Single-axis eccentric screw pump

Abstract

To provide a uniaxial eccentric screw pump capable of making a device configuration compact.SOLUTION: A uniaxial eccentric screw pump 100 is a uniaxial eccentric screw pump in which a male screw type rotor 20 is inserted to a stator 30 including a female screw type insertion hole. The uniaxial eccentric screw pump 100 comprises a rotor drive mechanism 50 by which a rotor 20 can be revolved while rotating. The rotor drive mechanism 50 includes an input-side pinion gear 52 and a rotation-side crown gear 54. The input-side pinion gear 52 inputs a motive force. The rotation-side crown gear 54 is eccentrically rotatable so as to revolve the rotor 20 while receiving transfer of a rotation motive force with which the rotor 20 rotates, around a fixed central axis C2 in a state where the rotation-side crown gear is connected with the input-side pinion gear 52.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a uniaxial eccentric screw pump provided with a rotor drive mechanism capable of rotating the rotor while revolving it.

Background Art

[0002] Conventionally, a uniaxial eccentric screw pump provided with a rotor drive mechanism capable of rotating the rotor while revolving it has been proposed (see, for example, Patent Documents 1 and 2).

[0003] Patent Document 1 describes a uniaxial eccentric screw pump provided with a rotor drive mechanism capable of rotating the rotor while revolving it. The rotor drive mechanism disclosed in Patent Document 1 includes a rotation power transmission member rotatable about a fixed central axis, a revolution orbit forming member capable of allowing the rotation of the base shaft portion of the rotor while revolving it, and a power transmission member (Oldham joint) capable of transmitting the rotation of the rotation power transmission member to the base shaft portion while allowing the revolution (eccentric rotation) of the base shaft portion of the rotor to rotate it.

[0004] The power transmission member (Oldham joint) disclosed in Patent Document 1 is provided with grooves orthogonal to each other on the rotation power transmission member and the disks provided at the ends of the base shaft portion, and a disk-shaped intermediate disk having protrusions in mutually perpendicular directions on the front and back is interposed therebetween, whereby the rotation power transmission member and the base shaft portion are connected. Thereby, the eccentricity between the rotation axis and the revolution axis of the rotor is absorbed.

[0005] Further, in the uniaxial eccentric screw pump disclosed in Patent Document 2, the rotor constituting the pump mechanism is connected to a power source via a coupling rod. Thereby, the rotor can rotate while revolving (eccentric rotation).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] Here, in the uniaxial eccentric screw pump disclosed in the above Patent Document 1, in order to transmit the power of the rotation power transmission member to the base shaft portion of the rotor, the rotation power transmission member and the base shaft portion are connected by the power transmission member. Further, in the uniaxial eccentric screw pump disclosed in the above Patent Document 2, it is necessary to provide a long rod such as a coupling rod.

[0008] For the reasons described above, the uniaxial eccentric screw pumps disclosed in Patent Documents 1 and 2 have a problem that the overall length becomes long and the size increases. Furthermore, accompanying this, there is also a problem that when the pumping of the fluid is stopped, the remaining amount of the fluid in the pump casing increases.

[0009] The present invention has been made to solve the above problems, and an object thereof is to provide a uniaxial eccentric screw pump capable of making the device configuration compact. [Means for Solving the Problems]

[0010] To achieve the above object, the present invention is configured as follows.

[0011] (1) The uniaxial eccentric screw pump according to the present invention is a uniaxial eccentric screw pump in which a male screw type rotor is inserted into a stator provided with a female screw type insertion hole, and includes a rotor drive mechanism capable of revolving the rotor while rotating it. The rotor drive mechanism has a rotation input portion for inputting power, and an eccentric rotation portion capable of eccentric rotation so as to revolve the rotor while receiving transmission of rotation power for rotating the rotor about a fixed central axis in a state of being connected to the rotation input portion.

[0012] According to the above configuration, in the prior art, in order to absorb the eccentricity between the rotation axis and the revolution axis of the rotor and transmit the power of the rotation power transmission member to the base shaft portion of the rotor, a power transmission member (Oldham joint) connecting the rotation power transmission member and the base shaft portion of the rotor, or a long rod such as a coupling rod used to connect the rotor to the power source so that it can revolve while rotating is not required, and thus the overall length can be shortened accordingly. Therefore, according to the above configuration, a single-axis eccentric screw pump with a short overall length and a compact configuration can be provided. In addition, when the single-axis eccentric screw pump is stopped, the remaining amount of the fluid remaining inside the pump casing can be minimized.

[0013] (2) In the single-axis eccentric screw pump according to the present invention, preferably, the rotor has a male screw portion inserted into the insertion hole of the stator and a shaft-shaped base shaft portion connected to the eccentric rotation portion, and the male screw portion and the base shaft portion are integrally coupled along the axis. With this configuration, a connecting member for connecting the male screw portion and the base shaft portion of the rotor can be omitted (jointless). As a result, the number of parts can be reduced.

[0014] (3) In the single-axis eccentric screw pump according to the present invention, preferably, the rotation input portion has an input portion side connection portion, the eccentric rotation portion has an eccentric rotation portion side connection portion, and the input portion side connection portion and the eccentric rotation portion side connection portion are connected so as to be able to transmit power while relatively moving in a direction intersecting the central axis. With this configuration, even when the input portion side connection portion and the eccentric rotation portion side connection portion relatively move according to the revolution of the rotor at the connection portion, power is transmitted from the rotation input portion to the eccentric rotation portion. Therefore, as the eccentric rotation portion eccentrically rotates, the rotor can be revolved while rotating.

[0015] (4) In the uniaxial eccentric screw pump according to the present invention, preferably, the rotary input portion and the eccentric rotary portion are arranged such that their respective axes intersect. The rotary input portion has an input portion side gear portion formed around the axis of the rotary shaft. The eccentric rotary portion is formed with an eccentric rotary portion side gear portion that meshes with the input portion side gear portion and allows sliding of the input portion side gear portion in a direction intersecting the central axis. With this configuration, even when the input portion side gear portion and the eccentric rotary portion side gear portion slide according to the revolution of the rotor at the meshing portion, power is transmitted from the rotary input portion to the eccentric rotary portion. Therefore, as the eccentric rotary portion rotates eccentrically, the rotor can revolve while rotating on its own axis.

[0016] (5) In the uniaxial eccentric screw pump according to the present invention, preferably, the rotary input portion and the eccentric rotary portion are arranged such that their respective axes intersect. The rotary input portion has an input portion side power transmission surface formed around the axis of the rotary shaft. The eccentric rotary portion has an eccentric rotary portion side power transmission surface that contacts the input portion side power transmission surface so as to enable power transmission by friction and allows sliding of the input portion side power transmission surface in a direction intersecting the central axis. With this configuration, even when the input portion side power transmission surface and the eccentric rotary portion side power transmission surface slide according to the revolution of the rotor at the contact portion, power is transmitted from the rotary input portion to the eccentric rotary portion. Therefore, as the eccentric rotary portion rotates eccentrically, the rotor can revolve while rotating on its own axis.

[0017] (6) In the uniaxial eccentric screw pump according to the present invention, preferably, the rotary input part and the eccentric rotary part are arranged such that their respective axes are parallel to each other. The rotary input part has an input part side gear part formed along the circumferential direction at the edge part, and the eccentric rotary part has an eccentric rotary part side gear part formed along the circumferential direction at the edge part, which meshes with the input part side gear part to transmit power. The rotary input part is configured to eccentrically rotate with respect to the rotation axis of the rotary input part, and the eccentric rotary part is configured to eccentrically rotate in synchronization with the eccentric rotation in the rotary input part. With such a configuration, since the input part side gear part and the eccentric rotary part side gear part eccentrically rotate while always meshing, the rotation power can be reliably transmitted from the rotary input part to the eccentric rotary part. Thereby, the rotor can be revolved while being rotated by the eccentric rotary part.

