Uniaxial eccentric screw pump

Abstract

[Problem] To provide a uniaxial eccentric screw pump which facilitates adjustment of the interference or clearance between a rotor and a stator, and which can also be automated. [Solution] A uniaxial eccentric screw pump 1 comprises: an input shaft 3 rotatably supported by a bearing 32 and rotated by the motive power of a drive machine; a rotor 5 connected to the input shaft 3 so as to be eccentrically rotatable; a stator 12 into which the rotor 5 can be inserted; and a bearing housing 30 into which the input shaft 3 can be inserted and which accommodates the bearing 32. The uniaxial eccentric screw pump 1 comprises a movement mechanism 50, which is capable of shaping the outer diameter of the rotor 5 and / or the inner diameter of an inner hole 12a of the stator 12 so as to decrease proceeding from one end toward the other end and / or changing the amount of eccentricity of the rotor, and which moves the bearing 32 closer to or farther from the stator 12 integrally with the input shaft 3 along an axial direction of the input shaft.

Description

Single-axis eccentric screw pump

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

[0002] Conventionally, a single-axis 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 rotor rotates to discharge the fluid sucked from the suction port from the discharge port (for example, Patent Document 1).

[0003] The single-axis 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 of the rotor and the stator to the other end. It has 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 single-axis 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. Thus, the invention described in Patent Document 1 above is intended to adjust the tightening allowance or clearance between the rotor and the stator (simply, also collectively referred to as the tightening allowance, etc.).

[0004] Japanese Patent No. 5320849

[0005] By the way, in recent years, in a single-axis eccentric screw pump as described in Patent Document 1 above, there are demands for simplifying the adjustment of the tightening allowance and the like between the rotor and the stator and for automation in the adjustment of the tightening allowance and the like. However, the single-axis 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 rotatably supported by at least one bearing and rotated by the power of a drive machine; a rotor connected to the input shaft so as to be eccentrically rotatable and composed of a male screw-type shaft body; and a stator formed in the shape of a female screw type through which the rotor can be inserted, wherein it is possible to form either or both of the outer diameter of the rotor and the inner diameter of the inner bore of the stator to decrease from one end to the other, or to change the amount of eccentricity of the rotor, and wherein the bearing is provided with a moving mechanism that moves the bearing toward and away from the stator along the axial direction of the input shaft, integrally with the input shaft.

[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 moving mechanism, allows the bearing to be moved closer to and further away from the stator, integrally with the input shaft. Therefore, there is no need to adjust the parts that come into contact with the fluid being pumped (also simply called the fluid) (also called the wetted parts). As a result, the single-screw pump of the present invention allows for rotor position adjustment without disassembling the pump, and also allows for easy adjustment of the rotor and stator's tension without worrying about the fluid resistance or sealing properties of the parts required for adjustment. Moreover, the single-screw pump of the present invention, through its moving mechanism, allows the bearing to be moved closer to and further away from the stator, integrally with the input shaft. Therefore, it is possible to easily adjust the rotor and stator's tension without changing the position of the fluid inlet or discharge piping.

[0010] (2) The single-screw pump of the present invention described above is preferably characterized in that it is capable of inserting the input shaft and includes a bearing housing that accommodates the bearing, and the moving mechanism moves the bearing relative to the bearing housing or integrally with the bearing housing.

[0011] In the single-screw pump of the present invention, for example, when the bearing is movable relative to the bearing housing, the bearing can be easily moved within the housing space of the bearing housing. Furthermore, in the single-screw pump of the present invention, for example, when the bearing is movable integrally with the bearing housing, the overlap of the rotor and stator can be easily adjusted simply by moving the bearing housing in the axial direction of the input shaft. Therefore, by configuring the single-screw pump of the present invention as described in (2) above, the overlap of the rotor and stator can be easily adjusted without adjusting the wetted parts or moving the suction port or discharge piping.

[0012] (3) The single-screw eccentric pump of the present invention described above comprises a bearing housing through which the input shaft can be inserted and which houses the bearing so that it cannot move relative to it, and a pump casing provided along the axial direction of the input shaft, wherein the moving mechanism moves the bearing housing closer to and further away from the pump casing along the axial direction.

[0013] The single-screw eccentric pump of the present invention allows for adjustment of the rotor and stator tension by moving the bearing housing closer to and further away from the pump casing along the axial direction. In other words, since the bearing housing, which is accessible from the outside, can be moved closer to and further away from the pump casing, the single-screw eccentric pump of the present invention allows for easy adjustment of the rotor and stator tension without disassembling the pump. Therefore, the single-screw eccentric pump of the present invention does not require adjustment of wetted parts. Here, the pump casing can be provided with, for example, a supply port (suction port) for introducing fluid. Therefore, the single-screw eccentric pump of the present invention allows for easy adjustment of the rotor and stator tension without moving the fluid supply port or discharge piping. Here, the pump casing and bearing housing can be arranged in various configurations, such as being adjacent to each other or having other members interposed between the pump casing and bearing housing.

[0014] (4) The single-screw eccentric pump of the present invention described above is characterized in that it comprises at least one adjustment bolt, a first bolt hole for fastening the adjustment bolt is formed through either the pump casing or the bearing housing, and a second bolt hole for fastening the adjustment bolt is formed in the other of the pump casing or the bearing housing, the adjustment bolt comprises an outer bolt portion having a first threaded portion formed on its outer circumference and a hollow hole, and an inner bolt portion inserted through the hollow hole and having a second threaded portion formed on its outer circumference, the outer bolt portion is screwed into the first bolt hole and its tip is able to abut against the outer circumference of the second bolt hole, the inner bolt portion is screwed into the second bolt hole to fasten the pump casing and the bearing housing, and the distance of movement of the bearing housing can be adjusted according to the degree of tightening of the outer bolt portion.

[0015] The single-screw pump of the present invention has an adjustment bolt, which is formed as a so-called double bolt having an outer bolt portion and an inner bolt portion. Furthermore, the single-screw pump of the present invention can adjust the travel distance of the bearing housing according to the degree of tightening of the outer bolt portion of the adjustment bolt. Therefore, the single-screw pump of the present invention can easily move the bearing housing. Here, if, for example, the adjustment bolt of the single-screw pump of the present invention can be operated from outside the pump casing and bearing housing, the tightening allowance of the rotor and stator can be easily adjusted without disassembling the single-screw pump. Here, for example, by providing multiple adjustment bolts evenly distributed in the circumferential direction on the outer circumference of the pump casing and bearing housing, the movement of the bearing housing can be adjusted in a balanced manner. The number of adjustment bolts should be set considering the balance between operability and adjustment accuracy, and various quantities from one to multiple can be provided.

[0016] Furthermore, on the side of the bearing housing that is fixed to the machine frame or the like, it is preferable to have, for example, an elongated hole aligned with the direction of movement formed in the fixing part, so that movement and fixing can be performed along the elongated hole. This makes it possible to adjust the movement of the bearing housing by tightening or loosening the adjustment bolts, even when the bearing housing is fixed to the machine frame or the like.

[0017] (5) In the single-screw eccentric pump of the present invention described above, the moving mechanism is preferably characterized in that the input shaft and the drive unit are directly or indirectly connected, and the input shaft is connected to the drive unit so as to be movable along the axial direction.

[0018] The single-screw pump of the present invention, with this configuration, allows the input shaft to be moved along the axial direction, so that even if the input shaft is connected to a drive unit (e.g., a motor), the overlap of the rotor and stator can be easily adjusted. Here, the connection between the drive unit and the input shaft can be made directly or indirectly via, for example, a spline, key, rail, coupling, etc., as a connecting part. As a result, the single-screw pump of the present invention can adjust the overlap of the rotor and stator without moving the drive unit. Therefore, the single-screw pump of the present invention does not require a mechanism to support and fix the drive unit in a movable manner, thus simplifying its configuration. Furthermore, as the single-screw pump of the present invention is configured as described in (5) above, the overlap of the rotor and stator can be adjusted with a simple configuration without moving the drive unit, so by providing an actuator or the like to move the input shaft, the adjustment of the overlap of the rotor and stator can be easily automated.

[0019] (6) The single-screw eccentric pump of the present invention described above is preferably characterized in that the moving mechanism is capable of moving the drive unit integrally with the input shaft along the axial direction.

[0020] The single-screw pump of the present invention, with this configuration, allows the drive unit to move in the axial direction of the input shaft in conjunction with the axial movement of the input shaft and rotor. In other words, the single-screw pump of the present invention allows for adjustment of the rotor and stator tension by moving the drive unit integrally with the input shaft without moving the main body such as the shaft seal casing, pump casing, and stator casing. Furthermore, the single-screw pump of the present invention allows for a wide range of methods to be selected for connecting the input shaft and the drive unit. Moreover, by configuring the single-screw pump of the present invention as described in (6) above, it is expected that the adjustment of the rotor and stator tension can be automated by moving the drive unit in the axial direction using an actuator or the like.

[0021] (7) The single-screw eccentric pump of the present invention described above is characterized in that a shaft seal is provided between the pump casing and the bearing housing to seal the area around the input shaft, and a shaft seal casing is provided to house the shaft seal, the shaft seal casing is integral with the bearing housing and is movable relative to the pump casing, and the moving mechanism moves the shaft seal casing in the axial direction.

