JP2023059353A - screw conveyor - Google Patents

Abstract

To improve maintainability with a simple configuration and to suppress pollution and leakage of lubricating oil with respect to a screw conveyor.SOLUTION: The disclosed screw conveyor 10 has a carrier casing 3, an intermediate suspension bearing 9 and a drive unit 27, and the intermediate suspension bearing 9 has a bracket 13 with a support 11 and a first recess 14 on the outer surface and a sliding part 17. The screw conveyor 10 has a first airtight cover 19 with a first protrusion 20, a first outer cover 7, and a first locking tool 23. The first protrusion 20 fits into the first recess 14, and the first outer cover 7 is fixed to a first joint 5. The first airtight cover 19 and the first outer cover 7 have shapes that can be divided in the circumferential direction of the intermediate shaft 4 and are assembled so that the division positions are different.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a screw conveyor for conveying liquid or solid materials such as garbage, sludge, foods (sugar, salt, etc.), chemicals, and sand.

2. Description of the Related Art Conventionally, there is known a screw conveyor that rotates a screw pipe arranged inside a casing to convey an object in the casing in one direction. The screw pipe may flex due to its own weight, the load of the conveyed object, the conveying resistance of the conveyed object, etc. The longer the screw pipe, the greater the flexure. Therefore, a structure has been proposed in which the screw pipe is divided in the axial direction, connected by an intermediate shaft, and the intermediate shaft is supported on the inner surface of the casing via an intermediate suspension bearing. With such a structure, the distance between fulcrums and the protrusion dimension of the screw pipe can be shortened, and the occurrence of deflection can be suppressed (see Patent Document 1).

Registered Utility Model No. 3210869

In the screw conveyor described in Patent Document 1, an airtight ring is interposed between a cover body with screw blades and a bearing portion. The airtight ring is attached to the outer peripheral surface of the cylindrical bracket piece so as to apply an elastic force to press the inner peripheral surface of the cover body radially outward. Since it takes time and effort to attach the airtight ring, there is room for improvement in maintainability. In addition, since the cover body is divided in the circumferential direction along the axis, lubricating oil (grease) of the airtight ring may leak from the divided surfaces. Alternatively, there is a possibility that part of the conveyed material may enter from the dividing surface and contaminate the lubricating oil of the airtight ring.

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned problems, and an object of the present invention is to provide a screw conveyor that has a simple structure, improves maintainability, and suppresses contamination and leakage of lubricating oil. and

In the disclosed screw conveyor, a first screw pipe and a second screw pipe arranged inside a conveying casing are arranged at one end of an intermediate shaft, and a first joint portion corresponding to the first screw pipe and the intermediate shaft is arranged at the other end of the second screw pipe and connected to the intermediate shaft via a second joint portion corresponding to the second screw pipe on the same axis, and an intermediate suspension bearing is fixed to the inner surface of the conveying casing and the intermediate A shaft is rotatably supported around the axis, and a driving device rotates the first and second screw pipes and the intermediate shaft around the axis, so that the conveyed object moves inside the conveying casing in one direction. It is a screw conveyor that is conveyed to

The intermediate suspension bearing has a support portion fixed to the inner surface of the transport casing at one end, and a central portion fixed to the other end of the support portion, and rotates the intermediate shaft on the side of the first joint portion from the central portion. A bracket having a plurality of circular first concave portions formed along the direction on its outer surface, and a sliding portion fixed to the bracket and slidably and rotatably sandwiching the intermediate shaft.

Further, a plurality of circular first protrusions formed in the rotational direction on the inner surface of the cylindrical shape extending from the first joint portion to the support portion are provided, and the intermediate shaft is provided with a plurality of circular first convex portions that are dividable in the circumferential direction of the intermediate shaft. an airtight cover, and a cylindrical first outer cover that is longer than the first airtight cover and that is in contact with the first airtight cover and the first joint portion on the inner surface, and that can be divided in the circumferential direction. have.

Further, it has a first locking tool for locking the first airtight cover and the first outer cover so that the division position of the first airtight cover and the division position of the first outer cover are different.
The first projection fits into the first recess, and the first outer cover is fixed to the first joint.

According to the disclosed screw conveyor, maintainability can be improved with a simple configuration, and contamination and leakage of lubricating oil can be suppressed.

1 is an exploded perspective view showing an exploded configuration of a screw conveyor according to an embodiment; FIG. FIG. 2 is a cross-sectional view of the screw conveyor of FIG. 1; FIG. 2 is an exploded perspective view showing an exploded configuration of a main part of the screw conveyor of FIG. 1; (A) is a cross-sectional view taken along A in FIG. 2, (B) is a cross-sectional view taken along B in FIG. 2, and (C) is a cross-sectional view taken along C in FIG. FIG. 4 is a cross-sectional view for explaining the flow of lubricating oil; It is sectional drawing of the screw conveyor which concerns on a 1st modification. It is sectional drawing of the screw conveyor which concerns on a 2nd modification.