[0018] (7) In the uniaxial eccentric screw pump according to the present invention, preferably, the rotor drive mechanism is connected to the rotary input part and further has a revolution power transmission part that eccentrically rotates the eccentric rotary part while receiving the transmission of the revolution power for revolving the rotor. With such a configuration, by transmitting the power of the rotary input part to both the eccentric rotary part and the revolution power transmission part, the rotor can be rotated by the eccentric rotary part and revolved by the revolution power transmission member while being rotated. By such a forced rotation and revolution type, the rotation posture of the rotor can be stabilized, and the discharge amount can be stabilized without pulsation.

[0019] (8) In this case, preferably, the rotary input part is connected to the eccentric rotary part and the revolution power transmission part so as to branch the power transmission system. With such a configuration, the eccentric rotary part and the revolution power transmission part can be operated by one power source (rotary input part). Thereby, the power source for operating the eccentric rotary part and the revolution power transmission part can be reduced. As a result, the device configuration can be simplified.

[0020] (9) In the configuration where the rotor drive mechanism includes an eccentric rotating portion and a revolution power transmission portion, preferably, the rotation input portion has an input portion side connection portion, the eccentric rotating portion has an eccentric rotating portion side connection portion, the revolution power transmission portion has a revolution power transmission portion side connection portion, the input portion side connection portion and the eccentric rotating portion side connection portion are connected so as to be able to transmit power while relatively moving in a direction intersecting the central axis, and the input portion side connection portion and the revolution power transmission portion side connection portion are preferably connected so as to be able to transmit power. With such a configuration, even when the input portion side connection portion and the eccentric rotating portion side connection portion relatively move in accordance with the revolution of the rotor at the connection portion, power is transmitted from the input portion side connection portion to the eccentric rotating portion side connection portion. Therefore, as the eccentric rotating portion eccentrically rotates, the rotor can be revolved while being rotated. Also, since power is transmitted from the input portion side connection portion to the revolution power transmission portion side connection portion, the rotor can be revolved as the revolution power transmission portion rotates.

[0021] (10) In the configuration where the rotor drive mechanism includes an eccentric rotating portion and a revolution power transmission portion, preferably, the rotation input portion and the eccentric rotating portion are arranged such that their respective axes intersect, the rotation input portion and the revolution power transmission portion are arranged such that their respective axes intersect, the rotation input portion has an input portion side gear portion formed around the axis of the rotation axis, the eccentric rotating portion is formed with an eccentric rotating portion side gear portion that meshes with the input portion side gear portion and allows sliding of the input portion side gear portion in a direction intersecting the central axis, and the revolution power transmission portion is preferably formed with a revolution power transmission portion side gear portion that meshes with the input portion side gear portion. With such a configuration, even when the input portion side gear portion and the eccentric rotating portion side gear portion slide in accordance with the revolution of the rotor at the meshing portion, power is transmitted from the input portion side gear portion to the eccentric rotating portion side gear portion. Therefore, as the eccentric rotating portion eccentrically rotates, the rotor can be revolved while being rotated. Also, since power is transmitted from the input portion side gear portion to the revolution power transmission portion side gear portion, the rotor can be revolved as the revolution power transmission portion rotates.

[0022] (11) In the configuration where the rotor drive mechanism includes an eccentric rotating portion and a revolution power transmission portion, preferably, the rotation input portion and the eccentric rotating portion are arranged such that their respective axes intersect, the rotation input portion and the revolution power transmission portion are arranged such that their respective axes intersect, the rotation input portion has an input portion side power transmission surface formed around the axis of the rotation shaft, the eccentric rotating portion has an eccentric rotating portion side power transmission surface that allows sliding of the input portion side power transmission surface in a direction intersecting the central axis while being in contact with the input portion side power transmission surface so that power transmission by friction is possible, and the revolution power transmission portion has a revolution power transmission portion side power transmission surface that is in contact with the input portion side power transmission surface so that power transmission by friction is possible. With the above configuration, even when the input portion side power transmission surface and the eccentric rotating portion side power transmission surface slide in accordance with the revolution of the rotor at the contact portion, power is transmitted from the input portion side power transmission surface to the eccentric rotating portion side power transmission surface. Therefore, as the eccentric rotating portion rotates eccentrically, the rotor can be rotated and revolved while rotating itself. Also, since power is transmitted from the input portion side power transmission surface to the revolution power transmission portion side power transmission surface, the rotor can be revolved as the revolution power transmission portion rotates.

[0023] (12) In the configuration where the above rotor drive mechanism includes an eccentric rotating portion and a revolution power transmission portion, preferably, the rotation input portion, the eccentric rotating portion, and the revolution power transmission portion are arranged such that their respective axes are parallel to each other. The rotation input portion has an input portion side gear portion formed along the circumferential direction at its edge. The eccentric rotating portion has an eccentric rotating portion side gear portion formed along the circumferential direction at its edge, which meshes with the input portion side gear portion to transmit power. The rotation input portion is configured to rotate eccentrically with respect to the rotation axis of the rotation input portion. The eccentric rotating portion is configured to rotate eccentrically in synchronization with the eccentric rotation of the rotation input portion. A drive pulley that rotates in drive with the rotation of the rotation input portion is provided coaxially with the rotation input portion. A driven pulley as the revolution power transmission portion is provided coaxially with the eccentric rotating portion. A transmission member for transmitting the power of the rotation input portion is preferably bridged between the drive pulley and the driven pulley. With this configuration, since the input portion side gear portion and the eccentric rotating portion side gear portion rotate eccentrically while always meshing with each other, the rotation power can be reliably transmitted from the rotation input portion to the eccentric rotating portion. Also, since the drive pulley drives the driven pulley (revolution power transmission portion) via the transmission member, the revolution power can be reliably transmitted from the rotation input portion to the driven pulley. As a result, while the eccentric rotating portion rotates the rotor, the driven pulley can revolve the rotor.

Advantages of the Invention

[0024] According to the aspect of the present invention, it is possible to provide a single-axis eccentric screw pump capable of making the device configuration compact.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0026] Hereinafter, with reference to the accompanying drawings, a uniaxial eccentric screw pump according to an embodiment of the present invention will be described. These drawings are schematic views and are not necessarily drawn to an accurate scale. Also, in the drawings, similar components are denoted by similar reference numerals.

[0027] (First Embodiment) With reference to FIGS. 1 to 3, the uniaxial eccentric screw pump 100 in the first embodiment will be described. The uniaxial eccentric screw pump 100 is a rotary displacement pump. As shown in FIG. 1(a), the uniaxial eccentric screw pump 100 includes a male screw type rotor 20 that receives power and eccentrically rotates, and a stator 30 having an inner peripheral surface formed in a female screw type. The uniaxial eccentric screw pump 100 has a configuration in which a pump mechanism 12 mainly constituted by the rotor 20 and the stator 30 is built in a pump casing 14.

[0028] The rotor 20 is a metal shaft body having an n-thread (n = 1 in the first embodiment) male screw shape. Specifically, the rotor 20 has a male screw portion 20a inserted into the insertion hole 34 of the stator 30, and a shaft-like base shaft portion 20b connected to a rotation-side crown gear 54 described later. These male screw portion 20a and base shaft portion 20b are integrally connected along the axis. In other words, the male screw portion 20a and the base shaft portion 20b are straight bar-shaped members without joints or creases. Also, the male screw portion 20a and the base shaft portion 20b may be integrally formed or machined by cutting, or may be connected by screws, welding, or the like.

[0029] The rotor 20 is formed such that its cross-sectional shape is substantially circular when viewed in cross-section at any position in the longitudinal direction. The stator 30 is substantially cylindrical, and is a member having an inner peripheral surface 32 formed in an (n + 1)-thread (n = 1 in the first embodiment) female screw shape. The insertion hole 34 of the stator 30 is formed such that its cross-sectional shape (opening shape) is substantially oval when viewed in cross-section at any position in the longitudinal direction of the stator 30.

[0030] The rotor 20 is inserted into the insertion hole 34 formed in the stator 30 described above, and is freely eccentrically rotatable inside the insertion hole 34. The end portion on the proximal end side of the rotor 20 is connected to a motor 80 as a drive source via a rotor drive mechanism 50, which will be described in detail later. The rotor drive mechanism 50 enables the rotor 20 to revolve (eccentrically rotate) while rotating itself by the power input from the motor 80.

