JPH0699014B2 - Bearing structure suitable for spiral conveyors - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a bearing structure suitable for being disposed below the liquid surface of a storage tank or the like containing a solid-liquid mixed phase, and more particularly to a bearing structure suitable for a spiral conveyor. .

2. Description of the Related Art Conventionally, an oil seal is used when a rotary shaft is provided on a container wall below the liquid surface of a container containing a liquid,
A laminated ring or a labyrinth ring has been used to prevent dust from entering the rotating part.

Here, the laminated ring is formed by winding one sheet of a long plate-shaped material in a spiral shape two or more times, and finishing both end surfaces in the central axis direction of the spiral into a flat plate shape. The laminated ring is used by cutting a groove on a rotary shaft or a bearing, and pressing and supporting the outer diameter surface (inscribed type) or the inner diameter surface (outer contact type) of the laminated ring in the groove area. When the oil seal and the laminated ring are used together, the laminated ring is arranged on the upstream side with respect to the invasion path of the liquid and the solid, and the oil seal is arranged behind it.

Such a bearing structure exerted a substantially good dustproof effect when the rotating shaft was rotating at a high speed. However, low speed rotation (30-40 rpm) like a spiral conveyor
(Or less), a complete dustproof effect cannot be obtained, and a solid-liquid mixture in which a large amount of solid is mixed in the liquid, such as a mixture of cutting oil and cutting chips, is not particularly effective. It has been found that when the rotary shaft is attached to the wall of the container that contains the particles, the cutting chips pass through the laminated ring and reach the oil seal, and the oil seal is damaged in a short time.

The cause of this is not always clear, but the rotation speed of the rotating shaft, the size and shape of the chips (solid), the properties of the cutting fluid (liquid),
It is presumed that the change in the behavior of the chips due to the combination of the chips and the cutting fluid and the difference in the mixing ratio and the like is related.

In the conventional usage of the laminated ring, the laminated rings are arranged at two or more positions on the sliding surface of one rotating shaft and the bearing, but the sliding surfaces of the rotating shaft and the bearing are straightened. In this case, a groove is cut in one of the sliding surfaces, and the laminated rings are arranged in the groove regions. More specifically, in the case of high speed rotation, a groove is cut on the rotary shaft side, and the circumscribed laminated ring is pressed against the bearing side.In the case of low speed rotation, the groove is cut on the bearing side to rotate the laminated ring. It was pressed against the shaft side. In addition, a combination of inscribed type and circumscribed type laminated rings has also been arranged in these groove regions. However,
Regardless of which of the conventional usage modes is adopted, when the rotating shaft is attached to the container wall containing the solid-liquid mixture as described above, it is necessary to completely prevent solids from entering the sliding surface. Could not be done.

When the inscribed laminated ring is pressed against the rotating shaft, the inner diameter of the laminated ring in the unloaded state must be smaller than the outer diameter of the cylindrical outer surface of the rotating shaft, and the diameter must be increased during mounting. However, it is extremely difficult to form the inscribed surface of the laminated ring so that the inscribed surface of the laminated ring becomes a perfect circle in the expanded state. Therefore, a slight gap is created between the inscribed laminated ring and the pressure contact portion between the rotary shaft. When the rotating shaft is rotating at a low speed, chips may fall onto the rotating shaft, and the chips may enter through the gap between the laminated ring and the rotating shaft.

Further, generally, when liquid or solid enters between the sliding surfaces of the rotating shaft and the bearing, it seems that the liquid and solid tend to enter along the surfaces thereof and enter.

Therefore, in the bearing structure arranged below the liquid surface of the solid-liquid mixture, the object of the present invention is to allow solids to enter between the sliding surfaces of the rotating shaft and the bearing even at low speed rotation. Is to prevent.

A further object of the present invention is to prevent solids and liquids from entering between the sliding surfaces of the rotating shaft and the bearing even at low speed rotation in the bearing structure arranged below the liquid surface of the solid-liquid mixture. is there.

