Vertical screw pump

Abstract

To transfer a liquid having high viscosity and low fluidity.SOLUTION: A vertical screw pump includes: a first rotor and a second rotor provided along a vertical direction; and a case having a cavity part in which at least parts of the first rotor and the second rotor are provided. The first rotor and the second rotor are provided adjacent to each other. An opening is formed on an upper end face of the case by the cavity part. When the case is viewed from the upper side in a vertical direction, the first rotor and the second rotor are exposed through the opening.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vertical screw pump. [Background technology]

[0002] Patent Document 1 discloses an oil circulation type mechanical pump that uses a so-called vertical pump in which the rotation axis of the screw rotor is installed so as to be nearly vertical. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-141260 Summary of the Invention [Problem to be solved by the invention]

[0004] The oil circulation type mechanical pump described in Patent Document 1 is a pump that sucks in gas, and therefore is not suitable for sucking in liquid. In particular, when sucking in highly viscous liquids (e.g., ink, mayonnaise), unless the non-treated liquid is easily sucked into the pump, the pumping action will not occur, which may result in poor liquid delivery. Also, in the case of liquids with low fluidity, unless the non-treated liquid is easily sucked into the pump, the pumping action will not occur, which may result in poor liquid delivery.

[0005] The present invention has been made in view of the above circumstances, and has as its object to provide a vertical screw pump that can transport a liquid with high viscosity and low fluidity. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, a vertical screw pump according to the present invention includes, for example, a first rotor having a first shaft arranged along a vertical direction and first spiral screw teeth arranged along the first shaft, a second shaft arranged along the vertical direction and a second rotor having second spiral screw teeth arranged along the second shaft and meshing with the first screw teeth, and a housing having a cavity in which the first rotor and the second rotor are arranged, wherein the housing has a case that accommodates the first rotor and the second rotor, and a hopper tank connected to the vertically upper side of the case, and the cavity forms an opening on the upper end surface of the case, and when the housing is viewed from vertically above, the first screw teeth and the second screw teeth are exposed through the opening.

[0007] In the vertical screw pump according to the present invention, when the housing is viewed from above in the vertical direction, the first screw teeth and the second screw teeth are exposed through the opening formed in the upper end surface of the case. Therefore, when a fluid to be treated that has high viscosity and low fluidity is poured into the hopper tank, the fluid to be treated comes into direct contact with the first screw teeth and the second screw teeth. Therefore, it is possible to transport a liquid that has high viscosity and low fluidity.

[0008] The first screw teeth and the second screw teeth may protrude vertically upward from the upper end surface. This allows a fluid with very high viscosity and low fluidity, such as bean paste, to come into direct contact with the first screw teeth and the second screw teeth. This allows the fluid with very high viscosity and low fluidity to be reliably transported.

[0009] To solve the above problems, a vertical screw pump according to the present invention includes, for example, a first rotor having a first shaft extending vertically and first helical screw teeth extending along the first shaft; a second rotor having a second shaft extending vertically and second helical screw teeth extending along the second shaft and meshing with the first screw teeth; and a case having a cavity in which the first rotor and the second rotor are disposed, the cavity forming an opening in the upper end surface of the case, and the first screw teeth and the second screw teeth protruding vertically above the upper end surface. This allows a highly viscous, low-fluidity fluid, such as bean paste, to come into direct contact with the first screw teeth and the second screw teeth. This ensures reliable transport of highly viscous, low-fluidity fluid.

[0010] The amount of protrusion of the first screw teeth and the second screw teeth from the upper end surface may be equal to or greater than one-third of the diameter of the first screw teeth and the second screw teeth, thereby enabling a fluid with very high viscosity and low fluidity to be reliably transported.

[0011] The rotor may further include an oil tank on which the case is placed and which contains oil, a pump that draws the oil from the oil tank and supplies it to bearings that hold the first rotor and the second rotor, and an actuator that is provided in the oil tank and drives the first rotor, the second rotor, and the pump. This allows for fewer power sources and a simpler configuration. Furthermore, using only one power source allows for a smaller size. [Effects of the Invention]

[0012] According to the present invention, it is possible to transfer a liquid having high viscosity and low fluidity. [Brief explanation of the drawings]