[0022] The single-screw eccentric pump of the present invention, with this configuration, allows the shaft seal casing to be moved in the axial direction of the input shaft to adjust the overlap between the rotor and stator. Therefore, the single-screw eccentric pump of the present invention can be easily automated, for example, by gripping the shaft seal casing with an actuator and moving it in the axial direction of the input shaft to adjust the overlap between the rotor and stator.

[0023] (8) The single-screw eccentric pump of the present invention described above is characterized in that a shaft seal is provided between the pump casing and the bearing housing to seal the area around the input shaft, and a shaft seal casing is provided to house the shaft seal, the shaft seal casing is integral with the bearing housing and movable relative to the pump casing, and at least a part of it can overlap with the pump casing, the movement mechanism comprises a shaft seal casing side threaded portion formed on at least a part of the shaft seal casing, and a pump casing side threaded portion formed on the bearing housing side of the pump casing and screwable with the shaft seal casing side threaded portion, and the amount of movement of the bearing housing relative to the pump casing can be adjusted by screwing the shaft seal casing side threaded portion to the pump casing side threaded portion.

[0024] The single-screw eccentric pump of the present invention, with this configuration, allows the screw portion on the screw seal casing side formed on the screw seal casing and the screw portion on the pump casing side formed on the pump casing to be screwed together, thereby allowing the screw seal casing to move relative to the pump casing integrally with the bearing housing. Therefore, the single-screw eccentric pump of the present invention allows for easy adjustment of the amount of movement of the bearing housing relative to the pump casing by rotating the screw seal casing relative to the pump casing, thus facilitating adjustment of the tightening allowance of the rotor and stator. Note that one of the screw portion on the screw seal casing side and the screw portion on the pump casing side may be a male thread and the other a female thread, and which one is a male thread and which is a female thread may be appropriately selected depending on the structure when the screw seal casing and pump casing are overlapped.

[0025] (9) In the single-screw eccentric pump of the present invention described above, the moving mechanism is preferably characterized in that the distance between the bearing housing and the drive unit is adjustable.

[0026] The single-screw pump of the present invention allows for adjustment of the distance between the bearing housing and the drive unit by moving the bearing housing and the drive unit relative to each other using a moving mechanism. This allows the single-screw pump of the present invention to adjust the tension between the rotor and stator by moving the input shaft in the axial direction. The moving mechanism can be, for example, an adjustment screw such as a so-called double bolt, or a combination of a push bolt and a pull bolt.

[0027] (10) In the single-screw pump of the present invention described above, the bearing housing is characterized in that a bearing housing side threaded portion is formed in at least a part of the bearing housing side threaded portion, a fixed side threaded member fixed so as not to move in the axial direction is screwed into the bearing housing side threaded portion, and the bearing housing is moved in the axial direction by rotating the fixed side threaded member to change the screwed position of the bearing housing side threaded portion.

[0028] The single-screw pump of the present invention allows the bearing housing to be moved in the axial direction of the input shaft by rotating the fixed-side screw member to change the screw engagement position with the bearing housing-side screw portion. As a result, the single-screw pump of the present invention allows the bearing and input shaft to be moved axially in conjunction with the bearing housing, making it easy to adjust the tightening allowance of the rotor and stator.

[0029] (11) The single-screw eccentric pump of the present invention described above comprises a bearing housing through which the input shaft can be inserted and which houses the bearing integrally with the input shaft so as to be movable relative to the input shaft in the axial direction, wherein the moving mechanism moves the bearing along the axial direction relative to the bearing housing.

[0030] The single-screw eccentric pump of the present invention allows the bearing to be moved integrally with the input shaft in the axial direction of the input shaft relative to the bearing housing, making it easy to adjust the tightening allowance of the rotor and stator.

[0031] (12) The uniaxial eccentric screw pump of the present invention described above comprises a bearing housing through which the input shaft can be inserted and which houses the bearing so as to be movable relative to the input shaft, wherein the moving mechanism comprises a moving groove formed on the outer circumference of the bearing housing along the axial direction of the input shaft, and an operating part that is directly or indirectly supported by the bearing and is movable along the moving groove, wherein the operating part can move the bearing integrally with the operating part along the axial direction by moving along the moving groove.

[0032] The single-screw pump of the present invention allows the bearing to be moved integrally with the input shaft along the axial direction of the input shaft by moving the operating unit along the axial direction of the input shaft. As a result, the single-screw pump of the present invention allows adjustment of the rotor and stator tension, etc., by operating the operating unit. Therefore, the single-screw pump of the present invention allows for easy adjustment of the rotor and stator tension, etc., by easily operating the operating unit from the outside of the main body.

[0033] (13) In the single-screw eccentric pump of the present invention as described above, the movable groove is formed spirally on the outer circumference of the bearing housing at a predetermined pitch and angle such that the helical axis extends along the axial direction of the input shaft, and the operating part rotates along the movable groove so that the bearing can move integrally with the operating part along the axial direction.

[0034] The single-screw pump of the present invention, with this configuration, can reduce the resistance to rotation when moving the operating part. That is, even when resistance to the rotor's movement relative to the stator occurs, the single-screw pump of the present invention can reduce the resistance to the operating part's movement through the principles of leverage and inclined planes. Therefore, the single-screw pump of the present invention can reduce the burden on the operator and advantageously advance the automation of adjustments such as the tightening allowance of the rotor and stator. Furthermore, since the moving groove of the single-screw pump of the present invention is formed in a helical shape (diagonal direction), even when the rotor is pushed towards the drive unit by the discharge pressure, the movement of the operating part can be suppressed by contact between the operating part and the moving groove. Therefore, the single-screw pump of the present invention can suppress unintended rotor movement.

[0035] (14) The single-screw eccentric pump of the present invention described above is preferably characterized in that it is equipped with a locking part for fixing the operating part at a predetermined position in the movable groove, and the locking part is switchable between a locked state that fixes the operating part and an unlocked state that allows the operating part to move.

[0036] The single-screw pump of the present invention, with this configuration, allows the rotor and stator to be fixed in their adjusted positions after adjusting the tightening tolerances of the rotor and stator. This makes it advantageous to automate the adjustment of the tightening tolerances of the rotor and stator in the single-screw pump of the present invention.

[0037] (15) The single-screw eccentric pump of the present invention described above is preferably characterized in that the moving mechanism includes an actuator, and the bearing moves toward and away from the stator along the axial direction by the actuator.

[0038] The single-screw pump of the present invention, with this configuration, allows the bearing to move toward and away from the stator axially via an actuator. In other words, the single-screw pump of the present invention allows for easy automation of adjustments such as the overlap between the rotor and stator.

[0039] (16) The single-screw eccentric pump of the present invention described above is characterized in that the moving mechanism includes an actuator, the actuator is connected to the operating section, the actuator is capable of moving the operating section along the moving groove, and the locking section is capable of automatically switching between a locked state and an unlocked state.

[0040] The single-screw eccentric pump of the present invention, with this configuration, can automatically adjust the tension of the rotor and stator and automatically fix the rotor and stator in the adjusted position. In the single-screw eccentric pump of the present invention, the automatic adjustment of the tension of the rotor and stator can be performed by first unlocking the locking mechanism, moving the operating mechanism along the moving groove in a predetermined direction, and then locking the locking mechanism after the adjustment of the tension is completed.

[0041] (17) The single-screw eccentric pump of the present invention described above is preferably characterized in that the movement of the operating part by the actuator and the switching of the locked and unlocked states of the locking part are performed either while the rotor is being driven to rotate, or while the rotor is stopped, or both.

[0042] The single-screw eccentric pump of the present invention, with this configuration, can automatically adjust the tension between the rotor and stator, whether the rotor is rotating or stopped. Therefore, the single-screw eccentric pump of the present invention can stably discharge fluids with high precision.

[0043] According to the present invention, it is possible to provide a single-screw eccentric pump that allows for simple adjustment of the overlap or gap between the rotor and stator, and that can also be automated.

[0044] (a) is a front-direction cross-sectional view and a partial side view showing the state before adjustment of the tightening allowance, etc. of a 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, etc. of the uniaxial eccentric screw pump of (a). It is a front-direction cross-sectional view of a uniaxial eccentric screw pump according to a first modification of the present invention. It is a front-direction cross-sectional view of a uniaxial eccentric screw pump according to a second modification of the present invention. It is a front-direction cross-sectional view of a uniaxial eccentric screw pump according to a third modification of the present invention. (a) is a front-direction cross-sectional view showing the state after adjusting the tightening allowance, etc. of the rotor in FIG. 4, and (b) is a cross-sectional view of a part related to the operation part of (a).

[0045] Hereinafter, the uniaxial eccentric screw pump 1 according to an embodiment of the present invention will be described in detail while referring to the drawings. Note that each figure is schematically represented for easy understanding, and it should be noted that it may be different from the actual shape, size, and arrangement of components. Also, note that in each figure, the hatching in the cross-section may be omitted. Also, in FIG. 1, the left side in the illustration may be described as the front side, and the right side in the illustration may be described as the rear side. Also, unless otherwise specified, the axial direction of the input shaft 3 may be simply referred to as the axial direction.

