JP7706142B2 - Single-shaft eccentric screw pump - Google Patents

Description

The present invention relates to a single-shaft eccentric screw pump equipped with a rotor drive mechanism that can rotate and revolve the rotor on its axis.

Conventionally, single-shaft eccentric screw pumps have been proposed that are equipped with a rotor drive mechanism that can rotate and revolve the rotor (see, for example, Patent Documents 1 and 2).

The above-mentioned Patent Document 1 describes a single-shaft eccentric screw pump equipped with a rotor drive mechanism capable of rotating the rotor on its axis while revolving it around its axis. The rotor drive mechanism disclosed in the above-mentioned Patent Document 1 has a rotation power transmission member capable of rotating around a fixed central axis, a revolution orbit forming member capable of allowing the base shaft part of the rotor to rotate on its axis while revolving it around its axis, and a power transmission member (Oldham joint) capable of transmitting the rotation of the rotation power transmission member to the base shaft part to rotate it on its axis while allowing the base shaft part of the rotor to revolve (eccentric rotation).

The power transmission member (Oldham joint) disclosed in the above-mentioned Patent Document 1 has grooves that are perpendicular to each other on the disks provided at the ends of the rotation power transmission member and the base shaft, and connects the rotation power transmission member and the base shaft by interposing a disk-shaped intermediate disk with protrusions on the front and back that are perpendicular to each other. This absorbs the eccentricity between the rotation axis and revolution axis of the rotor.

In addition, in the single-shaft eccentric screw pump disclosed in the above-mentioned Patent Document 2, the rotor that constitutes the pump mechanism is connected to a power source via a coupling rod. This allows the rotor to rotate on its own axis while revolving (rotating eccentrically).

Patent No. 6188015 JP 2012-154215 A

Here, in the single-shaft eccentric screw pump disclosed in the above Patent Document 1, in order to transmit the power of the rotating power transmission member to the base shaft of the rotor, the rotating power transmission member and the base shaft are connected by a power transmission member. Also, in the single-shaft eccentric screw pump disclosed in the above Patent Document 2, it is necessary to provide a long rod such as a coupling rod.

For the reasons mentioned above, the single-shaft eccentric screw pumps disclosed in Patent Documents 1 and 2 have the problem of being long in overall length and large in size. In addition, there is also the problem that a large amount of fluid remains in the pump casing when the pumping of the fluid is stopped.

The present invention has been made to solve the above problems, and aims to provide a single-shaft eccentric screw pump that can be made compact in configuration.

To achieve the above objective, the present invention is configured as follows:

(1) The uniaxial eccentric screw pump according to the present invention is a uniaxial eccentric screw pump in which a male-threaded rotor is inserted into a stator having a female-threaded insertion hole, and is equipped with a rotor drive mechanism capable of revolving the rotor while rotating on its axis, characterized in that the rotor drive mechanism has a rotation input section that inputs power, and an eccentric rotating section that is connected to the rotation input section and can eccentrically rotate to revolve the rotor while receiving the rotational power that rotates the rotor around a fixed central axis.

The above configuration eliminates the need for a power transmission member (Oldham joint) that connects the rotation power transmission member to the base shaft of the rotor in order to absorb the eccentricity between the rotor's rotation axis and revolution axis and transmit the power of the rotation power transmission member to the base shaft of the rotor, and a long rod such as a coupling rod that was used to connect the rotor to a power source so that it can rotate and revolve around its axis, as in the conventional technology, and therefore the overall length can be shortened accordingly. Therefore, the above configuration makes it possible to provide a single-shaft eccentric screw pump with a short overall length and a compact configuration. In addition, when the single-shaft eccentric screw pump is stopped, the amount of fluid remaining inside the pump casing can be minimized.

(2) In the single-shaft eccentric screw pump according to the present invention, preferably, the rotor has a male thread portion that is inserted into the insertion hole of the stator, and a shaft-shaped base shaft portion that is connected to the eccentric rotating portion, and the male thread portion and the base shaft portion are integrally joined along the axis. With this configuration, it is possible to omit the connection member for connecting the male thread portion and the base shaft portion of the rotor (jointless). This makes it possible to reduce the number of parts.

(3) In the single-shaft eccentric screw pump according to the present invention, preferably, the rotation input portion has an input portion-side connection portion, the eccentric rotating portion has an eccentric rotating portion-side connection portion, and the input portion-side connection portion and the eccentric rotating portion-side connection portion are connected so as to be capable of transmitting power while moving relatively in a direction intersecting the central axis. With this configuration, even if the input portion-side connection portion and the eccentric rotating portion-side connection portion move relatively at the connection portion in accordance with the revolution of the rotor, power is transmitted from the rotation input portion to the eccentric rotating portion, so that the rotor can be caused to rotate on its axis and revolve as the eccentric rotating portion rotates eccentrically.

(4) In the single-shaft eccentric screw pump according to the present invention, preferably, the rotation input section and the eccentric rotating section are arranged so that their respective axes intersect, the rotation input section has an input section side gear section formed around the axis of the rotating shaft, and the eccentric rotating section has an eccentric rotating section side gear section formed therein that meshes with the input section side gear section and allows the input section side gear section to slide in a direction intersecting the central axis. With this configuration, even if the input section side gear section and the eccentric rotating section side gear section slide in accordance with the revolution of the rotor at the meshing portion, power is transmitted from the rotation input section to the eccentric rotating section, so that the rotor can be caused to rotate on its axis and revolve as the eccentric rotating section rotates eccentrically.

(5) In the single-shaft eccentric screw pump according to the present invention, preferably, the rotation input section and the eccentric rotating section are arranged so that their respective axes intersect, the rotation input section has an input section side power transmission surface formed around the axis of the rotating shaft, and the eccentric rotating section has an eccentric rotating section side power transmission surface that contacts the input section side power transmission surface so as to enable power transmission by friction, and allows the input section side power transmission surface to slide in a direction intersecting the central axis. With this configuration, even if the input section side power transmission surface and the eccentric rotating section side power transmission surface slide in accordance with the revolution of the rotor at the contact portion, power is transmitted from the rotation input section to the eccentric rotating section, so that the rotor can be rotated and revolved as the eccentric rotating section rotates eccentrically.

(6) In the single-shaft eccentric screw pump according to the present invention, preferably, the rotation input section and the eccentric rotating section are arranged so that their respective axes are parallel to each other, the rotation input section has an input section side gear section formed along the circumferential direction at the edge, the eccentric rotating section has an eccentric rotating section side gear section formed along the circumferential direction at the edge to transmit power by meshing with the input section side gear section, the rotation input section is configured to rotate eccentrically with respect to the rotation axis of the rotation input section, and the eccentric rotating section is configured to rotate eccentrically in synchronization with the eccentric rotation of the rotation input section. With this configuration, the input section side gear section and the eccentric rotating section side gear section always rotate eccentrically in a meshed state, so that the rotational power can be reliably transmitted from the rotation input section to the eccentric rotating section. This allows the rotor to rotate on its axis while revolving around the eccentric rotating section.

