third modified example of the present invention, the single-screw eccentric pump 300, as shown in Figure 4, has a pump casing 20 that is elongated in the axial direction and a bearing housing 30 that is short in the axial direction. The pump casing 20 is also provided with an openable / closable cover 21, and the inside of the pump casing 20 can be accessed by opening the cover 21 in the direction of the arrow shown in the figure.

[0117] In the single-screw eccentric pump 300, the input shaft 60 is formed as a single, integrated shaft rather than a double-structured (nested) shaft, and the joint shaft 7 is divided into, for example, a first shaft 370 and a second shaft 372. The connecting ends of the first shaft 370 and the second shaft 372 are smaller in diameter than their outer diameter. Furthermore, the connecting ends of the first shaft 370 and the second shaft 372 are provided with a first shaft side locking hole 370a and a second shaft side locking hole 372a.

[0118] Furthermore, the telescopic mechanism 350 in the single-screw eccentric pump 300 is equipped with multiple (three in this third modified example) adjustment members of different lengths, as shown in Figures 5(a) to 5(c).

[0119] The telescopic mechanism 350 extends and retracts the joint shaft 7 in the axial direction by connecting the first shaft 370 and the second shaft 372 via at least one adjustment member 351 selected from among a plurality of adjustment members 351. The joint shaft 7 is formed by connecting the first shaft 370 and the second shaft 372 via the adjustment member 351. In other words, the adjustment member 351 in the third modified example functions as a coupling.

[0120] The adjustment member 351 is formed in a cylindrical shape when joined, and as shown in Figure 5(d), it is divided into two parts along the axial direction (radial direction). As shown in Figures 5(a) to 5(c), each adjustment member 351 has adjustment member-side locking holes 351a, 351a formed at intervals of L1, L2, and L3 in the axial direction. The adjustment member 351 can connect the first shaft 370 and the second shaft 372 by inserting the shaft members 352, 352 (also referred to as locking pins 352, 352) through the adjustment member-side locking holes 351a, 351a into the first shaft-side locking hole 370a and the second shaft-side locking hole 372a. In other words, as shown in Figures 5(a) to 5(c), the adjustment member 351 can maintain the distance between the first shaft 370 and the second shaft 372 at one of L1, L2, or L3.

[0121] Thus, the telescopic mechanism 350 in the single-screw eccentric pump 300 allows the joint shaft 7 to be extended or retracted in the axial direction by selectively using a plurality of adjustment members 351 of different lengths to connect the first shaft 370 and the second shaft 372. This allows the single-screw eccentric pump 300 to adjust the tightening allowance of the rotor 5 and stator 12. The adjustment members 351 can be replaced by opening the cover 21 (see Figure 4) and accessing them from outside the pump casing 20. The joint shaft 7 and input shaft 60 may also be divided into two or more parts as needed. Furthermore, the connection length of the adjustment members 351 can be changed in various configurations, such as a single member or a combination of multiple members, as needed.

[0122] A single-screw eccentric pump 300 according to a third modified example of the present invention can be configured as follows, for example, and this configuration can produce the following unique effects.

[0123] (i) In the single-screw eccentric pump 300 of the present invention, either one or both of the input shaft 60 or the joint shaft 7 are divided and formed into at least a first shaft 370 and a second shaft 372 along the axial direction, and the telescopic mechanism 350 is provided with a plurality of adjustment members 351 of different lengths to which the first shaft 370 and the second shaft 372 can be connected, and the input shaft 60 or the joint shaft 7, either one or both of them can be extended or retracted in the axial direction by connecting the first shaft 370 and the second shaft 372 via at least one of the plurality of adjustment members 351.

[0124] The single-screw eccentric pump 300 of the present invention allows the distance between the first shaft 370 and the second shaft 372 to be changed by arranging at least one of a plurality of adjustment members 351 of different lengths between the divided input shaft 60, etc. (first shaft 370 and second shaft 372). Therefore, the single-screw eccentric pump 300 of the present invention allows the length of the input shaft 60, etc. to be easily changed by replacing the initially installed adjustment member 351 with another adjustment member 351 of a different length. As a result, the single-screw eccentric pump 300 of the present invention allows for easy adjustment of the tightening allowance of the rotor 5 and stator 12, etc. Here, the adjustment member 351 can be arranged in various areas of the pump casing 20, bearing housing, etc., such as areas where maintenance holes accessible from the outside are provided.

[0125] The above describes the configuration and operation and effects of the single-screw eccentric pump 300 according to the third modification of the present invention. Next, an embodiment of the single-screw eccentric pump 400 according to the fourth modification of the present invention will be described below with reference to Figures 6 and 7. Note that Figures 6 and 7 omit the pump body and only show the telescopic mechanism 450.

[0126] ≪Fourth Modification≫ The single-screw pump 400 according to the fourth modification of the present invention has the same configuration as the single-screw pump 300 according to the third modification, except that the configuration of the telescopic mechanism 350 is changed to a telescopic mechanism 450. Therefore, a description of the configuration similar to that of the above-described embodiment will be omitted. Also, please note that the same reference numerals are used for the same components as in the above-described embodiment such as the single-screw pump 1.

[0127] The single-screw eccentric pump 400 according to the fourth modification of the present invention, although not shown in the figures, is similar to the single-screw eccentric pump 300 according to the third modification (see Figure 4) in that the pump casing 20 is formed to be elongated in the axial direction, and the bearing housing 30 is formed to be shorter in the axial direction. Furthermore, the pump casing 20 is provided with an openable and closable cover 21, and the inside of the pump casing 20 can be accessed by opening the cover 21.

[0128] Furthermore, as shown in Figures 6(a) to 6(c), the single-screw eccentric pump 400, like the single-screw eccentric pump 300 according to the third modification, has a joint shaft 7 that is divided into, for example, a first shaft 470 and a second shaft 472. The connecting ends of the first shaft 470 and the second shaft 472 are smaller in diameter than their outer diameter. In addition, a pair of first shaft side locking holes 470a, 470a are formed along the axial direction at the connecting end of the first shaft 470, and a pair of second shaft side locking holes 472a, 472a are formed along the axial direction at the connecting end of the second shaft 472. In the single-screw eccentric pump 400 according to the fourth modification, the telescopic mechanism 450 is equipped with an adjustment member 451.

[0129] The telescopic mechanism 450 extends and retracts the joint shaft 7 in the axial direction by moving the connection positions of the adjustment member 451 and the first shaft 470, and the adjustment member 451 and the second shaft 472, in the axial direction when connecting the first shaft 470 and the second shaft 472 via the adjustment member 451. The joint shaft 7 is formed by connecting the first shaft 470 and the second shaft 472 via the adjustment member 451. In other words, the adjustment member 451 in the fourth modified example functions as a coupling.

[0130] The adjustment member 451 is formed in a cylindrical shape when joined, and as shown in Figures 6(a) to 6(c), it is divided into two parts along the axial direction (radial direction). On both sides of the adjustment member 451 in the axial direction, a pair of adjustment member-side locking holes 451a, 451a are formed, spaced apart in the axial direction. In other words, the adjustment member 451 has four adjustment member-side locking holes 451a along the axial direction. The adjustment member 451 can be connected to the first shaft 470 by inserting the shaft member 452 (also referred to as the locking pin 452) through one of the pair of adjustment member-side locking holes 451a, 451a on the first shaft 470 side. The adjustment member 451 can also be connected to the second shaft 472 by inserting the shaft member 452 (also referred to as the locking pin 452) through one of the pair of adjustment member-side locking holes 451a, 451a on the second shaft 472 side.