[0046] As shown in FIGS. 1(a) and 1(b), the uniaxial eccentric screw pump 1 includes an input shaft 3 that transmits the driving force of a driving machine (not shown), a male screw type rotor 5 (also referred to as the rotor 5), a female screw type stator 12 (also referred to as the stator 12), and a moving mechanism 50. In addition to the above, the uniaxial eccentric screw 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 3, and a shaft seal casing 40, etc.

[0047] The uniaxial eccentric screw pump 1 is a rotary displacement pump. In the uniaxial eccentric screw pump 1, the rotor 5 inserted into the inner hole 12a of the stator 12 rotates relative to the stator 12, so that, for example, any fluid from low viscosity to high viscosity can be transferred or filled with high precision. Here, the fluid is defined to include liquids, gases, and fluids such as slurries and granular materials.

[0048] The rotor 5 is composed of a male screw-shaped shaft body with n (in this embodiment, n = 1) threads (leaves), and its longitudinal cross-sectional shape is formed into a substantially perfect circle. The pitch of the spiral shape is set to be the same as the pitch of the inner hole 12a of the stator 12. Also, the rotor 5 is formed of a material such as metal, e.g., stainless steel, and is inserted into the inner hole 12a of the stator 12. Further, a connecting shaft 7 is integrally provided at the rear end portion of the rotor 5. The connecting shaft 7 is eccentrically rotatably connected to the input shaft 3 via a connecting portion 9 such as a pin joint, a universal joint, a gear joint, an Oldham joint, a flexible rod, etc. Therefore, the rotor 5 (connecting shaft 7) can eccentrically rotate with respect to the input shaft 3. Note that a plurality of connecting portions 9 may be provided as necessary.

[0049] Also, both the outer diameter of the rotor 5 and the inner diameter of the stator 12 described later are formed so as to become smaller from one end portion toward the other end portion. In this embodiment, both the outer diameter of the rotor 5 and the inner diameter of the inner hole 12a of the stator 12 are formed so as to become smaller from one end portion on the connecting shaft 7 side (right side in the drawing) of the rotor 5 toward the other end portion on the tip side (left side in the drawing) of the rotor 5. Note that the direction in which the outer diameter of the rotor 5 and the inner diameter of the inner hole 12a of the stator 12 are made smaller can be changed according to the usage state. Also, it is sufficient that either one or both of the outer diameter of the rotor 5 and the inner diameter of the inner hole 12a of the stator 12 are formed so as to change from one end portion toward the other end portion.

[0050] Also, in the single-shaft eccentric screw pump 1 according to this embodiment, instead of or together with the change in the outer diameter of the rotor 5 and the inner diameter of the stator 12, the amount of eccentricity of the rotor 5 can also be changed.

[0051] The input shaft 3 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 3 is rotatably supported by a pair of bearings 32, 32 (bearings 32, 32) spaced apart within the bearing housing 30, and a connection portion 60 for connecting the drive shaft (not shown) of a drive unit is provided at the rear end (right side in the figure). The drive unit is connected to the input shaft 3 via the connection portion 60. Therefore, the input shaft 3 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 connection portion 60 is spline-connected to the input shaft 3 and constitutes part of the moving mechanism 50 of the single-axis eccentric screw pump 200 (see Figure 3) according to a second modified example described later. Here, various means can be used to directly or indirectly connect the input shaft 3 and the drive unit to the connection portion 60. For example, the connection part 60 may be a coupling or rail that indirectly connects the input shaft 3 and the drive unit, or it may be a spline, key, or other object that directly connects the input shaft 3 and the drive unit.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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 rear end of the stator casing 10. In other words, the pump casing 20 is provided along the axial direction of the input shaft 3. 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.

[0056] 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 3, the connecting portion 9, and the connecting 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 so as to be movable in the axial direction of the input shaft 3.

[0057] As shown in Figure 1(a), the pump casing 20 has a rectangular flange 24 formed on its rear end. Multiple (four in this embodiment) first bolt holes (not shown) are formed through the flange 24 for screwing in adjustment bolts 52 (also called double bolts 52), which will be described later as a moving mechanism 50. As will be described in detail later, the outer bolt portion 54 of the adjustment bolt 52 is screwed into the first bolt holes.

[0058] 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 as the rotor 5 rotates. The fluid delivered to the stator 12 is then discharged from the discharge port 16 as the rotor 5 rotates.

[0059] The bearing housing 30 is connected to the pump casing 20 via a shaft sealing casing 40 so as to be movable along the axial direction of the input shaft 3. The bearing housing 30 is formed in a substantially cylindrical shape using a material such as metal (stainless steel). A second bolt hole (not shown) is formed at the front end of the bearing housing 30 at a position corresponding to a first bolt hole (not shown) in the flange 24 of the pump casing 20. The second bolt hole has a female thread into which the inner bolt portion 56 of the adjustment bolt 52, which will be described later, can be screwed. Therefore, the second bolt hole can be fastened by screwing in the adjustment bolt 52. 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. The input shaft 3 is inserted through the bearing housing 30, and the input shaft 3 is rotatably supported by the bearings 32, 32. That is, the input shaft 3 is rotatably supported by the bearing housing 30.

[0060] A shaft seal casing 40 is connected to the front end (pump casing 20 side) of the bearing housing 30 so as not to rotate relative to the bearing housing 30. A cylindrical portion 34 is formed projecting axially from the rear end of the bearing housing 30, overlapping at least a portion of the connection portion 60 of the input shaft 3. An appropriate gap is formed between the cylindrical portion 34 and the connection portion 60, allowing the connection portion 60 and the input shaft 3 to rotate on the inner circumference of the cylindrical portion 34. The cylindrical portion 34 is slidably supported by support legs 34a and supported by a machine base (not shown) via the support legs 34a.

[0061] 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 has a pair of elongated holes 36a, 36a formed on its bottom surface, and the bearing housing 30 is detachably fixed to the machine base by fastening bolts (not shown) to the machine base through the elongated holes 36a, 36a. The elongated holes 36a form a range of motion when the bearing housing 30 is moved in the axial direction.

[0062] As shown in Figures 1(a) and 1(b), the bearing housing 30 houses the bearings 32, 32 in a manner that prevents relative movement. A bearing holder 33 is provided between the bearings 32, 32 to hold them together as a single unit. The bearing housing 30 can be moved integrally with the bearings 32, 32 and the input shaft 3 along the axial direction of the input shaft 3. In other words, the bearing housing 30, the bearings 32, 32 and the input shaft 3 can be moved integrally toward and away from the stator 12 (stator casing 10).

[0063] 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 (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 3, allowing the input shaft 3 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 3 and the shaft seal casing 40 (around the input shaft 3) sealed when the input shaft 3 is inserted. In other words, the shaft seal 42 prevents fluid from inside the pump casing 20 from entering the bearing housing 30. 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 shaft seal casing 40 is coupled at its rear end to the inner circumference of the front end of the bearing housing 30, and can move integrally with the bearing housing 30 along the axial direction of the input shaft 3. In other words, the shaft seal casing 40 can move integrally with the bearing housing 30 relative to the pump casing 20.

[0064] The front end of the shaft seal casing 40 is fitted into 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 seal 44, which prevents fluid from inside the pump casing 20 from leaking out.

[0065] The moving mechanism 50 moves the bearing housing 30 closer to and further away from the pump casing 20 along the axial direction of the input shaft 3. The details of the moving mechanism 50 in this embodiment will be described below.

[0066] As shown in Figure 1(a), the moving mechanism 50 is composed of at least one adjustment bolt 52 (double bolt 52). The adjustment bolt 52 comprises an outer bolt portion 54 and an inner bolt portion 56.

[0067] The outer bolt portion 54 is composed of a flange 54c formed on one end and a cylindrical portion 54d having a hollow hole 54b and a first threaded portion 54a formed on its outer circumference. The outer bolt portion 54 is screwed into a first bolt hole provided in the flange 24 of the pump casing 20, and its tip is made capable of contacting the outer circumference of a second bolt hole provided in the bearing housing 30.

[0068] The inner bolt portion 56 is inserted through the hollow hole 54b of the outer bolt portion 54, and a second threaded portion 56a is formed on its outer circumference. The inner bolt portion 56 is screwed into the second bolt hole to fasten the pump casing 20 and the bearing housing 30. A nut 56b is screwed onto the head of the inner bolt portion 56. By tightening the nut 56b, it comes into contact with the head of the outer bolt portion 54, thereby suppressing the movement of the inner bolt portion 56 (fixing the inner bolt portion 56). On the other hand, by loosening the nut 56b, the fixing of the inner bolt portion 56 is released, and the movement of the outer bolt portion 54 is permitted.

[0069] The moving mechanism 50 is configured as described above. Therefore, the moving mechanism 50 can adjust the travel distance of the pump casing 20 and the bearing housing 30 according to the degree of tightening of the outer bolt portion 54. Specifically, first, prior to adjustment, the nut 56b of the inner bolt portion 56 is loosened to release the fixing by the inner bolt portion 56 and make the outer bolt portion 54 operable. Next, as the outer bolt portion 54 is tightened, the first threaded portion 54a screws into the first bolt hole of the pump casing 20 and comes into contact with the outer circumference of the second bolt hole of the bearing housing 30, pressing the bearing housing 30. As a result, the distance between the bearing housing 30 and the pump casing 20 increases (they separate). Also, since the bearing housing 30 moves integrally with the bearings 32, 32 and the input shaft 3, the rotor 5 moves away from the stator 12. That is, the overlap or gap (collectively referred to as overlap, etc.) between the rotor 5 and the stator 12 is adjusted. After the adjustments such as the tightening allowance of the rotor 5 and stator 12 are made, the nut 56b is tightened to fix the inner bolt portion 56 and the outer bolt portion 54.