Hereinafter, screw conveyors according to embodiments and modifications will be described with reference to FIGS. 1 to 7. FIG. It should be noted that, in these drawings, illustration of elements (for example, fastening members, fastening holes, etc.) other than main elements that characterize the embodiments and modifications may be omitted as appropriate. It should also be noted that the technical content of the "invention for which a patent is sought" is not limited by the dimensions, angles, curvatures, shapes, etc. in the drawings. These diagrams are merely explanatory diagrams for supplementing the specification and allowing those skilled in the art to understand the technical content of the "invention for which a patent is sought." Therefore, unlike design drawings, for example, these drawings are not necessarily accurate in terms of dimensions, angles, curvatures, shapes, etc., and may be deformed, distorted, omitted, or simplified in some cases. In addition, the embodiments and modifications shown below are merely examples, and are not intended to exclude various modifications and application of techniques that are not explicitly stated. Each configuration described below can be modified in various ways without departing from the scope of the invention. In addition, each of the following configurations can be selected or discarded as required except for the configurations essential to the present invention, or can be combined with known configurations.

[1. composition]
FIG. 1 is an exploded perspective view showing an exploded configuration of a screw conveyor 10 according to an embodiment, and FIG. 2 is a cross-sectional view of the screw conveyor 10. As shown in FIG. The screw conveyor 10 includes a first screw pipe 1, a second screw pipe 2, and a cylindrical conveying casing 3 (outline shown by broken lines in FIG. 1). Here the transport casing 3 is provided with legs 32 to support itself, but the legs 32 can be omitted depending on the design.
The screw conveyor 10 further includes an intermediate shaft 4 coaxially arranged between the first screw pipe 1 and the second screw pipe 2, and a first joint interposed between the first screw pipe 1 and the intermediate shaft 4. and a second joint portion 6 interposed between the second screw pipe 2 and the intermediate shaft 4 .

The first screw pipe 1 and the second screw pipe 2 are shaft-like members having screw blades formed in a spiral shape. The first screw pipe 1 and the second screw pipe 2 are housed in a conveying casing 3 and arranged linearly via an intermediate shaft 4 . Each of the first screw pipe 1 and the second screw pipe 2 is provided with a hollow cylindrical pipe body and screw blades projecting outward from the outer peripheral surface thereof. The intermediate shaft 4 is a shaft-like member for connecting the first screw pipe 1 and the second screw pipe 2 in the axial direction. The intermediate shaft 4 is formed in a cylindrical shape having an outer diameter smaller than the inner diameters of the pipe bodies of the first screw pipe 1 and the second screw pipe 2 . The axis C (central axis) of the first screw pipe 1, the second screw pipe 2, and the intermediate shaft 4 is located on the same straight line.

The first joint portion 5 and the second joint portion 6 are cylindrical joint members that connect the first screw pipe 1 and the second screw pipe 2 to the intermediate shaft 4 . The first joint portion 5 is a joint member corresponding to the first screw pipe 1 and arranged at one end (lower left side in FIG. 1) of the intermediate shaft 4 connected to the first screw pipe 1 . The outer peripheral surface of the first joint portion 5 has a diameter corresponding to the inner peripheral surface of the first screw pipe 1, and the inner peripheral surface of the first joint portion 5 has a diameter corresponding to the outer peripheral surface of the intermediate shaft 4. . As shown in FIG. 2 , the first joint portion 5 is fixed to the first screw pipe 1 and one end side of the intermediate shaft 4 with arbitrary fastening members (for example, bolts, nuts, rivets, etc.).

Similarly, the second joint portion 6 is a joint member corresponding to the second screw pipe 2 and is arranged at the other end (upper right side in FIG. 1) of the intermediate shaft 4 connected to the second screw pipe 2 . The outer peripheral surface of the second joint portion 6 has a diameter corresponding to the inner peripheral surface of the second screw pipe 2, and the inner peripheral surface of the second joint portion 6 has a diameter corresponding to the outer peripheral surface of the intermediate shaft 4. . As shown in FIG. 2, the second joint portion 6 is fixed to the second screw pipe 2 and the other end side of the intermediate shaft 4 with an arbitrary fastening member.

The first joint portion 5 and the second joint portion 6 may have a cylindrical overall shape, and may be divided in the circumferential direction of the intermediate shaft 4. It can also be formed into a partially cylindrical surface shape).

The screw conveyor 10 includes an intermediate suspension bearing 9 that rotatably supports the intermediate shaft 4 around the axis C, a driving device 27 that rotates the first screw pipe 1 and the second screw pipe 2, and a lubricating oil supply device 28. Prepare. As shown in FIG. 2, the intermediate suspension bearing 9 is fixed to the inner surface of the conveying casing 3 and functions to suspend the intermediate shaft 4 while supporting the vicinity of the central portion in the extending direction.

The driving device 27 is provided, for example, at the ends of the first screw pipe 1 and the second screw pipe 2, and drives the first screw pipe 1 and the second screw pipe 2 to rotate about the axis C together with the intermediate shaft 4. function. By rotating the first screw pipe 1 and the second screw pipe 2, the conveyed material supplied from the conveyed material supply port 31 formed in the conveying casing 3 and existing inside the conveying casing 3 is pressed by the screw blades. , along the axis C in one direction. Here, since the conveyed material supply port 31 is arranged upstream of the first screw pipe 1, the conveyed material existing inside the conveying casing 3 is directed from the first screw pipe 1 to the second screw pipe 2. be transported.

