JP7432921B2 - Single shaft eccentric screw pump - Google Patents

Description

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

Conventionally, a uniaxial eccentric screw pump is known that includes a rotor that is formed in a spiral shape and becomes conical from one end to the other, and a stator that has a through hole through which the rotor is inserted (for example, , see Patent Document 1).

However, in the conventional uniaxial eccentric screw pump, a mechanism for adjusting the relative positional relationship in the axial direction between the stator and the rotor has not been sufficiently studied.

US Patent No. 9109595

An object of the present invention is to provide a uniaxial eccentric screw pump in which the relative positional relationship in the axial direction between the stator and the rotor can be freely set.

As a means for solving the above problems, the present invention provides a rotor comprising a male-threaded shaft body, a stator having a female-threaded through hole into which the rotor is inserted, and a casing connected to one end side of the stator. and an end stud connected to the other end of the stator, and a position adjustment member that adjusts the relative position of the stator with respect to the rotor in the axial direction.

According to this configuration, the relative positional relationship in the axial direction of the stator with respect to the rotor can be adjusted by the position adjustment member.

comprising a joint portion that transmits power from a drive source to the rotor,
It is preferable that the position adjustment member is removably provided at an end portion of at least one of the rotor, the stator, the casing, and the joint portion, or in the middle.

It is preferable that the position adjustment member is removable between at least one of the stator and the casing or between the stator and the end stud.

According to this configuration, by arranging the position adjusting member between the stator and the casing, the rotor can be moved toward the casing with respect to the stator. On the other hand, by arranging the position adjustment member between the stator and the end stud, the rotor can be moved toward the end stud with respect to the stator.

Preferably, the position adjustment member is removable between the stator and the casing and between the stator and the end stud.

According to this configuration, the rotor can be moved to either the casing side or the end stud side with respect to the stator.

The position adjustment member may be removably provided at the free end, midway, or base of the rotor.

The position adjustment member may be removably provided at an end or in the middle of the joint portion.

It is preferable to include a plurality of the position adjusting members.

According to this configuration, by changing the number of position adjustment members to be mounted, the rotor can be moved in any axial direction relative to the stator by a distance corresponding to the number of position adjustment members.

Preferably, the position adjustment members have the same length in the axial direction.

According to this configuration, the rotor can be moved in the axial direction with respect to the stator by a distance proportional to the number of position adjustment members to be attached and detached.

Preferably, the amount of eccentricity of the rotor changes in the axial direction.

According to this configuration, by changing the relative positional relationship between the rotor and the stator in the axial direction, the amount of eccentricity between the rotor and the stator can be adjusted, and the interference between the rotor and the stator can be freely adjusted. Can be set.

Preferably, at least one of the outer diameter of the rotor and the inner diameter of the through hole of the stator changes in the axial direction.

According to this configuration, by changing the relative positional relationship between the rotor and the stator in the axial direction, the radial positional relationship between the rotor and the stator can be adjusted, and the tightness between the rotor and the stator can be adjusted. You can freely set the amount.

As the outer diameter of the rotor decreases in the axial direction, the inner diameter of the through hole of the stator decreases in accordance with the change in the outer diameter of the rotor, and the eccentricity of the rotor increases as the rotor's large diameter increases. It is preferable that the diameter increases from the side toward the small diameter side.

According to this configuration, the interference between the rotor and the stator can be adjusted by changing the relative positional relationship between the rotor and the stator in the axial direction. However, since changes in the cavity volume are suppressed due to changes in eccentricity, it is possible to transfer in a more stable state.

Preferably, by inserting the rotor into the stator, the volumes of the plurality of cavities formed between the rotor and the stator are equal.

According to this configuration, the fluid to be transported is less likely to be expanded and contracted in each cavity, and a stable transport state can be obtained.

Preferably, the position adjustment member has a hollow cylindrical shape, and its inner peripheral surface is formed into a female screw type that is the same as or similar to the inner peripheral surface of the through hole of the stator.

According to this configuration, the relative positional relationship in the axial direction between the rotor and the stator can be changed, and depending on the size of the inner diameter of the position adjustment member, the pump can be provided with additional functions such as a defoaming function. I can do it.

According to the present invention, the position adjustment member allows the relative positional relationship of the stator to the rotor in the axial direction to be freely set.

