JPS6319408B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for installing a screw conveyor on a base, and in particular, by applying a bending moment in a direction that cancels out the bending stress due to its own weight, the bending stress is averaged, and the conveyor shaft is Concerning items designed to reduce their weight.

What is shown in Fig. 1 is a screw conveyor for collecting slag taken out from a blast furnace. A conveyor shaft 4 is rotatably supported, and one half of the conveyor shaft 4 is covered with a semicircular guide cover 5. By the carrying action of the blades 6, the slag deposited at the bottom of the pool is transported obliquely upward along the guide cover 5 and taken out of the pool. Since the screw conveyor has such a structure, the above-mentioned bearings 2 and 3 at both ends of the shaft
However, the distance between both bearings 2 and 3 generally reaches 17 to 20 m, and the weight of the conveyor shaft 4 and blade plate 6 is large. It is quite heavy, and due to special circumstances such as evenly distributed loads being applied to the conveyor shaft 4, the bending stress applied to the conveyor shaft is extremely large compared to other machines.

Figure 2a shows a schematic diagram of a beam supported at both ends when both ends 7 and 8 are rotatably supported and a uniformly distributed load of ω is applied between them, and Figure 2b shows a diagram corresponding to that state. Bending stress distribution curve (BMD)
shows. As is clear from the figure, the bending stress is maximum (σmax) at the center of the shaft. Therefore, in design, the diameter of the entire conveyor shaft must be made large to match the shaft diameter required in this area, resulting in an increase in the overall size of the machine. transformation,
This is causing cost increases. Such problems also occur in screw classifiers and screw pumps having similar structures.

Therefore, in the present invention, in order to reduce the peak value (σmax) of bending stress as described above,
A bending moment M is applied to one end 8 of the conveyor shaft in a direction that cancels the bending moment due to the weight of the conveyor shaft, etc., and for this purpose, a bearing supporting the conveyor shaft is attached so that its axis is relative to the axis of the screw conveyor. It is supported so that it is bent upward. Therefore, such a bending moment M in the opposite direction causes a bending stress distribution in the negative direction as shown in Figure 2c, and the sum of the stresses in Figures b and c results in the actual bending stress distribution as shown in Figure 2d. This results in stress distribution.
As shown in the figure, the bending stress (σmax) at the center of the shaft is reduced by the stress (σm) due to the bending moment M in the opposite direction, and becomes (σ ₁ ).

Next, embodiments embodying the present invention will be described with reference to the accompanying drawings starting from FIG. FIGS. 3 and 4 are schematic side views of a screw conveyor for explaining an installation method according to an embodiment of the present invention, and FIG. FIG. Hereinafter, the screw conveyor, screw classifier, and screw pump will be collectively referred to as the screw conveyor.

In FIGS. 3 and 4, reference numeral 10 denotes an underwater bearing provided in a granulated pool, and is mounted on a concrete base 11 in the pool. Reference numeral 12 denotes a double-row bearing mounted on a base 13 outside the granulated pool, and inside a bearing box 14 directly mounted on the base 13, double-row bearings 15 and 1 as shown in detail in FIG.
5, and the front end 16 of the conveyor shaft 17 is supported by the underwater bearing 10.
and 15, so that it is supported by the bearing box 14 in the form of a fixed beam.

The procedure for forming an installation structure for a screw conveyor installed on a base in order to apply a moment M in the direction opposite to its own weight to the conveyor shaft supported in this way will be explained based on FIG. 3. . First, the bearing box 14 is placed on the base 13.
At this time, the bearing 1 that supports the front end of the conveyor shaft 17
0 is lifted by a crane or the like in a state where it is suspended upward by an appropriate gap 30 from the base 11 in the water, as shown in the figure. The height positions of the bases 11 and 13 are set in advance so that the bottom surface 19 of the bearing box 14 is in close contact with the top surface 20 of the base 13 when the bearing 10 is lifted by the width l of the gap 30. . In this state, the mounting hole 21 provided at the rear end of the bearing box 14 and the mounting hole 22 provided at the rear end of the base 13 are aligned, and the bolt 23 is passed through the mounting hole 22.
A spring 25 and a nut 26 are attached to the threaded portion 24 of the bolt 23 which protrudes downward. Natsuto 2
6 is tightened using a torque wrench or the like until a certain pressing force is applied to the flat spring 25. Next, in order to bend the rear end (fixed beam end) 18 of the conveyor shaft 17 upward, a crane or the like that is floating the bearing 10 upward is driven to gradually lower the position of the bearing 10. Then, the inclination of the conveyor shaft 17 gradually increases, and the counter spring 25 bends, causing the rear edge 27 of the bearing box 14 and the upper surface 20 of the base 13 to bend.
A gap 28 is created between the rear end 18 and the rear end 18.
An upward deflection occurs in order to resist the counter spring 25. Then, a bending moment M in the direction of the arrow X corresponding to the amount of compression of the counter spring 25, in other words, according to the amount of deflection of the rear end 18, that is, in a direction that cancels the bending moment due to the conveyor shaft 17's own weight, is generated after the conveyor shaft. occurs at end 18. That is, at this time, a bearing box (bearing member) supporting the rear end 18 of the conveyor shaft 17 via the bearings 15, 15
14 is supported such that the axis of the bearing box 14 is slightly bent upward with respect to the axis of the conveyor shaft 17.