The lubricating oil supply device 28 is a device that supplies lubricating oil for lubricating the sliding surfaces. Lubricating oil is supplied continuously or intermittently from a lubricating oil supply device 28 . In this embodiment, lubricating oil is supplied via the intermediate suspension bearing 9 . As will be described later, the sliding contact surface referred to here includes the sliding contact surface between the intermediate shaft 4 and the sliding portion 17 and the sliding contact surface between the airtight covers 19 and 21 and the bracket 13 .

FIG. 3 is an exploded perspective view showing an exploded configuration around the intermediate suspension bearing 9 of the screw conveyor 10. As shown in FIG. The intermediate suspension bearing 9 includes a support portion 11 , a bracket 13 and a sliding portion 17 .
The support portion 11 is a tubular member having one end (upper end in FIG. 3) fixed to the inner surface of the transport casing 3 . Inside the support portion 11, a passage 12 is provided for passing lubricating oil supplied to the sliding contact surface. The lubricating oil supplied from the lubricating oil supply device 28 is introduced into the passage 12 through the conveying casing through hole 29 formed to penetrate the wall surface of the conveying casing 3 .

The bracket 13 is a cylindrical member fixed to the other end (lower end in FIG. 3) of the support portion 11 . The fixing position of the bracket 13 with respect to the support portion 11 is set at the central portion in the direction along the axis C. As shown in FIG. The bracket 13 may be formed into a shape divided in the circumferential direction of the intermediate shaft 4 (a partial cylindrical surface shape formed by cutting a cylinder along a plane including the axis C). The bracket 13 shown in FIG. 3 has a shape in which a cylinder is vertically divided into two on a horizontal plane including the axis C (a shape in which the cylinder is divided into two in the circumferential direction). However, the division direction and division number of the bracket 13 are not limited to those shown in FIG.

A first through hole 16 that communicates with the passage 12 and penetrates the bracket 13 in the radial direction of the intermediate shaft 4 is bored at a connecting portion between the support portion 11 and the bracket 13 . The arrangement position of the first through hole 16 is the central portion of the bracket 13 (the central portion in the direction along the axis C). Like the passage 12, the first through hole 16 functions as a flow path through which lubricating oil supplied to the sliding contact surface flows.

The sliding portion 17 is a cylindrical member fixed to the inner surface of the bracket 13 . The sliding portion 17 has a role of slidably sandwiching the intermediate shaft 4 along the axis C and rotatably sandwiching the intermediate shaft 4 around the axis C. As shown in FIG. The sliding portion 17 may be formed into a shape divided in the circumferential direction of the intermediate shaft 4 (a partial cylindrical surface shape formed by cutting a cylinder along a plane including the axis C). sell. The sliding portion 17 shown in FIG. 3 has a shape in which a cylinder is divided into left and right sides on a vertical plane including the axis C (a shape in which the cylinder is divided into two in the circumferential direction). However, the direction of division and the number of divisions of the sliding portion 17 are not limited to those shown in FIG.

A second through hole 18 is formed in the sliding portion 17 so as to extend through the sliding portion 17 in the radial direction of the intermediate shaft 4 . The second through-hole 18 is arranged at a position communicating with the first through-hole 16 and functions as a flow path through which lubricating oil supplied to the sliding contact surface flows. As a result, the lubricating oil supplied from the lubricating oil supply device 28 passes through the conveying casing through-hole 29, the passage 12 of the support portion 11, the first through-hole 16, and the second through-hole 18 in order, and then passes through the intermediate shaft 4. supplied to the exterior.

The outer surface of the bracket 13 is provided with a first recess 14 and a second recess 15 which are annularly recessed around the axis C. As shown in FIG. As shown in FIGS. 2 and 3 , a plurality of first recesses 14 are formed closer to the first joint portion 5 than the central portion of the bracket 13 (the central portion in the direction along the axis C). On the other hand, a plurality of second concave portions 15 are formed on the second joint portion 6 side of the central portion of the bracket 13 . If the shapes of the first recess 14 and the second recess 15 are similar to circular grooves, the extending direction of the grooves corresponds to the rotation direction of the intermediate shaft 4 . In the example shown in FIGS. 2 and 3, the cross-sectional shapes of the first recess 14 and the second recess 15 are substantially rectangular and hollow, and two of each are formed. However, the cross-sectional shape and number of the first concave portion 14 and the second concave portion 15 are not limited to this.

A first airtight cover 19 and a second airtight cover 21 are provided outside the bracket 13, and a first outer cover 7 and a second outer cover 8 are further provided outside thereof. The first airtight cover 19 and the second airtight cover 21 are cylindrical members arranged on the outer circumference of the bracket 13 while being in contact with the bracket 13 . The first outer cover 7 and the second outer cover 8 are cylindrical members that are arranged on the outer periphery of the first airtight cover 19 and the second airtight cover 21 while being in contact therewith. A first airtight cover 19 and a first outer cover 7 are provided on the first joint portion 5 side (lower left side in FIG. 3) with the central portion of the bracket 13 (the central portion in the direction along the axis C) as a reference. A second airtight cover 21 and a second outer cover 8 are provided on the second joint portion 6 side (upper right side in FIG. 3).