[0131] Here, as shown in Figure 6(a), when the first shaft 470 and the second shaft 472 are connected via the adjustment member 451 in such a way that the gap between them is narrowest, the joint shaft 7 can be retracted to its minimum length. Also, as shown in Figure 6(b), when the first shaft 470 and the second shaft 472 are connected using the outer and inner locking holes 451a on the adjustment member side, the joint shaft 7 can be extended to an intermediate length. Furthermore, as shown in Figure 6(c), when the first shaft 470 and the second shaft 472 are connected via the adjustment member 451 in such a way that the gap between them is widest, the joint shaft 7 can be retracted to its maximum length. Note that in the above, it is possible to arbitrarily select which of the adjustment member side locking holes 451a, the first shaft side locking hole 470a, and the second shaft side locking hole 472a are used for connection.

[0132] Thus, the telescopic mechanism 450 in the single-screw eccentric pump 400 can selectively use a plurality of adjustment member-side locking holes 451a, first shaft-side locking hole 470a, and second shaft-side locking hole 472a, which are located at different positions in the axial direction, to change the axial connection position of the first shaft 370 and the second shaft 372. As a result, the single-screw eccentric pump 400 can extend and retract the joint shaft 7 in the axial direction to adjust the tightening allowance of the rotor 5 and stator 12. The extension and retraction operation of the joint shaft 7 by the telescopic mechanism 450 can be performed by opening the cover 21 (see Figure 4) and accessing it from outside the pump casing 20. The joint shaft 7 and input shaft 60 may also be divided into two or more parts as needed. Furthermore, the formation positions and number of adjustment member-side locking holes 451a, first shaft-side locking hole 470a, and second shaft-side locking hole 472a can be changed as needed.

[0133] A single-screw eccentric pump 400 according to the fourth modification of the present invention can be configured as follows, for example, and this configuration can produce the following unique effects.

[0134] (j) In the single-screw eccentric pump 400 of the present invention, either one or both of the input shaft 60 or the joint shaft 7 are divided and formed into at least a first shaft 470 and a second shaft 472 along the axial direction, and the telescopic mechanism 450 is equipped with an adjustment member 451 to which the first shaft 470 and the second shaft 472 can be connected, and the adjustment member 451 is configured to change the connection position along the axial direction with respect to at least one or both of the first shaft 470 and the second shaft 472, and by changing the connection position, either one or both of the input shaft 60 or the joint shaft 7 can be extended or retracted.

[0135] The single-screw eccentric pump 400 of the present invention allows the spacing between the first shaft 470 and the second shaft 472 to be adjusted because the adjustment member 451 can change the connection position along the axial direction with respect to at least one or both of the first shaft 470 and the second shaft 472. As a result, the spacing between the first shaft 470 and the second shaft 472 can be adjusted in the single-screw eccentric pump 400 of the present invention without attaching or detaching the adjustment member 451, making it easy to adjust the tightening allowance of the rotor 5 and the stator 12. Here, the adjustment member 451 can be, for example, one that can change the connection position by sliding along the axial direction with respect to either one or both of the first shaft 470 and the second shaft 472. Alternatively, the adjustment member 451 can be, for example, a clamp member that can grip (clamp) the first shaft 470 or the second shaft 472. The adjustment member 451 can be placed in various areas of the pump casing 20 or bearing housing 30, such as areas with externally accessible maintenance holes.

[0136] Furthermore, in the fourth modified example of the single-axis eccentric screw pump 400, as shown in Figure 7, the first shaft 470 and the second shaft 472 can also be constructed of a flexible material. In this configuration, it is preferable that the first shaft side connection part 471, which is the connection end of the first shaft 470, and the second shaft side connection part 473, which is the connection end of the second shaft 472, are connected via the adjustment member 451 described above. Here, the joint shaft 7 should be appropriately widened in the intermediate part that does not contribute to eccentricity in order to ensure a thickness suitable for providing the telescopic mechanism 450 (adjustment member 451). This makes it easier to mount the telescopic mechanism 450 and also ensures rigidity, so the effect of preventing twisting and buckling can be expected. Note that although a detailed diagram of the adjustment member 451 is omitted in Figure 7, it should be noted that an adjustment member 451 similar to that in Figure 6 is provided.

[0137] Thus, the single-screw eccentric pump 400 according to the fourth modification of the present invention can be configured as shown in (k) below, thereby achieving the following unique effects.

[0138] (k) The single-screw eccentric pump 400 of the present invention is characterized in that at least a portion of the first shaft 470 and the second shaft 472 are formed of a flexible material, the connecting ends of the first shaft 470 and the second shaft 472 form a first shaft side connecting portion 471 and a second shaft side connecting portion 473, and the first shaft side connecting portion 471 and the second shaft side connecting portion 473 are connected via an adjustment member 451.

[0139] The single-screw pump 1 of the present invention, with this configuration, allows the input shaft 60 or the joint shaft 7 (referred to as the input shaft 60, etc.) to be extended or retracted via the adjustment member 451, even if either one or both are made of a flexible material. In other words, the single-screw pump 400 of the present invention, with the configuration described in (k) above, allows adjustment of the tightening allowance of the rotor 5 and stator 12 via the adjustment member 451, even if the input shaft 60, etc. is made of a flexible rod. If it is desired to improve the connectivity of the first shaft 470 and the second shaft 472 or to ensure rigidity, for example, at least one of the first shaft side connection portion 471 and the second shaft side connection portion 473 can be made larger in diameter than the parts other than the first shaft side connection portion 471 and the second shaft side connection portion 473.

[0140] The above describes the configuration and operation and effects of the single-screw eccentric pump 400 according to the fourth modification of the present invention. Next, an embodiment of the single-screw eccentric pump 500 according to the fifth modification of the present invention will be described below with reference to Figure 8. Note that Figure 8 omits the pump body and only shows the telescopic mechanism 550.

[0141] ≪Fifth Modification≫ The single-screw pump 500 according to the fifth modification of the present invention has the same configuration as the single-screw pump 400 according to the fourth modification, except that the configuration of the telescopic mechanism 450 is changed to a telescopic mechanism 550. Therefore, a description of the configuration, which is the same as that of the above-described embodiment, will be omitted. Also, please note that the same reference numerals are used for the same components as in the above-described embodiment such as the single-screw pump 1.

[0142] In the fifth modified example, the single-screw eccentric pump 500, as shown in Figures 8(a) and 8(b), has a joint shaft 7 that is divided into an outer shaft 570 and an inner shaft 575. The outer shaft 570 and the inner shaft 575 have a double-cylindrical nesting structure and are considered to constitute part of the telescopic mechanism 550.

[0143] The outer shaft 570 is formed in a cylindrical shape, and a circular hollow hole 571 is formed along its axial direction. The hollow hole 571 extends partway along the axial direction of the outer shaft 570. On the outer circumference of the portion of the outer shaft 570 in which the hollow hole 571 is formed, a screw groove is formed, which serves as the outer shaft side screw portion 572.

[0144] The inner shaft 575 is formed in a cylindrical shape along its axial direction and is slidably inserted into the hollow hole 571 via a key. Therefore, the inner shaft 575 is movable relative to the outer shaft 570 along its axial direction and can rotate integrally with the outer shaft 570. The inner shaft 575 has a larger diameter in a portion of its outer circumference that is exposed from the hollow hole 571, so that it is the same diameter as the outer circumference of the outer shaft 570. The inner shaft 575 has a threaded groove formed on the outer circumference of the enlarged portion, which serves as the inner shaft side threaded portion 576. That is, the inner shaft side threaded portion 576 is formed on the outer circumference of the exposed portion of the inner shaft 575 that is not inserted into the hollow hole 571. The outer shaft side threaded portion 572 and the inner shaft side threaded portion 576 have threads cut in opposite directions.