It is a sectional view showing a part of a uniaxial eccentric screw pump concerning a 1st embodiment. FIG. 2 is a sectional view showing a state in which the position adjustment member has been replaced from FIG. 1 . FIG. 2 is an explanatory diagram that simplifies the configuration of the stator and rotor in FIG. 1. FIG. It is a sectional view showing a part of a uniaxial eccentric screw pump concerning a 2nd embodiment. FIG. 5 is a sectional view showing a state in which the position adjustment member has been replaced from FIG. 4 . It is a sectional view showing a part of the uniaxial eccentric screw pump concerning a 3rd embodiment. FIG. 7 is a sectional view showing a state in which the position adjustment member has been replaced from FIG. 6 . It is an explanatory view showing an inventive concept of a uniaxial eccentric screw pump concerning a 4th embodiment. FIG. 9 is an explanatory diagram showing a state in which the position adjustment member has been replaced from FIG. 8; It is an explanatory view showing an inventive concept of a uniaxial eccentric screw pump concerning a 5th embodiment. 11 is an explanatory diagram showing a state in which the position adjustment member has been replaced from FIG. 10. FIG. It is a sectional view showing a rotor and a joint part of a uniaxial eccentric screw pump concerning a 6th embodiment. It is sectional drawing which shows a part of uniaxial eccentric screw pump based on another example of 6th Embodiment. FIG. 14 is a sectional view showing a state in which the position adjustment member is attached to FIG. 13; It is sectional drawing which shows a part of uniaxial eccentric screw pump based on another example of 6th Embodiment. 16 is a sectional view showing a state in which a position adjustment member is added to FIG. 15. FIG. It is sectional drawing which shows a part of uniaxial eccentric screw pump based on another example of 6th Embodiment. 18 is a sectional view showing a state in which a position adjustment member is added to FIG. 17. FIG. It is a sectional view showing a part of the uniaxial eccentric screw pump concerning a 7th embodiment. It is a sectional view showing a part of a uniaxial eccentric screw pump concerning an 8th embodiment. It is a side view which shows the position adjustment member of the uniaxial eccentric screw pump based on 9th Embodiment. FIG. 7 is a cross-sectional view of a stator according to another embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the following description is essentially just an example, and is not intended to limit the present invention, its applications, or its uses.

(First embodiment)
As shown in FIG. 1, the uniaxial eccentric screw pump according to the first embodiment includes a rotor 1, a stator 2, a casing 3, an end stud 4, and a position adjustment member 5.

The rotor 1 has a shaft body made of a metal material such as stainless steel, and has a single-stage or multi-stage male screw shape with n-1 threads. Further, the rotor 1 is formed to have a virtual conical shape as a whole from one end to the other end (see FIG. 3). In this embodiment, the cross-sectional shape of the rotor 1 is almost a perfect circle (n=2), but its outer diameter (cross-sectional area) gradually increases from one end to the other end (from the right side to the left side in the figure). It's getting smaller.

The stator 2 has a hollow cylindrical shape extending from one end to the other, and is made of an elastic material such as rubber or resin (e.g., silicone rubber, fluororubber) selected depending on the fluid to be conveyed. . The through hole 2a of the stator 2 has an n-thread, single-stage or multi-stage female screw shape, and the rotor 1 is inserted therethrough. The through hole 2a is formed to have a virtual conical shape as a whole from one end toward the other end in accordance with the shape of the rotor 1 (see FIG. 3). That is, the cross-sectional shape of the through hole 2a is an ellipse, but its inner diameter (cross-sectional area) gradually decreases from one end to the other end (from the right side to the left side in the figure). With the rotor 1 inserted into the through hole 2 a of the stator 2 , a plurality of conveyance spaces (cavities) 13 are formed between the inner surface of the through hole 2 a of the stator 2 and the outer surface of the rotor 1 . Here, the volume of each transport space 13 is the same. Further, an outer cylinder 6 made of a metal material such as stainless steel is attached to the outer circumferential surface of the stator 2 to prevent the stator 2 from deforming radially outward.

The axial center of the rotor 1 and the axial center of the stator 2 are eccentric, and the amount of eccentricity increases from one end to the other end. Thereby, the volume of each conveyance space 13 is the same.

Further, the rotor 1 and the stator 2 are formed to have a virtual conical shape as a whole. Therefore, when the rotor 1 is moved to the left side relative to the stator 2, the contact pressure between the inner surface forming the through hole 2a of the stator 2 and the outer surface of the rotor 1 increases. As a result, the interference of the stator 2 with respect to the rotor 1 can be increased. Conversely, if the rotor 1 is moved to the right side relative to the stator 2, the interference of the stator 2 with respect to the rotor 1 can be reduced.

Here, the outer diameter of the rotor 1 and the inner diameter of the through hole 2a of the stator 2 are configured to gradually decrease from one end to the other, but even if at least one of them is formed in this way, good.