Regarding composition, the first airtight cover 19 and the second airtight cover 21 may be made of metal, but may also be made of a material that is inexpensive and easy to process, such as rigid vinyl chloride. Further, in order to manufacture the first airtight cover 19 and the second airtight cover 21 at a lower cost, for example, a rigid vinyl chloride plate and a rectangular bar may be thermoformed and solvent-bonded to each other. The same applies to the first outer cover 7 and the second outer cover 8, and they may be made of metal, or may be made of resin such as a material that is inexpensive and easy to process (for example, rigid vinyl chloride).

As shown in FIGS. 1 and 2, the overall shape of the first airtight cover 19 has a cylinder length corresponding to the distance from the first joint portion 5 to the support portion 11 (the distance in the direction along the axis C). It is cylindrical in shape. The end surface of the first airtight cover 19 (the end surface on the side of the first joint portion 5 in the direction along the axis C) is in contact (surface contact) with the first joint portion 5 without a gap.

The inner surface of the first airtight cover 19 is provided with a plurality of first protrusions 20 formed along the rotation direction of the intermediate shaft 4 . Each first projection 20 is an annular (circular) projection protruding from the inner surface of the first airtight cover 19 and fitted into the first recess 14 . The cross-sectional shape of the first protrusions 20 shown in FIG. 2 is substantially rectangular, and the number of the first protrusions 20 is two. However, the cross-sectional shape and number of the first protrusions 20 are not limited to those shown in FIG. In addition, the first airtight cover 19 is formed in a shape that can be divided in the circumferential direction of the intermediate shaft 4 (a partial cylindrical surface shape formed by cutting a cylinder along a plane including the axis C). The first airtight cover 19 shown in FIG. 3 has a shape in which a cylinder is divided into two by a plane including the axis C (a shape in which the cylinder is divided into two in the circumferential direction). However, the division direction and division number of the first airtight cover 19 are not limited to those shown in FIG.

The second airtight cover 21 has a structure similar to that of the first airtight cover 19, and is formed in a shape symmetrical with the first airtight cover 19 with respect to a plane perpendicular to the axis C, for example. The overall shape of the second airtight cover 21 is a cylinder having a cylinder length corresponding to the distance from the second joint portion 6 to the support portion 11 (the distance in the direction along the axis C). The end surface of the second airtight cover 21 (the end surface on the side of the second joint portion 6 in the direction along the axis C) is in contact (surface contact) with the second joint portion 6 without a gap.

The inner surface of the second airtight cover 21 is provided with a plurality of second protrusions 22 formed along the rotation direction of the intermediate shaft 4 . Each second protrusion 22 is an annular (circular) protrusion protruding from the inner surface of the second airtight cover 21 and fitted into the second recess 15 . The cross-sectional shape of the second protrusions 22 shown in FIG. 2 is substantially rectangular, and the number of the second protrusions 22 is two. Moreover, the second airtight cover 21 is formed in a shape that can be divided in the circumferential direction of the intermediate shaft 4 . The second airtight cover 21 shown in FIG. 3 has a shape in which a cylinder is divided into two by a plane including the axis C (a shape in which the cylinder is divided into two in the circumferential direction). The division position of the second airtight cover 21 may be the same as the division position of the first airtight cover 19, or may be different.

The overall shape of the first outer cover 7 is a cylinder longer than the first airtight cover 19 and formed into a shape that can be divided in the circumferential direction of the intermediate shaft 4 . The first outer cover 7 shown in FIG. 3 has a shape in which a cylinder is divided into two by a plane including the axis C (a shape in which the cylinder is divided into two in the circumferential direction). Also, the inner surface of the first outer cover 7 is in contact with the first joint portion 5 and the first airtight cover 19 . These first outer cover 7, first joint portion 5, and first airtight cover 19 are integrally fixed. A first screw vane 25 smoothly continuous with the screw vane formed on the first screw pipe 1 is arranged on the outer circumference of the first outer cover 7 .

Regarding the fixed state of the first outer cover 7 , the first outer cover 7 is fixed to the first joint portion 5 by an arbitrary fastening member. This fastening member is provided on each of the first outer covers 7 divided into a plurality of pieces. On the other hand, the first outer cover 7 is locked to the first airtight cover 19 by the first locking tool 23 . The first locking tool 23 is provided on at least one of the plurality of divided first outer covers 7 . The first locking member 23 may be any member as long as it can restrain the relative movement (positional displacement) between the first outer cover 7 and the first airtight cover 19, and specific examples thereof include bolts and pins without thread grooves. be able to.

