JP4072477B2 - Twin screw pump - Google Patents

Description

  The present invention relates to a twin screw pump that transfers an object to be transferred without applying a shearing force.

Conventional illustrates this kind of twin-screw pump 6 and 7. The biaxial screw pump 51 shown in each figure includes a pump casing 52 that houses the pump chamber 6, and a bearing portion 5 that is connected to the pump casing 52. The pump casing 52 includes a cylindrical main body casing 3 having a pump chamber 6 and a base 53 connected to the main body casing 3. A pair of pump screws 7 a and 7 b are accommodated in the pump chamber 6. The pump screws 7a and 7b are fitted from the free ends of the shaft portions 8a and 8b, and are fixed by a mounting plate 54 and bolts 55. The above-mentioned free end refers to the tip portion that is not supported by a bearing or the like. A discharge port 19 is provided in the main body casing 3 at a position facing the discharge side space 21 between the pump chamber 6 and the bearing portion 5. One ends of the shaft portions 8a and 8b of the pump screws 7a and 7b are rotatably supported by bearings (not shown) in the bearing portion 5 and are synchronously rotated in opposite directions by synchronous gears 13a and 13b meshing with each other. Thereby, a pair of pump screws 7a and 7b mesh with each other in a non-contact manner and rotate.

In the above-described biaxial screw pump 51, the pump screw 7 a and the pump screw 7 b are synchronously rotated by the rotational drive of the motor M, and the transferred object is transferred from the inlet 56 of the base 53 to the free ends 26 of the pump screws 7 a and 7 b. 26 is taken in. The transferred object thus taken in is pumped through the pump chamber 6 by the pump action of the pump screws 7a and 7b, and is discharged from the discharge port 19 through the discharge side space 21.
A twin screw pump similar to this structure is disclosed in, for example, Patent Document 1 below. However, in the biaxial screw pump described in Patent Document 1, the discharge port 19 of the biaxial screw pump 51 is an inlet, and the intake port 56 of the biaxial screw pump 51 is an outlet.

Moreover, the surface shape of the meshing surface in pump screw 7a, 7b is formed in the gentle S character curve seeing from the front. Thereby, a fixed fine gap is generated between the meshing surfaces of the pump screws 7a and 7b at any rotation angle, and the pump screws 7a and 7b are not in contact with each other. Such a biaxial screw pump is suitable for transferring an object having a high viscosity so as not to leak from the fine gap between the pump screws 7a and 7b. It is known that it is suitable for transporting foods that are more susceptible to alteration. The non-contact structure of the pump screw described above is disclosed, for example, in Patent Document 2 below.
JP 62-276285 A JP 7-509295 A

  By the way, it is so viscous that it does not sag when it is held by hand, such as oil cake, freshly cooked rice cake, udon dough, bread dough, low-moisture okara, foodstuffs such as grain bean, or industrial materials such as grease. Even if the object to be transferred is close to solid, once it is taken into the pump chamber 6, it can be pumped by the pumping action of the pump screws 7a and 7b. However, since the intake port 56 has a relatively small diameter, it is difficult to suck the physically high-viscosity transfer object. Even if it passes through the intake port 56, the transferred object has almost no fluidity, so it is difficult to take it into the pump chamber 6, and the above-described biaxial screw pump 51 is not suitable for transferring a highly viscous material.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a twin-screw pump that can transfer a high-viscosity object without any problem.

In order to achieve the above object, a twin screw pump according to the present invention includes a main body casing containing a pump chamber containing a pair of pump screws rotating in a non-contact manner, and connected to the main body casing. A bearing portion for supporting one end of each of the pair of pump screws, and by rotationally driving the pair of pump screws, the object to be transferred is taken into the pump chamber from the free end of the pump screw of the main body casing, and the pump chamber and the bearing in the main body casing In a biaxial screw pump that discharges an object to be transferred from a discharge port provided at a position between parts, a screw connecting part that connects a conveyor screw coaxially with each pump screw at a free end of a pair of pump screws, a pair of conveyors Provided at one end of each screw and connected to a pair of pump screws An opening formed in an intake side casing having an intake port at an upper position of the pair of conveyor screws that can accommodate a pair of conveyor screws, and the intake side casing is formed on the free end side of the pump screw of the main body casing And a pair of pump screws and a pair of conveyor screws are connected via the screw connecting portion, and the main body casing and the intake-side casing are connected via the casing connecting portion. The material to be transferred is configured to be guided to the pump screw by the rotational drive of the pair of conveyor screws, and the pair of pump screws are arranged in parallel in the horizontal direction, and both of them wrap around from above and mesh with each other. It is configured to rotate in different directions, and the pump between the pump chamber and the bearing The mounting of the stirring blade shank clew, the discharge port but on the upper surface of the main body casing.