[0070] On the other hand, by loosening the nut 56b of the inner bolt portion 56 to release the fixing by the inner bolt portion 56, and then loosening the outer bolt portion 54, the first threaded portion 54a is loosened from the first bolt hole of the pump casing 20, and the inner bolt portion 56 is pulled by the flange 54c. As a result, the bearing housing 30 moves closer to the pump casing 20, and the distance between the bearing housing 30 and the pump casing 20 decreases (they get closer). Also, since the bearing housing 30 moves integrally with the bearings 32, 32 and the input shaft 3, the rotor 5 moves closer to the stator 12. In other words, adjustments such as the tightening allowance of the rotor 5 and the stator 12 are made. After the adjustments such as the tightening allowance of the rotor 5 and the stator 12 are made, the nut 56b is tightened to fix the inner bolt portion 56 and the outer bolt portion 54. Furthermore, when the bearing housing 30 moves closer to or further away from the moving mechanism 50, it is preferable to release the fastening (fastening of the elongated hole 36a and bolts, etc.) between the bearing housing 30 and the machine base (not shown). This allows the bearing housing 30 to be moved along the elongated hole 36a by utilizing the tightening allowance of the elongated hole 36a of the support part 36. In addition, by providing appropriate scales on the bearing housing 30 and the pump casing 20, it becomes easier to adjust the amount of movement of the bearing housing 30 relative to the pump casing.

[0071] In addition to the above, the moving mechanism 50 has the aforementioned connecting portion 60. The connecting portion 60 connects the input shaft 3 and the drive unit (not shown). In this embodiment, the connecting portion 60 is connected to the input shaft 3 via a spline (not shown). Therefore, the moving mechanism 50 can move the input shaft 3 in the axial direction without moving the drive unit. Although not shown in the figures, the adjustment of the adjustment bolt 52 by the moving mechanism 50 can be automated, for example, by driving the adjustment bolt 52 with an actuator or the like. Alternatively, for example, the bearing housing 30 can be moved by an actuator or the like. In such cases, the adjustment bolt 52 can be eliminated.

[0072] Furthermore, when connecting the connection part 60 to the input shaft 3 of the drive unit without using a spline, it is preferable to configure the drive unit to be movable in the axial direction. Here, it is preferable that the drive unit be fixed to the machine base or the like via an appropriate movable support member (for example, a support bracket with an elongated hole formed along the direction of movement). This allows the moving mechanism 50 to move the drive unit along the elongated hole. When moving the drive unit by the moving mechanism 50, it is preferable to release the fixing between the drive unit and the machine base or the like. Although not shown in the figures, the movement of the input shaft 3 of the drive unit along the axial direction can be easily automated by using an actuator such as a linear actuator to move the input shaft 3 in the axial direction. It can also be automated by providing an automatic locking mechanism using an actuator or an automatic adjustment mechanism for the adjustment bolt 52.

[0073] The above describes the configuration of one embodiment of the single-screw eccentric pump 1 of the present invention. Next, the operation and effects of the single-screw eccentric pump 1 according to this embodiment will be explained.

[0074] (a) The single-axis eccentric screw pump 1 of the present invention, provided to solve the above-mentioned problems, comprises an input shaft 3 that is rotatably supported by at least one bearing 32 and rotates by the power of a drive machine, a rotor 5 that is eccentrically rotatably connected to the input shaft 3 and is composed of a male screw-type shaft body, and a stator 12 that is formed in the shape of a female screw through which the rotor 5 can be inserted, wherein it is possible to form either one or both of the outer diameter of the rotor 5 and the inner diameter of the inner bore 12a of the stator 12 to decrease from one end to the other, or to change the amount of eccentricity of the rotor 5, and is characterized by comprising a moving mechanism 50 that moves the bearing 32 toward and toward the stator 12 along the axial direction of the input shaft 3, integrally with the input shaft 3.

[0075] The single-screw eccentric pump 1 of the present invention is designed so that either the outer diameter of the rotor 5 or the inner diameter of the inner bore 12a of the stator 12, or both, become smaller from one end to the other, or the eccentricity of the rotor 5 can be changed, 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.

[0076] Furthermore, in the single-screw pump 1 of the present invention, the moving mechanism 50 allows the bearing 32 to be moved closer to and further away from the stator 12 integrally with the input shaft 3, eliminating the need to adjust parts that come into contact with the fluid being pumped (also simply called the fluid) (also called wetted parts). Therefore, in the single-screw pump 1 of the present invention, the position of the rotor 5 can be adjusted without disassembling the pump 1, and adjustments such as the tightening tolerance of the rotor 5 and stator 12 can be easily made without worrying about the liquid resistance or sealing properties of the parts required for adjustment.

[0077] (b) The single-screw pump 1 of the present invention described above is characterized in that it is capable of inserting an input shaft 3 and includes a bearing housing 30 that houses a bearing 32, and the moving mechanism 50 moves the bearing 32 relative to the bearing housing 30 or integrally with the bearing housing 30.

[0078] In the single-screw eccentric pump 1 of the present invention, for example, when the bearing 32 is movable relative to the bearing housing 30, the bearing 32 can be easily moved within the housing space of the bearing housing 30. Furthermore, in the single-screw eccentric pump 1 of the present invention, for example, when the bearing 32 is movable integrally with the bearing housing 30, the tightening allowance of the rotor 5 and stator 12 can be easily adjusted simply by moving the bearing housing 30 in the axial direction of the input shaft 3. Therefore, by configuring the single-screw eccentric pump 1 of the present invention as described in (b) above, the tightening allowance of the rotor 5 and stator 12 can be easily adjusted without adjusting wetted parts or moving the suction port or discharge piping.

[0079] (c) The single-screw eccentric pump 1 of the present invention described above comprises a bearing housing 30 through which an input shaft 3 can be inserted and which houses a bearing 32 so that it cannot move relative to it, and a pump casing 20 provided along the axial direction of the input shaft 3, wherein the moving mechanism 50 moves the bearing housing 30 closer to and further away from the pump casing 20 along the axial direction.

[0080] The single-screw eccentric pump 1 of the present invention allows for adjustment of the tension between the rotor 5 and stator 12 by moving the bearing housing 30 closer to and further away from the pump casing 20 along the axial direction. In other words, since the bearing housing 30, which is accessible from the outside, can be moved closer to and further away from the pump casing 20, the single-screw eccentric pump 1 of the present invention allows for easy adjustment of the tension between the rotor 5 and stator 12 without disassembling the single-screw eccentric pump 1. Therefore, the single-screw eccentric pump 1 of the present invention does not require adjustment of wetted parts. Here, the pump casing 20 can be provided with, for example, a supply port (suction port) for introducing fluid. Therefore, the single-screw eccentric pump 1 of the present invention allows for easy adjustment of the tension between the rotor 5 and stator 12 without moving the fluid supply port or discharge piping. Here, the pump casing 20 and bearing housing 30 can be arranged in various ways, such as being adjacent to each other or having other members interposed between the pump casing 20 and bearing housing 30.

[0081] (d) The single-axis eccentric screw pump 1 of the present invention described above is characterized by comprising at least one adjustment bolt 52, a first bolt hole for fastening the adjustment bolt 52 formed through either the pump casing 20 or the bearing housing 30, and a second bolt hole for fastening the adjustment bolt 52 formed in the other of the pump casing 20 or the bearing housing 30, the adjustment bolt 52 comprising an outer bolt portion 54 having a first threaded portion 54a formed on its outer circumference and a hollow hole 54b, and an inner bolt portion 56 inserted through the hollow hole 54b and having a second threaded portion 56a formed on its outer circumference, the outer bolt portion 54 being screwed into the first bolt hole and its tip being able to abut against the outer circumference of the second bolt hole, and the inner bolt portion 56 being screwed into the second bolt hole to fasten the pump casing 20 and the bearing housing 30, and the distance of movement of the bearing housing 30 being adjustable according to the degree of tightening of the outer bolt portion 54.

[0082] The single-screw eccentric pump 1 of the present invention has an adjustment bolt 52, which is formed as a so-called double bolt having an outer bolt portion 54 and an inner bolt portion 56. Furthermore, the single-screw eccentric pump 1 of the present invention can adjust the travel distance of the bearing housing 30 according to the degree of tightening of the outer bolt portion 54 of the adjustment bolt 52. Therefore, the single-screw eccentric pump 1 of the present invention can easily move the bearing housing 30. Here, if, for example, the adjustment bolt 52 of the single-screw eccentric pump 1 of the present invention can be operated from outside the pump casing 20 and the bearing housing 30, the tightening allowance of the rotor 5 and the stator 12 can be easily adjusted without disassembling the single-screw eccentric pump 1. Here, for example, by providing multiple adjustment bolts 52 evenly distributed in the circumferential direction on the outer circumference of the pump casing 20 and the bearing housing 30, the movement of the bearing housing 30 can be adjusted in a balanced manner. The number of adjustment bolts 52 can be set considering the balance between operability and adjustment accuracy, and various quantities, from one to multiple, can be provided. In this embodiment, a double bolt is used as the adjustment bolt 52, but the adjustment bolt 52 is not limited to this, and various means can be used. For example, instead of a double bolt, the adjustment bolt 52 may be composed of a combination of a push bolt and a pull bolt.