The first locking member 23 locks the first airtight cover 19 and the first outer cover 7 so that the division position of the first airtight cover 19 and the division position of the first outer cover 7 are different. For example, the first locking tool 23 is inserted through a locking hole drilled in the first outer cover 7 from the outside, and the tip thereof is inserted into a locking recess formed in the first airtight cover 19. be done. Alternatively, the tip of the first locking tool 23 may be bitten into the outer surface of the first airtight cover 19 . Here, the dividing surface of the first airtight cover 19 is _P1 , the dividing surface of the first outer cover 7 is _P2 , and these dividing surfaces _P1 and _P2 are illustrated in FIG. 4(A). The dividing planes P ₁ and P ₂ are both planes containing the axis C, and have different surface gradients when viewed in the direction along the axis C. As shown in FIG. Each surface gradient can be arbitrarily set, and preferably each surface gradient is set so that the dividing planes P ₁ and P ₂ are orthogonal. In the example shown in FIG. 4A, the dividing plane _P1 has a downward slope from the upper left to the lower right in the figure, and the dividing plane _P2 has a downward slope from the upper right to the lower left in the figure.

The second outer cover 8 has a structure similar to that of the first outer cover 7, and is formed in a shape symmetrical with the first outer cover 7 with respect to a plane perpendicular to the axis C, for example. The overall shape of the second outer cover 8 is a cylinder longer than the second airtight cover 21 and formed into a shape that can be divided in the circumferential direction of the intermediate shaft 4 . The second outer cover 8 shown in FIG. 3 has a shape in which a cylinder is divided into two by a plane including the axis C (a shape in which the cylinder is divided into two in the circumferential direction). The dividing surface of the second outer cover 8 may be the same as or different from the dividing surface of the first outer cover 7 . Also, the inner surface of the second outer cover 8 is in contact with the second joint portion 6 and the second airtight cover 21 . The second outer cover 8, the second joint portion 6, and the second airtight cover 21 are integrally fixed. A second screw blade 26 is arranged on the outer surface of the second outer cover 8 so as to be smoothly continuous with the screw blade formed on the second screw pipe 2 .

Regarding the fixed state of the second outer cover 8 , the second outer cover 8 is fixed to the second joint portion 6 by an arbitrary fastening member. This fastening member is provided on each of the second outer covers 8 that are divided into a plurality of parts. On the other hand, the second outer cover 8 is locked to the second airtight cover 21 by a second locking tool 24 similar to the first locking tool 23 . The second locking member 24 is provided on at least one of the plurality of divided second outer covers 8 . The second locking member 24 may be any member as long as it can restrain the relative movement (positional deviation) between the second outer cover 8 and the second airtight cover 21, and specific examples thereof include bolts and pins without thread grooves. be able to.

The second locking member 24 locks the second airtight cover 21 and the second outer cover 8 so that the division position of the second airtight cover 21 and the division position of the second outer cover 8 are different. Here, the dividing surface of the second airtight cover 21 is _P3 , the dividing surface of the second outer cover 8 is _P4 , and these dividing surfaces _P3 and _P4 are illustrated in FIG. 4(B). Both the dividing planes P ₃ and P ₄ are planes including the axis C, and have different surface gradients when viewed in the direction along the axis C. As shown in FIG. Each surface gradient can be arbitrarily set, and preferably each surface gradient is set so that the dividing planes P ₃ and P ₄ are orthogonal to each other. In the example shown in FIG. 4B, the dividing plane _P3 has a downward slope from the upper left to the lower right in the figure, and the dividing plane _P4 has a downward slope from the upper right to the lower left in the figure. The surface gradient is not limited to such a configuration.

The sliding portion 17 and the bracket 13 are also preferably assembled so that the division positions are different. Here, the dividing surface of the sliding portion 17 is _P5 , the dividing surface of the bracket 13 is _P6 , and these dividing surfaces _P5 and _P6 are illustrated in FIG. 4(C). The dividing planes P ₅ and P ₆ are both planes containing the axis C, and have different surface gradients when viewed in the direction along the axis C. As shown in FIG. Each surface gradient can be arbitrarily set, and preferably each surface gradient is set so that the dividing planes _P5 and _P6 are orthogonal. In the example shown in FIG. 4(C), the dividing plane _P5 is a vertical plane and the dividing plane _P6 is a horizontal plane, but the respective surface gradients are not limited to such a configuration.

As shown in FIG. 2, inside the first outer cover 7 and the second outer cover 8, there is provided an oil chamber R in which lubricating oil supplied to the sliding contact surfaces is stored. The radially inner wall surface of the oil chamber R is the outer surface of the intermediate shaft 4 , and the radially outer wall surface is the inner surfaces of the first airtight cover 19 and the second airtight cover 21 . Further, the end faces of the first joint portion 5 and the second joint portion 6 form one end face of the oil chamber R in the direction along the axis C that is farther from the intermediate suspension bearing 9 . Of the two end faces of the oil chamber R in the direction along the axis C, one end face closer to the intermediate suspension bearing 9 is closed by end faces of the bracket 13 and the sliding portion 17 .

[2. Mounting procedure]
As shown in FIGS. 1 to 3, the upper bracket 13 of the vertically split bracket 13 is fixed to the support portion 11 in advance. The support portion 11 is fixed to the inner surface of the transport casing 3 . The support portion 11 has a cylindrical shape, and has a conveying casing through-hole 29 formed in the conveying casing 3 at the position of the internal cavity (passage 12 ), through which the lubricating oil is supplied. Further, the intermediate shaft 4 is sandwiched between the half-split sliding portions 17 from both sides of the intermediate shaft 4, and is brought into contact with the upper bracket 13 as it is, and is sandwiched by the other bracket 13 from below. After that, the bracket 13 and the sliding portion 17 are fixed with a fastening member (not shown).