[0013] [Figure 1]1A and 1B are schematic diagrams showing an example of a vertical screw pump 1, in which (A) is a front view, (B) is a left side view, and (C) is a plan view (only essential parts are shown). [Figure 2] FIG. 1 is a left side view showing an outline of a vertical screw pump 1. [Figure 3] 1 is a front view showing an outline of a vertical screw pump 1. FIG. [Figure 4] 1A and 1B are diagrams showing an outline of a pump 60, in which (A) is a cross-sectional view of the main part, and (B) is a view from below. [Figure 5] 3 is a diagram showing a schematic view of a pump 60 transferring oil. FIG. [Figure 6] 1A and 1B are schematic diagrams showing an example of a vertical screw pump 2, in which (A) is a front view, (B) is a left side view, and (C) is a plan view (only essential parts are shown). [Figure 7] 1A and 1B are schematic diagrams showing an example of a vertical screw pump 3, in which (A) is a front view, (B) is a left side view, and (C) is a plan view (only essential parts are shown). [Figure 8] 1A and 1B are schematic diagrams showing an example of a vertical screw pump 4, in which (A) is a front view, (B) is a left side view, and (C) is a plan view (only essential parts are shown). [Figure 9] FIG. 2 is a left side view showing an outline of a vertical screw pump 4. [Figure 10] 1A and 1B are schematic diagrams showing an example of a vertical screw pump 5, in which (A) is a front view, (B) is a left side view, and (C) is a plan view (only essential parts are shown). [Figure 11] FIG. 2 is a left side view showing an outline of a vertical screw pump 5. [Figure 12] 1A and 1B are schematic diagrams showing an example of a vertical screw pump 6, in which (A) is a front view, (B) is a left side view, and (C) is a plan view (only essential parts are shown). [Figure 13] FIG. 2 is a left side view showing an outline of a vertical screw pump 6. [Figure 14] 1A and 1B are schematic diagrams showing an example of a vertical screw pump 7, in which (A) is a front view, (B) is a left side view, and (C) is a plan view (only essential parts are shown). DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vertical screw pump according to an embodiment of the present invention is a device capable of transporting a liquid having high viscosity and low fluidity.

[0015] First Embodiment

[0016] FIG. 1 is a schematic diagram showing an example of a vertical screw pump 1 according to a first embodiment of the present invention, where (A) is a front view, (B) is a left side view, and (C) is a plan view (showing only essential parts). Here, the plan view is a view seen from above in the vertical direction. Note that FIG. 1 shows a partial cross section to illustrate essential parts provided inside.

[0017] The vertical screw pump 1 mainly includes a first rotor 10, a second rotor 20, a housing 30, an actuator 40, an oil tank 50, and a pump 60.

[0018] The housing 30 has a case 31 that houses the first rotor 10 and the second rotor 20, and a hopper tank 32 connected to the vertically upper side of the case 31. The hopper tank 32 is a hollow cylindrical member into which the fluid to be treated is introduced. The opening at the upper end of the hopper tank 32 is an inlet 32a, and the opening at the lower end is an outlet 32b. The hopper tank 32 has a shape in which the inlet 32a is wider than the outlet 32b, and the diameter gradually narrows toward the outlet 32b at the lower end. The outlet 32b of the hopper tank 32 is connected to the upper end surface 31b of the case 31.

[0019] A hollow portion 31a is formed in the case 31, and the first rotor 10 and the second rotor 20 are provided therein. An opening 31c is formed in the upper end surface 31b by the hollow portion 31a. When the housing 30 is viewed from above in the vertical direction (see FIG. 1(C)), the first rotor 10 and the second rotor 20 are exposed through the opening 31c.

[0020] The opening 31c is a supply port through which the fluid to be treated is supplied to the case 31. A discharge pipe 31d is provided on the side of the case 31, connecting the hollow portion 31a with the space outside the case 31. The fluid to be treated supplied from the opening 31c by the first rotor 10 and the second rotor 20 passes through the hollow portion 31a and is discharged from the discharge pipe 31d to the outside of the case 31. In this way, the fluid to be treated is transported by the vertical screw pump 1.

[0021] The case 31 and the actuator 40 are placed on an oil tank 50. Oil o is sealed inside the oil tank 50. A pump 60 is also provided inside the oil tank 50. The pump 60 sucks up the oil o from the oil tank 50 and supplies it to the bearings 33, 34 that hold the first rotor 10 and the second rotor 20.

[0022] Fig. 2 is a left side view showing an outline of the vertical screw pump 1. Fig. 3 is a front view showing an outline of the vertical screw pump 1. In Fig. 2, for the sake of explanation, a hopper tank 32 is shown by a dotted line.

[0023] The first rotor 10 has a first shaft 11 provided along the vertical direction and first helical screw teeth 12 (corresponding to the first conveying section of the present invention) provided along the first shaft 11. The second rotor 20 has a second shaft 21 provided along the vertical direction and second helical screw teeth 22 (corresponding to the second conveying section of the present invention) provided along the second shaft 21. The first screw teeth 12 and the second screw teeth 22 are provided on the outer circumferential surfaces of the first shaft 11 and the second shaft 21, respectively, along the longitudinal direction of the first shaft 11 and the second shaft 21, i.e., along the vertical direction.

[0024] The first screw teeth 12 and the second screw teeth 22 have substantially the same shape except that they are twisted in opposite directions. The first screw teeth 12 and the second screw teeth 22 mesh with each other such that one tooth is located between the other teeth (in the groove).

[0025] The first shaft 11 and the second shaft 21 are rotatably held by bearings 33 and 34, respectively, provided inside the case 31. The lower end of the first shaft 11 protrudes downward from an opening 31e provided in the lower end of the case 31 and is connected to a gear 73. The gear 73, i.e., the first shaft 11, is rotationally driven by the actuator 40 via gears 71 and 72.

[0026] A gear 13 is provided on the first shaft 11 (here, near the lower end of the first shaft 11). A gear 23 is provided on the second shaft 21 (here, near the lower end of the second shaft 21). The gears 13 and 23 are meshed, and when the first shaft 11 is rotated by the actuator 40, the second shaft 21 rotates. The first shaft 11 and the second shaft 21 rotate in opposite directions.