[0031] When the rotor 20 is inserted into the stator 30, the outer peripheral surface 22 of the rotor 20 and the inner peripheral surface 32 of the stator 30 are in close contact with each other at their tangents, and a fluid conveyance path 40 (cavity) is formed. The fluid conveyance path 40 is formed to extend spirally in the longitudinal direction of the stator 30 and the rotor 20.

[0032] The pump casing 14 is roughly divided into a pump mechanism housing portion 14a and a drive mechanism housing portion 14b. The pump mechanism housing portion 14a houses a pump mechanism 12 which is a cylindrical body having a cylindrical outer appearance shape and whose main part is constituted by the rotor 20 and the stator 30. Further, the drive mechanism housing portion 14b houses the above-described rotor drive mechanism 50.

[0033] The rotor drive mechanism 50 is a drive mechanism that enables the rotor 20 to revolve while rotating itself. The rotor drive mechanism 50 includes an input side pinion gear 52, a rotation side crown gear 54, and a revolution side crown gear 56. The input side pinion gear 52 is an example of the "rotation input portion" of the present invention. The rotation side crown gear 54 is an example of the "eccentric rotation portion" of the present invention. The revolution side crown gear 56 is an example of the "revolution power transmission portion" of the present invention.

[0034] The input side pinion gear 52 inputs the power transmitted from the motor 80 to the rotation side crown gear 54 and the revolution side crown gear 56, which will be described later. The rotation axis 52a of the input side pinion gear 52 is housed in the drive mechanism housing portion 14b via a bearing 58 so as to be rotatable along the axis center (central axis C3) of the rotation axis 52a.

[0035] The input-side pinion gear 52 has an input-section-side gear portion 52b formed around the axis of the rotation shaft 52a. Note that the input-section-side gear portion 52b is an example of the "input-section-side connection portion" of the present invention. The input-section-side gear portion 52b meshes with a gear portion 54c of a rotation-side crown gear 54 and a gear portion 56c of a revolution-side crown gear 56, which will be described later. The input-side pinion gear 52 is meshed (connected) with the rotation-side crown gear 54 and the revolution-side crown gear 56 so as to branch the power transmission system. That is, power is distributed in parallel and transmitted to the rotation-side crown gear 54 and the revolution-side crown gear 56 as the motor 80 is driven.

[0036] The rotation-side crown gear 54 is a member that can rotate eccentrically so as to revolve the rotor 20 while receiving the transmission of rotation power for rotating the rotor 20 about a fixed central axis C2 in a state of being connected to the input-side pinion gear 52 within the drive mechanism housing portion 14b. The rotation-side crown gear 54 is connected to the base shaft portion 20b of the rotor 20 so that power can be transmitted thereto. Therefore, the rotation of the rotation-side crown gear 54 enables the rotation of the rotor 20. Further, the rotation-side crown gear 54 and the rotation axis (central axis C2) of the rotor 20 are coaxial.

[0037] The rotation-side crown gear 54 has a base portion 54a, a shaft portion 54b, and a gear portion 54c. Note that the gear portion 54c is an example of the "eccentric rotation portion-side connection portion" and the "eccentric rotation portion-side gear portion" of the present invention. The base portion 54a is formed in a circular shape when viewed in the axial direction. A shaft portion 54b is provided at the center of the base portion 54a. The shaft portion 54b is provided so as to project from the base portion 54a toward the rotor 20 side. An insertion hole 54d for inserting and supporting the base shaft portion 20b of the rotor 20 is formed in the base portion 54a. Further, the rotation-side crown gear 54 and the input-side pinion gear 52 are arranged such that their respective axes intersect or are orthogonal.

[0038] On the edge 54e of the base 54a, a gear portion 54c is provided along the circumferential direction. The gear portion 54c meshes with the input portion side gear portion 52b of the input side pinion gear 52 while allowing sliding with respect to the input portion side gear portion 52b in a direction intersecting the central axis C2. In other words, when the rotor 20 revolves by the revolution side crown gear 56, the rotation side crown gear 54 revolves along with the revolution of the rotor 20, and the gear portion 54c of the rotation side crown gear 54 slides the teeth with respect to the input portion side gear portion 52b of the input side pinion gear 52 while the rotation side crown gear 54 rotates eccentrically.

[0039] The gear portion 54c of the rotation side crown gear 54 and the gear portion 56c of the revolution side crown gear 56 have the same number of teeth. Also, the gear portion 54c and the gear portion 56c rotate at the same rotational speed in opposite directions to each other. Thereby, rotation and revolution are synchronized.

[0040] The revolution side crown gear 56 is a member that enables the rotation side crown gear 54 to rotate eccentrically while receiving the transmission of the revolution power that revolves the rotor 20. That is, the revolution side crown gear 56 is a member that allows the revolution (eccentric rotation) of the base shaft portion 20b (rotor 20) while transmitting the rotation of the rotation side crown gear 54 to the base shaft portion 20b to cause rotation. Also, the revolution side crown gear 56 is a member that continues to rotate at a fixed position. Further, the revolution side crown gear 56 and the revolution axis (central axis C1) in the rotor 20 are coaxial.

[0041] The revolution side crown gear 56 is a member for allowing the base shaft portion 20b of the rotor 20 to revolve (see arrow B in FIG. 1(b)) in a predetermined revolution orbit while allowing the rotation of the base shaft portion 20b (see arrow A in FIG. 1(b)). Specifically, as shown in FIG. 1, the revolution side crown gear 56 is a member rotatably supported by a bearing 57 in the pump mechanism housing portion 14a and the drive mechanism housing portion 14b.

[0042] The revolving-side crown gear 56 has a base portion 56a, a shaft portion 56b, and a gear portion 56c. The gear portion 56c is an example of the "revolving power transmission portion side connection portion" and the "revolving power transmission portion side gear portion" of the present invention. The base portion 56a is formed in a circular shape when viewed in the axial direction. A shaft portion 56b is provided at the center of the base portion 56a. The shaft portion 56b is provided so as to protrude from the base portion 56a toward the rotor 20 side. An insertion hole 56d for inserting and supporting the base shaft portion 20b of the rotor 20 is formed at the center of the base portion 56a.

[0043] A gear portion 56c is provided along the circumferential direction at the edge portion 56e of the base portion 56a. The gear portion 56c meshes with the input portion side gear portion 52b of the input-side pinion gear 52 and is connected so as to be able to transmit the power from the input-side pinion gear 52.

[0044] The revolving-side crown gear 56 is supported so as to be able to rotate (revolve) the base shaft portion 20b via a bearing 59 in the insertion hole 56d. That is, the base shaft portion 20b is supported so as to be able to revolve at a position displaced by an eccentricity amount e (see FIGS. 3(b) to (e)) from the center (central axis C1) of the insertion hole 56d. Therefore, the base shaft portion 20b inserted into the insertion hole 56d can revolve freely.

[0045] Also, as shown in FIG. 1(b), the insertion hole 56d is a round hole provided at a position away from the axial center position of the revolving-side crown gear 56. Thereby, as shown in FIG. 1(b), the base shaft portion 20b is enabled to revolve around a central axis C2 deviated from the central axis C1. Also, as shown by an arrow B in FIG. 1(b), by revolving the revolving-side crown gear 56, the base shaft portion 20b inserted into the insertion hole 56d can be guided to revolve (eccentric rotation) as shown by an arrow A in FIG. 1(b). Therefore, the base shaft portion 20b can revolve around the central axis C1 while revolving around the central axis C2.

[0046] Further, unlike the rotating-side crown gear 56, the revolving-side crown gear 56 rotates about the central axis C1 without eccentric rotation, so there is no relative movement (sliding) between the gear portion 56c and the input-side gear portion 52b.

[0047] Also, the revolving-side crown gear 56 and the input-side pinion gear 52 are arranged such that their respective axes intersect or are orthogonal. Further, the revolving-side crown gear 56 and the rotating-side crown gear 54 are arranged such that their respective axes are parallel.