(7) In the single-shaft eccentric screw pump according to the present invention, preferably, the rotor drive mechanism further includes a revolution power transmission unit that is connected to the rotation input unit and that eccentrically rotates the eccentric rotation unit while receiving the revolution power that revolves the rotor. With this configuration, the power of the rotation input unit is transmitted to both the eccentric rotation unit and the revolution power transmission unit, so that the rotor can be rotated by the eccentric rotation unit while the rotor is revolved by the revolution power transmission member. This forced revolution system stabilizes the rotational posture of the rotor, and the discharge volume can be stabilized without pulsation.

(8) In this case, it is preferable that the rotation input unit is connected to the eccentric rotation unit and the revolution power transmission unit so as to branch off the power transmission system. With this configuration, the eccentric rotation unit and the revolution power transmission unit can be operated by a single power source (rotation input unit). This makes it possible to reduce the power sources for operating the eccentric rotation unit and the revolution power transmission unit. As a result, the device configuration can be simplified.

(9) In the configuration in which the rotor drive mechanism includes an eccentric rotating part and a revolution power transmission part, preferably, the rotation input part has an input part side connection part, the eccentric rotating part has an eccentric rotating part side connection part, the revolution power transmission part has a revolution power transmission part side connection part, the input part side connection part and the eccentric rotating part side connection part are connected to be able to transmit power while moving relatively in a direction intersecting the central axis, and the input part side connection part and the revolution power transmission part side connection part are connected to be able to transmit power. With this configuration, even if the input part side connection part and the eccentric rotating part side connection part move relatively in accordance with the revolution of the rotor at the connection part, power is transmitted from the input part side connection part to the eccentric rotating part side connection part, so that the rotor can be rotated on its axis and revolved as the eccentric rotating part rotates eccentrically. Also, power is transmitted from the input part side connection part to the revolution power transmission part side connection part, so that the rotor can be revolved as the revolution power transmission part rotates.

(10) In a configuration in which the rotor drive mechanism includes an eccentric rotating part and an orbital power transmission part, preferably, the rotational input part and the eccentric rotating part are arranged so that their respective axes intersect, the rotational input part and the orbital power transmission part are arranged so that their respective axes intersect, the rotational input part has an input part side gear part formed around the axis of the rotation shaft, the eccentric rotating part has an eccentric rotating part side gear part formed therein that meshes with the input part side gear part and allows the input part side gear part to slide in a direction intersecting the central axis, and the orbital power transmission part has an orbital power transmission part side gear part formed therein that meshes with the input part side gear part. With this configuration, even if the input gear portion and the eccentric rotating portion side gear portion slide at the meshing portion in accordance with the revolution of the rotor, power is transmitted from the input gear portion to the eccentric rotating portion side gear portion, so the rotor can be caused to rotate on its axis and revolve as the eccentric rotating portion rotates eccentrically. Also, power is transmitted from the input gear portion to the revolution power transmission portion side gear portion, so the rotor can be caused to revolve as the revolution power transmission portion rotates.

(11) In a configuration in which the rotor drive mechanism includes an eccentric rotating part and an orbital power transmission part, preferably, the rotational input part and the eccentric rotating part are arranged so that their respective axes intersect, the rotational input part and the orbital power transmission part are arranged so that their respective axes intersect, the rotational input part has an input part side power transmission surface formed around the axis of the rotation shaft, the eccentric rotating part has an eccentric rotating part side power transmission surface that contacts the input part side power transmission surface to enable power transmission by friction while allowing the input part side power transmission surface to slide in a direction intersecting the central axis, and the orbital power transmission part has an orbital power transmission part side power transmission surface that contacts the input part side power transmission surface to enable power transmission by friction. With the above configuration, even if the input side power transmission surface and the eccentric rotating part side power transmission surface slide at the contact area in accordance with the revolution of the rotor, power is transmitted from the input side power transmission surface to the eccentric rotating part side power transmission surface, so the rotor can be caused to rotate on its axis and revolve as the eccentric rotating part rotates eccentrically. Also, power is transmitted from the input side power transmission surface to the revolving power transmission part side power transmission surface, so the rotor can be caused to revolve as the revolving power transmission part rotates.

(12) In a configuration in which the rotor drive mechanism includes an eccentric rotating part and an orbital power transmission part, preferably, the rotational input part, the eccentric rotating part, and the orbital power transmission part are arranged so that their respective axes are parallel to each other, the rotational input part has an input part side gear part formed along the circumferential direction at its edge, the eccentric rotating part has an eccentric rotating part side gear part formed along the circumferential direction at its edge to transmit power by meshing with the input part side gear part, the rotational input part is configured to rotate eccentrically with respect to the rotation axis of the rotational input part, the eccentric rotating part is configured to rotate eccentrically in synchronization with the eccentric rotation in the rotational input part, a drive pulley that is rotationally driven in accordance with the rotation of the rotational input part is provided on the same axis as the rotational input part, a driven pulley as the orbital power transmission part is provided on the same axis as the eccentric rotating part, and a transmission member that transmits the power of the rotational input part is bridged between the drive pulley and the driven pulley. With this configuration, the input gear portion and the eccentric rotation portion side gear portion always rotate eccentrically while meshing, so that the rotational power can be reliably transmitted from the rotation input portion to the eccentric rotation portion. Also, the drive pulley drives the driven pulley (revolutionary power transmission portion) via a transmission member, so that the revolutionary power can be reliably transmitted from the rotation input portion to the driven pulley. As a result, the rotor can be rotated by the eccentric rotation portion while revolving by the driven pulley.

According to the aspects of the present invention, it is possible to provide a single-shaft eccentric screw pump that allows for a compact device configuration.

FIG. 1A is a cross-sectional view showing a single-shaft eccentric screw pump (crown gear type) according to a first embodiment of the present invention, and FIG. 1B is a schematic diagram showing a state in which a base shaft portion of a rotor is inserted into an orbital crown gear. FIG. 2A is a diagram showing a rotational power transmission path in a single-shaft eccentric screw pump, and FIG. 2B is a diagram showing a revolutionary power transmission path. FIG. 1A is a diagram for explaining the meshing position of the input side pinion gear and the orbital side crown gear, FIG. 1B to FIG. 1E are diagrams for explaining the meshing position of the input side pinion gear and the rotation side crown gear, and FIG. 1F is a diagram for explaining the outer diameter trajectory of the rotation side crown gear. 1 is a cross-sectional view showing a single-shaft eccentric screw pump (traction drive type) according to a second embodiment of the present invention. FIG. 2A is a diagram showing a rotational power transmission path in a single-shaft eccentric screw pump, and FIG. 2B is a diagram showing a revolutionary power transmission path. 1A is a diagram for explaining the contact position between the input side roller and the revolution side flange, (b) to (e) are diagrams for explaining the contact position between the input side roller and the rotation side flange, and (f) is a diagram for explaining the outer diameter trajectory of the rotation side flange. FIG. 11 is a cross-sectional view showing a single-shaft eccentric screw pump (eccentric gear + timing pulley type) according to a third embodiment of the present invention. FIG. 2A is a diagram showing a rotational power transmission path in a single-shaft eccentric screw pump, and FIG. 2B is a diagram showing a revolutionary power transmission path. FIG. 1A is a diagram for explaining the positional relationship between a rotation input shaft and an eccentric gear (drive gear), and FIGS. 1B to 1D are diagrams for explaining the positional relationship between a drive shaft, an orbital axis, and a rotation axis. FIG. 11 is a cross-sectional view showing a single-shaft eccentric screw pump (eccentric gear type) according to a modified example of the third embodiment of the present invention.

