JPH02276710A - Bearing construction suitable for spiral conveyor - Google Patents

Abstract

PURPOSE:To prevent intrusion of solid into the space between sliding surfaces at the time of low speed rotation, in the title bearing for a solid-liquid mixing phase storage tank, by forming a stepped part by which the radii of a shaft forming the sliding surfaces of the turning shaft and the bearing are varied, and by arranging laminated rings to the different radius parts respectively. CONSTITUTION:Two parts 11, 13 having shaft radii different to each other are formed to the part forming the sliding surfaces of both a bearing 30 and a turning shaft 10 to which a spiral S and a sprocket wheel SW are fitted, and on the cylindrical surface of the larger diameter part, a circumferential groove 12 is formed. On the other hand, the parts of the bearing 30 corresponding to both parts 11, 13 of the turning shaft 10 are formed into a larger diameter part 31 and a reduced diameter part 33 respectively, and on the cylindrical surface of the reduced diameter part 33, a circumferential groove 32 is formed. And, to these grooves 12, 32, laminated rings 51, 52 are arranged respectively, and the outside diametral surface of the ring 51 and the inside diametral surface of the ring 52 are pressedly brought into contact with the cylindrical inside surface of the larger diameter part 31 of the bearing 30, and with the cylindrical outside surface of the reduced diameter part 13 of the turning shaft 10 respectively. By this constitution, intrusion of solid can be prevented even at a low speed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention generally relates to a bearing suitable for accommodating a solid-liquid mixed phase; a bearing suitable for placement below the liquid level in a storage tank, etc. relates to a shaft bearing suitable for a spiral conveyor in particular. Bearings are about structure.

Prior Art Conventionally, an oil seal has been used when a rotating shaft is provided on the wall of a container below the surface of the container containing liquid.
Additionally, laminated rings or labyrinth rings have been used to prevent dust from entering the rotating parts.

Here, a laminated ring is one in which two or more elongated plate-shaped materials are wound in a spiral shape, and both end faces in the direction of the central axis of the spiral are finished in a flat plate shape. For laminated rings, a groove is cut in the rotating shaft or bearing, and the outer diameter surface (internal type) or inner diameter surface (external type) of the laminated ring is pressed into the groove area.

Support and use. When an oil seal and a laminated ring are used together, the laminated ring is placed on the upstream side with respect to the entry path for liquids and solids, and the oil seal is placed behind it.

The structure of such a bearing generally exhibits a good dust-proofing effect when the rotating shaft rotates at high speed.

However, low-speed rotation such as a spiral conveyor (
30~4Orpm or lower), complete dustproofing effect cannot be obtained, especially when a large amount of solids are mixed in the liquid, such as a mixture of cutting oil and chips. When a rotating shaft is attached to the wall of a container containing a solid-liquid mixture, it has been found that chips pass through the laminated ring and reach the oil seal, damaging the oil seal in a short period of time.

The causes of this are not necessarily clear, but include the rotational speed of the rotating shaft, the size and shape of the chips (solid), the properties of the cutting fluid (liquid),
It is presumed that this is related to changes in the behavior of chips due to differences in the combination of chips and cutting fluid and the mixing ratio.

In the conventional usage of de-layered rings, laminated rings were placed at two or more stress points on the sliding surface of one rotating shaft and bearing. had a straight shape, grooves were cut in one of their sliding surfaces, and laminated rings were placed in each groove area. Specifically, for high-speed rotation, a groove is cut on the side of the rotating shaft, and a circumscribed laminated ring is pressed against the side of the bearing.For low-speed rotation, a groove is cut on the side of the bearing, and a laminated ring is used. was pressed against the rotating shaft side. It has also been practiced to arrange a combination of inscribed and circumscribed laminated rings within these groove regions. However, no matter which of the conventional usage methods is adopted, if the rotating shaft is attached to the wall of the container containing the solid-liquid mixture as described above, the intrusion of solids into the sliding surfaces can be completely prevented. I was unable to do so.

When an internal laminated ring is brought into pressure contact with a rotating shaft, the inner diameter of the laminated ring under no load must be smaller than the outer diameter of the cylindrical outer surface of the rotating shaft, and the diameter must be expanded upon installation. However, it is extremely difficult to form the inscribed surface of the laminated ring so that it becomes a perfect circle in its expanded diameter state. Therefore, a slight gap is created between the press-contact portion of the internal laminated ring and the rotating shaft. When the rotating shaft is rotating at a low speed, chips may fall onto the rotating shaft and enter through the gap between the laminated ring and the rotating shaft.

Additionally, when liquids and solids generally enter between the sliding surfaces of the rotating shaft and the bearing, it appears that they tend to be guided along those surfaces.

Problems to be Solved by the Invention Therefore, an object of the present invention is to solve the problem in that a bearing disposed below the surface of a solid-liquid mixture has a structure in which solids invade between the sliding surfaces of the rotating shaft and the bearing even during low-speed rotation. The goal 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 during low-speed rotation due to the structure of the bearing placed below the liquid surface of the solid-liquid mixture. It is.