[0048] Next, the operation of the single-axis eccentric screw pump 100 will be described. The single-axis eccentric screw pump 100 can advance the fluid conveyance path 40 in the longitudinal direction within the stator 30 by rotating the rotor 20 within the insertion hole 34 of the stator 30. Therefore, by rotating the rotor 20, it is possible to suck the viscous liquid into the fluid conveyance path 40 from one end side of the stator 30 and transfer it toward the other end side of the stator 30. Also, by switching the rotation direction of the rotor 20, the advancing direction of the fluid conveyance path 40 can be switched.

[0049] Here, as shown in Fig. 2(a), in the single-axis eccentric screw pump 100, when the motor 80 is operated, the rotor drive mechanism 50 performs a characteristic operation. Specifically, as shown in the hatched portion (rotating power transmission path) in Fig. 2(a), when the motor 80 is operated, the rotating-side crown gear 54 rotates about the central axis C2 by the power transmitted from the input-side pinion gear 52. Along with this, the base shaft portion 20b (rotor 20) connected to the rotating-side crown gear 54 rotates about the central axis C2.

[0050] On the one hand, as shown in the hatched part (revolution power transmission path) in Fig. 2(b), the revolution side crown gear 56 rotates about the central axis C1 due to the power transmitted from the input side pinion gear 52 to the revolution side crown gear 56. Along with this, the base shaft portion 20b (rotor 20) inserted into the insertion hole 56d located at a position away from the central axis C1 revolves (eccentric rotation) with respect to the central axis C1. Therefore, the base shaft portion 20b (rotor 20) rotates by the power transmitted from the rotation side crown gear 54 side and at the same time performs an operation of revolving by the power transmitted from the revolution side crown gear 56 side. By operating the rotor 20 in the insertion hole 34 of the stator 30 in this way, the fluid conveyance path 40 advances in the longitudinal direction in the stator 30, and the flowing material can be pumped.

[0051] Also, as shown in Fig. 3(a), the meshing position between the gear portion 52b on the input portion side of the input side pinion gear 52 and the gear portion 56c always maintains the same positional relationship regardless of the rotational position (rotation angle) of the revolution side crown gear 56.

[0052] Also, as shown in Figs. 3(b) to 3(e), the meshing position between the gear portion 52b on the input portion side of the input side pinion gear 52 and the gear portion 54c of the rotation side crown gear 54 varies depending on the position of the central axis C2 (rotation axis center) in the rotation side crown gear 54. For example, as shown in Fig. 3(b), when the rotation angle of the rotation side crown gear 54 is 0°, the central axis C2 (rotation axis center) in the rotation side crown gear 54 is located on the lower side with respect to the central axis C1 (revolution axis center) in the revolution side crown gear 56.

[0053] Also, as shown in Fig. 3(c), when the rotation angle of the rotation side crown gear 54 is 90°, the central axis C2 (rotation axis center) in the rotation side crown gear 54 is located on the left side with respect to the central axis C1 (revolution axis center) in the revolution side crown gear 56.

[0054] Further, as shown in FIG. 3(d), when the rotation angle of the rotating-side crown gear 54 is 180°, the central axis C2 (rotation axis center) of the rotating-side crown gear 54 is located above the central axis C1 (revolution axis center) of the revolving-side crown gear 56.

[0055] Further, as shown in FIG. 3(e), when the rotation angle of the rotating-side crown gear 54 is 270°, the central axis C2 (rotation axis center) of the rotating-side crown gear 54 is located on the right side with respect to the central axis C1 (revolution axis center) of the revolving-side crown gear 56.

[0056] As described above, when the rotating-side crown gear 54 rotates eccentrically as shown in FIGS. 3(b) to 3(e), the outer diameter locus L of the rotating-side crown gear 54 is larger than the outer diameter D1 of the rotating-side crown gear 54 and the outer diameter D2 of the revolving-side crown gear 56 as shown in FIG. 3(f). Further, regardless of the rotation position (rotation angle) of the rotating-side crown gear 54, the gear portion 54c of the rotating-side crown gear 54 and the input portion side gear portion 52b of the input-side pinion gear 52 are in a meshed state, and power is always transmitted.

[0057] According to the first embodiment described above, the following effects (1) to (5) can be obtained.

[0058] (1) In the uniaxial eccentric screw pump 100 according to the first embodiment, the rotor drive mechanism 50 has an input side pinion gear 52 that inputs power, and a rotation side crown gear 54 that is eccentrically rotatable so as to revolve the rotor 20 while receiving the transmission of the rotation power that rotates the rotor 20 about a fixed central axis while being connected to the input side pinion gear 52. As a result, in order to transmit the power on the rotation side to the base shaft portion 20b of the rotor 20, there is no need to provide a power transmission member (Oldham joint) that connects the rotation power transmission member and the base shaft portion 20b of the rotor 20, or a long rod such as a coupling rod that is used to connect to the power source so that the rotor 20 can revolve while rotating. Therefore, the overall length can be shortened by that much. As a result, it is possible to provide a uniaxial eccentric screw pump 100 having a compact configuration with a short overall length. In addition, when the uniaxial eccentric screw pump 100 is stopped, the remaining amount of the fluid remaining inside the pump casing can be minimized.

[0059] (2) In the uniaxial eccentric screw pump 100 according to the first embodiment, the revolution side crown gear 56 is configured to eccentrically rotate the rotation side crown gear 54 while receiving the transmission of the revolution power that revolves the rotor 20 from the input side pinion gear 52. As a result, by transmitting the power of the input side pinion gear 52 to both the rotation side crown gear 54 and the revolution side crown gear 56, the rotor 20 can be rotated by the rotation side crown gear 54 and revolved by the revolution side crown gear 56 while rotating. According to such a forced rotation and revolution type, the rotor 20 is supported by both the rotation and revolution mechanisms and the rotation posture is maintained. As a result, when the discharge pressure is high, the phenomenon that the rotor 20 yields to the pressure, tilts, and is pressed against the stator 30, and the stator 30 elastically deforms and the cavity shape related to the discharge amount changes is less likely to occur. Therefore, it is possible to suppress pulsation and stabilize the discharge amount. In addition, since the rotor 20 can revolve even without the reaction force from the stator 30, when sending a slurry containing highly abrasive particles, it is also possible to make the rotor 20 thinner and keep the rotor 20 and the stator 30 non-contact.

[0060] (3) In the uniaxial eccentric screw pump 100 according to the first embodiment, the gear portion 54c of the rotating-side crown gear 54 is allowed to slide in a direction intersecting the central axis C1 (C2) while meshing with the input-side gear portion 52b. Also, the gear portion 56c of the revolving-side crown gear 56 is meshed with the input-side gear portion 52b. As a result, even when the input-side gear portion 52b and the gear portion 54c slide in the meshing portion, power is transmitted from the input-side gear portion 52b to the gear portion 54c, so that the rotor can be rotated as the rotating-side crown gear 54 rotates eccentrically. Further, since power is transmitted from the input-side gear portion 52b to the gear portion 56c, the rotor 20 can be revolved as the revolving-side crown gear 56 rotates.

[0061] (4) In the uniaxial eccentric screw pump 100 according to the first embodiment, the male screw portion 20a and the base shaft portion 20b of the rotor 20 are integrally coupled along the axis. Thereby, a connecting member for connecting the male screw portion 20a and the base shaft portion 20b of the rotor 20 can be omitted (jointless). Thereby, the number of parts can be reduced.

[0062] (5) In the uniaxial eccentric screw pump 100 according to the first embodiment, the power transmission system to the rotating-side crown gear 54 and the revolving-side crown gear 56 in the input-side pinion gear 52 is connected so as to branch. Thereby, the rotating-side crown gear 54 and the revolving-side crown gear 56 can be operated by one power source (input-side pinion gear 52). Thereby, the power source for operating the rotating-side crown gear 54 and the revolving-side crown gear 56 can be reduced. As a result, the device configuration can be simplified.

[0063] (Second Embodiment) Next, with reference to FIGS. 4 to 6, a uniaxial eccentric screw pump 200 according to the second embodiment of the present invention will be described. In the second embodiment, unlike the first embodiment described above, an example using a mechanism for transmitting rotation by rolling contact of the input-side roller will be described.