[0145] The adjustment member 551 has a first threaded portion 552 and a second threaded portion 553 whose screwing directions are opposite to each other. The first threaded portion 552 and the second threaded portion 553 are integrally formed to form a nut member as the adjustment member 551.

[0146] The first screw 552 is screwed into the outer shaft side threaded portion 572. As shown in Figure 8(a), the first screw portion 552 can be moved in its screwed position until a portion of it protrudes axially from the outer peripheral edge of the outer shaft 570 while being screwed into the outer shaft side threaded portion 572. The first screw portion 552 is equipped with a lock nut 552a and a set screw 552b. The lock nut 552a fixes the first screw portion 552 in an appropriate screwed position and prevents the adjustment member 551 from falling off the outer shaft 570. The set screw 552b prevents the lock nut 552a from loosening.

[0147] The second threaded portion 553 is screwed into the inner shaft-side threaded portion 576. The second threaded portion 553 can be moved in its screwed position until a portion of it protrudes axially from the inner shaft 575 while being screwed into the inner shaft-side threaded portion 576.

[0148] As shown in Figure 8(a), the telescopic mechanism 550 can pull out the inner shaft 575 from the hollow hole 571 by moving the screwing position so that the first threaded portion 552 and the second threaded portion 553 move together toward the connecting end. This extends the joint shaft 7. On the other hand, as shown in Figure 8(b), the telescopic mechanism 550 can move the inner shaft 575 toward the inside of the hollow hole 571 by moving the first threaded portion 552 and the second threaded portion 553 together toward the inner shaft 575. This retracts the joint shaft 7.

[0149] As described above, the single-screw eccentric pump 500 according to the fifth modified example can change the relative axial position of the inner shaft 575 and the outer shaft 570 by moving the screwing positions of the first screw portion 552 and the second screw portion 553 along the axial direction. This allows the single-screw eccentric pump 500 to adjust the tightening allowance of the rotor 5 and the stator 12. The extension and retraction operation of the joint shaft 7 by the extension and retraction mechanism 450 can be performed by opening the cover 21 (see Figure 4) and accessing it from outside the pump casing 20. Furthermore, by configuring the first screw portion 552 and the second screw portion 553 to be driven by actuators or the like as appropriate, it is possible to automate the adjustment of the tightening allowance of the rotor 5 and the stator 12.

[0150] A single-screw eccentric pump 500 according to the fifth modified example of the present invention can be configured as follows, for example, and this configuration can produce the following unique effects.

[0151] (l) In the single-screw eccentric pump 500 of the present invention, the outer shaft 570 has an outer shaft side threaded portion 572 formed on its outer circumference, and the inner shaft 575 has an inner shaft side threaded portion 576 formed on the outer circumference of the exposed portion not inserted into the hollow hole 571, with threads cut in the opposite direction to the outer shaft side threaded portion 572, and the adjustment member 551 has a first threaded portion 552 and a second threaded portion 553 whose screwing directions are opposite to each other, and the first threaded portion 552 and the outer shaft side threaded portion 572, and the second threaded portion 553 and the inner shaft side threaded portion 576 are screwed together, and the relative position of the inner shaft 575 and the outer shaft 570 is changed by moving the screwing position of the first threaded portion 552 and the second threaded portion 553 along the axial direction.

[0152] In the single-screw eccentric pump 500 of the present invention, the first threaded portion 552 and the second threaded portion 553 constituting the adjustment member 551 are formed as opposite threads to each other, and the relative position of the inner shaft 575 and the outer shaft 570 can be changed by moving the screwed position of the first threaded portion 552 and the second threaded portion 553 along the axial direction. As a result, the single-screw eccentric pump 500 of the present invention can easily adjust the tightening allowance of the rotor 5 and the stator 12. Here, it is preferable that the adjustment member 551 is provided with a lock nut 552a for fixing the screwed position of the first threaded portion 552 and the second threaded portion 553. Furthermore, it is preferable that either or both of the inner shaft 575 and the outer shaft 570 be provided with a stopper (engaging portion) that suppresses at least one of the extension or contraction of the inner shaft 575 and the outer shaft 570 in the axial direction. Furthermore, the first threaded member 552 and the second threaded portion 553 can be arranged in various areas of the pump casing 20, bearing housing 30, etc., such as areas where maintenance holes accessible from the outside are provided.

[0153] The above describes the configuration and operation and effects of the single-screw eccentric pump 500 according to the fifth modification of the present invention. Next, an embodiment of the single-screw eccentric pump 600 according to the sixth modification of the present invention will be described below with reference to Figure 9. Note that Figure 9 omits the pump body and only shows the telescopic mechanism 650.

[0154] ≪Sixth Modification≫ The single-screw pump 600 according to the sixth modification of the present invention has the same configuration as the single-screw pump 500 according to the fifth modification, except that the configuration of the telescopic mechanism 550 is changed to a telescopic mechanism 650. Therefore, a description of the configuration, which is the same as that of the above-described embodiment, will be omitted. Also, please note that the same reference numerals are used for the same components as in the embodiment of the single-screw pump 100 according to the first modification described above.

[0155] In the sixth modified example, the single-axis eccentric screw pump 600, as shown in Figure 9, has a joint shaft 7 that is divided into an outer shaft 670 and an inner shaft 675. The outer shaft 670 and the inner shaft 675 have a double-cylindrical nesting structure and are considered to constitute part of the telescopic mechanism 650.

[0156] The outer shaft 670 is formed in a cylindrical shape, and a circular hollow hole 671 is formed along its axial direction. The hollow hole 671 extends over substantially the entire axial length of the outer shaft 670.

[0157] The telescopic mechanism 650 includes a drive unit 680, a generator 682, a control unit 684, and a battery 686, etc., which are housed in the hollow hole 671. The telescopic mechanism 650 also includes a screw shaft 652 and a nut member 656, etc., which constitute the adjustment member 651.

[0158] The inner shaft 675 is formed in a cylindrical shape along its axial direction and is inserted into the hollow hole 671 so as to be movable in the axial direction. Therefore, the inner shaft 675 is movable relative to the outer shaft 670 along its axial direction.

[0159] The screw shaft 652 is housed inside the hollow hole 671 and is rotatably supported on the axis of the hollow hole 671. The screw shaft 652 is supported on its base end by a gear 653a, and rotates integrally with the gear 653a by rotating the gear 653a.

[0160] An outer peripheral gear 653b that meshes with gear 653a is provided on the outer circumference side of gear 653a. The outer peripheral gear 653b is rotatably supported in a hollow hole 671 (outer shaft 670). The outer peripheral gear 653b is supported by a bracket 654 and can rotate integrally with the bracket 654.

[0161] The drive unit 680 is composed of an electric motor, such as a servo motor, and is fixed to the hollow hole 671 so as not to rotate relative to it. The drive shaft of the drive unit 680 is connected to the bracket 654. Therefore, by rotating the drive unit 680, the bracket 654 is rotated, and the outer gear 653b rotates. In addition, as the outer gear 653b rotates, the gear 653a is rotated, and the screw shaft 652 rotates.