Yet a further object of the invention is to withstand extended use.
The object of the present invention is to provide a bearing structure arranged below the liquid surface of the solid-liquid mixture.

As a result of earnest studies on means for solving this problem, the present inventors have completed a nearly perfect bearing structure.

Means for Solving the Problems In the bearing structure under the liquid surface of the solid-liquid mixture of the present invention, between two adjacent laminated ring installation regions,
Stepped portions are formed by making the radii of the rubbing surfaces of the rotating shaft and the bearing different from each other, and the laminated rings are arranged at the different radius portions.

Although the reason is not always clear, it was confirmed that the above-mentioned structure drastically reduced the invasion of chips into the oil seal portion and could withstand long-term operation. Probably, it is presumed that the step of the large diameter portion and the reduced diameter portion of the rotary shaft and the bearing is provided, so that the dust intrusion path becomes complicated and the dustproof effect is improved. It may also be related to the fact that in the stepped portion, a gap is formed between the facing surfaces of the rotary shaft and the bearing that extend in the direction orthogonal to the axial direction. This air gap is of course necessary to avoid unnecessary friction between the rotating shaft and the bearing.

Practical Example FIG. 1 is a partial cross-sectional view of an example in which the bearing structure below the liquid surface of the solid-liquid mixture of the present invention is applied to a rotary drive shaft at the base end of a tray of a spiral conveyor.

In FIG. 1, a tray 1 having a U-shaped cross section
Shows a cross section along its longitudinal axis, showing a part of the bottom wall 1 and a part of the end wall 2 of the tray, and the cutting fluid containing a large amount of chips is In the figure, it is housed above the bottom wall 1 and on the right side of the end wall 2.

An assembly of the rotating shaft 10 and the bearing 30 is attached to the end wall 2 by a suitable fixing means such as a bolt B.

A spiral S with a rectangular cross section is provided at the right end of the rotary shaft 10.
Is attached by a screw SC, and a sprocket wheel SW is attached by a spring pin SP at the left end portion.

In this embodiment, the rotary shaft 10 is provided with two portions 11 and 13 having different axial radii according to the present invention, and a circumferential groove 12 is cut on the cylindrical surface of the large diameter portion. .

The bearing 30 is provided with a large diameter portion 31 and a reduced diameter portion 33 corresponding to the large diameter portion and the reduced diameter portion of the rotating shaft,
A circumferential groove 32 is cut on the cylindrical surface of the reduced diameter portion 33.

Laminated rings 51, 52 are provided in these groove portions 12, 32, and in the illustrated embodiment, the outer diameter surface of the laminated ring 51 is pressed against the inner cylindrical surface of the large diameter portion 31 of the bearing 30. The inner diameter surface of the laminated ring 52 is pressed against the cylindrical outer surface of the reduced diameter portion 13 of the rotating shaft 10.

In the step portion between the large-diameter portion and the reduced-diameter portion of the rotating shaft 10 and the bearing 30, a slight gap G is provided between the facing surfaces extending in the direction orthogonal to the axial direction, and these surfaces are mutually Avoiding contact.

In the illustrated embodiment, two oil seals 53,54
Is provided between the rotary shaft 10 and the bearing 30 behind the laminated rings 51, 52, and two bearings (deep groove ball bearings) 55, 56 are provided between them. Further, a metal ring or sleeve 57 is provided between the oil seal 54 and the rotary shaft, and an O-ring 58 is provided in the groove 13 provided in the rotary shaft 10 between the sleeve 57 and the rotary shaft. ing.