[0027] The first screw teeth 12 and the second screw teeth 22 protrude vertically upward from the upper end surface 31b. In FIG. 2, the protrusion amount p is 1 / 3 of the diameter of the first screw teeth 12 and the second screw teeth 22.

[0028] Since the first screw teeth 12 and the second screw teeth 22 protrude vertically above the upper end surface 31b, the high-viscosity, low-fluidity treated fluid introduced into the hopper tank 32 can be transported by the first rotor 10 and the second rotor 20.

[0029] Gears 71, 72, and 73 are provided inside the oil tank 50. The gear 71 is provided on the drive shaft 41 of the actuator 40, and rotates as the drive shaft 41 rotates. Gear 71 is engaged with gear 72, and gear 72 is engaged with gear 73, so that the gears 71, 72, and 73 rotate as the drive shaft 41 rotates. The pump 60 is connected to the gear 72.

[0030] 4A and 4B are diagrams showing an outline of a pump 60, where (A) is a cross-sectional view of the main part and (B) is a view from below. The pump 60 mainly has a pump body 61, a rotating shaft 62, impellers 63, and an inlet pipe 64.

[0031] Pump body 61 is provided with a cylindrical hollow portion 61a. Pump body 61 is also provided with an inlet pipe 64 that protrudes downward to suck in oil o. Pump body 61 is also formed with holes 611b and 61c that connect inlet pipe 64 to hollow portion 61a, and hole 61d that connects hollow portion 61a to the external space of pump body 61. Pipe 65 (see FIG. 3) is provided in hole 61d.

[0032] Plate-shaped blades 63 are provided on the rotating shaft 62, and the blades 63 are provided inside the hollow portion 61a. The rotating shaft 62 is connected to a gear 72 and rotates together with the gear 72. Therefore, the blades 63 also rotate in conjunction with the rotation of the gear 72. The center ax1 of the rotating shaft 62 and the blades 63 is misaligned with the center ax2 of the hollow portion 61a.

[0033] 5 is a diagram schematically illustrating how pump 60 transfers oil o. Because center ax1 of rotating shaft 62 is offset from center ax2 of cavity 61a, when blade 63 rotates, a gap g is formed between blade 63 and the outer circumferential surface of cavity 61a only on the hole 61d side. This reduces the pressure on the hole 61d side, and oil o flows from hole 61c into cavity 61a and out of cavity 61a into hole 61d, as shown by the arrows in FIG. 5.

[0034] Returning to the explanation of Figure 4, when the transfer of oil o begins due to the rotation of the rotary shaft 62, the oil o stored in the oil tank 50 flows from the inlet pipe 64 through the holes 61b and 61c into the hollow portion 61a, and then flows out into the pipe 65 through the hole 61d.

[0035] 2 and 3, the oil o sucked up into the pipe 65 by the rotating shaft 62 flows through the pipe 65 into the case 31 and is supplied to the space 31f inside the case 31, that is, to the bearings 33 and .

[0036] Next, a description will be given of the operation of the vertical screw pump 1. When the actuator 40 is driven, the first rotor 10 and the second rotor 20 are rotated via the gears 71, 72, and 73.

[0037] The fluid to be treated supplied via the hopper tank 32 is transferred from the opening 31c into the hollow portion 31a by the rotation of the first rotor 10 and the second rotor 20.

[0038] Because the first screw teeth 12 and the second screw teeth 22 are exposed from the opening 31c, it is possible to transport fluids with very high viscosity and low fluidity, such as bean paste. Bean paste has a very high viscosity of approximately 300,000 mPa·s. Because the first screw teeth 12 and the second screw teeth 22 are exposed from the opening 31c, the bean paste is caught in the first screw teeth 12 and the second screw teeth 22 as they rotate. This allows the vertical screw pump 1 to transport bean paste.

[0039] The bean paste has a structure in which starch particles are wrapped in protein, and if the rotation speed of the first rotor 10 and the second rotor 20 is high, excessive force is applied to the bean paste, causing it to deteriorate. Therefore, when transferring the bean paste, it is necessary to reduce the rotation speed of the first rotor 10 and the second rotor 20. In the vertical screw pump 1, by reducing the rotation speed of the first rotor 10 and the second rotor 20 to 300 rpm or less, preferably to about 180 rpm, it is possible to transfer the bean paste without causing it to deteriorate.

[0040] The vertical screw pump 1 can also transport fluids that are generally considered to have a high viscosity, although the viscosity is lower than that of ink, mayonnaise, and other fillings. In this case, the rotation speed of the first rotor 10 and the second rotor 20 can be increased to more than 300 rpm. However, the first rotor 10 and the second rotor 20 are suitable for rotation at approximately 1,800 rpm or less.

[0041] Furthermore, by driving the actuator 40, the first rotor 10 and the second rotor 20 rotate via gears 71, 72, and 73, and the pump 60 (rotating shaft 62) also rotates. Therefore, the pump 60 is driven at the same time as the first rotor 10 and the second rotor 20 start to rotate, and oil o is supplied to the bearings 33 and 34 (see the two-dot chain line in FIG. 3).

[0042] According to this embodiment, when the housing 30 is viewed from above in the vertical direction, the first screw teeth 12 and the second screw teeth 22 are exposed through the openings 31c, and the fluid to be treated, which has high viscosity and low fluidity, comes into direct contact with the first screw teeth 12 and the second screw teeth 22, so that the fluid, which has high viscosity and low fluidity, can be transported.