[0162] The nut member 656 is fixed to the insertion end of the inner shaft 675 into the hollow hole 671. In other words, the nut member 656 is attached to the inner shaft 675 in a way that prevents relative rotation. The nut member 656 is also screwed onto the screw shaft 652. Therefore, when the screw shaft 652 is rotated, the nut member 656 moves axially together with the inner shaft 675. This allows the inner shaft 675 to move relative to the outer shaft 670.

[0163] The generator 682 is housed in a hollow hole 671, and its main body is supported so as not to rotate relative to the outer shaft 670. The generator 682 has a weight 682a housed in the hollow hole 671. The weight 682a is rotatably supported relative to the generator 682. Here, the generator 682 rotates together with the outer shaft 670, and the weight 682a comes to rest vertically downwards due to its own weight. As a result, the generator 682 can generate electricity. The generator 682 is directly or indirectly connected to the drive unit 680 and can supply the generated electricity to the drive unit 680. Note that the generator 682 is not limited to one that generates electricity using the weight 682a; various types of generators can be used. For example, the generator 682 may utilize a MEMS (micro-electromechanical system) (for example, one that generates electricity using acceleration or vibration).

[0164] The battery 686 is directly or indirectly connected to the drive unit 680, the generator 682, and the control unit 684. The battery 686 can supply power to the drive unit 680 and the control unit 684. The battery 686 can also store the power generated by the generator 682. The battery 686 can be any type of rechargeable battery, such as a lithium-ion battery, nickel-metal hydride battery, or nickel-cadmium battery.

[0165] The control unit 684 can control the generator 682, the drive unit 680, and the battery 686. For example, the control unit 684 can control the relative movement of the inner shaft 675 with respect to the outer shaft 670 by controlling the amount of drive of the drive unit 680. Therefore, the single-axis eccentric screw pump 600 according to the sixth modified example can automatically adjust the tightening tolerance of the rotor 5 and stator 12, etc., under the control of the control unit 684.

[0166] A single-screw eccentric pump 600 according to six modifications of the present invention can be configured, for example, as follows, and this configuration can produce the following unique effects.

[0167] (m) In the single-screw eccentric pump 600 of the present invention, the telescopic mechanism 650 comprises a drive unit 680 housed in a hollow hole 671 that moves the inner shaft 675 relative to the outer shaft 670, a generator 682 housed in the hollow hole 671 that generates electricity in conjunction with the rotation of the outer shaft 670, a control unit 684 housed in the hollow hole 671 that controls the drive of at least the drive unit 680, and a battery 686 housed in the hollow hole 671 that supplies power to at least the drive unit 680 and the control unit 684, and stores the power generated by the generator 682, and is characterized in that the relative positions of the inner shaft 675 and the outer shaft 670 in the axial direction are changed by the drive of the drive unit 680.

[0168] The single-screw pump 600 of the present invention, by having the configuration described in (m) above, can automatically change the relative position of the inner shaft 675 and the outer shaft 670 using electricity generated by a generator 682 housed in a hollow hole 671 of the outer shaft 670. Furthermore, since the drive unit 680, generator 682, control unit 684, and battery 686 are housed in the aforementioned hollow hole 671, the relative position of the inner shaft 675 and the outer shaft 670 can be changed within the outer shaft 670 (hollow hole 671). Therefore, the single-screw pump 600 of the present invention can be miniaturized. Here, for example, a generator 682 that generates electricity by the relative rotation of the body of the generator 682 and the weight 682a can be used. For example, the body of the generator 682 is fixed to the hollow hole 671 so as not to rotate relative to it, and the body of the generator 682 rotates with the rotation of the outer shaft 670 relative to the weight 682a.

[0169] (n) In the single-axis eccentric screw pump 600 of the present invention, the adjustment member 651 comprises a screw shaft 652 that is rotationally driven by a drive unit 680, and a nut member 656 that is screwed onto the screw shaft 652 and is movable along the axial direction of the screw shaft 652 by rotationally driving the screw shaft 652, wherein the nut member 656 is attached to the inner shaft 675 so as not to rotate relative to it, and is movable integrally with the inner shaft 675.

[0170] Since the single-screw eccentric pump 600 of the present invention has the configuration described in (n) above, the relative positions of the inner shaft 675 and the outer shaft 670 can be automatically changed by rotating the screw shaft 652 with the drive unit 680. Therefore, the single-screw eccentric pump 600 of the present invention can automatically adjust the tightening allowance of the rotor 5 and the stator 12.

[0171] The above describes the configuration and operation and effects of the single-screw eccentric pump 600 according to the sixth modification of the present invention. Next, an embodiment of the single-screw eccentric pump 700 according to the seventh modification of the present invention will be described below with reference to Figure 10. Note that Figure 10 omits the pump body and only shows the telescopic mechanism 750.

[0172] <<Seventh Modification>> The single-screw eccentric pump 700 according to the seventh modification of the present invention has the same configuration as the single-screw eccentric pump 600 according to the sixth modification, except that the configuration of the telescopic mechanism 650 is changed to a telescopic mechanism 750. Therefore, a description of the configuration, which is the same as that of the above-described embodiment, will be omitted. Also, please note that the same reference numerals are used for the same components as in the above-described embodiments such as the single-screw eccentric pumps 1 and 600.

[0173] The seventh modified example of the single-axis eccentric screw pump 700 has a telescopic mechanism 750 that eliminates the drive unit 680, generator 682, control unit 684, and battery 686 found in the telescopic mechanism 650 of the sixth modified example. That is, the telescopic mechanism 750 is equipped with a screw shaft 652 and a nut member 656. In addition to the above, the telescopic mechanism 750 is also equipped with a rotation direction changing unit 753, a link shaft 754, and an opening 755, etc.

[0174] In the single-screw eccentric pump 700, a rotating shaft 752 is connected to a bracket 654 instead of the drive unit 680 in the sixth modification. The rotating shaft 752 is positioned to extend along the axial direction of the inner shaft 675 and can rotate integrally with the bracket 654. In other words, the rotating shaft 752 functions as an extension of the screw shaft 652.

[0175] The rotating shaft 752 is provided with a first bevel gear 753a, which serves as a rotation direction changing section 753, at one end opposite to the side to which the bracket 654 is connected.

[0176] The link shaft 754 is provided in a direction that intersects with the screw shaft 652 and the rotation shaft 752. In the seventh modified example, the link shaft 754 is arranged in a direction perpendicular to the screw shaft 652 and the rotation shaft 752. That is, the link shaft 754 is arranged in a direction perpendicular to the axial direction of the hollow hole 671. Therefore, one end of the link shaft 754 is positioned radially outward from the outer shaft 670.

[0177] A second bevel gear 753b, which serves as a rotation direction conversion section 753, is provided at the other end of the link shaft 754 (radially inward of the hollow hole 671). The first bevel gear 753a and the second bevel gear 753b are meshed so as to be perpendicular to each other. Therefore, the rotation direction of the link shaft 754 is converted to the rotation direction of the screw shaft 652 and the rotating shaft 752.

[0178] The opening 755 is located on the outer shaft 670, and one end of the link shaft 754 is inserted through it. In other words, the opening 755 allows the link shaft 754 to be rotated from the outside of the outer shaft 670. Therefore, by rotating the link shaft 754 through the opening 755, the rotating shaft 752 and the screw shaft 652 are rotationally driven via the link shaft 754, causing the inner shaft 675 to move axially relative to the outer shaft 670. This allows the single-axis eccentric screw pump 700 to adjust the tightening allowance of the rotor 5 and stator 12, etc.

[0179] A single-screw eccentric pump 700 according to seven modifications of the present invention can be configured, for example, as follows, and this configuration can produce the following unique effects.