The following describes a single-shaft eccentric screw pump according to one embodiment of the present invention with reference to the attached drawings. These drawings are schematic diagrams and are not necessarily drawn to exact scale. In addition, in the drawings, similar components are indicated by the same reference numerals.

First Embodiment
A uniaxial eccentric screw pump 100 according to a first embodiment will be described with reference to Figures 1 to 3. The uniaxial eccentric screw pump 100 is a rotary volumetric pump. As shown in Figure 1(a), the uniaxial eccentric screw pump 100 has a male-threaded rotor 20 that receives power and rotates eccentrically, and a stator 30 whose inner circumferential surface is formed into a female-threaded shape. The uniaxial eccentric screw pump 100 has a pump mechanism 12, the main part of which is formed by the rotor 20 and the stator 30, built into a pump casing 14.

The rotor 20 is a metallic 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 that is inserted into the insertion hole 34 of the stator 30, and a shaft-shaped base shaft portion 20b that is connected to the rotating crown gear 54 described later. The male screw portion 20a and the base shaft portion 20b are integrally joined along the axis. In other words, the male screw portion 20a and the base shaft portion 20b are straight rod-shaped members without joints or bends. The male screw portion 20a and the base shaft portion 20b may be integrally molded or machined, or may be connected by screws, welding, or the like.

The rotor 20 is formed so that its cross-sectional shape is approximately a perfect circle when viewed in cross section at any position in the longitudinal direction. The stator 30 is a member that is approximately cylindrical and has an inner circumferential surface 32 formed into an n+1 thread (n=1 in the first embodiment) female thread shape. The insertion hole 34 of the stator 30 is formed so that its cross-sectional shape (opening shape) is approximately oval when viewed in cross section at any position in the longitudinal direction of the stator 30.

The rotor 20 is inserted into the insertion hole 34 formed in the stator 30 described above, and can freely rotate eccentrically inside the insertion hole 34. The base end of the rotor 20 is connected to a motor 80, which serves 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 rotate on its axis and revolve (rotate eccentrically) using the power input from the motor 80.

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 come into close contact at their tangents, forming a fluid transport path 40 (cavity). The fluid transport path 40 is formed to extend in a spiral shape in the longitudinal direction of the stator 30 and the rotor 20.

The pump casing 14 is broadly divided into a pump mechanism housing section 14a and a drive mechanism housing section 14b. The pump mechanism housing section 14a houses the pump mechanism 12, which is a tubular body having a cylindrical external shape and whose main part is composed of a rotor 20 and a stator 30. The drive mechanism housing section 14b houses the rotor drive mechanism 50 described above.

The rotor drive mechanism 50 is a drive mechanism that enables the rotor 20 to rotate on its axis while revolving. The rotor drive mechanism 50 has 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 section" of the present invention. The rotation side crown gear 54 is an example of the "eccentric rotation section" of the present invention. The revolution side crown gear 56 is an example of the "revolution power transmission section" of the present invention.

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 shaft 52a of the input side pinion gear 52 is accommodated in the drive mechanism accommodation section 14b via a bearing 58 so as to be rotatable around the axis (center axis C3) of the rotation shaft 52a.

The input side pinion gear 52 has an input side gear portion 52b formed around the axis of the rotating shaft 52a. The input side gear portion 52b is an example of the "input side connection portion" of the present invention. The input side gear portion 52b meshes with a gear portion 54c of the rotation side crown gear 54 and a gear portion 56c of the 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. In other words, 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.

The rotating crown gear 54 is a member that can eccentrically rotate to revolve the rotor 20 while being connected to the input pinion gear 52 in the drive mechanism housing 14b and receiving a rotational force that rotates the rotor 20 about a fixed central axis C2. The rotating crown gear 54 is connected to the base shaft portion 20b of the rotor 20 so that the power can be transmitted. Therefore, the rotor 20 can be rotated by the rotation of the rotating crown gear 54. In addition, the rotating crown gear 54 and the rotation axis (central axis C2) of the rotor 20 are coaxial.

The rotating crown gear 54 has a base 54a, a shaft 54b, and a gear portion 54c. The gear portion 54c is an example of the "eccentric rotating part side connection portion" and the "eccentric rotating part side gear portion" of the present invention. The base 54a is formed in a circular shape when viewed from the axial direction. The shaft portion 54b is provided at the center of the base 54a. The shaft portion 54b is provided so as to protrude from the base 54a toward the rotor 20 side. The base 54a has an insertion hole 54d formed therein for inserting and supporting the base shaft portion 20b of the rotor 20. The rotating crown gear 54 and the input pinion gear 52 are also arranged so that their respective axes intersect or are perpendicular to each other.

A gear portion 54c is provided along the circumferential direction on the edge portion 54e of the base portion 54a. The gear portion 54c meshes with the input side gear portion 52b of the input side pinion gear 52, while allowing sliding relative to the input side gear portion 52b in a direction intersecting the central axis C2. In other words, when the rotor 20 revolves due to the revolution side crown gear 56, the rotation side crown gear 54 revolves in conjunction with the revolution of the rotor 20, and the gear portion 54c of the rotation side crown gear 54 slides against the input side gear portion 52b of the input side pinion gear 52, while the rotation side crown gear 54 rotates eccentrically.

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. Furthermore, the gear portion 54c and the gear portion 56c rotate in opposite directions at the same rotational speed. This allows the rotation and revolution to rotate synchronously.

The revolution side crown gear 56 is a member that allows the rotation side crown gear 54 to rotate eccentrically while receiving the revolution force that revolves the rotor 20. In other words, the revolution side crown gear 56 is a member that allows the rotation of the rotation side crown gear 54 to be transmitted to the base shaft portion 20b to rotate it on its axis while allowing the base shaft portion 20b (rotor 20) to revolve (eccentrically rotate). The revolution side crown gear 56 is also a member that continues to rotate at a fixed position. The revolution side crown gear 56 and the revolution axis (center axis C1) of the rotor 20 are coaxial.

The orbital crown gear 56 is a member for allowing the base shaft portion 20b of the rotor 20 to rotate (see arrow A in FIG. 1(b)) while revolving the base shaft portion 20b on a predetermined orbital path (see arrow B in FIG. 1(b)). Specifically, as shown in FIG. 1, the orbital crown gear 56 is a member rotatably supported by bearings 57 within the pump mechanism housing portion 14a and the drive mechanism housing portion 14b.