[0043] Furthermore, according to this embodiment, the first screw teeth 12 and the second screw teeth 22 protrude vertically upward from the upper end surface 31b, so that a fluid with a very high viscosity and low fluidity can come into direct contact with the first screw teeth 12 and the second screw teeth 22. This makes it possible to reliably transfer a fluid with a very high viscosity and low fluidity. In particular, by making the amount of protrusion of the first screw teeth 12 and the second screw teeth 22 from the upper end surface 31b equal to or greater than one-third of the diameter of the first screw teeth 12 and the second screw teeth 22, a fluid to be processed, such as a very high viscosity bean paste, can be easily entangled in the first screw teeth 12 and the second screw teeth 22, making it possible to reliably transfer a liquid with a very high viscosity and low fluidity.

[0044] Furthermore, according to this embodiment, the actuator 40 that drives the first rotor 10 and the second rotor 20 can be used to drive the pump 60 that draws up oil o from the oil tank 50 and supplies the oil o to the bearings 33, 34. This reduces the number of power sources and simplifies the configuration. Furthermore, using only one power source allows the vertical screw pump 1 to be made smaller.

[0045] In this embodiment, the protrusion amount p of the first screw teeth 12 and the second screw teeth 22 from the upper end surface 31b is 1 / 3 of the diameter of the first screw teeth 12 and the second screw teeth 22, but the protrusion amount p is not limited to this. If the first screw teeth 12 and the second screw teeth 22 protrude vertically upward from the upper end surface 31b, it is possible to transfer a fluid with very high viscosity and low fluidity. However, to ensure reliable transfer, it is preferable that the protrusion amount p be 1 / 3 or more of the diameter of the first screw teeth 12 and the second screw teeth 22.

[0046] In this embodiment, the pump 60 is used to rotate the blades 63 inside the cavity 61a to suck up the oil o, but the configuration of the pump 60 is not limited to this. However, it is preferable to use an actuator 40 to drive the first rotor 10, the second rotor 20, and the pump.

[0047] <Second embodiment> In the first embodiment of the present invention, the first screw teeth 12 and the second screw teeth 22 protrude vertically upward from the upper end surface 31b, but the configuration of the first screw teeth 12 and the second screw teeth 22 is not limited to this. A vertical screw pump 2 according to a second embodiment will be described below. Note that the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0048] Fig. 6 is a schematic diagram showing an example of a vertical screw pump 2, where (A) is a front view, (B) is a left side view, and (C) is a plan view (showing only the main parts). Note that Fig. 6 shows a partial cross section to show the main parts provided inside.

[0049] The vertical screw pump 2 mainly includes a first rotor 10, a second rotor 20, a housing 30A, an actuator 40, an oil tank 50, and a pump 60. The housing 30A also includes a case 31A that houses the first rotor 10 and the second rotor 20, and a hopper tank 32A connected to the vertically upper side of the case 31A.

[0050] The case 31A and the hopper tank 32A are similar to the case 31 and the hopper tank 32 except that they have different heights. The case 31A is taller than the case 31, and the hopper tank 32A is shorter than the hopper tank 32.

[0051] The tips 12a of the first screw teeth 12 and the tips 22a of the second screw teeth 22 are located vertically below the upper end surface 31b of the case 31A. When viewed from above in the vertical direction, the first screw teeth 12 and the second screw teeth 22 are exposed from openings 31c in the upper end surface 31b of the hollow portion 31a. Therefore, the fluid to be treated supplied to the hopper tank 32A flows into the hollow portion 31a through the openings 31c, is transported by the first rotor 10 and the second rotor 20, and is discharged to the outside of the case 31A.

[0052] According to this embodiment, when the housing 30A is viewed from above in the vertical direction, the first screw teeth 12 and the second screw teeth 22 are exposed through the opening 31c, so that a highly viscous fluid to be treated, such as mayonnaise, can be transported.

[0053] <Third embodiment> In the first embodiment of the present invention, a housing 30 having a case 31 and a hopper tank 32 is used, but the hopper tank 32 is not essential. A vertical screw pump 3 according to a third embodiment will be described below. Note that the same parts as those in the first embodiment are given the same reference numerals and description thereof will be omitted.

[0054] 7A and 7B are schematic diagrams showing an example of a vertical screw pump 3, in which (A) is a front view, (B) is a left side view, and (C) is a plan view (showing only the main parts) of the vertical screw pump 3. Note that in Fig. 7, a part is shown in cross section to show the main parts provided inside.

[0055] The vertical screw pump 3 mainly includes a first rotor 10, a second rotor 20, a case 31, an actuator 40, an oil tank 50, and a pump 60. That is, the vertical screw pump 3 differs from the vertical screw pump 1 in that it does not have a hopper tank 32.

[0056] Since the first screw teeth 12 and the second screw teeth 22 protrude vertically upward from the opening 31c, the vertical screw pump 3 can transport the treated fluid by transporting the treated fluid so that it rests on the first screw teeth 12 and the second screw teeth 22 using hoses, piping, etc. (not shown).