[0180] (o) In the single-axis eccentric screw pump 700 of the present invention, the telescopic mechanism 750 comprises a screw shaft 652 that is rotationally driven by power, a nut member 656 that is screwed onto the screw shaft 652 and can move along the axial direction of the screw shaft 652 by rotationally driving the screw shaft 652, a link shaft 754 provided in a direction intersecting the screw shaft 652, a rotation direction conversion unit 753 that converts the rotation direction of the link shaft 754 to the rotation direction of the screw shaft 652, and an opening 755 that opens in the outer shaft 670 and allows the link shaft 754 to be rotated from the outside of the outer shaft 670, wherein the nut member 656 is attached to the inner shaft 675 so as not to rotate relative to it and is movable integrally with the inner shaft 675, and by rotating the link shaft 754 through the opening 755, the screw shaft 652 is rotated and the relative position of the inner shaft 675 and the outer shaft 670 in the axial direction is changed.

[0181] The single-screw pump 700 of the present invention, by having the configuration described in (o) above, allows the relative position of the inner shaft 675 and the outer shaft 670 to be changed by operating the link shaft 754 from outside the outer shaft 670 through the opening 755 of the outer shaft 670. As a result, the single-screw pump 700 of the present invention allows adjustment of the tightening allowance of the rotor 5 and stator 12 by operating from outside the outer shaft 670, dramatically improving the operability of such adjustments and facilitating automation.

[0182] The above describes the configuration and operation and effects of the single-screw eccentric pump 700 according to seven modifications of the present invention. Next, an embodiment of the single-screw eccentric pump 800 according to eight modifications of the present invention will be described below with reference to Figure 11. Note that Figure 11 omits the pump body and only shows the telescopic mechanism 850.

[0183] <Eighth Modification> The single-screw eccentric pump 800 according to the eighth modification of the present invention has the same configuration as the single-screw eccentric pump 1 according to the above-described embodiment, except that the configuration of the telescopic mechanism 50 is changed to a telescopic mechanism 850. Therefore, a description of the configuration similar to that of the above-described embodiment will be omitted. Also, please note that the same reference numerals are used for the same components as in the above-described embodiments such as the single-screw eccentric pumps 1 and 600.

[0184] In the eighth modified example, the single-axis eccentric screw pump 800 is configured such that the adjustment member 851 in the telescopic mechanism 850 comprises a cylinder 852 and a piston 853.

[0185] The cylinder 852 is configured as an outer shaft. The cylinder 852 is provided with a hollow hole 852a. The piston 853 is configured as an inner shaft and is also capable of moving back and forth within the hollow hole 852a. Therefore, the cylinder 852 and piston 853 form a cylinder chamber 854.

[0186] The cylinder chamber 854 is provided with an intake / exhaust port 856 for drawing in and expelling liquids such as oil, or gases such as air (hereinafter, both are collectively referred to as liquids, etc.). In the eighth modification, the liquids, etc. drawn in and expelled from the intake / exhaust port 856 are distributed to and can also be drawn in and expelled from the piston chamber 855 that houses the piston 853. That is, by adjusting the pressure balance between the cylinder chamber 854 and the piston chamber 855, relative movement of the cylinder 852 and the piston 853 in the axial direction is achieved. This allows the single-axis eccentric screw pump 800 to adjust the tightening tolerance of the rotor 5 and the stator 12, etc. Furthermore, if a cylinder 852 with a locking mechanism is used, for example, the piston 853 can be fixed in a predetermined position.

[0187] The single-screw eccentric pump 800 according to the eighth modification of the present invention can be configured as follows, for example, and this configuration can produce the following unique effects.

[0188] (p) In the single-screw eccentric pump 800 of the present invention, the adjustment member 851 comprises a cylinder 852 that constitutes an outer shaft and a piston 853 that constitutes an inner shaft and is movable in and out of a hollow hole 852a provided in the cylinder 852, and is characterized in that relative movement of the cylinder 852 and the piston 853 in the axial direction can be performed by drawing in or discharging liquid or gas into a cylinder chamber 854 formed by the cylinder 852 and the piston 853.

[0189] The single-screw eccentric pump 800 of the present invention allows the piston 853 to move back and forth in the hollow hole 852a by drawing in or discharging liquid or gas into the cylinder 852, thereby allowing the input shaft 60 to be extended or retracted in the axial direction through the movement of the piston 853. Therefore, the single-screw eccentric pump 800 of the present invention allows for easy adjustment of the overlap between the rotor 5 and the stator 12 by controlling the pressure applied to the cylinder 852. Furthermore, since the single-screw eccentric pump 800 of the present invention allows for adjustment of the overlap between the rotor 5 and the stator 12 by controlling the pressure of the cylinder 852, automation can be easily performed.

[0190] The above describes the configuration and operation and effects of the single-screw eccentric pump 800 according to the eighth modification of the present invention. Next, an embodiment of the single-screw eccentric pump 900 according to the ninth modification of the present invention will be described below with reference to Figure 12. Note that Figure 12 omits the pump body and only shows the telescopic mechanism 950.

[0191] <<Ninth Modification>> The single-screw pump 900 according to the ninth modification of the present invention has the same configuration as the single-screw pump 300 according to the third modification, except that the configuration of the telescopic mechanism 350 is changed to a telescopic mechanism 950. Therefore, a description of the configuration, which is the same as that of the above-described embodiment, will be omitted. Also, please note that the same reference numerals are used for the same components as in the above-described embodiments such as the single-screw pumps 1 and 300.

[0192] The ninth modified single-screw pump 900, as shown in Figures 12(a) and 12(b), has an adjustment member 951, known as a pin joint, provided at the joint 9 as an extension mechanism 950. The adjustment member 951 comprises an outer member 952 and an inner member 953.

[0193] The outer member 952 is connected to the base end of the rotor 5 and is formed along the axial direction of the input shaft 60 (see Figure 4). The outer member 952 is formed in a cylindrical shape and is designed to house the inner member 953, which will be described later. The outer member 952 has a pair of outer locking holes 952a and 952b formed at intervals in the axial direction.

[0194] The inner member 953 is provided at one end of the joint shaft 7 on the rotor 5 side. The inner member 953 is formed in a substantially spherical shape and can move relative to the outer member 952 in the axial direction of the input shaft 60. An inner locking hole 953a is formed in the inner member 953. The joint shaft 7 is connected eccentrically to the input shaft 60 so that it can rotate eccentrically.

[0195] Figure 12(a) is an explanatory diagram showing the state in which the joint shaft 7 is retracted by the telescopic mechanism 950. As shown in the figure, the shaft member 954 (also referred to as the locking pin 954) is inserted into the inner locking hole 953a via the outer locking hole 952a closer to the rotor 5. As a result, the outer member 952 and the inner member 953 are fixed so that they cannot move relative to each other, and the joint shaft 7 is retracted in the axial direction of the input shaft 60.

[0196] Figure 12(b) is an explanatory diagram showing the state in which the joint shaft 7 is extended by the extension mechanism 950. As shown in the figure, the shaft member 954 is inserted into the inner locking hole 953a via the outer locking hole 952b on the joint shaft 7 side. As a result, the outer member 952 and the inner member 953 are fixed so that they cannot move relative to each other, and the joint shaft 7 is extended.

[0197] Thus, the ninth modified example of the single-axis eccentric screw pump 900 allows the joint shaft 7 to be extended or retracted in the axial direction of the input shaft 60 by changing the position through which the shaft member 954 is inserted along the axial direction.