[0064] In the second embodiment, the rotor drive mechanism 50, which enables the rotor 20 to rotate while revolving, includes an input-side roller 521, a rotation-side flange 541, and a revolution-side flange 561. The input-side roller 521 is an example of the "rotary input section" of the present invention. The rotation-side flange 541 is an example of the "eccentric rotation section" of the present invention. The revolution-side flange 561 is an example of the "revolution power transmission section" of the present invention.

[0065] The input-side roller 521 has an input-section-side power transmission surface 521c formed around the axis of the rotation shaft 521a. The input-section-side power transmission surface 521c is an example of the "input-section-side connection section" of the present invention. The input-section-side power transmission surface 521c (the tip of the rotation shaft 521a) is formed in a cylindrical shape with a slightly bulging central portion. The input-section-side power transmission surface 521c is in contact with the rotation-side power transmission surface 541f of the rotation-side flange 541 and the revolution-side power transmission surface 561f of the revolution-side flange 561. The rotation-side power transmission surface 541f is an example of the "eccentric rotation section-side power transmission surface" and the "eccentric rotation section-side connection section" of the present invention. The revolution-side power transmission surface 561f is an example of the "revolution power transmission section-side power transmission surface" and the "revolution power transmission section-side connection section" of the present invention.

[0066] The input-side roller 521 is in contact with the rotation-side flange 541 and the revolution-side flange 561 so as to branch the power transmission system. That is, when the motor 80 is driven, power is distributed and transmitted in parallel to the rotation-side flange 541 and the revolution-side flange 561. Specifically, the input-section-side power transmission surface 521c is strongly pressed against the rotation-side power transmission surface 541f and the revolution-side power transmission surface 561f via a lubricating oil film, and when the input-side roller 521 rotates, the rotation-side flange 541 and the revolution-side flange 561 also rotate.

[0067] The rotating-side flange 541 is a member that can eccentrically rotate to revolve the rotor 20 while receiving the transmission of the rotational power for rotating the rotor 20 about a fixed central axis C2 in a state of being connected to the input-side roller 521 within the drive mechanism housing portion 14b. The rotating-side flange 541 is connected to the base shaft portion 20b of the rotor 20 so as to enable power transmission. Therefore, when the rotating-side flange 541 rotates, the rotor 20 can be rotated. Further, the rotating-side flange 541 and the rotation axis (central axis C2) of the rotor 20 are coaxial.

[0068] The rotating-side flange 541 has a base portion 541a, a shaft portion 541b, and a rotating-side power transmission surface 541f. The base portion 541a is formed in a circular shape when viewed from the axial direction. A shaft portion 541b is provided at the central portion of the base portion 541a. The shaft portion 541b is provided so as to project from the base portion 541a toward the rotor 20 side. An insertion hole 541d for inserting and supporting the base shaft portion 20b of the rotor 20 is formed at the central portion of the base portion 541a. Further, the rotating-side flange 541 and the input-side roller 521 are arranged such that their respective axes intersect or are orthogonal.

[0069] A rotating-side power transmission surface 541f is provided along the circumferential direction at the edge portion 541e of the base portion 541a. The rotating-side power transmission surface 541f contacts the input portion-side power transmission surface 521c so as to enable power transmission by friction, and allows sliding with respect to the input portion-side power transmission surface 521c in a direction intersecting the central axis C2. In other words, when the rotor 20 revolves due to the revolving-side flange 561, the rotating-side flange 541 revolves along with the revolution of the rotor 20, and the rotating-side power transmission surface 541f of the rotating-side flange 541 slides the transmission surface with respect to the input portion-side power transmission surface 521c of the input-side roller 521 while the rotating-side flange 541 eccentrically rotates.

[0070] The rotation-side power transmission surface 541f (rotation-side flange 541) and the revolution-side power transmission surface 561f (revolution-side flange 561) rotate in opposite directions to each other. The rotational speed difference is absorbed by a slight slip, resulting in the same-speed rotation, and as a result, the rotation and revolution synchronously rotate.

[0071] The revolution-side flange 561 is a member that enables the rotation-side flange 541 to rotate eccentrically while receiving the transmission of the revolution power that rotates the rotor 20. That is, the revolution-side flange 561 is a member that allows the revolution (eccentric rotation) of the base shaft portion 20b (rotor 20) while transmitting the rotation of the rotation-side flange 541 to the base shaft portion 20b to cause rotation. Further, the revolution-side flange 561 is a member that continues to rotate at a fixed position. Also, the revolution-side flange 561 and the revolution axis (central axis C1) in the rotor 20 are coaxial.

[0072] The revolution-side flange 561 is a member for allowing the rotation of the base shaft portion 20b of the rotor 20 (see arrow A in Fig. 1(b)) while revolving the base shaft portion 20b in a predetermined revolution orbit (see arrow B in Fig. 1(b)). Specifically, as shown in Fig. 1, the revolution-side flange 561 is a member rotatably supported by a bearing 57 in the pump mechanism housing portion 14a and the drive mechanism housing portion 14b.

[0073] The revolution-side flange 561 has a base portion 561a, a shaft portion 561b, and a revolution-side power transmission surface 561f. The base portion 561a is formed in a circular shape when viewed from the axial direction. A shaft portion 561b is provided at the central portion of the base portion 561a. The shaft portion 561b is provided so as to project from the base portion 561a toward the rotor 20 side. An insertion hole 561d for inserting and supporting the base shaft portion 20b of the rotor 20 is formed at the central portion of the base portion 561a.

[0074] A revolution-side power transmission surface 561f is provided along the circumferential direction at the edge portion 561e of the base portion 561a. The revolution-side power transmission surface 561f is in contact with the input portion-side power transmission surface 521c of the input-side roller 521 and is connected so as to be able to transmit the power from the input-side roller 521.

[0075] The revolving flange 561 is configured to support the base shaft portion 20b so as to be rotatable (self-rotatable) via a bearing 59 within the insertion hole 561d. That is, the base shaft portion 20b is supported so as to be self-rotatable at a position displaced by an eccentricity amount e (see FIGS. 6(b) to 6(e)) from the center (central axis C1) of the insertion hole 561d. Therefore, the base shaft portion 20b inserted into the insertion hole 561d can freely rotate.

[0076] Further, the insertion hole 561d is a round hole provided at a position away from the axial center position of the revolving flange 561. Thereby, the base shaft portion 20b is enabled to rotate about a central axis C2 deviated from the central axis C1. Also, by rotating the revolving flange 561, the base shaft portion 20b inserted into the insertion hole 561d can be guided to revolve (eccentric rotation). Accordingly, the base shaft portion 20b can revolve about the central axis C1 while rotating about the central axis C2.

[0077] Also, unlike the rotating flange 541, the revolving flange 561 rotates about the central axis C1 without eccentric rotation, so there is no relative movement (sliding) between the revolving-side power transmission surface 561f and the input-side power transmission surface 521c.

[0078] Also, the revolving flange 561 and the input-side roller 521 are arranged such that their respective axes intersect or are orthogonal. Also, the revolving flange 561 and the rotating flange 541 are arranged such that their respective axes are parallel.

[0079] Next, the operation of the single-axis eccentric screw pump 200 will be described. The single-axis eccentric screw pump 200 can advance the fluid conveyance path 40 longitudinally within the stator 30 by rotating the rotor 20 within the insertion hole 34 of the stator 30. Therefore, by rotating the rotor 20, it is possible to suck the viscous liquid into the fluid conveyance path 40 from one end side of the stator 30 and transfer it toward the other end side of the stator 30. Also, by switching the rotation direction of the rotor 20, the advancing direction of the fluid conveyance path 40 can be switched.

[0080] Here, as shown in Fig. 5(a), in the single-axis eccentric screw pump 200, when the motor 80 is operated, the rotor drive mechanism 50 performs a characteristic operation. Specifically, as shown in the hatched portion (rotation power transmission path) in Fig. 5(a), when the motor 80 is operated, the rotation side flange 541 rotates about the central axis C2 by the power transmitted from the input side roller 521. Along with this, the base shaft portion 20b (rotor 20) connected to the rotation side flange 541 rotates about the central axis C2.