[0057] In particular, in the case of a fluid to be treated, such as bean paste, which has a very high viscosity and low fluidity, even if the fluid to be treated is placed on the first screw tooth 12 and the second screw tooth 22, the fluid will not flow out of the case 31, but will flow into the hollow portion 31a as the first screw tooth 12 and the second screw tooth 22 rotate, and can be discharged out of the case 31 through the discharge pipe 31d.

[0058] <Fourth embodiment> In the first embodiment of the present invention, the protrusion amount p of the first screw teeth 12 and the second screw teeth 22 from the upper end surface 31b is 1 / 3 of the diameter of the first screw teeth 12 and the second screw teeth 22, but the protrusion amount p is not limited to this. A vertical screw pump 4 according to a fourth embodiment will be described below. Note that the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0059] FIG. 8 is a schematic diagram showing an example of a vertical screw pump 4, where (A) is a front view, (B) is a left side view, and (C) is a plan view (showing only the essential parts). FIG. 9 is a left side view showing an outline of the vertical screw pump 4. Note that in FIGS. 8 and 9, a portion is shown in cross section to show the essential parts provided inside. Also, in FIGS. 8 and 9, for the sake of explanation, the hopper tank 32 is shown by a dotted line.

[0060] The vertical screw pump 4 mainly includes a first rotor 10A, a second rotor 20A, a housing 30, an actuator 40, an oil tank 50, and a pump 60.

[0061] The first rotor 10A has a first shaft 11A provided along the vertical direction and first helical screw teeth 12A (corresponding to the first conveying section of the present invention) provided along the first shaft 11A. The second rotor 20A has a second shaft 21A provided along the vertical direction and second helical screw teeth 22A (corresponding to the second conveying section of the present invention) provided along the second shaft 21A.

[0062] The first shaft 11A and the second shaft 21A are similar to the first shaft 11 and the second shaft 21 except for their lengths. The first shaft 11A and the second shaft 21A are rotatably supported by bearings 33 and 34, respectively. The lower end of the first shaft 11A protrudes downward from the opening 31e and is connected to a gear 73. The gear 73, i.e., the first shaft 11A, is rotationally driven by the actuator 40 via gears 71 and 72.

[0063] The first shaft 11A and the second shaft 21A are provided with gears 13 and 23, respectively. The gears 13 and 23 are engaged with each other, and the second shaft 21A is rotated when the first shaft 11A is rotated by the actuator 40. The first shaft 11A and the second shaft 21A rotate in opposite directions.

[0064] The first screw tooth 12A and the second screw tooth 22A are similar to the first screw tooth 12 and the second screw tooth 22, except for the number of pitches (number of turns) which differ from the first screw tooth 12 and the second screw tooth 22. The first screw tooth 12 and the second screw tooth 22 have two pitches, whereas the first screw tooth 12A and the second screw tooth 22A have four pitches.

[0065] The first screw teeth 12A and the second screw teeth 22A are provided on the outer peripheral surfaces of the first shaft 11A and the second shaft 21A, respectively, along the longitudinal direction of the first shaft 11A and the second shaft 21A, i.e., the vertical direction. Since the first screw teeth 12A and the second screw teeth 22A are provided with four pitches, the first shaft 11A and the second shaft 21A are long.

[0066] The first screw teeth 12A and the second screw teeth 22A have substantially the same shape except that they are twisted in opposite directions. The first screw teeth 12A and the second screw teeth 22A mesh with each other so that one tooth is located between the other teeth (in the groove).

[0067] In this embodiment, the first screw teeth 12A and the second screw teeth 22A are provided within the hollow portion 31a by two pitches, and protrude vertically upward from the upper end surface 31b by two pitches (protrusion amount p is two pitches). In other words, a portion of the first rotor 10A and the second rotor 20A is provided within the hollow portion 31a, and a portion near the tip of the first rotor 10A and the second rotor 20A is provided vertically above the upper end surface 31b.

[0068] By increasing the protrusion amount p (two pitches), the highly viscous and poorly fluid treated fluid introduced into the hopper tank 32 is more likely to be caught in the first screw teeth 12A and the second screw teeth 22A.

[0069] According to this embodiment, the first screw teeth 12A and the second screw teeth 22A protrude vertically upward beyond the two-pitch upper end surface 31b and are disposed inside the hopper tank 32, so that the highly viscous and low-fluidity fluid to be treated (such as bean paste or a paste-like food) introduced into the hopper tank 32 comes into contact with two pitches of the first screw teeth 12A and the second screw teeth 22A. Therefore, the first screw teeth 12A and the second screw teeth 22A can send the fluid to be treated from the opening 31c into the hollow portion 31a.

[0070] In this embodiment, the protrusion amount p is two pitches, but the protrusion amount p is not limited to two pitches. For example, the protrusion amount p may be one pitch. However, in order to efficiently transport the treated fluid, it is desirable that the protrusion amount p be two pitches or more.

[0071] <Fifth embodiment> In the fourth embodiment of the present invention, the first rotor 10A and the second rotor 20A have the first screw teeth 12A and the second screw teeth 22A, respectively, but the rotor configuration is not limited to this. A vertical screw pump 5 according to a fifth embodiment will be described below. Note that the same parts as those in the first and fourth embodiments are designated by the same reference numerals, and description thereof will be omitted.