[0198] Here, the ninth modified example of the single-axis eccentric screw pump 900 allows for a modification of part of the telescopic mechanism 950, as shown in Figure 13. The telescopic mechanism 950 includes an adjustment member 956, which is a modified part of the adjustment member 951.

[0199] The modified adjustment member 956 has an outer member 957 and an inner member 958 in a nested structure. That is, the inner member 958 is provided so as to be able to move relative to the outer member 957 in the axial direction of the input shaft 60 (see Figure 4).

[0200] The inner member 958 is formed in a cylindrical shape, and one end of the joint shaft 7 is inserted into it. The insertion end of the joint shaft 7 into the inner member 958 is formed in a substantially spherical shape and is connected to the inner member 958 via the shaft member 954 so as to be unable to rotate relative to it. The joint shaft 7 is positioned eccentrically with respect to the axial direction of the input shaft 60 (inner member 958) so that it can rotate eccentrically.

[0201] The outer member 957 is formed, for example, in a cylindrical shape and has a hollow hole 957a. The inner member 958 is inserted into the hollow hole 957a so as to be movable relative to it in the axial direction. Therefore, by moving the inner member 958 relative to the outer member 957 in the axial direction, the joint shaft 7 moves in the axial direction of the input shaft 60. This allows the single-axis eccentric screw pump 900 to adjust the tightening allowance of the rotor 5 and the stator 12. It is preferable to provide the outer member 957 and the inner member 958 with a locking mechanism or engaging pin, etc., as appropriate, so that they can be fixed and not moved relative to each other.

[0202] A single-screw eccentric pump 900 according to nine modifications of the present invention can be configured, for example, as follows, and this configuration can produce the following unique effects.

[0203] (q) In the single-screw eccentric pump 900 of the present invention, the telescopic mechanism 950 has an adjustment member 956 in the joint portion 9, and the adjustment member 956 comprises an outer member 952 connected to either the rotor 5 side or the input shaft 60 side and formed along the axial direction of the input shaft 60, and an inner member 953 connected to either the rotor 5 side or the input shaft 60 side and movable relative to the outer member 952 in the axial direction, and is characterized by changing the relative positions of the outer member 952 and the inner member 953.

[0204] The single-screw eccentric pump 900 of the present invention can change the relative positions of the outer member 952 and the inner member 953 by having the configuration described in (q) above. This allows the single-screw eccentric pump 900 of the present invention to easily adjust the tightening allowance of the rotor 5 and the stator 12. In this configuration, either the outer member 952 or the inner member 953 has a plurality of locking holes (for example, outer locking holes 952a, 952b) formed at predetermined intervals along the axial direction of the input shaft 60, and the other of the outer member 952 or the inner member 953 is provided with another locking hole (for example, an inner locking hole 953a) corresponding to at least one of the aforementioned locking holes (for example, outer locking holes 952a, 952b), and a shaft member 954 (locking pin 954) that can engage with both locking holes. Therefore, the telescopic mechanism 950 (adjustment member 956) can change the relative position of the outer member 952 and the inner member 953 by engaging the shaft member 954 with one of the multiple locking holes (for example, the outer locking holes 952a and 952b in this embodiment). This allows the single-axis eccentric screw pump 900 of the present invention to easily adjust the tightening allowance of the rotor 5 and the stator 12. Here, the multiple locking holes may be provided on the inner member 953 side rather than the outer member 952 side. In such cases, it is preferable to provide other locking holes on the outer member 952. Furthermore, the joint portion 9 (adjustment member 956) can be positioned in various areas of the pump casing 20, such as an area where an externally accessible maintenance hole is provided.

[0205] The above describes the configuration and operation and effects of the single-screw eccentric pump 900 according to the ninth modification of the present invention. Next, an embodiment of the single-screw eccentric pump 1000 according to the tenth modification of the present invention will be described below with reference to Figure 14. Note that Figure 14 omits the pump body and only shows the telescopic mechanism 1050.

[0206] ≪Tenth Modification≫ The single-screw pump 1000 according to the tenth modification of the present invention has the same configuration as the single-screw pump 900 according to the ninth modification, except that the configuration of the telescopic mechanism 950 is changed to a telescopic mechanism 1050. Therefore, a description of the configuration, which is the same as that of the above-described embodiments, will be omitted. Also, please note that the same reference numerals are used for the same components as in the above-described embodiments such as the single-screw pumps 1 and 300.

[0207] In the tenth modified example, the single-screw eccentric pump 1000, as shown in Figures 14(a) and 14(b), has an adjustment member 1051 provided at the joint 9 as an extension mechanism 1050. The adjustment member 1051 comprises a plurality of first engaging members 1052 and second engaging members 1053, etc., with different lengths in the axial direction. In the tenth modified example, the case in which the extension mechanism 1050 is provided with an adjustment member 1051, for example, called an Oldham joint, will be described as an example.

[0208] As shown in Figure 14(a), the first engaging member 1052 is formed, for example, as a female disc. As shown in Figure 14(b), multiple first engaging members 1052 (two in the tenth modified example) with different lengths in the axial direction are provided. As shown in Figure 14(a), a recess 1052a is formed at one end of the first engaging member 1052 on the rotor 5 side. The recess 1052a is formed along a direction perpendicular to the axial direction of the input shaft 60. The projection 1053a of the second engaging member 1053, which will be described later, is engaged with the recess 1052a, thereby connecting the second engaging member 1053 and the first engaging member 1052.

[0209] Furthermore, the input shaft 60 is connected to the other end of the first engaging member 1052. At the connection end of the input shaft 60 to the first engaging member 1052, a projection (not shown) similar to the projection 1053a of the rotor 5 is formed in a direction perpendicular to the axial direction of the input shaft 60. The first engaging member 1052 has a recess (not shown) similar to the recess 1052a of the rotor 5 formed on its other end, and by engaging with the projection on the input shaft 60, it is connected so as to be movable in a direction intersecting the axial direction of the input shaft 60 (for example, a direction perpendicular to it).

[0210] The second engaging member 1053 is connected to the base end of the rotor 5 and has a projection 1053a formed along a direction perpendicular to the axial direction. The second engaging member 1053 engages with the recess 1052a of the first engaging member 1052. Therefore, the second engaging member 1053 is connected to the first engaging member 1052 so as to be movable along a direction perpendicular to the axial direction of the input shaft 60 relative to the first engaging member 1052. Furthermore, the rotor 5 and the input shaft 60 are indirectly connected by the connection of the first engaging member 1052 and the second engaging member 1053. In addition, the second engaging member 1053 is connected at an eccentric position with respect to the axis of the first engaging member 1052.

[0211] Here, as shown in Figure 14(b), the input shaft 60 is extended in the axial direction by replacing the first engaging member 1052 with a longer first engaging member 1052. In this way, the single-axis eccentric screw pump 1000 according to the tenth modified example can extend or retract the input shaft 60 in the axial direction by selectively using a plurality of first engaging members 1052 of different lengths.

[0212] A single-screw eccentric pump 1000 according to the tenth modified version of the present invention can be configured as follows, for example, and this configuration can produce the following unique effects.

[0213] (r) In the single-screw eccentric pump 1000 of the present invention, the telescopic mechanism 1050 has an adjustment member 1051 in the joint portion 9, the adjustment member 1051 comprises a plurality of first engaging members 1052 having different lengths in the axial direction, and a second engaging member 1053 that slidably engages with one of the first engaging members 1052 selected from the plurality of first engaging members 1052, and is characterized in that by engaging at least one of the plurality of first engaging members 1052 selected from the plurality with the second engaging member 1053, either one or both of the input shaft 60 or the joint shaft 7 can be extended or retracted in the axial direction.

