JP2002060042A - Screw conveyor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely prevent idling between a rotating driveshaft and a screw shaft. SOLUTION: The cross section 3 of the rotating driveshaft and the cross section of the hollow part 5 of the screw shaft are both formed into shapes other than a circle, preferably polygons, so that the shafts are fitted together. A screw unit 6 molded with a screw blade 1 and a hollow screw shaft 2 integrated together and axially split apart is suitable for a screw conveyor assembled by fitting into the rotating driveshaft 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw conveyor for transporting powdery materials by rotation of a screw (also referred to as a screw feeder depending on the purpose of use).

[0002]

2. Description of the Related Art In a screw conveyor, a cylindrical or U-shaped conveyor is used.
The shaft on which the screw blades are mounted is rotated in the trough having the cross section of the letter shape, and the granular material is transferred in the direction of the screw shaft.
It has a feature that the supply and discharge of the transferred material are easy and the transfer amount can be easily controlled, and it is preferably used for the transfer of powder and granules over a relatively short distance. Screw conveyor
Generally, a screw blade is attached to a hollow shaft (screw shaft), a rotary drive shaft is inserted and fixed to the hollow shaft, and the assembly is set in a trough. Conventionally, a steel pipe was used for the screw shaft, and the screw blades were attached by welding or the like. However, recently, the material and molding technology have advanced, and the production cost has been reduced, and the screw blade and screw shaft have been integrated into a single piece by plastic molding or die casting, and the screw shaft has been divided into multiple parts in the horizontal plane. The required number of screw units 6 (see FIGS. 1 and 2) are manufactured according to the length of the conveyor, and the rotary drive shaft 3 is sequentially inserted into the screw units 6 to constitute the entire screw (see FIG. 3). Began to take place. Both the rotary drive shaft and the hollow portion of the screw shaft of the conventional screw conveyor have a cross section formed by a perfect circle centered on the center of rotation, and are fitted together.

[0003]

Now, since the joint section between the rotary drive shaft and the screw shaft is a perfect circle, conventionally, the joint surface is fixed by a key, a pin, a cotter, or the like.
Had been detained. When the above-mentioned screw units are used, for example, as shown in FIGS. 1 to 3, the shaft ends of the screw units 6 are cut out and engaged with each other (an engaging portion: 7), and further, the screw units at both ends, or A fixing ring 8 was inserted at both ends, and an insertion bolt 9 was inserted between the screw shaft 2 and the rotary drive shaft 3 to stop rotation.

However, in a screw unit manufactured by a plastic molding or die-casting which is inferior in strength to a conventionally used steel pipe, the torsional load applied to the screw blade 1 must be sufficiently supported by the screw shafts at both ends. However, there was an accident that the rotation stop was broken due to the biting of the transferred object and the idle rotation between the rotary drive shaft 3 and the screw shaft 2 occurred. The present invention has been completed for the purpose of simply and reliably preventing idle rotation between a rotary drive shaft and a screw shaft, including when a screw unit is assembled.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a hollow screw shaft 2 on which a screw blade 1 is mounted, a rotary drive shaft 3 fitted to the hollow screw shaft 2, and the screw blades are rotated. In the screw conveyor for transferring the supplied substance, the cross section of the rotary drive shaft and the cross section of the hollow portion 5 of the screw shaft are both formed into a shape other than a perfect circle centered on the rotation center and fitted together. I will provide a. In particular, it is preferable that the cross section of the rotary drive shaft and the cross section of the hollow portion 5 of the screw shaft are both formed in a polygonal shape and fitted together.

According to the present invention, in particular, a plurality of screw units 6 formed and manufactured integrally with the screw blade 1 and the hollow screw shaft 2 at required lengths are sequentially fitted to the rotary drive shaft 3. Suitable for assembled screw conveyors. Usually, the screw unit 6 is made of plastic or a die-cast alloy.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings. FIG. 1 is a front view of a screw unit 6 in which a screw shaft and a screw blade of the present invention are integrally formed, and FIG. 2 is a side view of the screw unit 6 as viewed from an axial direction. FIG. 3 is a front view of a conventional screw portion in which the screw unit 6 and the rotary drive shaft 3 are assembled, and FIG. 4 is an overall view of the screw conveyor. Each of these drawings shows a specific embodiment.