[0072] FIG. 10 is a schematic diagram showing an example of a vertical screw pump 5, where (A) is a front view, (B) is a left side view, and (C) is a plan view (showing only the main parts). FIG. 11 is a left side view showing an outline of the vertical screw pump 5. Note that in FIGS. 10 and 11, a portion is shown in cross section to show the main parts provided inside.

[0073] The vertical screw pump 5 mainly includes a first rotor 10B, a second rotor 20B, a housing 30, an actuator 40, an oil tank 50, and a pump 60.

[0074] The first rotor 10B has a first shaft 11A arranged along the vertical direction and a first spiral screw blade 12B (corresponding to the first conveying section of the present invention) arranged along the first shaft 11A. The second rotor 20B has a second shaft 21A arranged along the vertical direction and a second spiral screw blade 22B (corresponding to the second conveying section of the present invention) arranged along the second shaft 21A.

[0075] The first screw blade 12B and the second screw blade 22B are blades made by bending a steel plate into a spiral shape and spirally winding and fixing them to the shafts (first shaft 11A, second shaft 21A). The first screw blade 12B and the second screw blade 22B are provided on the outer peripheral surfaces of the first shaft 11A and the second shaft 21A, respectively, along the longitudinal direction of the first shaft 11A and the second shaft 21A, i.e., the vertical direction.

[0076] The first screw flight 12B and the second screw flight 22B have the same pitch and the same number of pitches (number of turns) as the first screw teeth 12A and the second screw teeth 22A, respectively.

[0077] The first screw flight 12B and the second screw flight 22B have almost the same shape except that they are twisted in opposite directions. One of the first screw flight 12B and the second screw flight 22B is located between the other flight (in the groove).

[0078] The first screw blade 12B and the second screw blade 22B protrude vertically upward from the upper end surface 31b. In other words, a portion of the first rotor 10B and the second rotor 20B is provided inside the hollow portion 31a, and a portion near the tip of the first rotor 10B and the second rotor 20B is provided vertically upward from the upper end surface 31b. In Figures 10 and 11, the first screw blade 12B and the second screw blade 22B protrude two pitches from the upper end surface 31b (the protrusion amount p is two pitches).

[0079] Since the protrusion amount p is large (2 pitches), the highly viscous and poorly fluid treated fluid introduced into the hopper tank 32 is likely to be caught in the first screw blade 12B and the second screw blade 22B.

[0080] According to this embodiment, the first screw blade 12B and the second screw blade 22B protrude vertically upward beyond the two-pitch upper end surface 31b and are disposed inside the hopper tank 32, so that the highly viscous and poorly fluid fluid (such as bean paste or pasty food) introduced into the hopper tank 32 comes into contact with the first screw blade 12B and the second screw blade 22B for two pitches. Therefore, the first screw blade 12B and the second screw blade 22B can send the fluid to be treated from the opening 31c into the hollow portion 31a.

[0081] Furthermore, the first screw blade 12B and the second screw blade 22B are thin and the gap between adjacent first screw blades 12B and second screw blades 22B is wide, so that the highly viscous treated fluid can be efficiently drawn into this gap and a large amount of treated fluid can be transported.

[0082] In this embodiment, the protrusion amount p is 2 pitches, as in the vertical screw pump 4, but the protrusion amount p is not limited to 2 pitches. However, in order to efficiently transport the treated fluid, it is desirable that the protrusion amount p be 2 pitches or more.

[0083] Sixth Embodiment In the fourth embodiment of the present invention, the first rotor 10A and the second rotor 20A have the first screw teeth 12A and the second screw teeth 22A, respectively, but the rotor configuration is not limited to this. A vertical screw pump 6 according to a sixth embodiment will be described below. Note that the same parts as those in the first, fourth, and fifth embodiments are designated by the same reference numerals, and description thereof will be omitted.

[0084] Fig. 12 is a schematic diagram showing an example of a vertical screw pump 6, where (A) is a front view, (B) is a left side view, and (C) is a plan view (showing only the main parts). Fig. 13 is a left side view showing an outline of the vertical screw pump 6. Note that Figs. 12 and 13 show a partial cross section to show the main parts provided inside.

[0085] The vertical screw pump 6 mainly includes a first rotor 10C, a second rotor 20C, a housing 30, an actuator 40, an oil tank 50, and a pump 60.

[0086] The first rotor 10C has a first shaft 11A that is provided along the vertical direction and a first spiral conveying section 12C that is provided along the first shaft 11A. The second rotor 20C has a second shaft 21A that is provided along the vertical direction and a second spiral conveying section 22C that is provided along the second shaft 21A.

[0087] The first conveying section 12C has a first screw tooth 12b and a first screw flight 12c, and the second conveying section 22C has a second screw tooth 22b and a second screw flight 22c.

[0088] The first screw teeth 12b and the second screw teeth 22b are the same as the first screw teeth 12 and the second screw teeth 22, respectively.

[0089] The first screw blade 12c and the second screw blade 22c, like the first screw blade 12B and the second screw blade 22B, are blades made by bending steel plate into a spiral shape and then spirally wrapping and fixing them around the shafts (first shaft 11A, second shaft 21A).