[0214] The single-screw eccentric pump 1000 of the present invention, by having the configuration described in (r) above, allows the connection length in the axial direction of the input shaft 60 to be changed by selecting a first engaging member 1052 of an appropriate length from a plurality of first engaging members 1052 of different lengths. This allows the single-screw eccentric pump 1000 of the present invention to adjust the tightening allowance of the rotor 5 and stator 12. Here, the first engaging member 1052 can be formed, for example, as a female disc (male disc) as an Oldham joint, and the second engaging member 1053 can be formed as a male disc (female disc) that can engage with the corresponding female disc (male disc).

[0215] The above describes the configuration and operation and effects of the single-screw eccentric pump 1000 according to the tenth modified version of the present invention. Hereinafter, the above-described embodiment and the single-screw eccentric pump 1 according to the first to tenth modified versions can adopt the following configuration (s).

[0216] (s) The single-screw eccentric pump 1 of the present invention is characterized by comprising a pump casing 20 that houses an extension mechanism 50, and the pump casing 20 having an access area that allows access to at least a part of the extension mechanism 50.

[0217] The single-screw eccentric pump 1 of the present invention, by having the configuration described in (s) above, has an accessible access area in the pump casing 20 that houses the telescopic mechanism 50, so that the telescopic mechanism 50 can be accessed through this access area. Therefore, with the single-screw eccentric pump 1 of the present invention, the telescopic mechanism 50 can be easily extended and retracted and maintained through the access area. Here, the access area can be formed, for example, by providing an openable or detachable lid 21 on the pump casing 20. When using the lid 21 as the access area, it is desirable that the space between the pump casing 20 and the lid 21 be sealed with a seal or the like.

[0218] The above describes various embodiments of the single-screw eccentric pump of the present invention. However, the single-screw eccentric pump of the present invention is not limited to the embodiments described above or the first to tenth modified examples, and various modifications can be made within the scope of the invention. For example, the single-screw eccentric pump of the present invention may not have some or all of the components described in (b) to (s) above, or it may have some or all of the components described in (b) to (s) above, along with other components.

[0219] In this embodiment, the input shaft 60 is connected to the rotor 5 via a joint shaft 7. However, various forms of input shafts 60 can be used, such as those connected to the rotor 5 without a joint shaft 7, or those having one or more joint shafts 7. Also, in this embodiment, the rotor 5 is formed as a single groove, but various numbers of grooves can be used for the rotor 5. Furthermore, the shape, size, and material of the rotor 5 can be changed to various types depending on the type of fluid, etc. Also, various types of stators 12 with different numbers of grooves can be used depending on the number of grooves of the rotor 5. Various shapes, sizes, and materials of the stator 12 can be used depending on the shape, size, and material of the rotor 5.

[0220] In this embodiment, the outer diameter of the rotor 5 and the inner diameter of the inner bore 12a of the stator 12 are formed to decrease from the rear end to the front end. However, the present invention is not limited to this, and it is acceptable as long as either or both of the outer diameter of the rotor 5 and the inner diameter of the inner bore 12a of the stator 12 are formed to decrease from one end to the other, or the eccentricity of the rotor 5 is changed, or both of these are possible. It is also possible that the inner diameters of the rotor 5 and the inner bore 12a of the stator 12 do not change from one end to the other, but this makes it difficult to adjust the tightening allowance, etc., by moving the rotor 5 relative to the stator 12. Therefore, it is desirable that either or both of the inner diameters of the rotor 5 and the inner bore 12a of the stator 12 are formed to decrease from one end to the other.

[0221] In this embodiment, the input shaft 60 is configured as a nested structure with an outer shaft 61 and an inner shaft 65. However, the input shaft 60 and joint shaft 7 are not limited to nested structures; various means of relative movement, such as those that can slide against each other, can be used. Furthermore, the input shaft 60 and joint shaft 7 may be formed in various quantities. The input shaft 60 and joint shaft 7 can be of various lengths, outer diameters, and materials.

[0222] In this modified example, the configuration is as shown in (r) above, but the first engaging member 1052 can be of various lengths, and various shapes and sizes can be used. The second engaging member 1053 can also be of various shapes and sizes. Furthermore, whether the first engaging member 1052 or the second engaging member 1053 is female or male can be appropriately selected depending on the connection configuration. In addition, although this modified example uses an Oldham joint, the present invention is not limited to this, and various connection means can be used.

[0223] In this embodiment, the pump casing 20 is provided with an access area that allows access to at least a part of the telescopic mechanism 50. However, the access area may be provided only as needed, and a configuration without an access area is also possible. In such a case, the single-screw eccentric pump 1 may be disassembled to access the access area. Alternatively, the access area may utilize a maintenance hole or the like.

[0224] The above describes various embodiments and modifications of the single-screw eccentric pump according to the present invention. However, the present invention is not limited to those exemplified in the embodiments and modifications described above, and it will be readily apparent to those skilled in the art that other embodiments may exist in the spirit and teachings thereof, without departing from the scope of the claims.

[0225] The single-screw eccentric pump of the present invention can be used as a pump for transferring various fluids (especially viscous fluids).

[0226] 1 Single-screw eccentric pump 5 Rotor (male screw type rotor) 7 Joint shaft (connecting shaft) 9 Joint part (connecting part) 12 Stator (female screw type stator) 12a Inner bore 20 Pump casing 50 Telescopic mechanism 51 Adjustment member 60 Input shaft 61 Outer shaft 62 Hollow hole 65 Inner shaft 66 Engagement part 70 Locking part 71 Nut member 100 Single-screw eccentric pump 151 Nut member 153 Bolt (adjustment member) 152 Threaded part 200 Single-screw eccentric pump 251 Clamp member (adjustment member) 252 Clamp side locking hole 253 Shaft member 266a Slotted hole 266b Shaft side locking hole 300 Single-screw eccentric pump 352 Shaft member 370 First shaft 372 Second shaft 400 Single-shaft eccentric screw pump 452 Shaft member 470 First shaft 471 First shaft side connection part 472 Second shaft 473 Second shaft side connection part 500 Single-shaft eccentric screw pump 552 First threaded part 553 Second threaded part 570 Outer shaft 572 Outer shaft side threaded part 575 Inner shaft 576 Inner shaft side threaded part 600 Single-shaft eccentric screw pump 652 Threaded shaft 656 Nut member 670 Outer shaft 671 Hollow hole 675 Inner shaft 680 Drive unit 682 Generator 684 Control unit 686 Battery 700 Single-shaft eccentric screw pump 753 Rotation direction changing unit 754 Link shaft 755 Opening 800 Single-shaft eccentric screw pump 852 Cylinder 853 Piston 854 Cylinder chamber 900 Single-screw eccentric pump 952 Outer member 953 Inner member 1000 Single-screw eccentric pump 1052 First engaging member 1053 Second engaging member

Claims

1. A single-screw eccentric pump comprising: an input shaft that rotates by the power of a drive machine; a rotor that is eccentrically rotatable with respect to the input shaft and is composed of a male screw-type shaft body; a joint portion that connects the input shaft and the rotor directly or indirectly via a joint shaft; and a stator formed in the shape of a female screw through which the rotor can be inserted, wherein either or both of the outer diameter of the rotor and the inner diameter of the inner bore of the stator are formed to decrease from one end to the other, or the amount of eccentricity of the rotor is changed, and at least one of the input shaft, the joint shaft, and the joint portion is provided with an extension / retraction mechanism that moves the rotor closer to or further away from the stator by extending or retracting in the axial direction.