[0081] On the other hand, as shown in the hatched portion (revolution power transmission path) in Fig. 5(b), the revolution side flange 561 rotates about the central axis C1 by the power transmitted from the input side roller 521 to the revolution side flange 561. Along with this, the base shaft portion 20b (rotor 20) inserted into the insertion hole 561d located at a position away from the central axis C1 revolves (eccentrically rotates) with respect to the central axis C1. Therefore, the base shaft portion 20b (rotor 20) performs an operation of revolving by the power transmitted from the revolution side flange 561 side while rotating by the power transmitted from the rotation side flange 541 side. In this way, when the rotor 20 operates within the insertion hole 34 of the stator 30, the fluid conveyance path 40 advances longitudinally within the stator 30, and the flowing material can be pumped.

[0082] Also, as shown in Fig. 6(a), the contact position between the input-side power transmission surface 521c of the input-side roller 521 and the revolution-side power transmission surface 561f always maintains the same positional relationship regardless of the rotational position (rotation angle) of the revolution-side flange 561.

[0083] Also, as shown in Figs. 6(b) to 6(e), the contact position between the input-side power transmission surface 521c of the input-side roller 521 and the rotation-side power transmission surface 541f of the rotation-side flange 541 is different depending on the position of the central axis C2 (rotation axis center) in the rotation-side flange 541 when viewed from the axial direction. For example, as shown in Fig. 6(b), when the rotation angle of the rotation-side flange 541 is 0°, the central axis C2 (rotation axis center) in the rotation-side flange 541 is located below the central axis C1 (revolution axis center) in the revolution-side flange 561.

[0084] Also, as shown in Fig. 6(c), when the rotation angle of the rotation-side flange 541 is 90°, the central axis C2 (rotation axis center) in the rotation-side flange 541 is located to the left of the central axis C1 (revolution axis center) in the revolution-side flange 561.

[0085] Also, as shown in Fig. 6(d), when the rotation angle of the rotation-side flange 541 is 180°, the central axis C2 (rotation axis center) in the rotation-side flange 541 is located above the central axis C1 (revolution axis center) in the revolution-side flange 561.

[0086] Also, as shown in Fig. 6(e), when the rotation angle of the rotation-side flange 541 is 270°, the central axis C2 (rotation axis center) in the rotation-side flange 541 is located to the right of the central axis C1 (revolution axis center) in the revolution-side flange 561.

[0087] As described above, when the rotating-side flange 541 rotates eccentrically as shown in FIGS. 6(b) to 6(e), the outer diameter locus L of the rotating-side flange 541 is larger than the outer diameter D1 of the rotating-side flange 541 and the outer diameter D2 of the revolving-side flange 561 as shown in FIG. 6(f). Further, regardless of the rotational position (rotation angle) of the rotating-side flange 541, the rotating-side power transmission surface 541f of the rotating-side flange 541 and the input-side power transmission surface 521c of the input-side roller 521 are in contact with each other, and power is always transmitted.

[0088] Note that other configurations of the second embodiment are the same as those described in the first embodiment.

[0089] According to the second embodiment described above, in addition to the effects (1), (2), (4), and (5) of the first embodiment, the following effect (6) can be obtained.

[0090] (6) In the uniaxial eccentric screw pump 200 according to the second embodiment, the rotating-side power transmission surface 541f of the rotating-side flange 541 is in contact with the input-side power transmission surface 521c so that power can be transmitted by friction, and sliding in a direction intersecting the central axis C1 (C2) with respect to the input-side power transmission surface 521c is allowed. The revolving-side power transmission surface 561f of the revolving-side flange 561 is in contact with the input-side power transmission surface 521c so that power can be transmitted by friction. Thereby, even when the input-side power transmission surface 521c and the rotating-side power transmission surface 541f slide at the contact portion, power is transmitted from the input-side power transmission surface 521c to the rotating-side power transmission surface 541f, so that the rotor 20 can be rotated as the rotating-side flange 541 rotates eccentrically. Further, since power is transmitted from the input-side power transmission surface 521c to the revolving-side power transmission surface 561f, the rotor 20 can be revolved as the revolving-side flange 561 rotates.

[0091] (Third Embodiment) Next, with reference to FIGS. 7 to 9, the uniaxial eccentric screw pump 300 in the third embodiment of the present invention will be described. In the third embodiment, different from the first and second embodiments described above, an example will be described in which an eccentric gear is used as the rotation input portion and a timing pulley is used as the revolution power transmission portion.

[0092] The rotor drive mechanism 60 in the third embodiment is a drive mechanism that enables the rotor 20 to rotate and revolve. This rotor drive mechanism 60 includes an eccentric gear 62, a driven gear 64, a driven pulley 66, a driven pulley support portion 68, a rotation input shaft 70, a drive pulley 72, and a timing belt 74.

[0093] Note that the driven gear 64 is an example of the "eccentric rotating portion" of the present invention. The driven pulley 66 and the driven pulley support portion 68 are examples of the "revolution power transmission portion" of the present invention. The rotation input shaft 70 and the eccentric gear 62 are examples of the "rotation input portion" of the present invention. The timing belt 74 is an example of the "transmission member" of the present invention. Further, the eccentric gear 62, the driven gear 64, the driven pulley 66, the driven pulley support portion 68, the rotation input shaft 70, and the drive pulley 72 are arranged such that their respective axes are parallel to each other.

[0094] The eccentric gear 62 has an eccentric gear portion 62a formed along the circumferential direction at its edge portion. Note that the eccentric gear portion 62a is an example of the "input portion side connection portion" and the "input portion side gear portion" of the present invention. The eccentric gear portion 62a meshes with a driven gear portion 64a of the driven gear 64 described later. An insertion hole 62b through which the rotation input shaft 70 is inserted is formed in the eccentric gear 62. The insertion hole 62b is formed at a position deviated from the central axis C4 of the eccentric gear 62. In other words, as shown in FIG. 9(a), the central axis of the rotation input shaft 70 and the eccentric gear 62 are arranged at positions eccentric by an eccentricity amount e. Thereby, when the rotation input shaft 70 rotates by the power of the motor 80, the eccentric gear 62 eccentrically rotates with respect to the central axis C4.

[0095] The driven gear 64 is a member that can eccentrically rotate so as to revolve the rotor 20 while receiving the transmission of the rotation power for rotating the rotor 20 about a fixed central axis C2 in a state of being connected to the eccentric gear 62 within the drive mechanism housing portion 14b. The driven gear 64 is connected to the base shaft portion 20b of the rotor 20 so as to be able to transmit power. Therefore, when the driven gear 64 rotates, the rotor 20 can be rotated. Since the driven gear 64 eccentrically rotates due to the revolution of the rotor 20 and the eccentric gear 62 also eccentrically rotates, it is always possible to rotate while being engaged. Further, the driven gear 64 and the rotation axis (central axis C2) of the rotor 20 are coaxial.

[0096] The driven gear 64 has a perfect circular shape when viewed from the axial direction. The driven gear portion 64a is formed along the circumferential direction at the edge portion of the driven gear 64. Note that the driven gear portion 64a is an example of the "eccentric rotation portion side connection portion" and the "eccentric rotation portion side gear portion" of the present invention. An insertion hole 64b for inserting and supporting the base shaft portion 20b of the rotor 20 is formed at the center of the driven gear 64.

[0097] Power is transmitted by the driven gear portion 64a meshing with the eccentric gear portion 62a. As a result, the driven gear 64 rotates in a direction opposite to that of the eccentric gear 62 and rotates the base shaft portion 20b. Further, the driven gear 64 and the eccentric gear 62 have the same number of teeth.

[0098] The drive pulley 72 is provided coaxially with the eccentric gear 62 (rotation input shaft 70). The drive pulley 72 is rotationally driven as the eccentric gear 62 (rotation input shaft 70) rotates. The drive pulley 72 has a circular shape when viewed from the axial direction. A circular hole-shaped insertion hole 72a through which the rotation input shaft 70 is inserted is formed at the central portion of the drive pulley 72. A tooth portion 72b around which one end of the timing belt 74 is looped is formed along the circumferential direction at the edge portion of the drive pulley 72.