The revolution side crown gear 56 has a base 56a, a shaft 56b, and a gear portion 56c. The gear portion 56c is an example of the "revolution power transmission side connection portion" and the "revolution power transmission side gear portion" of the present invention. The base 56a is formed in a circular shape when viewed from the axial direction. The shaft portion 56b is provided in the center of the base 56a. The shaft portion 56b is provided so as to protrude from the base 56a toward the rotor 20 side. The center of the base 56a is formed with an insertion hole 56d into which the base shaft portion 20b of the rotor 20 is inserted and supported.

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

The revolution-side crown gear 56 can support the base shaft portion 20b rotatably (on its axis) via a bearing 59 in the insertion hole 56d. That is, the base shaft portion 20b is supported rotatably at a position offset from the center (center axis C1) of the insertion hole 56d by an eccentricity amount e (see Figures 3(b) to (e)). Therefore, the base shaft portion 20b inserted into the insertion hole 56d can freely rotate on its axis.

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 revolution-side crown gear 56. As a result, as shown in FIG. 1(b), the base shaft portion 20b is capable of rotating about a central axis C2 that is offset from the central axis C1. As shown by arrow B in FIG. 1(b), the revolution-side crown gear 56 is rotated, so that the base shaft portion 20b inserted into the insertion hole 56d can be guided to revolve (rotate eccentrically) as shown by arrow A in FIG. 1(b). Therefore, the base shaft portion 20b can revolve about the central axis C1 while rotating about the central axis C2.

In addition, unlike the rotation-side crown gear 54, the revolution-side crown gear 56 rotates around 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.

The revolution side crown gear 56 and the input side pinion gear 52 are arranged so that their respective axes intersect or are perpendicular to each other. The revolution side crown gear 56 and the rotation side crown gear 54 are arranged so that their respective axes are parallel to each other.

Next, the operation of the uniaxial eccentric screw pump 100 will be described. The uniaxial eccentric screw pump 100 can advance the fluid transport 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 viscous liquid into the fluid transport path 40 from one end side of the stator 30 and transport it toward the other end side of the stator 30. In addition, the direction of travel of the fluid transport path 40 can be switched by switching the direction of rotation of the rotor 20.

As shown in FIG. 2(a), in the single-shaft eccentric screw pump 100, the rotor drive mechanism 50 performs a characteristic operation by operating the motor 80. Specifically, as shown in the shaded area (rotation power transmission path) in FIG. 2(a), when the motor 80 is operated, the rotation side crown gear 54 rotates about the central axis C2 due to the power transmitted from the input side pinion gear 52. As a result, the base shaft portion 20b (rotor 20) connected to the rotation side crown gear 54 rotates about the central axis C2.

On the other hand, as shown in the shaded area (revolution power transmission path) in FIG. 2(b), the power transmitted from the input pinion gear 52 to the revolution crown gear 56 causes the revolution crown gear 56 to rotate about the central axis C1. As a result, the base shaft portion 20b (rotor 20) inserted into the insertion hole 56d located away from the central axis C1 revolves (rotates eccentrically) about the central axis C1. Therefore, the base shaft portion 20b (rotor 20) rotates on its own axis due to the power transmitted from the rotation crown gear 54 side, while revolving due to the power transmitted from the revolution crown gear 56 side. In this way, the rotor 20 operates within the insertion hole 34 of the stator 30, and the fluid transport path 40 advances in the longitudinal direction within the stator 30, allowing the fluid to be pumped.

In addition, as shown in FIG. 3(a), the meshing position between the input side gear portion 52b of the input side pinion gear 52 and the gear portion 56c always maintains the same positional relationship regardless of the rotational position (rotational angle) of the orbital side crown gear 56.

Also, as shown in Figures 3(b) to (e), the meshing position between the input side gear portion 52b 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 (center of the rotation axis) of the rotation side crown gear 54. For example, as shown in Figure 3(b), when the rotation angle of the rotation side crown gear 54 is set to 0°, the central axis C2 (center of the rotation axis) of the rotation side crown gear 54 is located below the central axis C1 (center of the revolution axis) of the revolution side crown gear 56.

Also, as shown in FIG. 3(c), when the rotation angle of the rotating crown gear 54 is 90°, the central axis C2 (center of the rotation axis) of the rotating crown gear 54 is located to the left of the central axis C1 (center of the revolution axis) of the orbital crown gear 56.

Also, as shown in FIG. 3(d), when the rotation angle of the rotating crown gear 54 is set to 180°, the central axis C2 (center of the rotation axis) of the rotating crown gear 54 is located above the central axis C1 (center of the revolution axis) of the orbital crown gear 56.

Also, as shown in FIG. 3(e), when the rotation angle of the rotating crown gear 54 is set to 270°, the central axis C2 (center of the rotation axis) of the rotating crown gear 54 is located to the right of the central axis C1 (center of the revolution axis) of the orbital crown gear 56.

As described above, when the rotating crown gear 54 rotates eccentrically as shown in Figures 3(b) to (e), the outer diameter path L of the rotating crown gear 54 is larger than the outer diameter D1 of the rotating crown gear 54 and the outer diameter D2 of the revolution side crown gear 56 as shown in Figure 3(f). Furthermore, regardless of the rotational position (rotational angle) of the rotating crown gear 54, the gear portion 54c of the rotating crown gear 54 and the input side gear portion 52b of the input side pinion gear 52 are in mesh with each other, and power is always transmitted.

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

(1) In the single-shaft eccentric screw pump 100 according to the first embodiment, the rotor drive mechanism 50 has an input pinion gear 52 that inputs power, and a rotation crown gear 54 that can eccentrically rotate so as to revolve the rotor 20 while receiving the rotation power that rotates the rotor 20 around a fixed central axis while connected to the input pinion gear 52. This eliminates the 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 to transmit the rotation power to the base shaft portion 20b of the rotor 20, or a long rod such as a coupling rod that was used to connect the rotor 20 to a power source so that it can rotate and revolve around its axis. This makes it possible to shorten the overall length accordingly. As a result, it is possible to provide a single-shaft eccentric screw pump 100 with a short overall length and a compact configuration. In addition, when the single-shaft eccentric screw pump 100 is stopped, the amount of fluid remaining inside the pump casing can be minimized.

(2) In the single-shaft eccentric screw pump 100 according to the first embodiment, the revolution side crown gear 56 rotates the rotation side crown gear 54 eccentrically while receiving the revolution power from the input side pinion gear 52 to revolve the rotor 20. 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 while the rotor 20 can be revolved by the revolution side crown gear 56. According to such a forced revolution type, the rotor 20 is supported by both the rotation and revolution mechanisms and the rotational posture is maintained. As a result, when the discharge pressure is high, the rotor 20 is not easily affected by the pressure and is pressed against the stator 30, and the stator 30 is elastically deformed, changing the cavity shape related to the discharge amount. Therefore, it is possible to suppress pulsation and stabilize the discharge amount. In addition, because the rotor 20 can revolve without any reaction force from the stator 30, when sending a slurry containing highly abrasive particles, it is possible to make the rotor 20 thin and eliminate contact between the rotor 20 and the stator 30.