Subsequently, the first joint portion 5 and the second joint portion 6 are installed at the ends of the intermediate shaft 4 and fixed with fastening members. At this time, the first screw pipe 1 , the first joint portion 5 and the intermediate shaft 4 are fixed on one end side of the intermediate shaft 4 . On the other end side of the intermediate shaft 4, the second screw pipe 2, the second joint portion 6 and the intermediate shaft 4 are fixed.

Also, the first convex portion 20 of the first airtight cover 19 is fitted into the first concave portion 14 formed on the outer surface of the bracket 13 , and the bracket 13 is sandwiched between the half-split first airtight cover 19 . Similarly, on the second joint portion 6 side, while fitting the second convex portion 22 of the second airtight cover 21 into the second concave portion 15 formed on the outer surface of the bracket 13, the half split second airtight cover 21 is attached. The bracket 13 is sandwiched.

Further, the half-split first outer cover 7 is appropriately arranged outside the first airtight cover 19 and the first locking member 23 is attached. Also, the half-split second outer cover 8 is appropriately arranged outside the second airtight cover 21 and the second locking member 24 is attached. After that, the first outer cover 7 and the first joint portion 5 are fixed with a fastening member, and the second outer cover 8 and the second joint portion 6 are fixed with a fastening member.

[3. action]
When the driving device 27 rotates the first screw pipe 1 and the second screw pipe 2, the intermediate screw pipe fixed to the first screw pipe 1 and the second screw pipe 2 via the first joint part 5 and the second joint part 6 is rotated. Axis 4 also rotates. At this time, the first outer cover 7 and the second outer cover 8 fixed to the first joint portion 5 and the second joint portion 6 also rotate together and are locked by the first outer cover 7 and the second outer cover 8. The first airtight cover 19 and the second airtight cover 21 also rotate.

The lubricating oil supplied from the lubricating oil supply device 28 is supplied to the outer surface of the intermediate shaft 4 through the conveying casing through-hole 29, the passage 12 of the support portion 11, the first through-hole 16, and the second through-hole 18 in order. be done. As a result, the sliding surfaces of the intermediate shaft 4 and the sliding portion 17 are lubricated (see white arrows in FIG. 5). After that, the lubricating oil is stored in the oil chamber R and supplied to the gap between the airtight covers 19 and 21 (the first airtight cover 19 and the second airtight cover 21 ) and the bracket 13 . As a result, the sliding contact surfaces between the airtight covers 19 and 21 and the bracket 13 are lubricated (see white arrows in FIG. 5). Compared to the seal structure using an airtight ring described in Patent Document 1, the area of the sliding contact surfaces between the airtight covers 19 and 21 and the bracket 13 is large, so the amount of lubricating oil that seeps out is reduced. The lubricating oil that seeps out here is conveyed mixed with the conveyed material.

The first airtight cover 19 is pressed from the outside by the first outer cover 7 fixed to the first joint portion 5 . During rotation, the outer surface of the first airtight cover 19 is pressed against the inner surface of the first outer cover 7 by centrifugal force. Therefore, no lubricating oil path is formed between the outer surface of the first airtight cover 19 and the inner surface of the first outer cover 7 . Similarly, the second airtight cover 21 is pressed from the outside by the second outer cover 8 fixed to the second joint portion 6 . During rotation, the outer surface of the second airtight cover 21 is pressed against the inner surface of the second outer cover 8 by centrifugal force. Therefore, no lubricating oil path is formed between the outer surface of the second airtight cover 21 and the inner surface of the second outer cover 8 .

In addition, the end face of the first airtight cover 19 (the end face on the first joint portion 5 side in the direction along the axis C) is in contact (surface contact) with the first joint portion 5 without a gap. Therefore, no lubricating oil path is formed between the first airtight cover 19 and the first joint portion 5 either.
Similarly, the end surface of the second airtight cover 21 (the end surface on the side of the second joint portion 6 in the direction along the axis C) is in contact (surface contact) with the second joint portion 6 without any gap. Therefore, no lubricating oil path is formed between the second airtight cover 21 and the second joint portion 6 either.

Relatively wide contact between the inner surfaces of the outer covers 7, 8 (the first outer cover 7 and the second outer cover 8) and the outer surfaces of the airtight covers 19, 21 compared to the airtight ring described in Patent Document 1 area is crimped. Therefore, entry of foreign matter (minute objects) through the dividing surface _P2 of the first outer cover 7 and the dividing surface _P4 of the second outer cover 8 is prevented. In addition to this, entry of foreign matter from the dividing surface _P1 of the first airtight cover 19 and the dividing surface _P3 of the second airtight cover 21 is also prevented. Therefore, the airtight covers 19 and 21 are less likely to deteriorate and have a longer life than the airtight ring described in Patent Document 1.