The casing 3 is made of a metal material such as stainless steel and has a hollow cylindrical shape, and one end of the casing 3 is connected to one end of the stator 2 . A stepped connection receiving portion 7 with an enlarged inner diameter is formed on one end surface of the casing 3 . One end of the outer tube 6 and a connecting portion 11 of a position adjustment member 5, which will be described later, are connected to this connection receiving portion 7. A connecting pipe (not shown) is connected to the casing 3 so that fluid can be supplied thereto. Further, a joint portion 8 is arranged within the casing 3. A drive shaft (not shown) extending from a drive source is connected to one end of the joint portion 8 . The rotor 1 is connected to the other end of the joint portion 8 . Thereby, the driving force from the driving source is transmitted to the rotor 1, and the rotor 1 is rotationally driven.

The end stud 4 is made of a metal material such as stainless steel, and one end thereof is connected to the other end of the stator 2 . A stepped connection receiving portion 9 with an enlarged inner diameter is formed on one end surface of the end stud 4. The other end of the outer tube 6 and a connecting portion 11 of a position adjustment member 5, which will be described later, are connected to this connection receiving portion 9. Further, the end stud 4 constitutes an outlet for discharging the fluid flowing through the through hole 2a of the stator 2.

The position adjustment member 5 is made of a metal material such as stainless steel and shaped into a hollow cylinder, and is arranged between one end of the outer cylinder 6 and one end of the casing 3 (here, four position adjustment members 5 are connected). One end opening of the position adjustment member 5 is configured with a stepped connection receiving portion 10 having a larger inner diameter. The opening at the other end of the position adjustment member 5 is configured with a stepped connecting portion 11 having a smaller outer diameter. The position adjustment members 5 are connected in a sealed state by connecting the connection portion 11 to the connection receiving portion 10 via the packing 12. The position adjustment member 5 and the casing 3 are connected in a sealed state by connecting the connection receiving portion 7 of the casing 3 to the connection portion 11 of the position adjustment member 5 via the packing 12. The position adjustment member 5 and the outer cylinder 6 are connected by connecting one end of the outer cylinder 6 to the connection receiving part 10 of the position adjustment member 5. At this time, a part of the stator 2 is interposed between the connection receiving part 10 of the position adjustment member 5 and one end of the outer cylinder 6, thereby creating a sealed state. The position adjustment member 5 can be replaced between the end stud 4 and the stator 2. In this case, the position adjustment member 5 and the end stud 4 are connected in a sealed state by connecting the connection portion 11 of the position adjustment member 5 to the connection receiving portion 9 of the end stud 4 via the packing 12. Further, the position adjustment member 5 and the outer cylinder 6 of the stator 2 are connected by connecting the other end of the outer cylinder 6 to the connection receiving portion 10 of the position adjustment member 5. At this time, a part of the stator 2 is interposed between the connection receiving part 10 of the position adjustment member 5 and the other end of the outer cylinder 6, thereby creating a sealed state.

In the uniaxial eccentric screw pump configured as described above, in the initial stage, for example, as shown in FIG. Use it so that the desired interference can be obtained between the two. In this state, when the rotor 1 is rotated by power being transmitted from the drive system (not shown) through the joint part 8, the fluid supplied into the casing 3 is transferred to the conveyor belt formed between the stator 2 and the rotor 1. It is conveyed to the end stud 4 side via the space (cavity) 13.

As the inner surface of the through hole 2a of the stator 2 wears out due to use, and the tightness of the stator 2 with respect to the rotor 1 becomes smaller, as shown by the arrows in FIG. One of the position adjustment members 5 is removed and replaced between the stator 2 and the end stud 4 as shown by the arrow in FIG. As a result, the relative positional relationship between the stator 2 and the rotor 1 is shifted by the length of the moved one position adjustment member 5 in the axial direction. That is, the rotor 1 that slides into contact with the inner surface of the through hole 2a of the stator 2 is changed to a portion having a larger cross-sectional area, and the interference between the stator 2 and the rotor 1 can be corrected to be larger.

Thereafter, if the stator 2 wears out further, the remaining position adjustment members 5 located between the stator 2 and the casing 3 may be successively removed and replaced between the stator 2 and the end stud 4. Note that the state of wear of the stator 2 may be determined by visually observing the state of conveyance of the fluid, or simply by automatically determining the number of revolutions of the rotor 1.