(3) In the single-shaft eccentric screw pump 100 according to the first embodiment, the gear portion 54c of the rotation-side crown gear 54 is meshed with the input-side gear portion 52b while allowing the input-side gear portion 52b to slide in a direction intersecting the central axis C1 (C2). In addition, the gear portion 56c of the revolution-side crown gear 56 is meshed with the input-side gear portion 52b. As a result, even if the input-side gear portion 52b and the gear portion 54c slide at 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 rotation-side crown gear 54 rotates eccentrically. In addition, power is transmitted from the input-side gear portion 52b to the gear portion 56c, so that the rotor 20 can be revolved as the revolution-side crown gear 56 rotates.

(4) In the uniaxial eccentric screw pump 100 according to the first embodiment, the male thread portion 20a and the base shaft portion 20b of the rotor 20 are integrally connected along the axis. This makes it possible to omit the connection member for connecting the male thread portion 20a and the base shaft portion 20b of the rotor 20 (jointless). This makes it possible to reduce the number of parts.

(5) In the single-shaft eccentric screw pump 100 according to the first embodiment described above, the power transmission system for the rotation side crown gear 54 and the revolution side crown gear 56 in the input side pinion gear 52 is connected so as to branch off. This allows the rotation side crown gear 54 and the revolution side crown gear 56 to be operated by a single power source (input side pinion gear 52). This makes it possible to reduce the power sources for operating the rotation side crown gear 54 and the revolution side crown gear 56. As a result, the device configuration can be simplified.

Second Embodiment
Next, a single-shaft eccentric screw pump 200 according to a second embodiment of the present invention will be described with reference to Figures 4 to 6. The second embodiment differs from the first embodiment described above in that it uses a mechanism for transmitting rotation by rolling contact of an input roller.

In the second embodiment, the rotor drive mechanism 50, which is a drive mechanism that enables the rotor 20 to rotate and revolve around its axis, has 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 "rotation 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.

The input roller 521 has an input side power transmission surface 521c formed around the axis of the rotating shaft 521a. The input side power transmission surface 521c is an example of the "input side connection part" of the present invention. The input side power transmission surface 521c (the tip of the rotating shaft 521a) is formed into a cylindrical shape with a slight central bulge. The input 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 part side power transmission surface" and the "eccentric rotation part side connection part" of the present invention. The revolution side power transmission surface 561f is an example of the "revolution power transmission part side power transmission surface" and the "revolution power transmission part side connection part" of the present invention.

The input 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, as the motor 80 is driven, power is distributed in parallel and transmitted to the rotation side flange 541 and the revolution side flange 561. Specifically, the input 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 roller 521 rotates, the rotation side flange 541 and the revolution side flange 561 also rotate.

The rotating flange 541 is a member that can rotate eccentrically to revolve the rotor 20 while being connected to the input roller 521 in the drive mechanism housing 14b and receiving a rotational force that rotates the rotor 20 about a fixed central axis C2. The rotating flange 541 is connected to the base shaft portion 20b of the rotor 20 so that the power can be transmitted. Therefore, the rotating flange 541 can rotate the rotor 20. The rotating flange 541 and the rotation axis (central axis C2) of the rotor 20 are coaxial.

The rotating side flange 541 has a base 541a, a shaft 541b, and a rotating side power transmission surface 541f. The base 541a is formed in a circular shape when viewed from the axial direction. The shaft 541b is provided in the center of the base 541a. The shaft 541b is provided so as to protrude from the base 541a toward the rotor 20. The center of the base 541a is formed with an insertion hole 541d into which the base shaft 20b of the rotor 20 is inserted and supported. The rotating side flange 541 and the input side roller 521 are also arranged so that their respective axes intersect or are perpendicular to each other.

The edge 541e of the base 541a is provided with a rotation-side power transmission surface 541f along the circumferential direction. The rotation-side power transmission surface 541f contacts the input-side power transmission surface 521c so that power can be transmitted by friction, while allowing sliding against the input-side power transmission surface 521c in a direction intersecting the central axis C2. In other words, when the rotor 20 revolves due to the revolution-side flange 561, the rotation-side flange 541 revolves in conjunction with the revolution of the rotor 20, and the rotation-side power transmission surface 541f of the rotation-side flange 541 slides against the input-side power transmission surface 521c of the input-side roller 521, while the rotation-side flange 541 rotates eccentrically.

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. The difference in rotational speed is absorbed by slight slippage, resulting in the same speed rotation, and as a result, the rotation and revolution rotate synchronously.

The revolution side flange 561 is a member that allows the rotation side flange 541 to rotate eccentrically while receiving the revolution force that revolves the rotor 20. In other words, the revolution side flange 561 is a member that allows the rotation of the rotation side flange 541 to be transmitted to the base shaft portion 20b to rotate it about its axis while allowing the base shaft portion 20b (rotor 20) to revolve (eccentrically rotate). The revolution side flange 561 is also a member that continues to rotate at a fixed position. The revolution side flange 561 and the revolution axis (center axis C1) of the rotor 20 are coaxial.

The revolution side flange 561 is a member for allowing the base shaft portion 20b of the rotor 20 to rotate (see arrow A in FIG. 1(b)) on its own axis while revolving the base shaft portion 20b on 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 bearings 57 within the pump mechanism housing portion 14a and the drive mechanism housing portion 14b.

The revolution side flange 561 has a base 561a, a shaft 561b, and a revolution side power transmission surface 561f. The base 561a is formed in a circular shape when viewed from the axial direction. The shaft 561b is provided at the center of the base 561a. The shaft 561b is provided so as to protrude from the base 561a toward the rotor 20. An insertion hole 561d is formed at the center of the base 561a into which the base shaft 20b of the rotor 20 is inserted and supported.

An orbital power transmission surface 561f is provided along the circumferential direction on the edge 561e of the base 561a. The orbital power transmission surface 561f is in contact with the input side power transmission surface 521c of the input side roller 521, and is connected so as to be able to transmit power from the input side roller 521.

The revolution side flange 561 is capable of supporting the base shaft portion 20b so that it can rotate (spin) within the insertion hole 561d via the bearing 59. In other words, the base shaft portion 20b is supported so that it can rotate at a position that is offset from the center (central axis C1) of the insertion hole 561d by the eccentricity amount e (see Figures 6(b) to (e)). Therefore, the base shaft portion 20b inserted into the insertion hole 561d can freely rotate on its own axis.

The insertion hole 561d is a round hole provided at a position away from the axial center position of the revolution side flange 561. This allows the base shaft portion 20b to rotate about a central axis C2 that is offset from the central axis C1. By rotating the revolution side flange 561, the base shaft portion 20b inserted into the insertion hole 561d can be guided to revolve (rotate eccentrically). Therefore, the base shaft portion 20b can revolve about the central axis C1 while rotating about the central axis C2.

In addition, unlike the rotation side flange 541, the revolution side flange 561 rotates around the central axis C1 without eccentric rotation, so there is no relative movement (sliding) between the revolution side power transmission surface 561f and the input side power transmission surface 521c.

The revolution side flange 561 and the input side roller 521 are arranged so that their respective axes intersect or are perpendicular to each other. The revolution side flange 561 and the rotation side flange 541 are arranged so that their respective axes are parallel to each other.