In the bearing structure according to the illustrated embodiment, it is considered that the rotary shaft 10 and the bearing 30 can be mounted on the end wall 2 after being assembled. The laminated ring 51 is assembled in the groove 12 of the rotary shaft 10 and the O-ring 58 is assembled in the groove 13.
At this time, since the laminated ring 51 is of an outer diameter type that is pressed against the inner surface of the large diameter portion 31 of the bearing 30, it is received with a slight play in the groove 12, and the outer diameter of the laminated ring 51 is It projects outward from the cylindrical surface of the large-diameter portion 11 of the rotating shaft. The laminated ring 52 is fitted in the groove 32 of the bearing 30, and the oil seal 53, the bearings 55 and 56, the oil seal 54, and the sleeve 57 are sequentially assembled. Here, since the laminated ring 52 is of an inner diameter type that is pressed against the cylindrical outer surface of the reduced diameter portion 13 of the rotating shaft 10, it is received with a slight play in the groove 32. Protrudes inward from the cylindrical inner surface of the reduced diameter portion 33 of the bearing 30.

Thus, when the rotary shaft 10 is inserted from the right side of the bearing 30, the oblique chamfered portion 15 at the shoulder on the left side of the reduced diameter portion 13 of the rotary shaft 10 comes into contact with the inner diameter surface of the laminated ring 52 to form the laminated ring 52. Intrude while expanding the inner diameter of. Similarly, the diagonal chamfered portion 34 on the right shoulder of the large diameter portion of the bearing 30 comes into contact with the outer diameter surface of the laminated ring 51 to form the laminated ring.
The rotating shaft 10 enters the bearing 30 while compressing the outer diameter of 51. After that, by mounting the sprocket wheel SW, the assembly of the rotary shaft and the bearing is completed.

A flange portion which is fitted between the opening portion of the end wall 2 of the tray and the outer surface of the large diameter portion of the bearing 30 via a packing 35 so as to extend radially from the large diameter portion of the bearing 30. Ring-shaped packing 36 between 35 and the end wall 2
They are pressed against each other via and are tightened and fixed by an appropriate fixing means such as a bolt B. Thereafter, the spiral S is fixed to the right end of the rotary shaft 10 by a suitable fixing means.

It has been confirmed that the spiral conveyor provided with the bearing structure according to the above-mentioned embodiment withstands continuous operation for a long time under normal operating conditions and is sufficiently practical. When two laminated rings having exactly the same arrangement relationship as described above are arranged on a straight rotary shaft having no large diameter portion and no reduced diameter portion and a bearing, the dustproof effect is obtained as described above. In view of the fact that the large-diameter portion and the reduced-diameter portion, the bent path of the solid matter entering between the sliding surfaces contributes to the dustproof effect of the present invention for some reason. It seems to be.

Although one embodiment of the present invention has been described above in detail, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the technical idea of the present invention.

For example, in the illustrated embodiment, inscribed and circumscribed laminated rings may be used in combination in each groove. Further, in the embodiment of FIG. 1, grooves are provided in the large diameter portion and the reduced diameter portion of the bearing 30, respectively, and the inscribed laminated ring rotating in the grooves is pressed against the cylindrical outer surface of the rotating shaft. Alternatively, conversely, grooves may be provided in the large diameter portion and the reduced diameter portion of the rotary shaft 10, and a circumscribing type laminated ring for stopping may be arranged in the grooves.

2 to 4 are schematic cross-sectional views illustrating some modified examples of the bearing structure of the present invention.

In the modified example of FIG. 2, the arrangement of the grooves of the large diameter portion and the reduced diameter portion of the rotary shaft 10 and the bearing 30 and the laminated ring is completely opposite to that of the embodiment of FIG. More specifically, a groove 32 is cut on the inner surface of the large diameter portion 31 of the bearing 30, and
An inscribed laminated ring 52 is attached to the outside of the cylindrical surface of the large diameter portion 11 of 10. A groove 12 is cut on the cylindrical outer surface of the reduced diameter portion of the rotating shaft 10, and a circumscribed laminated ring 51 is attached to the cylindrical inner surface of the reduced diameter portion 33 of the bearing 30. The oil seal 53 is arranged behind the two laminated rings.