In this way, by increasing the number of position adjustment members 5 that are replaced between the stator 2 and the casing 3 and between the stator 2 and the end studs 4 according to the degree of wear of the stator 2, the tightness by the stator 2 can be adjusted as needed. It can be improved to something appropriate. Improvement of the tightening margin can be continued until all position adjustment members 5 are replaced.

Further, the conditions for obtaining a desired interference between the rotor 1 and the stator 2 differ depending on the type of fluid to be transported and the environment in which it is used. Therefore, standard conditions are determined, and between the stator 2 and the casing 3, and between the stator 2 and the end stud 4, so that the rotor 1 and the stator 2 are in a position where the desired tightness can be obtained at that time. The position adjusting member 5 may be attached to each of the.

For example, if the ambient atmosphere temperature is higher than a certain reference temperature (normal temperature of 15°C to 25°C, for example 20°C), it is necessary to consider the expansion of the stator 2, etc. The rotor 1 may be moved to the right in the figure with respect to the stator 2 by increasing the number of position adjustment members 5 between the stator 2 and the casing 3. Thereby, the interference of the stator 2 with respect to the rotor 1 can be prevented from becoming too large, and the fluid can be transported appropriately. In addition, when the ambient atmosphere temperature is lower than the reference temperature, the number of position adjustment members 5 between the stator 2 and the end studs 4 is increased to prevent the tightening margin of the stator 2 with respect to the rotor 1 from decreasing. Just do it.

In addition, if the fluid has a high viscosity relative to a certain standard viscosity (for example, the viscosity of a standard calibration solution), the number of position adjustment members 5 between the stator 2 and the casing 3 may be increased to 1 to the right side in the figure, the interference can be suppressed to make it easier to convey the fluid. In addition, when the viscosity of the fluid is low compared to a certain reference viscosity, conversely, the number of position adjustment members 5 between the stator 2 and the end stud 4 is increased to increase the interference, and the fluid is removed from the conveyance space 13. All you have to do is prevent leakage.

According to the uniaxial eccentric screw pump having the above configuration, the following effects can be obtained.
(1) Even if the stator 2 wears out, the tightness of the stator 2 with respect to the rotor 1 can be adjusted by simply changing the mounting location of the position adjustment member 5 from between the stator 2 and the casing 3 to between the stator 2 and the end stud 4. It can be restored to its original state.
(2) By changing the mounting location of the position adjustment member 5, the interference of the stator 2 with respect to the rotor 1 can be set to an appropriate value according to differences in conditions such as the viscosity of the fluid and the ambient temperature, It becomes possible to maintain the conveyance state of the fluid in a good state.
(3) Since it is only necessary to replace the position adjustment member 5 between the stator 2 and the casing 3 or between the stator 2 and the end stud 4, the tightness of the stator 2 with respect to the rotor 1 can be adjusted with good work efficiency. can.

(Second embodiment)
As shown in FIG. 4, the uniaxial eccentric screw pump according to the second embodiment has substantially the same configuration as the first embodiment, and differs only in the following points.

In the second embodiment, the rotor 1 is configured to have the same cross-sectional area from one end to the other end. Further, the through holes 2a of the stator 2 are also configured to have the same cross-sectional area from one end to the other end. The rotor 1 has a first region located within the through hole 2a of the stator 2 and a second region located within the position adjustment member 5 at the initial stage of use.

According to the uniaxial eccentric screw pump according to the second embodiment, when a part of the rotor 1 is damaged due to use, for example, by a fluid, the position adjustment member 5 is replaced as shown in FIG. The position at which the rotor 1 makes sliding contact with the rotor 1 is changed. Thereby, the conveyance of the fluid can be restored to an appropriate state.

In addition, when changing the eccentricity of the rotor 1 with respect to the axial direction of the stator 2, by shifting the axial position of the rotor 1, the volume of the transfer space 13 can be made smaller or larger in the axial direction. You can do it. For example, in the case where the rotation center of the rotor 1 is gradually brought closer to the axial center of the stator 2 in the axial direction of the stator 2 toward the conveyance direction of the fluid, it is possible to move the rotor 1 in the conveyance direction. Accordingly, the proportion of the cross-sectional area occupied by the transport space 13 can be reduced. In other words, the volume of the transport space 13 can be gradually reduced in the transport direction. Furthermore, by moving the rotor 1 in the opposite direction to the transport direction, the proportion of the cross-sectional area occupied by the transport space 13 can be increased.

(Third embodiment)
As shown in FIG. 6, the uniaxial eccentric screw pump according to the third embodiment has substantially the same configuration as the first and second embodiments, and differs only in the following points.