Next, the operation of the uniaxial eccentric screw pump 200 will be described. The uniaxial eccentric screw pump 200 can advance the fluid transport 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 viscous liquid into the fluid transport path 40 from one end side of the stator 30 and transport it toward the other end side of the stator 30. In addition, the direction of travel of the fluid transport path 40 can be switched by switching the direction of rotation of the rotor 20.

As shown in FIG. 5(a), in the single-shaft eccentric screw pump 200, the rotor drive mechanism 50 performs a characteristic operation by operating the motor 80. Specifically, as shown in the shaded area (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 due to the power transmitted from the input side roller 521. As a result, the base shaft portion 20b (rotor 20) connected to the rotation side flange 541 rotates about the central axis C2.

On the other hand, as shown in the shaded area (revolution power transmission path) in FIG. 5(b), the power transmitted from the input roller 521 to the revolution side flange 561 causes the revolution side flange 561 to rotate about the central axis C1. As a result, the base shaft portion 20b (rotor 20) inserted into the insertion hole 561d located away from the central axis C1 revolves (rotates eccentrically) about the central axis C1. Therefore, the base shaft portion 20b (rotor 20) rotates on its own axis due to the power transmitted from the rotation side flange 541 side, while revolving due to the power transmitted from the revolution side flange 561 side. In this way, the rotor 20 operates within the insertion hole 34 of the stator 30, and the fluid transport path 40 advances in the longitudinal direction within the stator 30, allowing the fluid to be pumped.

In addition, 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 (rotational angle) of the revolution side flange 561.

As shown in Figures 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 varies depending on the position of the central axis C2 (center of the rotation axis) of the rotation side flange 541 when viewed from the axial direction. For example, as shown in Figure 6(b), when the rotation angle of the rotation side flange 541 is set to 0°, the central axis C2 (center of the rotation axis) of the rotation side flange 541 is located below the central axis C1 (center of the revolution axis) of the revolution side flange 561.

Also, as shown in FIG. 6(c), when the rotation angle of the rotation side flange 541 is set to 90°, the center axis C2 (center of the rotation axis) of the rotation side flange 541 is located to the left of the center axis C1 (center of the revolution axis) of the orbital side flange 561.

Also, as shown in FIG. 6(d), when the rotation angle of the rotation side flange 541 is set to 180°, the center axis C2 (center of the rotation axis) of the rotation side flange 541 is located above the center axis C1 (center of the revolution axis) of the orbital side flange 561.

Also, as shown in FIG. 6(e), when the rotation angle of the rotation side flange 541 is set to 270°, the center axis C2 (center of the rotation axis) of the rotation side flange 541 is located to the right of the center axis C1 (center of the revolution axis) of the orbital side flange 561.

As described above, when the rotation side flange 541 rotates eccentrically as shown in Figures 6(b) to (e), the outer diameter trajectory L of the rotation side flange 541 is larger than the outer diameter D1 of the rotation side flange 541 and the outer diameter D2 of the revolution side flange 561 as shown in Figure 6(f). Furthermore, regardless of the rotation position (rotation angle) of the rotation side flange 541, the rotation side power transmission surface 541f of the rotation 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.

The rest of the configuration of the second embodiment is the same as that described in the first embodiment above.

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.

(6) In the uniaxial eccentric screw pump 200 according to the second embodiment, the rotation side power transmission surface 541f of the rotation side flange 541 is in contact with the input side power transmission surface 521c so as to transmit power by friction, while allowing sliding against the input side power transmission surface 521c in a direction intersecting the central axis C1 (C2). The revolution side power transmission surface 561f of the revolution side flange 561 is in contact with the input side power transmission surface 521c so as to transmit power by friction. As a result, even if the input side power transmission surface 521c and the rotation side power transmission surface 541f slide at the contact portion, power is transmitted from the input side power transmission surface 521c to the rotation side power transmission surface 541f, so that the rotor 20 can be rotated along with the eccentric rotation of the rotation side flange 541. In addition, power is transmitted from the input side power transmission surface 521c to the revolution side power transmission surface 561f, so the rotor 20 can revolve as the revolution side flange 561 rotates.

Third Embodiment
7 to 9, a single-shaft eccentric screw pump 300 according to a third embodiment of the present invention will be described. Unlike the first and second embodiments described above, the third embodiment uses an eccentric gear as a rotation input unit and a timing pulley as a revolution power transmission unit.

The rotor drive mechanism 60 in the third embodiment is a drive mechanism that allows the rotor 20 to rotate on its axis while revolving. This rotor drive mechanism 60 has an eccentric gear 62, a driven gear 64, a driven pulley 66, a driven pulley support 68, a rotation input shaft 70, a drive pulley 72, and a timing belt 74.

The driven gear 64 is an example of an "eccentric rotating portion" of the present invention. The driven pulley 66 and the driven pulley support portion 68 are an example of a "revolutionary power transmission portion" of the present invention. The rotation input shaft 70 and the eccentric gear 62 are an example of a "rotation input portion" of the present invention. The timing belt 74 is an example of a "transmission member" of the present invention. 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 so that their respective axes are parallel to one another.

The eccentric gear 62 has an eccentric gear portion 62a formed along the circumferential direction at the edge. The eccentric gear portion 62a is an example of the "input side connection portion" and the "input 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. The eccentric gear 62 has an insertion hole 62b through which the rotation input shaft 70 is inserted. The insertion hole 62b is formed at a position shifted from the central axis C4 of the eccentric gear 62. In other words, as shown in FIG. 9(a), the central axes of the rotation input shaft 70 and the eccentric gear 62 are positioned eccentrically by the eccentricity amount e. As a result, when the rotation input shaft 70 rotates due to the power of the motor 80, the eccentric gear 62 rotates eccentrically with respect to the central axis C4.

The driven gear 64 is a member that can eccentrically rotate so as to revolve the rotor 20 while being connected to the eccentric gear 62 in the drive mechanism housing 14b and receiving the rotational force that rotates the rotor 20 about a fixed central axis C2. The driven gear 64 is connected to the base shaft portion 20b of the rotor 20 so that the power can be transmitted. Therefore, the rotor 20 can be rotated by the rotation of the driven gear 64. The driven gear 64 rotates eccentrically due to the revolution of the rotor 20, while the eccentric gear 62 also rotates eccentrically, so that it can rotate in a constantly meshed state. In addition, the driven gear 64 and the rotation axis (central axis C2) of the rotor 20 are coaxial.

The driven gear 64 has a perfect circle shape when viewed from the axial direction. The driven gear 64 has a driven gear portion 64a formed along the circumferential direction at the edge. The driven gear portion 64a is an example of the "eccentric rotation part side connection portion" and "eccentric rotation part side gear portion" of the present invention. An insertion hole 64b is formed in the center of the driven gear 64, into which the base shaft portion 20b of the rotor 20 is inserted and supported.

The driven gear portion 64a is engaged with the eccentric gear portion 62a to transmit power. As a result, the driven gear 64 rotates in the opposite direction to the eccentric gear 62, causing the base shaft portion 20b to rotate. In addition, the driven gear 64 and the eccentric gear 62 have the same number of teeth.