[0083] Furthermore, the side of the bearing housing 30 that is fixed to the machine frame or the like may be configured such that, for example, an elongated hole aligned with the direction of movement is formed in the fixing part, allowing movement and fixing along the elongated hole. This makes it possible to adjust the movement of the bearing housing 30 by tightening the adjustment bolt 52, even when the bearing housing 30 is fixed to the machine frame or the like.

[0084] (e) In the single-screw eccentric pump 1 of the present invention described above, the moving mechanism 50 is characterized in that the input shaft 3 and the drive unit are directly or indirectly connected, and the input shaft 3 is connected to the drive unit so as to be movable along the axial direction.

[0085] The single-screw pump 1 of the present invention, with this configuration, allows the input shaft 3 to be moved along the axial direction, so that even if the input shaft 3 is connected to a drive unit (e.g., a motor), the tightening tolerance of the rotor 5 and stator 12 can be easily adjusted. Here, the connection between the drive unit and the input shaft 3 can be made via, for example, a spline, key, rail, coupling, etc., as the connection part 60. As a result, the single-screw pump 1 of the present invention can adjust the tightening tolerance of the rotor 5 and stator 12 without moving the drive unit. Therefore, the single-screw pump 1 of the present invention does not require a mechanism to support and fix the drive unit in a movable manner, thus simplifying its configuration. Furthermore, by configuring the single-screw pump 1 of the present invention as described in (e) above, the tightening tolerance of the rotor 5 and stator 12 can be adjusted with a simple configuration without moving the drive unit, so by providing an actuator or the like to move the input shaft 3, the adjustment of the tightening tolerance of the rotor 5 and stator 12 can be easily automated.

[0086] (f) The single-axis eccentric screw pump 1 of the present invention described above is characterized in that the moving mechanism 50 is capable of moving the drive unit integrally with the input shaft 3 along the axial direction.

[0087] The single-screw pump 1 of the present invention, with this configuration, allows the drive unit to move in the axial direction of the input shaft 3 in conjunction with the axial movement of the input shaft 3 and rotor 5. In other words, the single-screw pump 1 of the present invention can adjust the tightening allowance of the rotor 5 and stator 12 by moving the drive unit integrally with the input shaft 3 without moving the main body parts such as the shaft seal casing 40, pump casing 20, and stator casing 10. Furthermore, the single-screw pump 1 of the present invention allows for a wide range of methods to be selected for connecting the input shaft 3 and the drive unit. Moreover, by configuring the single-screw pump 1 of the present invention as described in (f) above, it is expected that the adjustment of the tightening allowance of the rotor 5 and stator 12 can be automated by moving the drive unit in the axial direction using an actuator or the like.

[0088] The above describes the configuration and operation and effects of one embodiment of the single-screw eccentric pump 1 of the present invention. Next, an embodiment of the single-screw eccentric pump 100 according to a first modified example of the present invention will be described below with reference to Figure 2.

[0089] <First Modification> The single-axis eccentric screw pump 100 according to the first modification has the same configuration as the embodiment described above, except for the configuration of the moving mechanism 50. Therefore, a description of the configuration similar to that of the embodiment described above will be omitted. Also, please note that the same reference numerals are used for the same components as in the embodiment described above.

[0090] The single-screw eccentric pump 100 according to the first modified example is equipped with a shaft seal casing 40, similar to the embodiment described above. The moving mechanism 50 in the single-screw eccentric pump 100 includes a screw portion 140 on the shaft seal casing side and a screw portion 120 on the pump casing side.

[0091] Furthermore, the front end of the bearing housing 30 and the rear end of the shaft seal casing 40 are fastened together by a ring-shaped fastening member 31. Therefore, the bearing housing 30 and the shaft seal casing 40 can move together as a single unit.

[0092] The threaded portion 140 on the shaft seal casing side is formed as a male thread on at least a portion of the outer circumference of the shaft seal casing 40. In this first modified example, the threaded portion 140 on the shaft seal casing side is formed from the rear end of the shaft seal casing 40 toward the front, extending to the middle of the shaft seal casing 40 (a position overlapping with a portion of the rear end portion of the pump casing 20). In addition, a hole 142 is formed on a portion of the outer circumference of the threaded portion 140 on the shaft seal casing side in a direction intersecting the axial direction of the input shaft 3. The hole 142 can be used to rotate the shaft seal casing 40 in forward and reverse directions by inserting and engaging a pin spanner, for example, and rotating the pin spanner in the direction around the axis.

[0093] The pump casing-side threaded portion 120 is formed on the bearing housing 30 side of the pump casing 20. In this first modification, the pump casing-side threaded portion 120 is formed as a female thread on the inner wall surface at the rear end of the pump casing 20. The pump casing-side threaded portion 120 is designed to be screwable with the shaft seal casing-side threaded portion 140. Therefore, for example, by rotating the shaft seal casing 40 in forward and reverse directions, the bearing housing 30 moves toward and away from the pump casing 20 integrally with the bearings 32, 32 and the input shaft 3. As a result, the moving mechanism 50 can adjust the amount of movement of the bearing housing 30 relative to the pump casing 20 by screwing the shaft seal casing-side threaded portion 140 into the pump casing-side threaded portion 120. The single-shaft eccentric screw pump 100 according to the first modification can be automated, for example, by using an actuator to screw the shaft seal casing-side threaded portion 140 and the pump casing-side threaded portion 120. More specifically, for example, a gear can be provided on the outer surface of the shaft sealing casing 40, and a timing belt can be attached to rotate it using a motor or the like.

[0094] 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.

[0095] (g) The single-screw eccentric pump 100 of the present invention described above is characterized in that a shaft seal 42 that seals the area around the input shaft 3 is provided between the pump casing 20 and the bearing housing 30, and a shaft seal casing 40 that houses the shaft seal 42 is provided, the shaft seal casing 40 is integral with the bearing housing 30 and is movable relative to the pump casing 20, and the moving mechanism 50 moves the shaft seal casing 40 in the axial direction.

[0096] The single-screw eccentric pump 100 of the present invention, with this configuration, allows the shaft seal casing 40 to be moved in the axial direction of the input shaft 3 to adjust the overlap of the rotor 5 and stator 12. Therefore, the single-screw eccentric pump 100 of the present invention can be easily automated, for example, by gripping the shaft seal casing 40 with an actuator or the like and moving it in the axial direction of the input shaft 3 to adjust the overlap of the rotor 5 and stator 12.

[0097] (h) The single-screw eccentric pump 100 of the present invention described above is characterized in that a shaft seal 42 that seals the area around the input shaft 3 is provided between the pump casing 20 and the bearing housing 30, and a shaft seal casing 40 that houses the shaft seal 42 is provided, the shaft seal casing 40 is integral with the bearing housing 30 and is movable relative to the pump casing 20, and at least a part of it is overlapping with the pump casing 20, and the movement mechanism 50 comprises a shaft seal casing side threaded portion 140 formed on at least a part of the shaft seal casing 40, and a pump casing side threaded portion 120 formed on the bearing housing 30 side of the pump casing 20 and screwable with the shaft seal casing side threaded portion 140, and the amount of movement of the bearing housing 30 relative to the pump casing 20 can be adjusted by screwing the shaft seal casing side threaded portion 140 into the pump casing side threaded portion 120.

[0098] The single-screw eccentric pump 1 of the present invention, with this configuration, allows the screw portion 140 on the screw seal casing 40 to be screwed into the screw portion 120 on the pump casing 20, thereby enabling the screw seal casing 40 to move relative to the pump casing 20 integrally with the bearing housing 30. Therefore, the single-screw eccentric pump 1 of the present invention allows for easy adjustment of the amount of movement of the bearing housing 30 relative to the pump casing 20 by rotating the screw seal casing 40 relative to the pump casing 20, thus enabling easy adjustment of the tightening allowance of the rotor 5 and stator 12. Note that one of the screw portion 140 on the screw seal casing 40 and the other on the screw casing 20 may be a male thread and the other a female thread, and which one is a male thread and which is a female thread can be appropriately selected according to the structure when the screw seal casing 40 and the pump casing 20 are overlapped.

[0099] 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 200 according to the second modified example of the present invention will be described below with reference to Figure 3.

[0100] ≪Second Modification≫ The single-axis eccentric screw pump 200 according to the second modification has the same configuration as the embodiment described above, except for the configuration of the moving mechanism 50. Therefore, a description of the configuration similar to that of the embodiment described above will be omitted. Also, please note that the same reference numerals are used for the same components as in the embodiment described above.

[0101] The moving mechanism 50 in the single-axis eccentric screw pump 200 according to the second modified example comprises a bearing housing side threaded portion 230 provided on the bearing housing 30 and a fixed side threaded member 234 screwed into the bearing housing side threaded portion 230.