Since the space between the inner surfaces of the outer covers 7 and 8 and the outer surfaces of the airtight covers 19 and 21 does not form a flow path for lubricating oil, leakage of the lubricating oil from these gaps is also prevented. Moreover, by making the dividing surface _P1 of the first airtight cover 19 and the dividing surface _P2 of the first outer cover 7 different, even if the lubricating oil tries to flow out from these dividing surfaces _P1 and _P2 , Outflow is suppressed. Furthermore, as shown in FIG. 4A, when the dividing plane _P1 of the first airtight cover 19 and the dividing plane _P2 of the first outer cover 7 are perpendicular to each other, the effect of suppressing the outflow of lubricating oil is improved. do. The same applies to the relationship between the dividing surface _P3 of the second airtight cover 21 and the dividing surface _P4 of the second outer cover 8 . Outflow of lubricating oil is suppressed by making these dividing planes P ₃ and P ₄ different. Furthermore, as shown in FIG. 4(B), when the dividing planes P ₃ and P ₄ are perpendicular to each other, the effect of suppressing the outflow of lubricating oil is improved.

[4. effect]
By adopting a structure in which the airtight covers 19 and 21 are divided in the circumferential direction, the concave portions 14 and 15 of the bracket 13 and the convex portions 20 and 22 of the airtight covers 19 and 21 can be easily fitted in a short time. , the maintenance can be improved with a simple configuration. Further, as shown in FIGS. 4(A) and 4(B), since the airtight covers 19 and 21 and the external covers 7 and 8 are locked at different positions, contamination of the lubricating oil and Leakage of lubricating oil can be suppressed.

In the screw conveyor 10, the first airtight cover 19, the second airtight cover 21, the first outer cover 7, and the second outer cover 8 are divided into two in the circumferential direction. With such a half-split structure, the airtight covers 19 and 21 and the outer covers 7 and 8 can be easily attached and detached, and the simple structure can further improve maintainability. In addition, compared to the case where the number of divisions of the member is three or more, the work of attaching and detaching is less complicated, and workability can be improved. Workability may be further improved by connecting a plurality of divided members with hinges.

In the screw conveyor 10 , as shown in FIG. 2 , the first screw blades 25 are arranged on the outer circumference of the first outer cover 7 and the second screw blades 26 are arranged on the outer circumference of the second outer cover 8 . The first screw blade 25 has a shape that is smoothly continuous with the screw blades formed on the first screw pipe 1, and the second screw blade 26 is smoothly continuous with the screw blades formed on the second screw pipe 2. It has a shape that With such a configuration, it is possible to smoothly convey the article to be conveyed and, for example, to suppress the deterioration of the conveying ability due to the retention of the article to be conveyed (remaining undelivered). In addition, since the objects to be conveyed are less likely to stay in the vicinity of the outer covers 7 and 8, minute objects to be conveyed are less likely to enter the path of the lubricating oil, and contamination of the lubricating oil can be further suppressed.

In the screw conveyor 10, the lubricating oil supply device 28 supplies lubricating oil to the outer surface of the intermediate shaft 4 through the conveying casing through-hole 29, the support portion 11, the first through-hole 16, and the second through-hole 18 in sequence. . Thus, by forming the lubricating oil path inside the intermediate suspension bearing 9 fixed to the conveying casing 3, it is possible to reliably lubricate the sliding contact surface while preventing contamination of the lubricating oil.

[5. Modification]
In the above embodiment, a structure in which lubricating oil is supplied via the intermediate suspension bearing 9 was exemplified, but the lubricating structure is not limited to this.
FIG. 6 is a cross-sectional view of a screw conveyor 10' according to a first modified example. In the first modification, lubricating oil supply pipes are arranged inside the first screw pipe 1 , the second screw pipe 2 , and the intermediate shaft 4 . A third through-hole 30 is formed in the intermediate shaft 4 so as to radially penetrate through the cylindrical surface of the intermediate shaft 4 , and a lubricating oil supply pipe is connected to the third through-hole 30 . The lubricating oil is stored in the oil chamber R through the outer surface of the intermediate shaft 4 and supplied to the sliding contact surfaces between the airtight covers 19 and 21 and the bracket 13 .
Even in such a structure, lubricating oil can be appropriately supplied using the screw pipes 1 and 2 and the hollow space of the intermediate shaft 4 . Moreover, the passage 12, the first through hole 16, and the second through hole 18 of the support portion 11 can be omitted, and the configuration can be simplified.
Moreover, FIG. 7 is sectional drawing of screw conveyor 10'' which concerns on a 2nd modification.
Unlike the bracket 13 of the embodiment and the first modification, the bracket 13' of the second modification has an asymmetrical shape between the upstream side and the downstream side when viewed from the fixed position to the support portion 11. As shown in FIG. Specifically, the first airtight cover 19 and the first outer cover 7 are arranged on the upstream side of the intermediate hanging bearing 9 in terms of the flow of the conveyed material, as in the embodiment and the first modification.
On the other hand, on the downstream side of the intermediate suspension bearing 9, the second airtight cover 21 is not arranged because the second recess 15 is not formed in the bracket 13'. The bracket 13' is attached to both the sliding portion 17 and the second outer cover 8', which is shorter than the first outer cover 7 when viewed in the direction of the axis C, with fastening members 33 (for example, bolts, nuts, rivets, etc.). Fixed. Due to this configuration, unlike the embodiment and the first modification, the second outer cover 8' does not rotate together with the second screw pipe 2, and is short, for example, about 5 cm to 10 cm. A corresponding screw vane for vane 26 need not be formed.
Even in such a structure, lubricating oil can be appropriately supplied on the upstream side by utilizing the screw pipe 1 and the hollow space of the intermediate shaft 4 .