In the third embodiment, similarly to the second embodiment, the rotor 1 is configured to have the same cross-sectional area from one end to the other end. Further, the through hole 2a of the stator 2 is also configured to have the same cross-sectional shape from one end to the other end. However, the length of the stator 2 is different from that of the second embodiment in that it is set longer. Here, the length of the stator 2 is set to be approximately three times that of the second embodiment.

According to the uniaxial eccentric screw pump according to the third embodiment, in the initial stage, the rotor 1 is inserted only into one end side of the stator 2 (here, about 2 pitches indicated by the arrow in the figure). When the stator 2 becomes worn, the position adjustment member 5 between the stator 2 and the casing 3 is removed and replaced between the stator 2 and the end stud 4 as shown in FIG. 1 is further increased (here, the position is about 3 pitches from the position of about 2 pitches of the through hole 2a). This makes it possible to add a new, unworn area to the contact range between the inner surface of the stator 2 through-hole 2a and the outer surface of the rotor 1, making it possible to restore the conveyance state of the fluid. Become. Since the area where the stator 2 is not worn out can be used, the conveyance state of the fluid can be improved compared to the first embodiment in which the worn area is continued to be used.

(Fourth embodiment)
The uniaxial eccentric screw pump according to the fourth embodiment has substantially the same configuration as the first embodiment, and differs only in the following points.

As schematically shown in FIG. 8, the cross-sectional area of the rotor 1 is formed so that it gradually decreases from one end to the other end (from the right side to the left side in the figure). As in the first embodiment, it is formed into a single-stage or multi-stage male screw shape with n-1 threads.) On the other hand, the cross-sectional areas of the through holes 2a of the stator 2 are the same.

According to the uniaxial eccentric screw pump according to the fourth embodiment, when the rotor 1 is rotated to transport the fluid, the transport space 13 gradually becomes larger toward the downstream side, so that the transport space 13 is kept in a negative pressure state. Dissolved gas dissolved in the fluid can be removed by precipitating it as bubbles. Then, in order to further bring the conveying space 13 into a negative pressure state and make it easier to generate bubbles, the position adjustment member 5 that was placed between the end stud 4 and the stator 2 is moved from the stator 2 to the end stud 4, as shown in FIG. and a casing (not shown). As a result, the rotor 1 is moved backward relative to the stator 2 to increase the volume of the conveyance space 13 (not shown in FIG. 9), thereby making it easier to remove dissolved gas dissolved in the fluid. I can do it.

(Fifth embodiment)
The uniaxial eccentric screw pump according to the fifth embodiment has almost the same configuration as the first embodiment, and differs only in the following points.

As schematically shown in FIG. 10, the cross-sectional area of the rotor 1 is formed to gradually increase from one end to the other end (from the right side to the left side in the figure). On the other hand, the cross-sectional areas of the through holes 2a of the stator 2 are the same.

According to the uniaxial eccentric screw pump according to the fifth embodiment, when the rotor 1 is rotated to transport the fluid, if the fluid contains air bubbles, the bubbles can be pressurized and dissolved in the fluid. I can do it. In order to further pressurize the fluid and dissolve air bubbles in the fluid, the position adjustment member 5, which had been placed between the end stud 4 and the stator 2, is moved between the stator 2 and the stator 2, as shown in FIG. It can be replaced with a casing that does not. As a result, the tip side of the rotor 1 having a larger outer diameter can be moved into the through hole 2a (not shown in FIG. 11) of the stator 2, reducing the volume of the conveying space 13 and further eliminating air bubbles. It becomes possible to easily dissolve it in a fluid.

Note that in the fourth and fifth embodiments, only the cross-sectional area of the rotor 1 was changed, but the same effect can be achieved by changing the cross-sectional area of the through hole 2a of the stator 2 or by changing both. It can also be configured so as to have the following effects.

(Sixth embodiment)
The uniaxial eccentric screw pump according to the sixth embodiment has substantially the same configuration as the first embodiment, and differs only in the following points.

As shown in FIG. 12, the position adjustment member 5 can be removably provided at the free end of the rotor 1, in the middle, at the base (the connection part with the joint part 8), and in the middle of the joint part 8. The positions at which the position adjustment member 5 is attached and detached may be any three, two, or one of these four locations.