[0102] The fixed-side screw member 234 is rotatably supported by a support leg 34a erected on a machine base (not shown). Specifically, the support member 236 has a circular hole formed along the axial direction of the input shaft 3, into which the fixed-side screw member 234 is fitted and supported so as to be rotatable around the axis. The fixed-side screw member 234 has at least one hole portion 234a formed along the axial direction for engaging a pin spanner or the like. The fixed-side screw member 234 can be rotated around the axis by engaging a pin spanner or the like in the hole portion 234a.

[0103] The bearing housing side threaded portion 230 is formed as a male thread on the outer circumference of a cylindrical portion 34 provided along the axial direction on the rear end side of the bearing housing 30. The fixed side threaded member 234 is screwed into the bearing housing side threaded portion 230. Therefore, by rotating the fixed side threaded member 234 in forward and reverse directions around the axis, the bearing housing 30 moves toward and away from the pump casing 20 integrally with the bearings 32, 32 and the input shaft 3. Since the input shaft 3 and the connecting portion 60 are spline connected, by rotating the fixed side threaded member 234 and changing the screwing position with the bearing housing side threaded portion 230 in the axial direction, the input shaft 3 moves toward the stator 12 integrally with the bearing housing 30, and the tightening allowance of the rotor 5 and the stator 12 is adjusted. In other words, the moving mechanism 50 can adjust the amount of movement of the bearing housing 30 relative to the pump casing 20 by screwing the fixed side threaded member 234 into the bearing housing side threaded portion 230.

[0104] Furthermore, the single-axis eccentric screw pump 200 according to the second modified example can be automated, for example, by using an actuator or the like to screw together the fixed-side screw member 234 and the bearing housing-side screw portion 230.

[0105] 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.

[0106] (i) In the single-axis eccentric screw pump 200 of the present invention described above, the moving mechanism 50 is characterized in that the distance between the bearing housing 30 and the drive unit is adjustable.

[0107] The single-screw pump 200 of the present invention can adjust the distance between the bearing housing 30 and the drive unit by moving the bearing housing 30 and the drive unit relative to each other using a moving mechanism 50. This allows the single-screw pump 200 of the present invention to adjust the tightening allowance of the rotor 5 and stator 12 by moving the input shaft 3 in the axial direction. The moving mechanism 50 can be, for example, an adjustment screw such as a so-called double bolt, or a combination of a push bolt and a pull bolt.

[0108] (j) In the single-screw eccentric pump 200 of the present invention described above, the bearing housing 30 has a bearing housing side threaded portion 230 formed in at least a part of it, and a fixed side threaded member 234 which is fixed so as not to move in the axial direction is screwed into the bearing housing side threaded portion 230, and the bearing housing 30 is moved in the axial direction by rotating the fixed side threaded member 234 to change the screwed position of the bearing housing side threaded portion 230.

[0109] The single-screw eccentric pump 200 of the present invention allows the bearing housing 30 to be moved in the axial direction of the input shaft 3 by rotating the fixed-side screw member 234 to change the screwing position with the bearing housing-side screw portion 230. As a result, the single-screw eccentric pump 200 of the present invention allows the bearings 32, 32 and the input shaft 3 to be moved axially in conjunction with the bearing housing 30, making it easy to adjust the tightening allowance of the rotor 5 and stator 12.

[0110] 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.

[0111] ≪Third Modification≫ The single-screw eccentric pump 300 according to the third modification has the same configuration as the embodiment described above, except that the configuration of the moving mechanism 50 is different and a sealing member 340 is provided instead of the shaft sealing casing 40. Therefore, a description of the configuration similar to the embodiment described above will be omitted. Also, note that the same reference numerals are used for the same components as in the embodiment described above. Also, note that in the third modification, the drive unit (motor, etc.) is connected using, for example, a key instead of the connection part 60.

[0112] As shown in Figure 4, in the single-screw eccentric pump 300, the bearings 32, 32 are configured to be movable relative to the bearing housing 30 integrally with the input shaft 3. That is, the bearing housing 30 is designed to house the bearings 32, 32 integrally with the input shaft 3 and to be movable relative to the input shaft 3 in the axial direction of the input shaft 3. Therefore, the movement mechanism 50 in the single-screw eccentric pump 300 can move the bearings 32, 32 along the axial direction relative to the bearing housing 30. The movement mechanism 50 will be described in detail below.

[0113] In the third modified example, the space between the pump casing 20 and the bearing housing 30 is sealed with a sealing member 342 such as an O-ring, and the space between the input shaft 3, the pump casing 20, and the bearing housing 30 is sealed with a sealing member 340.

[0114] The moving mechanism 50 includes a moving groove 332 formed on the outer circumference of the bearing housing 30 along the axial direction of the input shaft 3, and an operating part 334 that is directly or indirectly supported by the bearings 32, 32 and is movable along the moving groove 332.

[0115] In the third modification, the movable groove 332 is formed spirally on the outer circumference of the bearing housing 30 at a predetermined pitch and angle such that the helical axis extends along the axial direction of the input shaft 3. In the third modification, the movable groove 332 is formed spirally over 180 degrees.

[0116] As shown in Figure 5(b), the operating part 334 is formed as a knob that protrudes radially outward from the bearing housing 30. As shown in Figures 5(a) and 5(b), the base end of the operating part 334 is connected to the bearing holder 33. In the third modified example, as shown by the arrow in Figure 5(b), the operating part 334 rotates 180 degrees, causing it to rotate along the movable groove 332, and the bearings 32, 32 and the input shaft 3 to move axially together with the operating part 334. At this time, the outer rings of the bearings 32, 32 rotate relative to the inner rings, so even if the operating part 334 is rotated, the input shaft 3 and rotor 5 do not rotate. That is, the rotational motion of the operating part 334 is converted into axial movement of the input shaft 3, and adjustments such as the tightening allowance of the rotor 5 and stator 12 are made.

[0117] In a third modification, the operating part 334 is provided with a locking part 336 for fixing it in a predetermined position in the movable groove 332. Although detailed diagrams are omitted, the locking part 336 can switch between a locked state that fixes the operating part 334 and an unlocked state that allows the operating part 334 to move. For example, the locking part 336 is formed as a nut and can be engaged with counterbore holes (not shown) formed in the movable groove 332 at predetermined intervals (for example, at both ends or in the middle of the movable groove 332). The locking part 336 can fix (lock) the operating part 334 in the position after operation by tightening the nut at the position where the counterbore hole is formed. The locking part 336 can also release (unlock) the fixing of the operating part 334 by loosening the nut.

[0118] Here, the movable groove 332 can be formed in a straight line, for example. However, considering the resistance to movement of the operating part 334, it is desirable to form it as a helical groove having a predetermined pitch and angle. Specifically, by rotating the operating part 334 in a helical manner, the lever principle and the inclined plane principle can be utilized, thereby improving the operability of the operating part 334. On the other hand, when the single-screw eccentric pump 300 is driven, the operating part 334 comes into contact with the movable groove 332 due to the discharge pressure, so unintended movement of the rotor 5 and the operating part 334 can be suppressed.

[0119] Figure 5(a) shows the state after the operating unit 334 has been rotated 180 degrees around the axis integrally with the input shaft 3 from the state shown in Figure 4. In other words, Figure 5(a) shows the state after adjustments such as the tightening allowance of the rotor 5 and stator 12 have been made. As shown in the figure, in the third modified example, the rotor 5 is moved relative to the stator 12 towards the rear (right side in the figure).

[0120] The single-screw eccentric pump 300 according to the third modified example can be configured as follows, for example, and this configuration can produce specific effects.

[0121] (k) The single-axis eccentric screw pump 300 of the present invention described above includes a bearing housing 30 through which an input shaft 3 can be inserted and which houses a bearing 32 integrally with the input shaft 3 so as to be movable relative to the input shaft 3 in the axial direction of the input shaft 3, and the moving mechanism 50 moves the bearing 32 along the axial direction relative to the bearing housing 30.

[0122] In the single-screw eccentric pump 300 of the present invention, the bearing 32 can be moved integrally with the input shaft 3 in the axial direction of the input shaft 3 relative to the bearing housing 30, so that adjustments such as the tightening allowance of the rotor 5 and stator 12 can be easily made.

[0123] (l) The single-screw eccentric pump 300 of the present invention described above includes a bearing housing 30 through which an input shaft 3 can be inserted and which houses a bearing 32 so as to be movable relative to it, and the moving mechanism 50 includes a moving groove 332 formed on the outer circumference of the bearing housing 30 along the axial direction of the input shaft 3, and an operating part 334 that is directly or indirectly supported by the bearing 32 and is movable along the moving groove 332, wherein the operating part 334 can move the bearing 32 integrally with the operating part 334 along the axial direction by moving the operating part 332.

[0124] The single-screw eccentric pump 300 of the present invention allows the bearing 32 to be moved integrally with the input shaft 3 along the axial direction of the input shaft 3 by moving the operating unit 334 along the axial direction of the input shaft 3. As a result, the single-screw eccentric pump 300 of the present invention allows adjustment of the tightening tolerance of the rotor 5 and stator 12 by operating the operating unit 334. Therefore, the single-screw eccentric pump 300 of the present invention allows for easy adjustment of the tightening tolerance of the rotor 5 and stator 12 by easily operating the operating unit 334 from the outside of the main body.