A further object of the present invention is to withstand long-term use.
The bearing placed below the liquid level of the solid-liquid mixture is to provide structure.

As a result of intensive research into means for solving this problem, the inventors of the present invention have completed a nearly perfect bearing structure.

Means for Solving the Problems The subsurface bearing of the solid-liquid mixture of the present invention has a structure in which between two adjacent laminated ring installation areas,
The radii of the rubbing surfaces of the rotating shaft and the bearing are made different to form stepped portions, and laminated rings are arranged at the different radial portions, respectively.

Although the reason is not entirely clear, it has been confirmed that the structure described above greatly reduces the amount of chips entering the oil seal, allowing it to withstand long-term operation. Presumably, by providing a stepped portion between a large diameter portion and a reduced diameter portion in the rotating shaft and bearing, the dust-proofing effect is improved because the path for dust to enter is complicated. It may also be related that, in the stepped portion, a gap is formed between opposing surfaces of the rotating shaft and the bearing that extend in a direction orthogonal to the axial direction. This gap is naturally necessary to avoid unnecessary friction between the rotating shaft and the bearing.

Embodiment FIG. 1 is a partial cross-sectional view of an embodiment in which the subsurface bearing structure for 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.

In FIG. 1, a tray l having a U-shaped cross-sectional shape is shown in cross section along its longitudinal axis, and a part of the bottom jJl and a part of the end wall 2 of the tray are shown. A cutting fluid containing a large amount of chips is stored above the bottom wall 1 and on the right side of the end wall 2 in FIG.

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

A spiral S having a rectangular cross section is attached to the right end of the rotating shaft 10 by a screw SC, and a tin rocket wheel SW is attached to the left end by a spring bin SP.

In this embodiment, the rotating shaft lO is provided with two portions 11.13 having different shaft radii based on the present invention, and a circumferential groove 12 is cut in 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, and the cylindrical surface of the reduced-diameter portion 33 has a diameter extending in the circumferential direction. A groove 32 is cut.

In these groove portions 12.32 there are laminated rings 51.52.
is provided, and in the illustrated embodiment, a laminated ring 51
The outer diameter surface of the laminated ring 52 is pressed against the cylindrical inner surface of the large diameter portion 31 of the bearing 30, and 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.

At the stepped portion between the rotating shaft 10 and the large-diameter portion and the reduced-diameter portion of the bearing 30, a slight gap G is provided between opposing surfaces extending in a direction perpendicular to the axial direction, so that these surfaces are mutually connected. Avoiding contact.

In the illustrated embodiment, two oil seals 53.5
4 is provided between the rotating shaft lO and the bearing 30 behind the laminated ring 51, 52, and two bearings (deep groove ball bearings) 55, 56 are provided between them. Furthermore, a metal ring or sleeve 57 is provided between the oil seal 54 and the rotating shaft, and an O-ring 58 is provided in the groove 13 provided in the rotating shaft IO between the sleeve 57 and the rotating shaft. ing.

The bearing according to the illustrated embodiment has a structure in which the rotating shaft 10
It is designed so that it can be attached to the end wall 2 after the and bearing 30 are assembled.

A laminated ring 51 is installed in the groove 12 of the rotating shaft 10, and an O-ring 58 is installed in the groove 13, respectively. 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, the receiver is inserted into the groove 12 with a slight play, and the outer diameter of the laminated ring 51 is The diameter projects outward from the cylindrical surface of the large diameter portion 11 of the rotating shaft.

The 1tJT layer ring 52 is fitted into the groove 32 of the bearing 30, and the oil seal 53, bearings 55, 56, oil seal 54, and sleeve 57 are assembled in this order. 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 rotation axis lO, the groove 3
The bearing is inserted into the bearing 30 with a slight play, and the inner diameter of the laminated ring 52 projects inward from the cylindrical inner surface of the reduced diameter portion 33 of the bearing 30.

Thus it rotates! When the FlhlO is inserted from the right side of the bearing 30, the diagonal chamfered portion 15 on the left shoulder of the reduced diameter portion 13 of the rotating shaft 10 contacts the inner diameter surface of the laminated ring 52, expanding the inner diameter of the laminated ring 52. Invade while doing so. Similarly, the diagonal chamfered portion 34 on the right shoulder of the large diameter portion of the bearing 30 contacts the outer diameter surface of the laminated ring 51, and the rotary shaft 10 moves toward the bearing 30 while compressing the outer diameter of the laminated ring 51. invade inside. After that,
By installing the sprocket wheel SW, the assembly of the rotating shaft and the bearing is completed.

A flange portion that fits between the opening in the end wall 2 of the tray and the outer surface of the large diameter portion of the bearing 30 via a backing 35, and extends radially from the large diameter portion of the bearing 30. 35 and the end wall 2 via a ring-shaped backing 36, they are brought into pressure contact with each other, and are tightened and fixed by suitable fixing means such as bolts B. Thereafter, the spiral S is fixed to the right end of the rotating shaft IO by suitable fixing means.