FIG. 13 shows an example in which a position adjustment member 5 is removably provided at the connection portion between the rotor 1 and the joint portion 8. As shown in FIG. A connecting portion 15 is connected to one end of the joint portion 8 by a joint pin 14 . A shaft portion 15a protrudes from the end surface of the connecting portion 15, and a through hole 15b is formed in the center thereof. On the other hand, an engagement hole 1a is formed at one end of the rotor 1, into which the shaft portion 15a of the connecting portion 15 is inserted. A key groove is formed between the shaft portion 15a and the engagement hole 1a, and a key 16 is disposed therein. By screwing the bolt 17 into the connecting portion 15, the shaft portion 15a expands toward the outer diameter side, and the outer peripheral surface of the shaft portion 15a of the connecting portion 15 comes into pressure contact with the inner peripheral surface of the engagement hole 1a of the rotor 1. Both are connected. Further, the presence of the key 16 prevents rotation of the rotor 1 relative to the connecting portion 15. When changing the sliding contact position of the rotor 1 with respect to the stator 2, the position adjusting member 5 may be placed between the connecting portion 15 and the rotor 1, as shown in FIG. In this case, the key 16 may be replaced to prevent rotation between the position adjustment member 5 and the shaft portion 15a of the connecting portion 15. As a result, if the cross-sectional area of the rotor 1 is configured to become thicker toward the base end, the pressure contact force between the inner surface of the through hole 2a of the stator 2 and the outer surface of the rotor 1 can be reduced. can be increased.

FIG. 15 shows an example in which a position adjustment member 5 is detachably provided on the rotor 1. The distal end and part of the proximal end of the rotor 1 are constituted by position adjusting members 5, which are fixed by bolts 17 inserted from the distal end of the rotor 1. Here, one position adjustment member 5 corresponds to one pitch of the rotor 1. When changing the sliding contact position of the rotor 1 with respect to the stator 2, as shown in FIG. 16, the position adjusting member 5 provided at the tip of the rotor 1 may be removed and replaced at the base end. Thereby, the sliding contact position of the rotor 1 with respect to the stator 2 can be shifted by one pitch from the distal end side to the proximal end side. As a result, if the cross-sectional area of the rotor 1 is configured so that it becomes thicker toward the base end, the pressure contact force between the inner surface forming the through hole 2a of the stator 2 and the outer surface of the rotor 1 can be reduced. can be increased.

FIG. 17 shows an example in which the position adjustment member 5 is detachably provided on the joint portion 8. As shown in FIG. A part of the joint portion 8 is composed of position adjustment members 5 that are connected to each other and can be separated. Each position adjustment member 5 has a threaded portion 5a at the center of one end surface, and a threaded hole 5b at the center of the other end surface. By screwing the threaded portion 5a into the threaded hole 5b, the position adjustment members 5 can be connected to each other. By increasing the number of position adjustment members 5 to be connected, the rotor 1 can be moved toward the tip side in the axial direction with respect to the stator 2. In FIG. 18, one position adjustment member 5 is added to the three position adjustment members 5 connected in FIG. 17, so that a total of four position adjustment members 5 are connected. Thereby, the rotor 1 can be moved by one length of the position adjustment member 5 in the axial direction. As a result, if the cross-sectional area of the rotor 1 is configured so that it becomes thicker toward the base end, the pressure contact force between the inner surface forming the through hole 2a of the stator 2 and the outer surface of the rotor 1 can be reduced. It is possible to increase it.

(Seventh embodiment)
The uniaxial eccentric screw pump according to the seventh embodiment has substantially the same configuration as the first embodiment, and differs only in the following points.

As shown in FIG. 19, the lengths of the position adjustment members 5 in the axial direction are different. Here, the position adjustment member 5 is composed of four position adjustment members, ie, the first to fourth position adjustment members, and the ratio of the lengths of these members in the axial direction is 1:2:3:4. However, the number, length, and length ratio of the position adjustment members 5 can be freely set.

According to the uniaxial eccentric screw pump according to the seventh embodiment, the degree of freedom in adjusting the position of the rotor 1 with respect to the stator 2 can be further increased by appropriately combining the position adjusting members 5. That is, from the initial state in which the first position adjusting member 5-1 to the fourth position adjusting member 5-4 are interposed between the stator 2 and the casing 3 in order, only the first position adjusting member 5-1 is interposed between the stator 2 and the end. Replace between studs 4. Hereinafter, only the second position adjustment member 5-2, the third position adjustment member 5-3, and the fourth position adjustment member 5-4 are replaced in order. Thereafter, the combinations of the position adjustment members 5 are replaced. Thereby, the range of position adjustment of the rotor 1 can be expanded compared to the case where all the lengths are the same.

(Eighth embodiment)
The uniaxial eccentric screw pump according to the eighth embodiment has almost the same configuration as the first embodiment, and differs only in the following points.