  According to the biaxial screw pump according to the present invention, since the intake is provided above the conveyor screw, the transferred object supplied from the intake always falls on the conveyor screw. Thereby, a to-be-transferred object can be reliably supplied to a conveyor screw. Even if the transported material supplied in this way has a high viscosity, it is guided to the free end side of the pump screw by the conveyor screw, taken into the pump chamber, and then pumped by the pump action of the pump screw. Therefore, even a high-viscosity transfer object can be transferred smoothly without hindrance.

  Further, even if the object to be transferred is pressed in the space between the pump chamber and the bearing portion by the pump action of the pump screw, the object to be transferred in the space is always moved by the rotation of the stirring blade. Therefore, the object to be transferred is not clogged hard in the space, and the object to be transferred can be smoothly discharged from the discharge port.

The best mode for carrying out the present invention will be described with reference to the drawings. The embodiment described below is merely an example embodying the present invention, and does not limit the technical scope of the present invention. FIG. 1 is a side view showing a biaxial screw pump according to an embodiment of the present invention, and is a cross-sectional view taken along line BB in FIG. 2, and FIG. 2 is a plan sectional view of the biaxial screw pump. 3 is a cross-sectional view taken along line AA in FIG. However, the same components as those of the conventional biaxial screw pump 51 shown in FIGS. 6 and 7 are denoted by the same reference numerals and detailed description thereof may be omitted.
In each of the drawings, a biaxial screw pump 1 according to this embodiment includes a pump casing 2 containing a pump chamber 6 having a bowl shape in front view, and a bearing portion 5 connected to the pump casing 2. The pump casing 2 includes a front and rear cylindrical main body casing 3 having the pump chamber 6 and an intake side casing 4 connected to the main body casing 3. A pair of pump screws 7 a and 7 b are accommodated in the pump chamber 6. The flanges 14 and 14 are fixed to the free ends 26 and 26 of the shaft portions 8a and 8b of the pump screws 7a and 7b, for example, with bolts 55 (FIGS. 6 and 7 ). The spiral direction of the pump screw 7a and the spiral direction of the pump screw 7b are opposite to each other. A space between the pump chamber 6 and the bearing portion 5 in the main body casing 3 is a discharge side space 21. A discharge port 19 for discharging the object to be transferred is provided on the upper surface of the main casing 3 at a position facing the discharge side space 21. In addition, a flange 32 provided on the opening edge near the main body casing of the intake side casing 4 is provided by a bolt 33 on the flange 31 provided on the periphery of the opening 30 formed on the free end side of the pump screw of the main body casing 3. Fixed. That is, the flange 32 and the bolt 33 constitute a casing connecting portion 34 that connects the intake-side casing 4 to the main body casing 3.

  The bearing portion 5 is formed in a box from a housing 9 and a cover plate 10, and a cylinder end surface of the main body casing 3 is connected to an end surface of the cover plate 10. Conical roller bearings 11 and 11 and roller bearings 12 and 12 are arranged in the housing 9. These roller bearings 11 and 12 rotatably support one end of the shaft portion 8a of the pump screw 7a. One end of the shaft portion 8b of the pump screw 7b is also rotatably supported by other roller bearings 11 and 12. A synchronous gear 13a is fixed to the shaft portion 8a of the pump screw 7a, and a synchronous gear 13b that meshes with the synchronous gear 13a is fixed to the shaft portion 8b of the pump screw 7b. By the synchronous meshing of the synchronous gear 13a and the synchronous gear 13b, the pair of pump screws 7a and 7b mesh with each other in a non-contact manner and rotate. In this case, the shaft portion 8a of the pump screw 7a is connected to the motor M as a drive shaft.