The drive pulley 72 is provided coaxially with the eccentric gear 62 (rotation input shaft 70). The drive pulley 72 rotates in accordance with the rotation of the eccentric gear 62 (rotation input shaft 70). The drive pulley 72 has a circular shape when viewed from the axial direction. A round through hole 72a is formed in the center of the drive pulley 72, through which the rotation input shaft 70 is inserted. A tooth portion 72b is formed on the edge of the drive pulley 72 in the circumferential direction, around which one end of the timing belt 74 is stretched.

The driven pulley 66 is provided coaxially with the driven gear 64. When viewed from the axial direction, the driven pulley 66 has a circular shape. A toothed portion 66b is formed on the edge of the driven pulley 66, around which the other end of the timing belt 74 is stretched in the circumferential direction. The driven pulley 66 and the driving pulley 72 have the same number of teeth. The driven pulley 66 rotates (eccentrically rotates) in the same direction as the rotation of the eccentric gear 62 as the timing belt 74 rotates due to the rotation of the driving pulley 72. A round hole-shaped insertion hole 66a is formed in the center of the driven pulley 66, through which the end 68a of the driven pulley support portion 68 is inserted.

At a position away from the axial center position of the driven pulley support part 68, an insertion hole 68b is formed into which the base shaft part 20b of the rotor 20 is inserted to support it. As a result, the driven pulley support part 68 can support the base shaft part 20b so that it can rotate (spin) within the insertion hole 68b via the bearing 59. In other words, the base shaft part 20b is supported so that it can rotate at a position that is offset from the center (center axis C1) of the insertion hole 68b by the eccentricity e (see FIG. 9(a)). Therefore, the base shaft part 20b inserted into the insertion hole 68b can freely rotate. The center axis C1, which is the revolution axis of the base shaft part 20b, and the axis of the driven pulley 66 are coaxial.

The timing belt 74 may be a standard cog belt or V-belt. When used with a large pump, a chain may be used instead of a belt. As another example, a magnetic coupling may also be used.

Next, the operation of the uniaxial eccentric screw pump 300 will be described. The basic operation is the same as that of the first and second embodiments. Here, as shown in FIG. 8(a), in the uniaxial eccentric screw pump 300, the rotor drive mechanism 60 performs a characteristic operation by operating the motor 80. Specifically, as shown in the shaded area (rotational 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 due to the power transmitted from the rotation input shaft 70, and the driven gear 64 rotates (eccentrically rotates) about the central axis C1. Accordingly, the base shaft portion 20b (rotor 20) connected to the driven gear 64 rotates about the central axis C2.

On the other hand, as shown in the shaded area (revolutionary power transmission path) in FIG. 8(b), the driven pulley support portion 68 rotates about the central axis C1 due to the power transmitted from the rotation input shaft 70 to the drive pulley 72, timing belt 74, and driven pulley 66. As a result, the base shaft portion 20b (rotor 20) inserted into the insertion hole 68b located away from the central axis C1 revolves (rotates eccentrically) about the central axis C1. Therefore, the base shaft portion 20b (rotor 20) rotates due to the power transmitted from the driven gear 64 side, while revolving due to the power transmitted from the driven pulley 66 side. In this way, the rotor 20 operates within the insertion hole 34 of the stator 30, and the fluid transport path 40 advances in the longitudinal direction within the stator 30, allowing the fluid to be pumped.

Also, as shown in FIG. 9(a), the central axis C5 of the rotation input shaft 70 and the central axis C4 of the eccentric gear 62 are positioned eccentrically by an eccentricity amount e.

As shown in Figures 9(b) to (d), the revolution shaft (center axis C1) of the base shaft portion 20b of the rotor 20 is driven by a timing belt 74, and rotates by the same angle (0°, 45°, 90°) as the rotation input shaft 70 because the drive pulley 72 and the driven pulley 66 have the same number of teeth. When the revolution shaft rotates, the rotation shaft (center axis C2) moves in the same direction and by the same angle as the rotation input shaft 70, but the positional relationship between the eccentric gear 62 and the driven gear 64 does not change. The rotation shaft is also driven by the eccentric gear 62 and the driven gear 64, and rotates by the same angle as the rotation input shaft 70 because both gears have the same number of teeth. This results in synchronous rotation and revolution.

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.

(7) In the single-shaft eccentric screw pump 300 according to the third embodiment, a drive pulley 72 that rotates in accordance with the rotation of the eccentric gear 62 is provided on the same axis as the eccentric gear 62, a driven pulley 66 is provided on the same axis as the driven gear 64, and a timing belt 74 is stretched between the drive pulley 72 and the driven pulley 66. As a result, the eccentric gear portion 62a and the driven gear portion 64a rotate eccentrically while always meshing with each other, so that the rotational force can be reliably transmitted from the eccentric gear 62 to the driven gear 64. In addition, the drive pulley 72 drives the driven pulley 66 via the timing belt 74, so that the revolution force can be reliably transmitted to the driven pulley 66. As a result, the rotor 20 can be rotated by the driven gear 64 while the rotor 20 can be revolved by the driven pulley 66.

(Modification of the third embodiment)
Next, a uniaxial eccentric screw pump 301 according to a modified example of the third embodiment of the present invention will be described with reference to Fig. 10. In the modified example of the third embodiment, unlike the third embodiment described above, an example will be described in which the forced revolution mechanism on the revolution side (drive pulley, driven pulley, and timing belt) is omitted.

As shown in FIG. 10, in the single-shaft eccentric screw pump 301 in the modified third embodiment, the rotor drive mechanism 601 has an eccentric gear 62, a driven gear 64, and a rotation input shaft 70. In other words, unlike the third embodiment described above, the drive pulley, driven pulley, and timing belt are omitted.

In the single-shaft eccentric screw pump 301, when the motor 80 is operated with the above-mentioned configuration, the eccentric gear 62 rotates (eccentrically rotates) about the central axis C5 due to the power transmitted from the rotation input shaft 70, and the driven gear 64 rotates (eccentrically rotates) about the central axis C1. As a result, the base shaft portion 20b (rotor 20) connected to the driven gear 64 rotates about the central axis C2. Furthermore, the rotation power and the reaction force of the stator 30 enable the driven gear 64 (eccentric rotating portion on the rotating side) to rotate eccentrically.

In this way, in the single-shaft eccentric screw pump 301 according to the modified example of the third embodiment, the forced revolution mechanism on the revolution side is removed, and only the power transmission on the rotation side is used, so the driven gear 64 (the eccentric rotating part on the rotation side) can rotate eccentrically. This is suitable for applications where the discharge pressure is low and contact between the rotor 20 and the stator 30 is not a problem, and it is possible to further miniaturize the entire pump.

(Other Modifications)
The above embodiment can be modified as follows.

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

In the first and second embodiments, the crown gear and the transmission surface are shown as an example of the connection between the rotation input part and the eccentric rotation part and the revolution power transmission part, but the present invention is not limited to this. In the present invention, a mechanism other than the above may be applied as long as it is possible to transmit power while moving relative to the rotation input part and the eccentric rotation part.