[0090] The first conveying section 12C and the second conveying section 22C have almost the same shape except that they are twisted in opposite directions. The first screw teeth 12b and the second screw teeth 22b are interlocked such that one tooth is located between the other teeth (groove). The first screw blade 12c and the second screw blade 22c are interlocked such that one blade is located between the other blades (groove).

[0091] In the first conveying section 12C, the first screw blade 12c is located vertically above the first screw tooth 12b, and in the second conveying section 22C, the second screw blade 22c is located vertically above the second screw tooth 22b. The first screw tooth 12b and the second screw tooth 22b are provided inside the hollow portion 31a. The first screw blade 12c and the second screw blade 22c protrude vertically upward from the upper end face 31b. In Figures 12 and 13, the first screw blade 12c and the second screw blade 22c protrude two pitches from the upper end face 31b (the protrusion amount p is two pitches).

[0092] According to this embodiment, the first screw blade 12c and the second screw blade 22c, which have small thicknesses, protrude vertically upward from the two-pitch upper end surface 31b and are disposed inside the hopper tank 32, so that a large amount of the treated fluid comes into contact with the first screw blade 12c and the second screw blade 22c. This allows the treated fluid to be sent from the opening 31c into the hollow portion 31a.

[0093] Furthermore, according to this embodiment, the first screw teeth 12b and the second screw teeth 22b are located below the first screw blade 12c and the second screw blade 22c, respectively, and the first screw teeth 12b and the second screw teeth 22b are located inside the cavity 31a, so that the treated fluid transported into the cavity 31a by the first screw blade 12c and the second screw blade 22c can be transported reliably and efficiently toward the discharge pipe 31d. Therefore, the vertical screw pump 6 is suitable for transporting bean paste, which has a high viscosity among treated fluids.

[0094] In this embodiment, the protrusion amount p is 2 pitches, as in the vertical screw pump 4, but the protrusion amount p is not limited to 2 pitches. However, in order to efficiently transport the treated fluid, it is desirable that the protrusion amount p be 2 pitches or more.

[0095] In addition, in the present embodiment, the first screw teeth 12b and the second screw teeth 22b are provided over two pitches, and the first screw flight 12c and the second screw flight 22c are provided over two pitches, but the number of turns of the screw teeth and the screw flight is not limited to this. For example, the first screw teeth 12b and the second screw teeth 22b may be provided over one pitch, and the first screw flight 12c and the second screw flight 22c may be provided over three pitches, and a portion (e.g., one pitch) of the first screw teeth 12b and the second screw teeth 22b and the first screw flight 12c and the second screw flight 22c may be provided inside the hollow portion 31a. In short, it is sufficient that the first screw teeth 12b and the second screw teeth 22b are provided inside the hollow portion 31a, and the first screw flight 12c and the second screw flight 22c provided above the first screw teeth 12b and the second screw teeth 22b, respectively, protrude from the upper end surface 31b by at least two pitches.

[0096] Seventh Embodiment In the first embodiment of the present invention, the oil 0 is sucked up using the pump 60, but the pump configuration is not limited to this. A vertical screw pump 7 according to a fourth embodiment will be described below. Note that the same parts as those in the first embodiment are given the same reference numerals and their description will be omitted.

[0097] Fig. 14 is a schematic diagram showing an example of a vertical screw pump 7, where (A) is a front view, (B) is a left side view, and (C) is a plan view (showing only the main parts). Note that Fig. 14 shows a partial cross section to show the main parts provided inside.

[0098] The vertical screw pump 7 mainly includes a first rotor 10, a second rotor 20, a housing 30, an actuator 40, an oil tank 50, a pipe 65A, and a pump 66. In other words, the vertical screw pump 7 is provided with a pump 66 and a pipe 65A instead of the pump 60 and the pipe 65 of the vertical screw pump 1.

[0099] One end of the pipe 65A is provided in the case 31, and the other end is provided inside the oil tank 50. The end of the pipe 65A provided inside the oil tank 50 is immersed in the oil 0 stored inside the oil tank 50.

[0100] The pump 66 is provided in the pipe 65A. Various types of pumps capable of transporting liquid, such as a positive displacement pump or a piston pump, can be used as the pump 66. The pump 66 sucks up the oil o from the oil tank 50, and the sucked up oil o flows into the case 31 through the pipe 65A and is supplied to the bearings 33, 34 that hold the first rotor 10 and the second rotor 20.

[0101] According to this embodiment, the internal structure of the oil tank 50 can be simplified because it is only necessary to provide the pump 66 to the pipe 65A.

[0102] Furthermore, according to this embodiment, the oil o can be reliably supplied to the bearings 33, 34 by using the pump 66. For example, when the first rotor 10 and the second rotor 20, i.e., the pump 60, are rotating at a low speed, it may be difficult for the pump 60 to suck up the oil o. However, by using the pump 66, the oil o can be supplied to the bearings 33, 34 even when the rotation speeds of the first rotor 10 and the second rotor 20 are low.

[0103] The vertical screw pump 7 of this embodiment is obtained by applying the piping 65A and the pump 66 to the vertical screw pump 1, and providing the pump 66 and the piping 65A instead of the pump 60 and the piping 65 of the vertical screw pump 1, but the piping 65A and the pump 66 can be applied not only to the vertical screw pump 1 but also to the vertical screw pumps 2 to 6. In other words, the pump 66 and the piping 65A can be provided instead of the pump 60 and the piping 65 of the vertical screw pumps 2 to 6.