It has been confirmed that the spiral conveyor provided with the bearing structure according to the above-mentioned example can withstand continuous operation for a long time under normal operating conditions and is sufficiently practical. If two laminated rings in exactly the same arrangement as above are arranged on a straight rotating shaft and bearing that have no large diameter part and reduced diameter part, the barrier effect will be improved as mentioned above. In view of the fact that this could not be obtained, it was found that the path for solids to enter between the sliding surfaces is bent between the large diameter part and the reduced diameter part.
It seems that this contributes to the dustproof effect of the present invention for some reason.

Although one embodiment of the present invention has been described in detail above, 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, a combination of inscribed and circumscribed laminated rings may be used within each groove. In addition, in the embodiment shown in FIG. 1, grooves are provided in each of the large diameter part and the reduced diameter part of the bearing 30, and the internal laminated ring that rotates in these grooves is pressed against the cylindrical outer surface of the rotating shaft. Alternatively, grooves may be provided in each of the large diameter portion and the reduced diameter portion of the rotating shaft 10, and circumferential laminated rings for restraining may be placed in these grooves.

2 to 4 are schematic cross-sectional views illustrating some structural variations of the bearing of the present invention.

In the modification shown in FIG. 2, the rotating shaft 10 and the bearing 30
The arrangement of the grooves and laminated rings in the large-diameter part and the reduced-diameter part in the embodiment shown in FIG. 1 is completely reversed. In detail,
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 mounted on the outside of the cylindrical surface of the large diameter portion 11 of the rotating shaft 10. A groove 12 is cut in the cylindrical outer surface of the reduced diameter portion of the rotating shaft IO, and a reduced diameter portion 33 of the bearing 30 is formed.
A circumscribed laminated ring 51 is attached to the cylindrical inner surface of the ring. The oil seal 53 is arranged behind the two laminated rings.

In the modification shown in FIG. 3, the rotation axis lO and the bearing are as follows:
The large diameter section and the reduced diameter section are reversed from the embodiment shown in FIG. Specifically, the reduced diameter section 13.33 is arranged on the right side and the large diameter section 11.31 is arranged on the left side. Reduced diameter portion 1 of rotating shaft 10
3 has a groove 12 cut therein, and a reduced diameter portion 33 of the bearing 30
A circumscribed type 31 ring 5J is attached to the holder. A groove 32 is cut in the large diameter portion 31 of the bearing, and an internal laminated ring 52 is attached to the large diameter portion li of the rotating shaft. The oil seal 53 is arranged behind the two laminated rings.

In the modification shown in FIG. 4, the rotating shaft 10 and the bearing 30
The arrangement of the grooves and laminated rings in the large diameter part and the reduced diameter part is completely reversed from that of the embodiment shown in FIG. In detail,
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 rotating shaft 10. A groove 12 is cut in the large diameter portion 11 of the rotating shaft, and a circumscribed 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.

Furthermore, if the rotating shaft IO in FIGS. 1 and 2 is the drive shaft of a motor, it will be impossible to assemble the bearing, but in that case, the large diameter portion of the rotating shaft may be used as a removable member.
After the bearing is assembled to the drive shaft, the members of the large diameter portion of the rotating shaft may be assembled and fixed.

In the modified examples shown in FIGS. 2 to 4, the laminated ring used may be either an internal type or a circumscribed type, or a combination of these may be used. In this case, the groove in which they are placed should have appropriate film clearance on either the rotating shaft or the bearing.

Effect of the invention The effects of the present invention are as follows.

l) The bearing under the liquid surface of the solid-liquid mixture has the following structure:
It is possible to prevent solids from entering between the rubbing surfaces of the rotating shaft and the bearing, and also to prevent liquid from leaking.

2) Can withstand continuous use for long periods of time.

3) Excellent dust-proofing effect, especially at low speed rotation, regardless of the rotation speed of the rotating shaft.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of an embodiment in which the subsurface bearing structure 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. 2 to 4 FIG. 2 is a schematic cross-sectional view illustrating some of various modifications. Explanation of symbols 1 Nidle, 2: End wall, 1O: Rotating shaft, 12 Large diameter portion, 12: Groove, 13: Reduced diameter portion, 30: Bearing, 31: Large diameter portion, 32: m, 33: Reduced diameter Part, 34: Punching, 35: 7 Ring part, 36: Packing, 51.52
: Laminated ring, 53° 54 = oil seal, 55, 56
: Bearing, 57 : SW IJ-bu, 58: O-ring, B: Bolt, S: Spiral, SC: Screw, SW: Sprocket wheel, SP spring pin,

Claims (1)

[Claims] [1] In the case where a groove is cut in one of the sliding surfaces of one rotating shaft and a bearing at two or more locations separated in the axial direction, and a laminated ring is placed in each groove area, the rotating shaft and the bearing are A bearing structure suitable for a spiral conveyor, characterized by forming stepped portions with different radii of sliding surfaces with the bearing, and arranging laminated rings at each of the different radius portions.