In the screw conveyor of the present invention, a rotary drive shaft 3 having a shaft cross section formed in a shape other than a perfect circle centered on the center of rotation is used. The screw blade 1 is rotated by being inserted into the screw shaft 2 having the same shape as the cross-sectional shape of the shaft 3. Examples of shapes other than a perfect circle whose cross section is the center of rotation include a convex polygon such as a regular tetragon, a regular pentagon, a regular hexagon, a spline type including a cross and a star, a missing circle, and an ellipse. Can be Above all, regular squares, regular pentagons, and regular hexagons which are easy to produce, have strength, and have a large effect of preventing slippage in the torsional direction are preferably used.

In the conventional rotary drive shaft 3 and screw shaft 2 in which the cross-sectional shape of the rotary drive shaft 3 and the screw shaft 2 is a perfect circle, the torsional load received by the screw blade 1 is changed by the engagement portion 7 for joining the unit 6. And the like, concentrated on the non-slip keys, pins, cotters and insertion bolts 9 attached to the shaft end. However, by employing the rotary drive shaft 3 and the screw shaft 2 having the above-described cross-sectional shape according to the present invention, the torsional load received by the screw blade 1 is transmitted from the screw shaft 2 to the rotary drive shaft 3 in a dispersed manner. Therefore, only the axial load applied to the screw blade 1 is received at the shaft end, and the idle rotation between the rotary drive shaft 3 and the screw shaft 2 can be prevented.

Since there is no need to consider a torsional load between the screw units 6, it is not always necessary to cut out the joint surface and design and manufacture the meshing. A screw unit 6 molded integrally with the screw blade 1 and the hollow screw shaft 2 and divided in the axial direction,
It is suitable for a screw conveyor that is assembled by being sequentially fitted to the rotary drive shaft 3.

[0011]

According to the screw conveyor according to the present invention, the torsional load of the screw blade is not concentrated on the connecting member (for example, the insertion bolt) between the screw shaft and the rotary drive shaft, and is almost entirely in the axial direction. Since the dispersion is transmitted from the screw shaft to the rotary drive shaft, the load on the connection member is reduced, and it is possible to avoid many cases in which the connection shaft is damaged due to the entrapment of the moving powder fluid and the drive shaft idles,
Stable operation becomes possible.

[Brief description of the drawings]

Fig. 1 Example of screw unit (front view)

[Fig. 2] Example of screw unit (side view from axial direction)

FIG. 3 shows a conventional screw part including a screw unit and a rotary drive shaft.

FIG. 4 is an example (schematic diagram) of a screw conveyor.

[Explanation of symbols]

1: screw blade 2: hollow screw shaft 3: rotary drive shaft 4: trough 5: screw shaft hollow portion 6: screw unit 7: engaging portion 8: fixing ring 9: insertion bolt 10: supply port 11: discharge port

Claims (4)

[Claims] A rotary drive shaft (3) is fitted to a hollow screw shaft (2) to which a screw blade (1) is attached, and the screw blade is rotated to transfer a substance supplied into a trough (4). In the screw conveyor, a cross section of the rotary drive shaft and a cross section of the hollow portion (5) of the screw shaft are both formed into shapes other than a perfect circle centered on the rotation center and fitted together. 2. The screw conveyor according to claim 1, wherein the cross section of the rotary drive shaft and the cross section of the hollow portion of the screw shaft are both formed in a polygonal shape and fitted together. 3. A plurality of screw units (6) formed and manufactured integrally with a screw blade and a hollow screw shaft for a required length are sequentially fitted to a rotary drive shaft (3). The screw conveyor according to claim 1 or 2, wherein 4. The screw conveyor according to claim 3, wherein the screw unit is made of a plastic or a die-cast alloy.