[0125] (m) In the single-screw eccentric pump 300 of the present invention described above, the movable groove 332 is formed spirally on the outer circumference of the bearing housing 30 at a predetermined pitch and angle such that the helical axis extends along the axial direction of the input shaft 3, and the bearing 32 can be moved integrally with the operating part 334 along the axial direction by the rotational movement of the operating part 332.

[0126] The single-screw pump 300 of the present invention, with this configuration, can reduce the resistance to movement when rotating the operating unit 334. That is, even when resistance to movement of the rotor 5 relative to the stator 12 occurs, the single-screw pump 300 of the present invention can reduce the resistance to movement of the operating unit 334 by the principle of leverage and the principle of inclined plane. Therefore, the single-screw pump 300 of the present invention can reduce the burden on the operator and advantageously advance automation in adjusting the tightening allowance of the rotor 5 and stator 12. Furthermore, since the moving groove 332 of the single-screw pump 300 of the present invention is formed in a helical shape (diagonal direction), even when the rotor 5 is pushed toward the drive unit by the discharge pressure, the movement of the operating unit 334 can be suppressed by contact between the operating unit 334 and the moving groove 332. Therefore, the single-screw pump 300 of the present invention can suppress unintended movement of the rotor 5.

[0127] (n) The single-screw eccentric pump 300 of the present invention described above is equipped with a locking part 336 for fixing the operating part 334 at a predetermined position in the movable groove 332, and the locking part 336 is characterized in that it can switch between a locked state that fixes the operating part 334 and an unlocked state that allows the operating part 334 to move.

[0128] The single-screw eccentric pump 300 of the present invention, with this configuration, allows the rotor 5 and stator 12 to be fixed in their adjusted positions after adjusting the tightening allowance of the rotor 5 and stator 12. This makes it advantageous for the single-screw eccentric pump 300 of the present invention to automate the adjustment of the tightening allowance of the rotor 5 and stator 12.

[0129] (o) The single-axis eccentric screw pump 300 of the present invention described above is characterized in that the moving mechanism 50 is equipped with an actuator, and the bearing 32 moves toward and away from the stator 12 along the axial direction by the actuator.

[0130] The single-screw pump 300 of the present invention, with this configuration, allows the bearing 32 to move toward and away from the stator 12 along the axial direction via an actuator. In other words, the single-screw pump 300 of the present invention can easily automate the adjustment of the tightening tolerance of the rotor 5 and the stator 12.

[0131] (p) The single-axis eccentric screw pump 300 of the present invention described above is characterized in that the moving mechanism 50 is equipped with an actuator, the actuator is connected to an operating section 334, the actuator is capable of moving the operating section 334 along the moving groove 332 and is capable of automatically switching between the locked state and the unlocked state of the locking section 336.

[0132] The single-screw eccentric pump 300 of the present invention, with this configuration, can automatically adjust the tightening tolerance of the rotor 5 and stator 12, and automatically fix the rotor 5 and stator 12 in the adjusted position. In the single-screw eccentric pump 300 of the present invention, the automatic adjustment of the tightening tolerance of the rotor 5 and stator 12 can be performed by first unlocking the locking part 336, moving the operating part 334 along the movable groove 332 in a predetermined direction, and then locking the locking part 336 after the adjustment of the tightening tolerance is completed.

[0133] Although not shown in the diagram, the single-axis eccentric screw pump 300 according to the third modified example can be configured as follows to automate the adjustment of the tightening allowance of the rotor 5 and stator 12.

[0134] For example, the operating unit 334 is connected to an actuator (not shown). The actuator can move the operating unit 334 along the movable groove 332 and can automatically switch between the locked and unlocked states of the locking unit 336. For example, the operating unit 334 may have a crank mechanism, and the crank mechanism may be driven by the actuator to move the operating unit 334 along the movable groove 332. Alternatively, the operating unit 334 may be configured such that the locking unit 336, which is a nut, can be rotated around the axis of the operating unit 334 by an actuator or the like to switch between the locked and unlocked states. The locking unit 336 and automation described above can also be adopted in the single-screw eccentric pumps 100 and 200 according to the first and second modified examples.

[0135] Furthermore, if the adjustment of the tightening allowance of the rotor 5 and stator 12 is to be performed automatically as described above, it is preferable to configure the system so that the adjustment can be performed either while the single-screw eccentric pump 300 is operating, stopped, or both. For example, the single-screw eccentric pump 300 can be configured as follows, and this configuration can produce the following unique effects.

[0136] (q) In the single-screw eccentric pump 300 of the present invention described above, the movement of the operating section 334 by the actuator, and the switching of the locked state and unlocked state of the locking section 336 are performed either while the rotor 5 is being rotated, or while the rotor 5 is stopped, or both.

[0137] The single-screw eccentric pump 300 of the present invention, with this configuration, can automatically adjust the tension between the rotor 5 and the stator 12, whether the rotor 5 is rotating or stopped. Therefore, the single-screw eccentric pump 300 of the present invention can stably discharge fluids with high precision.

[0138] In the third modified example of the single-axis eccentric screw pump 300, when the drive unit is moved in the axial direction, the bearing 32 can be moved axially relative to the bearing housing 30 integrally with the input shaft 3 along with the movement of the drive unit. As a result, the single-axis eccentric screw pump 300 of the present invention can adjust the tightening allowance of the rotor 5 and stator 12 by moving the drive unit integrally with the input shaft 3 without moving the main body such as the shaft seal casing 40, bearing housing 30, pump casing 20, and stator casing 10.

[0139] The above describes the configuration and effects of the single-screw eccentric pump 300 according to the third modified example of the present invention. However, the single-screw eccentric pumps 1,100, 200, and 300 of the present invention are not limited to the embodiments or the first to second modified examples described above, and various modifications can be made within the scope of the invention. For example, the single-screw eccentric pumps 1,100, 200, and 300 may not have some or all of the configurations described in (b) to (q) above, or they may have some or all of the configurations described in (b) to (q) above, along with other configurations.

[0140] In this embodiment, the input shaft 3 is connected to the rotor 5 via a connecting shaft 7. However, various forms of input shaft 3 can be used, such as one that is connected to the rotor 5 without a connecting shaft 7, or one or more connecting shafts 7. When the input shaft 3 is directly connected to the rotor 5, it is preferable to connect it in such a way that the rotor 5 can rotate eccentrically. 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 numbers of grooves can be used for the stator 12 depending on the number of grooves of the rotor 5. Various shapes, sizes, and materials can be used for the stator 12 depending on the shape, size, and material of the rotor 5.

[0141] 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 one 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. It is also possible for the inner diameters of the rotor 5 and the inner bore 12a of the stator 12 to 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 to form either one or both of the inner diameters of the rotor 5 and 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.

[0142] In this embodiment, the input shaft 3 is rotatably supported by a pair of bearings 32, 32. However, the present invention is not limited to this, and various numbers of bearings 32 can be provided, such as a single bearing or two or more bearings. Furthermore, the arrangement of the bearings 32 is not limited to this embodiment, and various arrangements can be made. In addition, the type of bearing 32 can be changed as appropriate.

[0143] Furthermore, the bearing housing 30 is not limited to that of this embodiment, and can be of various shapes, sizes, and materials. Similarly, the pump casing 20 is not limited to that of this embodiment, and can be of various shapes, sizes, and materials, and the shape, size, arrangement, and number of supply ports 22 can also be modified in various ways. In this embodiment, the stator casing 10 and the pump casing 20 are provided independently, but the stator casing 10 and the pump casing 20 may be formed integrally.

[0144] Furthermore, in this embodiment, the pump casing 20 and the bearing housing 30 are screwed together from the pump casing 20 side to the bearing housing 30 side by four adjustment bolts 52 (double bolts 52), but the present invention is not limited to this. The adjustment bolts 52 may also be fastened from the bearing housing 30 side to the pump casing 20 side, and various numbers of adjustment bolts 52 can be used, from one to multiple. The arrangement of the adjustment bolts 52 is also not limited to this, and although it is desirable to provide them evenly or symmetrically around the bearing housing 30 so that the bearing housing 30 can move smoothly, various numbers and arrangements can be used.In addition, in this embodiment, double bolts 52 are used as adjustment bolts 52, but this is not limited to this, and various bolts and means that can move the pump casing 20 and the bearing housing 30 closer to and further apart can be used.For example, the adjustment bolts 52 may be composed of a combination of a push screw and a pull screw. Furthermore, in this embodiment, the pump casing 20 is provided between the stator casing 10 and the bearing housing 30, but the stator casing 10 and the pump casing 20 may be integrally formed. Also, other components besides the pump casing 20 may be interposed between the stator casing 10 and the bearing housing 30.

[0145] In this embodiment, the input shaft 3 and the drive unit's connection portion 60 are connected via a spline, but the input shaft 3 and the drive unit can be connected in various ways. For example, the input shaft 3 and the connection portion 60 may be connected by a key or rail, or by a fixed connection that prevents relative movement in the axial direction.

[0146] In this embodiment, a shaft seal casing 40 is provided, but the shaft seal casing 40 may be provided only if necessary, and the system may be designed without a shaft seal casing 40. In such cases, various means such as sealing members can be used to seal the space between the input shaft 3, the bearing housing 30, and the pump casing 20.