In the modification of FIG. 3, the rotary shaft 10 and the bearing have a large diameter portion and a reduced diameter portion which are opposite to those of the embodiment of FIG. More specifically, the reduced diameter portion 13, 33 is on the right side and the large diameter portion 11, 33 on the left side.
31 are arranged. A groove 12 is cut in the reduced diameter portion 13 of the rotary shaft 10, and a circumscribed type laminated ring 51 is attached to the reduced diameter portion 33 of the bearing 30. A groove 32 is cut in the large diameter portion 31 of the bearing, and an inscribed laminated ring 52 is attached to the large diameter portion 11 of the rotating shaft. The oil seal 53 is arranged behind the two laminated rings.

In the modified example of FIG. 4, the arrangement of the grooves of the large diameter portion and the reduced diameter portion of the rotary shaft 10 and the bearing 30 and the laminated ring is completely opposite to that of the embodiment of FIG. More specifically, a groove 32 is cut in the reduced diameter portion 33 of the bearing 30, and an inscribed laminated ring 52 is attached to the reduced diameter portion 13 of the rotary shaft 10.
A groove 12 is cut in the large diameter portion 11 of the rotating shaft, and a circumscribing type laminated ring 51 is attached to the large diameter portion 31 of the bearing. The oil seal 53 is arranged behind the two laminated rings.

When the rotary shaft 10 shown in FIGS. 1 and 2 is the drive shaft of the motor, the bearing cannot be assembled. In that case, the large diameter portion of the rotary shaft is used as a detachable member. After assembling the bearing to the drive shaft, the member of the large diameter portion of the rotary shaft may be assembled and fixed.

In the modified examples of FIGS. 2 to 4, the laminated ring used may be either an inscribed type or an circumscribed type, or may be used in combination. In this case, the groove for receiving them may be appropriately provided on either the rotary shaft or the bearing.

Effects of the Invention The effects of the present invention are as follows.

1) In the bearing structure below the liquid surface of the solid-liquid mixture,
It is possible to prevent solids from entering between the rubbing surfaces of the rotating shaft and the bearing and also to prevent liquid leakage.

2) Can withstand continuous use for a long time.

3) The dustproof effect is excellent especially at low speed rotation regardless of the rotation speed of the rotary shaft.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an embodiment in which the bearing structure below the liquid surface of a solid-liquid mixture of the present invention is applied to a rotary drive shaft at the base end of a tray of a spiral conveyor, and FIGS. FIG. 8 is a schematic cross-sectional view illustrating some of various modifications. Explanation of symbols 1: Tray, 2: End wall, 10: Rotating shaft, 11: Large diameter part, 12: Groove, 1
3: reduced diameter part, 30: bearing, 31: large diameter part, 32: groove, 33: reduced diameter part, 34: packing, 35: flange part, 36: packing, 51, 52: laminated ring, 53, 54: Oil seal, 55, 56: Bearing, 57: Sleeve, 58: O-ring, B: Bolt, S: Spiral, SC: Screw, SW: Sprocket wheel, SP: Spring pin,

Claims (1)

[Claims] 1. A bearing structure provided generally outside of a container for supporting one rotating shaft provided through a container wall below a liquid surface of a container containing a solid-liquid mixed phase. A large-diameter portion and a reduced-diameter portion are formed on the rotary shaft along the axial direction thereof, and the large-diameter portion and the reduced-diameter portion which are substantially in sliding contact with the large-diameter portion and the reduced-diameter portion of the rotary shaft, respectively. And a step portion formed on the bearing and formed in a ring shape between the large diameter portion and the reduced diameter portion of the rotating shaft, and a step formed in the ring shape between the large diameter portion and the reduced diameter portion of the bearing. And a portion facing each other with a slight gap, and either one of the outer peripheral surface of the large diameter portion of the rotating shaft and the inner peripheral surface of the large diameter portion of the bearing,
And at least one groove is formed on either one of the outer peripheral surface of the reduced diameter portion of the rotating shaft and the inner peripheral surface of the reduced diameter portion of the bearing, and the laminated ring is arranged in each of the grooves.
Further, the bearing structure suitable for the spiral conveyor is characterized in that at least one oil seal is arranged between the rotary shaft and the bearing outside the container with respect to the laminated rings.