On the other hand, a conveyor screw 17a having the same spiral direction as the pump screw 7a and a conveyor screw 17b having the same spiral direction as the pump screw 7b are disposed in the supply-side space 20 secured in the intake-side casing 4. The spiral pitch of the conveyor screws 17a and 17b is not particularly limited. In this example, the spiral pitch of the pump screws 7a and 7b is the same. The flanges 15 and 15 are fixed to one end of the shaft portions 24a and 24b of the conveyor screws 17a and 17b by welding or the like. The flanges 15 and 15 are connected to the flanges 14 and 14 of the pump screws 7a and 7b by bolts 16 and 16, respectively. As a result, the shaft portion 8a of the pump screw 7a and the shaft portion 24a of the conveyor screw 17a are connected by the coaxial core Xa, and the shaft portion 8b of the pump screw 7b and the shaft portion 24b of the conveyor screw 17b are connected by the coaxial core Xb. The That is, the screw connection portion 35 is configured by the flange 15 and the bolt 16. The conveyor screws 17a and 17b and the intake casing 4 inner wall are relatively distant from each other, but this requires the ability to pump the objects to be transferred such as the pump screws 7a and 7b and the pump chamber 6. This is because it only needs to have a function of guiding the transferred object toward the pump screws 7a and 7b. The upper position of the conveyor screws 17a and 17b in the intake-side casing 4 is an intake port 18 for supplying an object to be transferred.

  In the discharge-side space 21 between the pump chamber 6 and the bearing portion 5, a stirring blade 22a having a screw shape in the same spiral direction as that of the pump screw 7a is attached to the shaft portion 8a of the pump screw 7a with a bolt 25. A stirring blade 22b having a screw shape in the same spiral direction as that of the pump screw 7b is attached to the shaft portion 8b of the pump screw 7b with a bolt 25. These stirring blades 22a and 22b only need to have the ability to move the transferred object that is compressed in the discharge-side space 21 by the pump screws 7a and 7b.

  In the biaxial screw pump 1 having the above-described configuration, when the pump screw 7a, the conveyor screw 17a, and the stirring blade 22a rotate in one direction (the direction of the arrow Ra in FIG. 3) by the rotational drive of the motor M, the synchronous gear 13a, The pump screw 7b, the conveyor screw 17b, and the stirring blade 22b, which are transmitted with power through 13b, rotate in the reverse direction (in the direction of arrow Rb in FIG. 3). Therefore, when the transferred object is supplied from the intake 18 into the supply side space 20, the conveyor screws 17a and 17b guide the transferred object to the pump screws 7a and 7b (in the direction of arrow F in FIG. 1).

  In this case, since the intake 18 is disposed above the conveyor screws 17a and 17b, the transferred object supplied from the intake 18 always falls on the conveyor screws 17a and 17b. It is surely guided to the pump screws 7a and 7b in contact with the conveyor screws 17a and 17b. Incidentally, when an intake port is provided on the back surface or side surface of the intake side casing 4, another mechanism for supplying an object to be transferred to the conveyor screws 17a and 17b is required. Moreover, the intake 18 can also be taken large by lengthening the conveyor screws 17a and 17b, and can take in a to-be-transferred object easily. In addition, when the supply amount of the transported object to the supply side space 20 is excessive, the conveyor screws 17a and 17b cannot send the transported object, but only run idle in the transported object and there is no problem.

  When the object to be transferred is guided to the free ends 26 and 26 of the pump screws 7a and 7b in this way, even if the object to be transferred is a high-viscosity material as described in the background art, the pump screws 7a and 7b It is easily taken in and pumped into the pump chamber 6 by the pump action. Thus, the transferred object that has reached the discharge side space 21 is pressed against the inner wall of the discharge side space 21 by the pump pressure, but is always moved by the rotation of the stirring blades 22a and 22b. Therefore, the transferred object is not tightly clogged and stays in the discharge side space 21, and the transferred object sent into the discharge side space 21 is sent to the discharge port 19 relatively smoothly and in a short time. It is done.