As shown in FIG. 20, the position adjustment member 5 is composed of a cylindrical portion 5A made of a metal material such as stainless steel, and an inner diameter portion 5B made of the same material as the stator 2, which is disposed on the inner diameter side of the cylindrical portion 5A. There is. In the inner diameter portion 5B, a single-stage or multi-stage female thread-shaped through hole 5C is formed with n-stripes similar to the stator 2. For example, the position adjusting member 5 can be arranged between the stator 2 and the end stud 4 by making the through hole 5C of the position adjusting member 5 have a smaller inner diameter than the stator 2. According to this, by simply mounting the position adjustment member 5 without performing any special processing on the stator 2, the fluid can be pressurized in addition to adjusting the axial positional relationship between the rotor 1 and the stator 2. This makes it possible to obtain a configuration in which the remaining air bubbles are dissolved in the fluid. Conversely, the position adjusting member 5 can be arranged between the stator 2 and the end stud 4 by making the through hole 5C of the position adjusting member 5 have a larger inner diameter than the stator 2. According to this, by simply attaching the position adjustment member 5 without performing any special processing on the stator 2, the axial positional relationship between the rotor 1 and the stator 2 can be adjusted, and the stator 2 can be blended into the fluid. A configuration can be obtained in which dissolved gas is precipitated as bubbles and removed. Furthermore, it is also possible to replace the stator 2 with a plurality of position adjustment members 5 having the above configuration. According to this, only the damaged position adjustment member 5 can be replaced, which is economical.

(Ninth embodiment)
The uniaxial eccentric screw pump according to the ninth embodiment has substantially the same configuration as the first embodiment, and differs only in the following points.

As shown in FIG. 21, the position adjustment member 5 can be divided into a plurality of parts in the circumferential direction. Here, the position adjustment member 5 includes a first position adjustment section 18 and a second position adjustment section 19 that are divided into two in the circumferential direction. Both the first position adjusting part 18 and the second position adjusting part 19 have a semi-cylindrical shape, and an extending part 20 extending radially outward is formed on opposing surfaces. The extending portions are connected to each other by bolts 17 via packing 12. According to this configuration, only the position adjustment member 5 can be easily attached or detached by simply tightening or loosening the bolt 17.

Note that the present invention is not limited to the configuration described in the above embodiments, and various changes are possible.

In the embodiment described above, an example in which one to four position adjustment members 5 are provided has been described, but the number is not particularly limited and may be five or more. If only one position adjustment member 5 is provided, it may be provided between the stator 2 and the casing 3 or between the stator 2 and the end stud 4, and it may be replaced at the remaining position. . Alternatively, the position adjustment member 5 may be attached or detached only between the stator 2 and the casing 3 or between the stator 2 and the end stud 4. However, it is more convenient to replace the position adjustment member 5 between the stator 2 and the casing 3 and between the stator 2 and the end stud 4 in that the positional relationship can be adjusted without changing the overall length of the pump. Excellent in sex.

In the embodiment described above, the position adjustment member 5 is made of metal, but it may also be made of synthetic resin or rubber. If it is made of synthetic resin or rubber, it can be easily removed by simply cutting it, without requiring disassembly of the pump. Furthermore, if the position adjustment member 5 is configured to be divided into a plurality of parts in the circumferential direction as described above, disassembly of the pump itself is not necessary when installing the position adjustment member 5.

In the embodiment, the volume of the conveyance space 13 can be increased toward one end by, for example, gradually decreasing or increasing the pitch of the screw shapes of the rotor 1 and stator 2 toward one end. It can also be increased or decreased.

In the embodiment described above, the outer diameter of the rotor 1 is gradually decreased toward the end stud 4, but it may be gradually increased. Further, in the embodiment described above, the amount of eccentricity of the rotor 1 with respect to the stator 2 is increased toward the end stud 4 side, but it may be decreased.

In the embodiment described above, the position adjustment member 5 is attached between the stator 2 and the casing 3, but the position adjustment member 5 may be attached between the casing 3 and the divided parts. Moreover, the position adjustment member 5 can also be attached to the end of the stator 2 or in the middle. In short, the position adjustment member 5 only needs to be removably provided at the end or midway of at least one of the rotor 1, stator 2, casing 3, and joint portion 8. It is also possible to provide position adjusting members 5 for each of the rotor 1 and casing 3, the stator 2 and casing 3, etc.