2. The single-screw pump according to claim 1, wherein either or both of the input shaft or the joint shaft comprises an outer shaft having a hollow hole formed along the axial direction, and an inner shaft inserted through the hollow hole and movable relative to the outer shaft along the axial direction, the extension mechanism comprises an adjustment member for changing the relative positional relationship of the inner shaft and the outer shaft in the axial direction, and the input shaft or the joint shaft is extended or retracted by moving the inner shaft and the outer shaft relative to each other via the adjustment member.

3. The single-screw eccentric pump according to claim 2, characterized in that a locking mechanism is provided that allows the relative positional relationship between the inner shaft and the outer shaft to be changed when the lock is released, and fixes the inner shaft and the outer shaft so that they cannot move relative to each other when the lock is released.

4. The uniaxial eccentric screw pump according to claim 2 or 3, characterized in that the adjusting member is disposed between the inner shaft and the outer shaft, suppresses relative movement of the inner shaft and the outer shaft along the axial direction, and is detachably provided on at least one of the inner shaft and the outer shaft, and the amount of relative movement of the inner shaft and the outer shaft in the axial direction can be changed by attaching or detaching the adjusting member.

5. The uniaxial eccentric screw pump according to claim 2 or 3, characterized in that the adjusting member is made of an elastic member.

6. The single-screw eccentric pump according to claim 2 or 3, characterized in that the outer shaft has a threaded portion formed at a position corresponding to the adjustment member on the inner surface of the hollow hole, the adjustment member has a bolt and the bolt is screwed into the threaded portion, and the relative amount of movement of the inner shaft and the outer shaft can be changed by adjusting the screwing position of the bolt.

7. The single-screw eccentric pump according to claim 2, characterized in that the adjusting member is a clamping member capable of gripping the inner shaft, the clamping member allows relative movement between the inner shaft and the outer shaft when the inner shaft is not gripped, and prevents relative movement between the inner shaft and the outer shaft when the inner shaft is gripped.

8. The single-screw eccentric pump according to claim 7, characterized in that the inner shaft has an elongated hole formed longitudinally along the axial direction, or a plurality of shaft-side locking holes formed at intervals along the axial direction of the input shaft, the clamp member has a clamp-side locking hole corresponding to at least one of the elongated hole or the shaft-side locking hole, and the inner shaft and the outer shaft are locked so as not to rotate relative to each other by inserting the shaft member through the shaft-side locking hole via the clamp-side locking hole.

9. The single-screw eccentric pump according to claim 1, characterized in that either one or both of the input shaft or the joint shaft are divided into at least a first shaft and a second shaft along the axial direction, the telescopic mechanism comprises a plurality of adjustment members of different lengths to which the first shaft and the second shaft can be connected, and the input shaft or the joint shaft is extended or retracted in the axial direction by connecting the first shaft and the second shaft via at least one selected from the plurality of adjustment members.

10. The single-screw eccentric pump according to claim 1, characterized in that either one or both of the input shaft or the joint shaft are divided into at least a first shaft and a second shaft along the axial direction, the telescopic mechanism includes an adjustment member to which the first shaft and the second shaft can be connected, the adjustment member is configured to change the connection position along the axial direction with respect to at least one or both of the first shaft and the second shaft, and by changing the connection position, either one or both of the input shaft or the joint shaft can be extended or retracted.

11. The single-screw eccentric pump according to claim 9 or 10, characterized in that at least a portion of the first shaft and the second shaft are formed of a flexible material, the connecting ends of the first shaft and the second shaft form a first shaft side connecting portion and a second shaft side connecting portion, and the first shaft side connecting portion and the second shaft side connecting portion are connected via the adjustment member.

12. The uniaxial eccentric screw pump according to claim 2, characterized in that the outer shaft has an outer shaft side threaded portion formed on its outer circumference, the inner shaft has an inner shaft side threaded portion formed on the outer circumference of the exposed portion not inserted into the hollow hole, the inner shaft side threaded portion having threads in the opposite direction to the outer shaft side threaded portion, the adjusting member has a first threaded portion and a second threaded portion whose screwing directions are opposite to each other, the first threaded portion and the outer shaft side threaded portion, and the second threaded portion and the inner shaft side threaded portion are screwed together, and the relative position of the inner shaft and the outer shaft is changed by moving the screwing position of the first threaded portion and the second threaded portion along the axial direction.

13. The telescopic mechanism comprises: a drive unit housed in the hollow hole and moving the inner shaft relative to the outer shaft; a generator housed in the hollow hole and generating electricity in conjunction with the rotation of the outer shaft; a control unit housed in the hollow hole and controlling the drive of at least the drive unit; and a battery housed in the hollow hole and supplying power to at least the drive unit and the control unit, and storing the power generated by the generator, wherein the drive unit changes the relative position of the inner shaft and the outer shaft in the axial direction, as described in claim 2.

14. The uniaxial eccentric screw pump according to claim 13, wherein the adjusting member comprises a screw shaft that is rotationally driven by the drive unit, and a nut member that is screwed onto the screw shaft and is movable along the axial direction of the screw shaft by rotationally driving the screw shaft, wherein the nut member is attached to the inner shaft so as not to rotate relative to it and is movable integrally with the inner shaft.

15. The telescopic mechanism comprises: a screw shaft that is rotationally driven by power; a nut member that is screwed onto the screw shaft and can move along the axial direction of the screw shaft by rotationally driving the screw shaft; a link shaft provided in a direction intersecting the screw shaft; a rotation direction conversion unit that converts the rotation direction of the link shaft to the rotation direction of the screw shaft; and an opening that opens in the outer shaft and allows the link shaft to be rotated from the outside of the outer shaft, wherein the nut member is attached to the inner shaft so as not to rotate relative to it and is movable integrally with the inner shaft, and the screw shaft is rotated by rotating the link shaft through the opening, thereby changing the relative position of the inner shaft and the outer shaft in the axial direction, as described in claim 2.

16. The uniaxial eccentric screw pump according to claim 2, wherein the adjusting member comprises a cylinder constituting the outer shaft and a piston constituting the inner shaft and movable in and out of the hollow hole provided in the cylinder, and the cylinder and the piston can move relative to each other in the axial direction by drawing in or discharging liquid or gas into the cylinder chamber formed by the cylinder and the piston.

17. The telescopic mechanism has an adjustment member in the joint portion, the adjustment member comprising: an outer member connected to either the rotor side or the input shaft side and formed along the axial direction of the input shaft; and an inner member connected to either the other of the rotor side or the input shaft side and movable relative to the outer member in the axial direction, the single-screw eccentric pump according to claim 1, characterized by changing the relative positions of the outer member and the inner member.

18. The extension mechanism has an adjustment member in the joint portion, the adjustment member comprising: a plurality of first engaging members having different lengths in the axial direction; and a second engaging member that slidably engages with one of the first engaging members selected from the plurality of first engaging members, the single-screw eccentric pump according to claim 1, characterized in that the input shaft or the joint shaft, or both, are extended or retracted in the axial direction by engaging at least one of the plurality of first engaging members selected with the second engaging member.

19. A single-screw eccentric pump according to any one of claims 1 to 3, 7 to 10, or 12 to 18, comprising a pump casing for housing the telescopic mechanism, wherein the pump casing includes an access area that allows access to at least a portion of the telescopic mechanism.

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