[0104] This embodiment has been described above in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of this invention.

[0105] In particular, although the vertical screw pumps 1 to 7 are twin-shaft screw pumps having first rotors 10, 10A, 10B, 10C and second rotors 20, 20A, 20B, 20C, the vertical screw pumps 1, 2, 3 may be single-shaft screw pumps having only first rotors 10, 10A, 10B, 10C (without second rotors 20, 20A, 20B, 20C).

[0106] Furthermore, in the vertical screw pumps 1, 2, and 4 to 7, the hopper tank 32 is provided with a shape in which the inlet 32a is wider than the outlet 32b and the diameter gradually narrows toward the outlet 32b at the lower end, but the shape of the hopper tank 32 is not limited to this. For example, the hopper tank may be cylindrical and not narrow at the lower end. Also, instead of a hopper tank, for example, a pipe provided in a device that supplies the fluid to be treated may be arranged above the case 31, and the fluid to be treated may be supplied directly from this pipe to the first screw teeth 12A and the second screw teeth 22A, the first screw blades 12B and 12c, and the second screw blades 22B and 22c.

[0107] Furthermore, "substantially" is a concept that includes not only cases where something is strictly identical, but also errors or deformations that do not cause loss of identity. For example, "substantially orthogonal" is not limited to cases where something is strictly orthogonal, but also includes cases where something can be regarded as being the same as orthogonal. Furthermore, for example, when simply expressing something as orthogonal, parallel, coincident, etc., it includes not only cases where something is strictly orthogonal, parallel, coincident, etc., but also cases where something is approximately parallel, approximately orthogonal, approximately coincident, etc.

[0108] Furthermore, "vicinity" means including a certain range (which can be arbitrarily determined) near a reference position. For example, "near an edge" is a concept that indicates a certain range near the edge, which may or may not include the edge. [Explanation of symbols]

[0109] 1, 2, 3, 4, 5, 6, 7: Vertical screw pump 10, 10A, 10B, 10C: First rotor 11, 11A: 1st axis 12, 12A, 12b: First screw tooth 12a: Tip 12B, 12c: First screw blade 12C: First conveyor section 13: Gear 20, 20A, 20B, 20C: Second rotor 21, 21A: 2nd axis 22, 22A, 22b: Second screw teeth 22a: Tip 22B, 22c: Second screw blade 22C: Second conveying section 23: Gear 30, 30A: Housing 31, 31A: Case 31a: Cavity part 31b: Upper end surface 31c: opening 31d: Discharge pipe 31e:Aperture 31f: Space 32, 32A: Hopper tank 32a: Inlet 32b: Outlet 33, 34: Bearings 40: Actuator 41: Drive shaft 50: Oil tank 60, 66: Pump 61: Pump body 61a: Cavity 61b, 61c, 61d: Hole 62: Rotation axis 63: Feather 64:Inflow pipe 65, 65A: Piping 71, 72, 73: Gear

Claims

1. a first rotor and a second rotor provided along a vertical direction; a case having a cavity in which at least a portion of the first rotor and the second rotor are provided; Equipped with the first rotor and the second rotor are provided adjacent to each other, The cavity forms an opening in the upper end surface of the case, When the case is viewed from above in the vertical direction, the first rotor and the second rotor are exposed through the opening. A vertical screw pump characterized by:

2. The first rotor and the second rotor have portions that protrude vertically upward beyond the upper end surfaces.

2. The vertical screw pump according to claim 1.

3. the first rotor has a first shaft provided along a vertical direction, and a first conveying portion including at least one of helical screw teeth and screw blades provided along the first shaft, the second rotor has a second shaft provided along a vertical direction, and a second conveying portion including at least one of helical screw teeth and screw blades provided along the second shaft, a convex portion of the first conveying portion is inserted between two adjacent convex portions of the second conveying portion, and a convex portion of the second conveying portion is inserted between two adjacent convex portions of the first conveying portion, The first and second conveying portions protrude from the upper end surface by at least two pitches.

3. The vertical screw pump according to claim 2.

4. the first rotor has a first shaft provided along a vertical direction, and a first conveying portion having first spiral screw teeth and first screw blades provided along the first shaft, the second rotor has a second shaft provided along a vertical direction, and a second conveying portion having second spiral screw teeth and second screw blades provided along the second shaft, a convex portion of the first conveying portion is inserted between two adjacent convex portions of the second conveying portion, and a convex portion of the second conveying portion is inserted between two adjacent convex portions of the first conveying portion, the first screw teeth and the second screw teeth are provided inside the hollow portion, the first screw flight and the second screw flight are located vertically above the first screw tooth and the second screw tooth, respectively; The first screw flight and the second screw flight protrude from the upper end surface by at least two pitches.

3. The vertical screw pump according to claim 2.

5. an oil tank on which the case is placed and in which oil is sealed; a pump that draws the oil from the oil tank and supplies it to bearings that hold the first rotor and the second rotor; an actuator provided in the oil tank and configured to drive the first rotor, the second rotor, and the pump; 5. The vertical screw pump according to claim 1, further comprising:

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