In the above first to third embodiments, an example is shown in which one rotation input section is branched into an eccentric rotation section and a revolution power transmission section, but the present invention is not limited to this. In the present invention, it is also possible to provide one rotation input section each for the eccentric rotation section and the revolution power transmission section.

The above embodiments are merely examples of applications of the present invention, and it goes without saying that any other embodiments within the scope of the claims are also included within the technical scope of the invention.

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

Claims (10)

A single-shaft eccentric screw pump in which a male-threaded rotor is inserted into a stator having a female-threaded insertion hole,
The rotor drive mechanism is capable of rotating and revolving the rotor,
The rotor drive mechanism includes:
A rotation input unit for inputting power;
an eccentric rotation unit that is connected to the rotation input unit and that can eccentrically rotate so as to revolve the rotor while receiving a rotational force that rotates the rotor about a certain central axis,
the rotation input portion and the eccentric rotation portion are arranged such that their respective axes intersect,
the rotation input portion has an input portion-side gear portion formed around an axis of a rotation shaft,
a gear portion on the input side that meshes with the gear portion on the input side and allows the gear portion on the input side to slide in a direction intersecting the central axis. A single-shaft eccentric screw pump in which a male-threaded rotor is inserted into a stator having a female-threaded insertion hole,
The rotor drive mechanism is capable of rotating and revolving the rotor,
The rotor drive mechanism includes:
A rotation input unit for inputting power;
an eccentric rotation unit that is connected to the rotation input unit and that can eccentrically rotate so as to revolve the rotor while receiving a rotational force that rotates the rotor about a certain central axis,
the rotation input portion and the eccentric rotation portion are arranged such that their respective axes intersect,
the rotation input portion has an input portion-side power transmission surface formed around an axis of a rotation shaft,
a power transmission surface on the input portion side that is in contact with the power transmission surface on the input portion side so as to transmit power by friction, and that allows sliding of the power transmission surface on the input portion side in a direction intersecting the central axis. A single-shaft eccentric screw pump in which a male-threaded rotor is inserted into a stator having a female-threaded insertion hole,
The rotor drive mechanism is capable of rotating and revolving the rotor,
The rotor drive mechanism includes:
A rotation input unit for inputting power;
an eccentric rotation unit that is connected to the rotation input unit and that can eccentrically rotate so as to revolve the rotor while receiving a rotational force that rotates the rotor about a certain central axis,
the rotation input portion and the eccentric rotation 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 a circumferential direction at an edge portion,
the eccentric rotation portion has an eccentric rotation portion-side gear portion formed therein, the eccentric rotation portion having an edge portion that meshes with the input portion-side gear portion along a circumferential direction to transmit power;
the rotation input portion is configured to rotate eccentrically with respect to a rotation axis of the rotation input portion;
13. A single- shaft eccentric screw pump, wherein the eccentric rotation portion is configured to rotate eccentrically in synchronization with eccentric rotation of the rotation input portion. A single-shaft eccentric screw pump in which a male-threaded rotor is inserted into a stator having a female-threaded insertion hole,
The rotor drive mechanism is capable of rotating and revolving the rotor,
The rotor drive mechanism includes:
A rotation input unit for inputting power;
an eccentric rotation unit that is connected to the rotation input unit and that can eccentrically rotate so as to revolve the rotor while receiving a rotational force that rotates the rotor about a certain central axis,
The rotor drive mechanism includes:
a revolution power transmission unit connected to the rotation input unit and eccentrically rotating the eccentric rotation unit while receiving a revolution power that revolves the rotor,
the rotation input portion is connected to the eccentric rotation portion and the revolution power transmission portion so as to branch a power transmission system ,
the rotation input portion is configured as a first power transmission path for transmitting rotational power to the eccentric rotation portion, and the rotation input portion is configured as a second power transmission path for transmitting revolutionary power to the revolutionary power transmission portion,
1. A single-shaft eccentric screw pump , wherein the eccentric rotating portion is directly connected to the rotor and causes the rotor to rotate on its axis while revolving around the axis . the rotor has a male thread portion that is inserted into an insertion hole of the stator, and a shaft-shaped base shaft portion that is connected to the eccentric rotation portion,
5. The uniaxial eccentric screw pump according to claim 1, wherein the male screw portion and the base shaft portion are integrally joined along an axis. The rotation input portion has an input portion side connection portion,
The eccentric rotation portion has an eccentric rotation portion side connection portion,
The single-shaft eccentric screw pump according to any one of claims 1 to 5, characterized in that the input section side connection portion and the eccentric rotation section side connection portion are connected to be capable of transmitting power while moving relatively in a direction intersecting the central axis. The rotation input portion has an input portion side connection portion,
The eccentric rotation portion has an eccentric rotation portion side connection portion,
the revolutionary power transmission part has a revolutionary power transmission part side connection part,
the input unit side connection portion and the eccentric rotation unit side connection portion are connected to each other so as to be capable of transmitting power while moving relatively in a direction intersecting the central axis,
5. The uniaxial eccentric screw pump according to claim 4 , wherein the input portion side connection portion and the revolution power transmission portion side connection portion are connected to each other so as to be capable of transmitting power. the rotation input portion and the eccentric rotation portion are arranged such that their respective axes intersect,
the rotation input portion and the revolution power transmission portion are disposed so that their respective axes intersect,
the rotation input portion has an input portion-side gear portion formed around an axis of a rotation shaft,
the eccentric rotation portion is formed with an eccentric rotation portion-side gear portion that meshes with the input portion-side gear portion and allows the input portion-side gear portion to slide in a direction intersecting the central axis,
8. The uniaxial eccentric screw pump according to claim 4 or 7 , wherein the revolutionary power transmission portion is formed with a revolutionary power transmission portion side gear portion that meshes with the input portion side gear portion. the rotation input portion and the eccentric rotation portion are arranged such that their respective axes intersect,
the rotation input portion and the revolution power transmission portion are disposed so that their respective axes intersect,
the rotation input portion has an input portion-side power transmission surface formed around an axis of a rotation shaft,
the eccentric rotation portion has an eccentric rotation portion side power transmission surface that contacts the input portion side power transmission surface so as to transmit power by friction and allows the input portion side power transmission surface to slide in a direction intersecting the central axis,
8. The uniaxial eccentric screw pump according to claim 4 or 7, characterized in that the revolutionary power transmission portion has a revolutionary power transmission portion side power transmission surface that contacts the input portion side power transmission surface so as to transmit power by friction. the rotation input portion, the eccentric rotation 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 a circumferential direction at an edge portion,
the eccentric rotation portion has an eccentric rotation portion-side gear portion formed therein, the eccentric rotation portion having an edge portion that meshes with the input portion-side gear portion along a circumferential direction to transmit power;
the rotation input portion is configured to rotate eccentrically with respect to a rotation axis of the rotation input portion;
the eccentric rotation portion is configured to eccentrically rotate in synchronization with eccentric rotation of the rotation input portion,
a drive pulley that is rotationally driven in association with rotation of the rotation input part 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,
5. The uniaxial eccentric screw pump according to claim 4 , wherein a transmission member for transmitting the power of the rotation input portion is stretched between the drive pulley and the driven pulley.

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