The bending moment M due to the deflection of the rear end 18 of the conveyor shaft 17 is
Since it is proportional to the amount of deflection, that is, the amount of inclination of the bearing box 14, it can be adjusted to any value by detecting the amount of uplift of the bearing box 14 using the dial gauge 29, and the predetermined bending moment M At that point, the bearing 10 stops descending, and a spacer corresponding to the width of the gaps 30 and 28 at that time is inserted into the gap 3.
0 and 28, and fix the bearing 10 to the base 11 and the bearing box 14 to the base 13. Through the above operations, the conveyor shaft 17 can be installed on the base while applying a bending moment in the direction of arrow X to the rear end 18 of the conveyor shaft 17, and the above installation structure is formed. .

Next, other procedures for forming the above-mentioned installation structure will be explained based on FIG. 4. Bearing 1
0' and the bearing box 14' are placed on the bases 11' and 13' as shown in FIG. the base 1 so that a gap 28' is created from the beginning.
1' and 13' and their inclinations are set in advance, and in this state, the bearing 10' is first placed on the base 1.
Fixed at 1'. Next, install base 1 in the same manner as in the above procedure.
3' and the nut 26' screwed onto the bolt 23' attached to the bearing box 14' and press the spring 25', a bending moment M in the direction of the arrow X is applied to the conveyor shaft 17 as before, and this As before, the value of the bending moment is proportional to the amount of inclination of the bearing box 14'.
Tighten the nut 26' while measuring with
8' and fix the bearing box 14' to the base 13'.
The installation structure is formed by completing the installation of the conveyor shaft onto the base.

As described above, the present invention provides a method for installing on a base a screw conveyor that is supported at both ends by bearing members and receives a distributed load, in which one end of the conveyor shaft is fixedly supported by the bearing member, In order to bend the fixed shaft end upward in order to apply a bending moment to the fixed shaft end in a direction that cancels out the bending moment due to the screw conveyor's own weight, the shaft center of the bearing member is Since this screw conveyor installation method is characterized by supporting the bearing member so as to be oriented upward with respect to the axis of the screw conveyor, even in a screw conveyor with a long distance between bearings, the conveyor shaft Since the bending stress applied to the screw conveyor can be averaged and the maximum bending stress value can be lowered, the conveyor shaft can be made smaller in diameter. The same applies to screw classifiers and screw pumps, which can be treated as

[Brief explanation of the drawing]

Fig. 1 is a side view of a screw conveyor for mining, Fig. 2 a and b are diagrams showing the load distribution and bending stress distribution of the conventional screw conveyor shaft, and c and d are diagrams showing the present invention. A diagram showing the distribution of bending stress when a bending moment in the opposite direction is applied to the shaft end according to the method, and FIGS. 3 and 4 are screw diagrams for explaining the installation method according to an embodiment of the present invention. FIG. 5, a schematic side view of the conveyor, is a side sectional view of a bearing section that applies a bending moment in the opposite direction. (Explanation of symbols), 17... conveyor shaft, 25,
25'...Flat spring (elastic body), 13,13'...
Base, 16... end, 14, 14'... bearing box,
28, 28'...Gap, 15...Bearing, 23,2
3'...Bolt, 26, 26'...Nut, 10,
10'...Underwater bearing, 11,11'...Base.

Claims (1)

[Claims] 1. In a method for installing a screw conveyor on a base that is supported at both ends by bearing members and receives a distributed load, one end of the conveyor shaft is fixedly supported by the bearing member, and a screw conveyor is mounted on the fixed shaft end. In order to bend the fixed shaft end upward in order to apply a bending moment in a direction that cancels out the bending moment due to the screw conveyor's own weight, the axis of the bearing member is aligned relative to the axis of the screw conveyor. A method for installing a screw conveyor, characterized in that the bearing member is supported so as to be oriented upward.