In the embodiment described above, the thickness of the stator 2 is configured to change in the axial direction, but it is preferable to configure it so that it is uniform and does not change. FIG. 22 is a longitudinal sectional view of the stator 2. The inner surface of the outer cylinder 6 made of a metal material such as stainless steel is formed into a single-stage or multi-stage internal thread shape with n threads. The stator 2, which is made of an elastic material such as rubber having a larger coefficient of thermal expansion than the outer cylinder 6, has the same thickness in the cross section at any position, and the thickness in each cross section shifted in the axial direction. It is formed to have a uniform thickness throughout so that it is the same in all cross sections.

According to the uniaxial eccentric screw pump equipped with the stator 2 having such a configuration, even when the temperature of the fluid or the surrounding atmosphere changes, variations in the interference with respect to the rotor 1 do not occur. In other words, since the thickness of the stator 2 in the cross section is the same at any position, the pressing force against the outer surface of the rotor 1 does not increase or decrease at any position in the cross section. . In addition, since the thickness is the same regardless of the cross section in the axial direction of the stator, when the rotor 1 rotates, the friction may increase or decrease at any position in the axial direction. There's nothing to do. Therefore, the interference of the stator 2 with respect to the rotor 1 can be appropriately adjusted regardless of temperature changes in the fluid or the surrounding atmosphere, and the rotational state of the rotor 1 can be stabilized. Note that the thickness of the stator 2 may be determined depending on the magnitude of temperature change in the fluid and the surrounding atmosphere. That is, if it is used under conditions where temperature changes are large, the thickness may be set thin, and if it is used under conditions where temperature changes are small, the thickness may be set thick.

1... Rotor 2... Stator 3... Casing 4... End stud 5... Position adjustment member 6... Outer cylinder 7... Connection receiving part 8... Joint part 9... Connection receiving part 10... Connection receiving part 11... Connection part 12... Packing 13... Conveyance space 14... Joint pin 15... Connecting part 16... Key 17... Bolt 18... First position adjustment part 19... Second position adjustment part 20... Extension part

Claims (12)

A rotor consisting of a male threaded shaft body,
a stator having a female threaded through hole through which the rotor is inserted;
a casing connected to one end of the stator;
an end stud connected to the other end of the stator;
a position adjustment member that adjusts the relative position of the stator with respect to the rotor in the axial direction;
Equipped with
The position adjustment member is removable between the stator and the casing and between the stator and the end stud . comprising a joint portion that transmits power from a drive source to the rotor,
The uniaxial eccentric according to claim 1, wherein the position adjustment member is removably provided at an end of at least one of the rotor, the stator, the casing, and the joint part, or in the middle. screw pump. The uniaxial eccentric screw pump according to claim 1 or 2, wherein the position adjustment member is removable between at least one of the stator and the casing or between the stator and the end stud. The uniaxial eccentric screw pump according to claim 1 or 2, wherein the position adjustment member is removably provided at the free end, midway, or base of the rotor. 3. The uniaxial eccentric screw pump according to claim 2, wherein the position adjustment member is removably provided at an end or in the middle of the joint part. The uniaxial eccentric screw pump according to any one of claims 1 to 5 , comprising a plurality of said position adjustment members. The uniaxial eccentric screw pump according to claim 6 , wherein the axial lengths of the position adjustment members are the same. The uniaxial eccentric screw pump according to any one of claims 1 to 7 , wherein the eccentricity of the rotor changes in the axial direction. The uniaxial eccentric screw pump according to any one of claims 1 to 8 , wherein at least one of the outer diameter of the rotor and the inner diameter of the through hole of the stator changes in the axial direction. A rotor consisting of a male threaded shaft body,
a stator having a female threaded through hole through which the rotor is inserted;
a casing connected to one end of the stator;
an end stud connected to the other end of the stator;
a position adjustment member that adjusts the relative position of the stator with respect to the rotor in the axial direction;
Equipped with
The outer diameter of the rotor decreases in the axial direction,
the inner diameter of the through hole of the stator decreases in response to a change in the outer diameter of the rotor;
A uniaxial eccentric screw pump, wherein the eccentricity of the rotor changes in the axial direction and increases from a large diameter side to a small diameter side of the rotor. 11. The uniaxial eccentric screw pump according to claim 10 , wherein the plurality of cavities formed between the rotor and the stator by inserting the rotor into the stator have equal volumes. A rotor consisting of a male threaded shaft body,
a stator having a female threaded through hole through which the rotor is inserted;
a casing connected to one end of the stator;
an end stud connected to the other end of the stator;
a position adjustment member that adjusts the relative position of the stator with respect to the rotor in the axial direction;
Equipped with
The position adjusting member has a hollow cylindrical shape, and the inner circumferential surface thereof is formed into a female thread type that is the same as or similar to the inner circumferential surface of the through hole of the stator.

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