[0099] The driven pulley 66 is provided coaxially with the driven gear 64. The driven pulley 66 has a circular shape when viewed axially. At the edge of the driven pulley 66, a tooth portion 66b is formed along the circumferential direction, over which the other end of the timing belt 74 is spanned. Note that the driven pulley 66 and the driving pulley 72 have the same number of teeth. As the timing belt 74 rotates due to the rotation of the driving pulley 72, the driven pulley 66 is rotationally driven (eccentric rotation) in the same direction as the rotation direction of the eccentric gear 62. In the central portion of the driven pulley 66, a circular hole-shaped insertion hole 66a through which the end portion 68a of the driven pulley support portion 68 is inserted is formed.

[0100] At a position away from the axial center position of the driven pulley support portion 68, an insertion hole 68b for inserting and supporting the base shaft portion 20b of the rotor 20 is formed. Thereby, the driven pulley support portion 68 can be supported so as to be rotatable (self-rotatable) about the base shaft portion 20b via the bearing 59 within the insertion hole 68b. That is, the base shaft portion 20b is supported so as to be self-rotatable at a position offset from the center (central axis C1) of the insertion hole 68b by an eccentricity amount e (see Fig. 9(a)). Therefore, the base shaft portion 20b inserted into the insertion hole 68b can rotate freely. Note that the central axis C1, which is the revolution axis of the base shaft portion 20b, is coaxial with the axial center of the driven pulley 66.

[0101] As the timing belt 74, a general cog belt, V belt, etc. are used. When applying to a large pump, instead of a belt, a chain or the like is used. Also, as another example, a magnetic coupling is applicable.

[0102] Next, the operation of the single-axis eccentric screw pump 300 will be described. The basic operation is the same as that of the first and second embodiments described above. Here, as shown in Fig. 8(a), in the single-axis eccentric screw pump 300, when the motor 80 is operated, the rotor drive mechanism 60 performs a characteristic operation. Specifically, as shown in the hatched portion (rotation power transmission path) in Fig. 8(a), when the motor 80 is operated, the eccentric gear 62 rotates (eccentrically rotates) about the central axis C5 by the power transmitted from the rotary input shaft 70, and the driven gear 64 rotates (eccentrically rotates) about the central axis C1. Along with this, the base shaft portion 20b (rotor 20) connected to the driven gear 64 rotates about the central axis C2.

[0103] On the other hand, as shown in the hatched portion (revolution power transmission path) in Fig. 8(b), the driven pulley support portion 68 rotates about the central axis C1 by the power transmitted from the rotary input shaft 70 to the drive pulley 72, the timing belt 74, and the driven pulley 66. Along with this, the base shaft portion 20b (rotor 20) inserted into the insertion hole 68b located at a position away from the central axis C1 revolves (eccentrically rotates) with respect to the central axis C1. Therefore, the base shaft portion 20b (rotor 20) performs an operation of rotating by the power transmitted from the driven gear 64 side and revolving by the power transmitted from the driven pulley 66 side. By operating the rotor 20 in the insertion hole 34 of the stator 30 in this way, the fluid conveyance path 40 advances in the longitudinal direction in the stator 30, and the flowing material can be pumped.

[0104] Also, as shown in Fig. 9(a), the central axis C5 of the rotary input shaft 70 and the central axis C4 of the eccentric gear 62 are arranged at positions eccentric by an eccentric amount e.

[0105] Also, as shown in FIGS. 9(b) to 9(d), the revolution axis (central axis C1) of the base shaft portion 20b of the rotor 20 is driven by the timing belt 74. Since the driving pulley 72 and the driven pulley 66 have the same number of teeth, they rotate by the same angle (0°, 45°, 90°) as the rotation input shaft 70. When the revolution axis rotates, the rotation axis (central axis C2) moves by the same angle in the same direction as the rotation input shaft 70, but the positional relationship between the eccentric gear 62 and the driven gear 64 remains unchanged. Also, the rotation axis is driven by the eccentric gear 62 and the driven gear 64. Since the number of teeth of both gears is the same, it rotates by the same angle as the rotation input shaft 70. As a result, the rotation and revolution rotate synchronously.

[0106] According to the third embodiment described above, in addition to the effects (1), (2), (4), and (5) of the first and second embodiments, the following effect (7) can be obtained.

[0107] (7) In the uniaxial eccentric screw pump 300 according to the third embodiment, a driving pulley 72 that rotates and drives along with the rotation of the eccentric gear 62 is provided coaxially with the eccentric gear 62, a driven pulley 66 is provided coaxially with the driven gear 64, and a timing belt 74 is bridged between the driving pulley 72 and the driven pulley 66. As a result, since the eccentric gear portion 62a and the driven gear portion 64a eccentrically rotate while always meshing, the rotation power can be reliably transmitted from the eccentric gear 62 to the driven gear 64. Also, since the driving pulley 72 drives the driven pulley 66 via the timing belt 74, the revolution power can be reliably transmitted to the driven pulley 66. As a result, while the rotor 20 is rotated by the driven gear 64, the rotor 20 can be revolved by the driven pulley 66.

[0108] (Modification of the Third Embodiment) Next, with reference to FIG. 10, a uniaxial eccentric screw pump 301 in a modification of the third embodiment of the present invention will be described. In the modification of the third embodiment, different from the third embodiment described above, an example in which the forced revolution mechanism (driving pulley, driven pulley, and timing belt) on the revolution side is omitted will be described.

[0109] As shown in FIG. 10, in the uniaxial eccentric screw pump 301 according to the modification of the third embodiment, the rotor drive mechanism 601 includes an eccentric gear 62, a driven gear 64, and a rotary input shaft 70. That is, unlike the third embodiment described above, the drive pulley, the driven pulley, and the timing belt are omitted.

[0110] With the above configuration, in the uniaxial eccentric screw pump 301, when the motor 80 is operated, the eccentric gear 62 rotates (eccentrically rotates) about the central axis C5 by the power transmitted from the rotary input shaft 70, and the driven gear 64 rotates (eccentrically rotates) about the central axis C1. Along with this, the base shaft portion 20b (rotor 20) connected to the driven gear 64 rotates about the central axis C2. Further, due to the rotational power and the reaction force of the stator 30, the driven gear 64 (the eccentric rotating portion on the rotation side) can eccentrically rotate.

[0111] Thus, in the uniaxial eccentric screw pump 301 according to the modification of the third embodiment, by removing the revolution-side forced revolution mechanism and only using the rotation-side power transmission, the driven gear 64 (the eccentric rotating portion on the rotation side) can eccentrically rotate. It is suitable for applications where the discharge pressure is low and the rotor 20 and the stator 30 may contact each other, and the entire pump can be made smaller.

[0112] (Other Modifications) The above embodiments can also have the following modified configurations.

[0113] In the first to third embodiments above, an example in which the rotor drive mechanism has a rotary input portion, an eccentric rotating portion, and a revolution power transmission portion is shown, but the present invention is not limited to this. In the present invention, as shown in the modification of the third embodiment, it is also possible to adopt a configuration in which the revolution power transmission portion is omitted. In this case, the eccentric rotating portion on the rotation side can eccentrically rotate due to the rotational power and the reaction force of the stator.

[0114] In the above-described first and second embodiments, a crown gear and a transmission surface were shown as an example of the connection portion between the rotary input portion and the eccentric rotary portion and the revolution power transmission portion. However, the present invention is not limited to this. In the present invention, any mechanism other than the above may be applied as long as power can be transmitted while relatively moving between the rotary input portion and the eccentric rotary portion.

[0115] In the above-described first to third embodiments, an example of a configuration in which power is branched from one rotary input portion to the eccentric rotary portion and the revolution power transmission portion was shown. However, the present invention is not limited to this. In the present invention, it is also possible to provide one rotary input portion for each of the eccentric rotary portion and the revolution power transmission portion.

[0116] All of the above embodiments are merely examples of the application of the present invention, and it goes without saying that any other embodiments within the scope described in the claims are also included in the technical scope of the invention.