[0147] In the third modified example, a bearing housing-side threaded portion 230 is formed on the bearing housing 30 as a male thread, and a fixed-side threaded member 234 (for example, a nut member) is screwed onto the bearing housing-side threaded portion 230 as a female thread. Whether one is the male thread or the other can be appropriately selected depending on the structure of the fixed-side threaded member 234 and the bearing housing 30. Furthermore, the formation position and range of the bearing housing-side threaded portion can be modified in various ways depending on the structure of the fixed-side threaded member 234 and the bearing housing 30.

[0148] In this third modification, a movable mechanism 50 is provided with a helical movable groove 332 and an operating part 334 as an example. However, the movable groove 332 is not limited to a helical shape; for example, it may be linear. The movable groove 332 can be formed with various forming angles, forming ranges, number of turns, etc. The operating part 334 can also be formed with various sizes and rotation angles depending on the shape of the movable groove 332.

[0149] Furthermore, although not shown in the figures, in a third modified example, a plurality of operating parts 334 are provided, and the operating parts 334 have handle shafts, and the configuration is as follows. Specifically, the single-axis eccentric screw pump 300 has a bearing holder 33 that holds a bearing 32 so as not to rotate relative to it and is movable integrally with the bearing 32 in the axial direction, and the operating part 334 is fixed to the bearing holder 33 so as not to rotate relative to it and has a plurality of handle shafts formed in the direction around the axis so as to extend in a direction intersecting the axial direction, a plurality of movable grooves 332 are formed in the direction around the axis corresponding to the handle shafts, and the plurality of handle shafts are inserted so as to be movable along the plurality of movable grooves 332 provided in relation to each of them, and by rotating the plurality of handle shafts in the same direction along the plurality of movable grooves 332 provided in relation to each of them, the bearing 32 and the operating part 334 move integrally in the axial direction, which is a feature of this configuration.

[0150] In the single-screw eccentric pump 300 of the present invention, the multiple handle shafts in the operating section 334 are formed to intersect in the axial direction, so that the operating section 334 can be operated by using the multiple handle shafts as levers. As a result, the single-screw eccentric pump 300 of the present invention can reduce the force required to operate the operating section 334 (handle shafts). Therefore, the single-screw eccentric pump 300 of the present invention can reduce the burden on the operator (worker) and facilitate automation. Here, it is preferable that the multiple (for example, a pair) handle shafts are arranged perpendicular to the axial direction of the input shaft 3, and that they be set to an appropriate length that reduces the movement resistance of the bearing 32.

[0151] In the third modified example, automation of adjustments such as the tightening allowance of the rotor 5 and stator 12 in the single-screw eccentric pump 300 was illustrated. However, this automation can be adopted not only in the single-screw eccentric pump 300 according to the third modified example, but also in any embodiment or modified example.

[0152] 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.

[0153] The single-screw eccentric pump of the present invention can be used as a pump for transferring various fluids (especially viscous fluids).

[0154] 1 Single-screw eccentric pump 3 Input shaft 5 Rotor (male screw type rotor) 10 Stator casing 12 Stator (female screw type stator) 12a Inner bore 20 Pump casing 30 Bearing housing 32 Bearing 40 Shaft seal casing 50 Moving mechanism 52 Adjustment bolt (double bolt) 54 Outer bolt section 54a First thread section 54b Hollow hole 56 Inner bolt section 56a Second thread section 60 Connection section 100 Single-screw eccentric pump 120 Pump casing side thread section 140 Shaft seal casing side thread section 200 Single-screw eccentric pump 234 Fixed side thread member 300 Single-screw eccentric pump 330 Bearing housing side thread section 332 Moving groove 334 Operating section 336 Locking section

Claims

1. A single-screw eccentric pump comprising: an input shaft rotatably supported by at least one bearing and rotated by the power of a drive machine; a rotor eccentrically rotatably connected to the input shaft and configured as a male screw-type shaft body; and a stator formed as a female screw type through which the rotor can be inserted, wherein it is possible to form either or both of the outer diameter of the rotor and the inner diameter of the inner bore of the stator to decrease from one end to the other, or to change the amount of eccentricity with the rotor, and wherein the bearing is provided with a moving mechanism that moves the bearing toward and away from the stator in the axial direction of the input shaft, integrally with the input shaft.

2. The single-screw eccentric pump according to claim 1, comprising a bearing housing through which the input shaft can be inserted and which houses the bearing, wherein the moving mechanism moves the bearing relative to the bearing housing or integrally with the bearing housing.

3. A single-screw eccentric pump according to claim 1 or 2, comprising: a bearing housing through which the input shaft can be inserted and which houses the bearing so that it cannot move relative to it; and a pump casing provided along the axial direction of the input shaft, wherein the moving mechanism moves the bearing housing closer to and further away from the pump casing along the axial direction.

4. A single-screw eccentric pump according to claim 3, comprising at least one adjustment bolt, wherein a first bolt hole for fastening the adjustment bolt is formed through either the pump casing or the bearing housing, and a second bolt hole for fastening the adjustment bolt is formed in the other of the pump casing or the bearing housing, wherein the adjustment bolt comprises an outer bolt portion having a first threaded portion formed on its outer circumference and a hollow hole, and an inner bolt portion inserted through the hollow hole and having a second threaded portion formed on its outer circumference, wherein the outer bolt portion is screwed into the first bolt hole and its tip is able to abut against the outer circumference of the second bolt hole, and the inner bolt portion is screwed into the second bolt hole to fasten the pump casing and the bearing housing, and the distance of movement of the bearing housing can be adjusted according to the degree of tightening of the outer bolt portion.

5. The single-screw eccentric pump according to claim 3, characterized in that the moving mechanism is directly or indirectly connected to the input shaft and the drive unit, and the input shaft is connected to the drive unit so as to be movable along the axial direction.

6. The uniaxial eccentric screw pump according to claim 3, characterized in that the moving mechanism is capable of moving the drive unit integrally with the input shaft along the axial direction.

7. The single-screw eccentric pump according to claim 3, characterized in that a shaft seal is provided between the pump casing and the bearing housing to seal the periphery of the input shaft, and a shaft seal casing is provided to house the shaft seal, the shaft seal casing is integrally movable with the bearing housing relative to the pump casing, and the moving mechanism moves the shaft seal casing in the axial direction.

8. A single-screw eccentric pump according to claim 3, characterized in that a shaft seal is provided between the pump casing and the bearing housing to seal the periphery of the input shaft and a shaft seal casing is provided to house the shaft seal, the shaft seal casing is integral with the bearing housing and movable relative to the pump casing, and at least a portion of it overlaps with the pump casing, the movement mechanism comprises a shaft seal casing side threaded portion formed on at least a portion of the shaft seal casing, and a pump casing side threaded portion formed on the bearing housing side of the pump casing and screwable with the shaft seal casing side threaded portion, the amount of movement of the bearing housing relative to the pump casing can be adjusted by screwing the shaft seal casing side threaded portion to the pump casing side threaded portion.

9. The single-screw eccentric pump according to claim 5, characterized in that the moving mechanism is adjustable in the distance between the bearing housing and the drive unit.

10. The bearing housing has a bearing housing-side threaded portion formed in at least a part of it, a fixed-side threaded member that is fixed so as not to move in the axial direction is screwed into the bearing housing-side threaded portion, and the bearing housing is moved in the axial direction by rotating the fixed-side threaded member to change the screwed position of the bearing housing-side threaded portion.

11. The uniaxial eccentric screw pump according to claim 1 or 2, comprising a bearing housing through which the input shaft can be inserted and which houses the bearing integrally with the input shaft so as to be movable relative to the input shaft in the axial direction, wherein the moving mechanism moves the bearing along the axial direction relative to the bearing housing.

12. A single-screw eccentric pump according to claim 1, comprising a bearing housing through which the input shaft can be inserted and which houses the bearing so as to be movable relative to the bearing, wherein the moving mechanism comprises a moving groove formed on the outer circumference of the bearing housing along the axial direction of the input shaft, and an operating part that is directly or indirectly supported by the bearing and is movable along the moving groove, wherein the operating part can move the bearing integrally with the operating part along the axial direction by moving along the moving groove.

13. The uniaxial eccentric screw pump according to claim 12, characterized in that the movable groove is formed spirally on the outer circumference of the bearing housing at a predetermined pitch and angle such that the helical axis extends along the axial direction of the input shaft, and the operating part rotates along the movable groove so that the bearing can be moved integrally with the operating part along the axial direction.

14. The single-screw eccentric pump according to claim 11 or 12, further comprising a locking mechanism for fixing the operating mechanism at a predetermined position in the movable groove, wherein the locking mechanism is switchable between a locked state that fixes the operating mechanism and an unlocked state that allows the operating mechanism to move.

15. The uniaxial eccentric screw pump according to claims 1, 2, 11, and 12, characterized in that the moving mechanism comprises an actuator, the actuator causes the bearing to move toward and away from the stator along the axial direction.

16. The single-screw eccentric pump according to claim 14, characterized in that the moving mechanism includes an actuator, the actuator is connected to the operating section, the actuator is capable of moving the operating section along the moving groove, and is capable of automatically switching between the locked state and the unlocked state of the locking section.

17. The single-screw eccentric pump according to claim 16, characterized in that the movement of the operating part by the actuator and the switching of the locked and unlocked states of the locking part are performed while the rotor is being rotated, or while the rotor is stopped, or both.

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