1 First screw pipe 2 Second screw pipe 3 Conveying casing 4 Intermediate shaft 5 First joint part 6 Second joint part 7 First outer cover 8, 8' Second outer cover 9 Intermediate hanging bearings 10, 10', 10'' Screw conveyor 11 Supporting portion 12 Passage 13, 13 ' Bracket 14 First concave portion 15 Second concave portion 16 First through hole 17 Sliding portion 18 Second through hole 19 First airtight cover 20 First convex portion 21 Second airtight cover 22 Second convex portion 23 First locking device 24 Second locking device 25 First screw blade 26 Second screw blade 27 Driving device 28 Lubricating oil supply device 29 Carrying casing through-hole 30 Third through-hole 31 Conveyed object supply port 32 leg 33 fastening member C axis line R oil chamber P ₁ to P ₆ division surface

Claims (6)

A first screw pipe and a second screw pipe arranged inside the conveying casing are arranged at one end of the intermediate shaft and arranged at the other end of the first joint portion corresponding to the first screw pipe and the intermediate shaft. and is connected coaxially to the intermediate shaft via a second joint portion corresponding to the second screw pipe, and an intermediate suspension bearing is fixed to the inner surface of the conveying casing and rotates the intermediate shaft around the axis. A screw conveyor that is rotatably supported, and a driving device rotates the first and second screw pipes and the intermediate shaft about the axis, thereby conveying an object in one direction inside the conveying casing. in
The intermediate suspension bearing is
a support part, one end of which is fixed to the inner surface of the transport casing;
a bracket having a center portion fixed to the other end of the support portion, and having a plurality of circular first concave portions formed on the outer surface along the rotation direction of the intermediate shaft and toward the first joint portion side from the center portion; ,
a sliding portion that is fixed to the bracket and slidably and rotatably sandwiches the intermediate shaft;
A plurality of circular first protrusions formed in the rotational direction on the inner surface of the cylindrical shape extending from the first joint part to the support part, and a first airtight seal that can be divided in the circumferential direction of the intermediate shaft. a cover;
a first outer cover that is longer than the first airtight cover, has a cylindrical shape that is in contact with the first airtight cover and the first joint part on the inner surface, and is divisible in the circumferential direction;
a first locking member that locks the first airtight cover and the first outer cover so that the division position of the first airtight cover and the division position of the first outer cover are different,
A screw conveyor in which the first convex portion is fitted into the first concave portion, and the first outer cover is fixed to the first joint portion. a second airtight cover that is divisible in the circumferential direction, comprising a plurality of circular second protrusions formed in the rotational direction on the inner surface of the cylindrical shape extending from the second joint portion to the support portion;
a second outer cover that is longer than the second airtight cover, has a cylindrical shape that is in contact with the second airtight cover and the second joint part on the inner surface, and is divisible in the circumferential direction;
a second locking tool that locks the second airtight cover and the second outer cover so that the division position of the second airtight cover and the division position of the second outer cover are different,
The bracket further includes a plurality of circular second recesses formed on the outer surface along the direction of rotation and on the second joint portion side of the central portion,
2. The screw conveyor according to claim 1, wherein said second convex portion is fitted into said second concave portion, and said second outer cover is fixed to said second joint portion. The screw conveyor according to claim 2, wherein the first airtight cover, the second airtight cover, the first outer cover, and the second outer cover are divided into two parts in the circumferential direction. The number of the first protrusions, the second protrusions, the first recesses, and the second recesses is two each, and the two first protrusions fit into the two first recesses 4. The screw conveyor according to claim 3, wherein the two second protrusions are fitted into the two second recesses. A first screw blade smoothly continuous with the screw blade formed on the first screw pipe is arranged on the outer periphery of the first outer cover,
5. The screw conveyor according to claim 4, wherein second screw blades smoothly continuing from the screw blades formed on the second screw pipe are arranged on the outer periphery of the second outer cover. further comprising a lubricating oil supply device;
A conveying casing through-hole is formed in the conveying casing,
The support part is cylindrical and is fixed to the transport casing at a position corresponding to the transport casing through-hole,
A first through hole is formed in the central portion of the bracket,
A second through hole is formed in the sliding portion at a position corresponding to the first through hole,
The lubricating oil supply device supplies lubricating oil to the outer surface of the intermediate shaft through the conveying casing through-hole, the support portion, the first through-hole, and the second through-hole in sequence.
or,
The intermediate shaft has a cylindrical shape, and a third through hole is formed near the center of the sliding portion,
6. The lubricating oil supply device supplies lubricating oil from the third through hole to the outer surface of the intermediate shaft via the inside of the first or second screw pipe and the inside of the intermediate shaft. The screw conveyor described in .

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