Explanation of Reference Numerals

[0117] 100, 200, 300, 301: Single-axis eccentric screw pump 20: Rotor 20a: Male screw portion 20b: Base shaft portion 30: Stator 50, 60, 601: Rotor drive mechanism 52: Input side pinion gear (rotary input portion) 52b: Input portion side gear portion (input portion side connection portion) 521c: Input portion side power transmission surface (input portion side connection portion) 521: Input side roller (rotary input portion) 54: Self-rotating side crown gear (eccentric rotary portion) 541: Self-rotating side flange (eccentric rotary portion) 54c: Gear portion (eccentric rotary portion side connection portion, eccentric rotary portion side gear portion) 541f: Self-rotating side power transmission surface (eccentric rotary portion side power transmission surface, eccentric rotary portion side connection portion) 56: Revolution side crown gear (revolution power transmission portion) 561: Revolution side flange (revolution power transmission portion) 56c: Gear part (revolving power transmission part side connection part, revolving power transmission part side gear part) 561f: Revolving side power transmission surface (revolving power transmission part side power transmission surface, revolving power transmission part side connection part) 62: Eccentric gear (rotation input part) 62a: Eccentric gear part (input part side connection part, input part side gear part) 64: Driven gear (eccentric rotation part) 64a: Driven gear part (eccentric rotation part side connection part, eccentric rotation part side gear part) 66: Driven pulley (revolving power transmission part) 68: Driven pulley support part (revolving power transmission part) 70: Rotation input shaft (rotation input part) 72: Driving pulley 74: Timing belt (transmission member) C1, C2, C3, C4, C5: Central axis

Claims

A uniaxial eccentric screw pump in which a male screw type rotor is inserted into a stator having a female screw type insertion hole, comprising a rotor drive mechanism capable of revolving the rotor while rotating it, wherein the rotor drive mechanism has a rotary input part for inputting power, and an eccentric rotary part capable of eccentric rotation so as to revolve the rotor while receiving transmission of rotational power for rotating the rotor about a fixed central axis while being connected to the rotary input part, the rotary input part and the eccentric rotary part are arranged such that their respective axes intersect, the rotary input part has an input part side gear part formed around the axis of the rotary shaft, and the eccentric rotary part is formed with an eccentric rotary part side gear part that meshes with the input part side gear part and allows sliding of the input part side gear part in a direction intersecting the central axis, a uniaxial eccentric screw pump characterized by this. A uniaxial eccentric screw pump in which a male screw type rotor is inserted into a stator having a female screw type insertion hole, comprising a rotor drive mechanism capable of revolving the rotor while rotating it, wherein the rotor drive mechanism has a rotary input part for inputting power, and an eccentric rotary part capable of eccentric rotation so as to revolve the rotor while receiving transmission of rotational power for rotating the rotor about a fixed central axis while being connected to the rotary input part, the rotary input part and the eccentric rotary part are arranged such that their respective axes intersect, the rotary input part has an input part side power transmission surface formed around the axis of the rotary shaft, and the eccentric rotary part has an eccentric rotary part side power transmission surface that contacts the input part side power transmission surface so as to enable power transmission by friction and allows sliding of the input part side power transmission surface in a direction intersecting the central axis, a uniaxial eccentric screw pump characterized by this. A uniaxial eccentric screw pump in which a male screw type rotor is inserted into a stator having a female screw type insertion hole, comprising a rotor drive mechanism capable of revolving the rotor while rotating it, wherein the rotor drive mechanism has a rotary input part for inputting power, and an eccentric rotary part capable of eccentric rotation so as to revolve the rotor while receiving transmission of rotational power for rotating the rotor about a fixed central axis while being connected to the rotary input part, The rotary input part and the eccentric rotary part are arranged such that their respective axes are parallel to each other. The rotary input part has an input part side gear part formed along the circumferential direction at the edge part. The eccentric rotary part has an eccentric rotary part side gear part formed along the circumferential direction at the edge part, and power is transmitted by meshing with the input part side gear part. The rotary input part is configured to rotate eccentrically with respect to the rotation axis of the rotary input part. The eccentric rotary part is configured to rotate eccentrically in synchronization with the eccentric rotation in the rotary input part. A single-axis eccentric screw pump characterized by this.

4. A single-axis eccentric screw pump in which a male screw type rotor is inserted into a stator having a female screw type insertion hole, comprising a rotor drive mechanism capable of revolving the rotor while rotating it. The rotor drive mechanism has a rotary input part for inputting power, and an eccentric rotary part that can rotate eccentrically so as to revolve the rotor while receiving the transmission of the rotation power for rotating the rotor about a certain central axis while being connected to the rotary input part. The rotor drive mechanism further has a revolution power transmission part that is connected to the rotary input part and eccentrically rotates the eccentric rotary part while receiving the transmission of the revolution power for revolving the rotor. The rotary input part is connected to the eccentric rotary part and the revolution power transmission part so as to branch the power transmission system. The rotary input part is configured with a first power transmission path for transmitting the rotation power to the eccentric rotary part and a second power transmission path for transmitting the revolution power to the revolution power transmission part as separate systems. The eccentric rotary part is directly connected to the rotor and revolves the rotor while rotating it. A single-axis eccentric screw pump characterized by this.

5. The rotor has a male screw part inserted into the insertion hole of the stator and a shaft-like base shaft part connected to the eccentric rotary part, The single-axis eccentric screw pump according to any one of claims 1 to 4, characterized in that the male screw part and the base shaft part are integrally coupled along the axis.

6. The rotary input part has an input part side connection part, The eccentric rotary part has an eccentric rotary part side connection part. The input unit side connection part and the eccentric rotation part side connection part are connected so as to be able to transmit power while relatively moving in a direction intersecting the central axis, and the uniaxial eccentric screw pump according to any one of claims 1 to 5 is characterized in this regard.

7. The rotary input unit has an input unit side connection part, The eccentric rotation part has an eccentric rotation part side connection part, The revolution power transmission unit has a revolution power transmission unit side connection part, The input unit side connection part and the eccentric rotation part side connection part are connected so as to be able to transmit power while relatively moving in a direction intersecting the central axis, The input unit side connection part and the revolution power transmission unit side connection part are connected so as to be able to transmit power, and the uniaxial eccentric screw pump according to claim 4 is characterized in this regard.

8. The rotary input unit and the eccentric rotation part are arranged such that their respective axes intersect, The rotary input unit and the revolution power transmission unit are arranged such that their respective axes intersect, The rotary input unit has an input unit side gear part formed around the axis of the rotary shaft, The eccentric rotation part has an eccentric rotation part side gear part that meshes with the input unit side gear part and allows sliding of the input unit side gear part in a direction intersecting the central axis, The revolution power transmission unit has a revolution power transmission unit side gear part that meshes with the input unit side gear part, and the uniaxial eccentric screw pump according to claim 4 or 7 is characterized in this regard.

9. The rotary input unit and the eccentric rotation part are arranged such that their respective axes intersect, The rotary input unit and the revolution power transmission unit are arranged such that their respective axes intersect, The rotary input unit has an input unit side power transmission surface formed around the axis of the rotary shaft, The eccentric rotation part has an eccentric rotation part side power transmission surface that contacts the input unit side power transmission surface so as to enable power transmission by friction and allows sliding of the input unit side power transmission surface in a direction intersecting the central axis, The revolution power transmission unit has a revolution power transmission unit side power transmission surface that contacts the input unit side power transmission surface so as to enable power transmission by friction, and the uniaxial eccentric screw pump according to claim 4 or 7 is characterized in this regard.

10. The rotation input part, the eccentric rotation part, and the revolution power transmission part are arranged such that their respective axes are parallel to each other. The rotation input part has an input part side gear part formed along the circumferential direction at the edge. The eccentric rotation part has an eccentric rotation part side gear part formed at the edge, and power is transmitted by meshing with the input part side gear part along the circumferential direction. The rotation input part is configured to rotate eccentrically with respect to the rotation axis of the rotation input part. The eccentric rotation part is configured to rotate eccentrically in synchronization with the eccentric rotation in the rotation input part. A drive pulley that rotates drivenly as the rotation input part rotates is provided coaxially with the rotation input part. A driven pulley as the revolution power transmission part is provided coaxially with the eccentric rotation part. A transmission member for transmitting the power of the rotation input part is bridged between the drive pulley and the driven pulley. The single-axis eccentric screw pump according to claim 4, characterized in that.

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