  In the above embodiment, the stirring blades 22a and 22b having the same screw shape in the spiral direction as the pump screws 7a and 7b are attached to the shaft portions 8a and 8b of the pump screws 7a and 7b. For example, the stirring blade 22b having a screw shape in the reverse spiral direction with the pump screw 7a is attached to the shaft portion 8a of the pump screw 7a, and the stirring blade having a screw shape in the reverse spiral direction with the pump screw 7b. You may attach 22a to the axial part 8b of the pump screw 7b. In the case of such a configuration, the transferred object is moved against the compression force in the direction of arrow F received by the transferred object from the pump screws 7a and 7b, so that the transferred object in the discharge-side space 21 is more efficiently used. It can be directed to the discharge port 19.

  Further, as the shape of the stirring blade, as in the biaxial screw pump 1A shown in FIGS. 4 and 5, flat stirring blades 23a and 23a protruding outward in the radial direction are bolted to the shaft portion of the pump screw 7a. The plate-like stirring blades 23b and 23b which are attached to 8a and protrude outwardly in the radial direction may be attached to the shaft portion 8b of the pump screw 7b with bolts or the like. The stirring blades 23a and 23a and the stirring blades 23b and 23b are attached with a phase difference of 90 degrees in the axial circumferential direction so as not to interfere with each other. Even with such flat stirring blades 23a and 23b, the object to be transferred in the discharge side space 21 can be moved toward the discharge port 19 smoothly.

It is a side view which shows the biaxial screw pump which concerns on one Embodiment of this invention, and is BB arrow sectional drawing in FIG. It is a plane sectional view of the 2 axis screw pump. It is an AA arrow directional cross-sectional view in FIG. It is a side view which shows the biaxial screw pump which concerns on another embodiment of this invention, and is a figure containing the CC arrow directional cross section in FIG. It is a figure which shows a part of flat cross section of another said biaxial screw pump. It is a side view including the partial cross section of the conventional biaxial screw pump. It is a top view including the partial cross section of the conventional biaxial screw pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1 A 2 axis screw pump 2 Pump casing 3 Main body casing 4 Intake side casing 5 Bearing part 6 Pump chamber 7a, 7b Pump screw 8a, 8b Shaft part
15 Flange
16 Bolts 17a, 17b Conveyor screw 18 Inlet 19 Discharge port 21 Discharge side space 22a, 22b, 23a, 23b Stirring blade 26 Free end
30 opening
32 Flange
33 volts
34 Flange joint
35 Screw connection part Xa Axis center Xb Axis center

Claims (1)

A main body casing that houses a pump chamber that houses a pair of pump screws that rotate in mesh with each other, and a bearing that is connected to the main body casing and supports one end of the pair of pump screws. Two shafts that take the transferred object into the pump chamber from the free end of the pump screw of the main body casing and discharge the transferred object from the discharge port provided at the position between the pump chamber and the bearing portion in the main body casing by rotating the pump screw. In the screw pump, a screw connection portion for connecting the conveyor screw coaxially with each pump screw is provided at each free end of the pair of pump screws, and a pair of pump screws connected to the pair of pump screws. A pair of conveyors that can accommodate conveyor screws A casing connecting portion for connecting the intake side casing to an opening formed on the free end side of the pump screw of the main body casing is provided in an intake side casing having an intake port at a position above the Liu, and a pair of pump screws and A pair of conveyor screws are connected via a screw connecting portion, and a main body casing and an intake-side casing are connected via a casing connecting portion, and an object to be transferred supplied from the intake port is rotated by the pair of conveyor screws. The pump is configured to be guided to the pump screw by driving , and the pair of pump screws are arranged in parallel in the horizontal direction, and both are configured to be driven to rotate in different directions that wrap around from above and mesh with each other. Agitating blades are attached to the shaft of the pump screw between the bearings, and the discharge port is connected to the body casing. 2 screw pump, characterized in that provided on the surface.