JP2013224209A - Intermediate bearing for vertical screw conveyor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermediate bearing for a vertical screw conveyor which can achieve cost-reduction of a bearing, does not require a grease supply unit, can reduce a filling frequency of grease within a fixed period and a filling amount of grease per once, and thus can reduce maintenance cost, and in which grease is hardly mixed in granular materials in conveyance.SOLUTION: A radial roller bearing is adopted as an intermediate bearing, so that cemented carbide used in a conventional slide bearing is unnecessary, and cost reduction of the bearing can be achieved. Further, friction resistance and friction heat of an inner ring and an outer ring are reduced than the slide bearing, a small amount of grease filling with a grease gun by several times per year is sufficient, and a filling frequency of grease during a fixed period and a filling amount of grease per once can be reduced. Consequently, maintenance cost of the intermediate bearing becomes low-cost, a grease supply unit is unnecessary, and installation cost can be reduced. Further, mixing of grease into granular materials during conveyance can be reduced.

Description

  The present invention relates to an intermediate bearing for a vertical screw conveyor, and more particularly to an intermediate bearing for a vertical screw conveyor that rotatably supports an intermediate portion of a rotating shaft of the vertical screw conveyor.

2. Description of the Related Art A cement tanker that transports a cement produced by a cement production plant by sea is known to have a vertical screw conveyor for loading cement from the hold to the outside of the ship. Since the vertical screw conveyor is a long object, in order to prevent the rotation of the rotating shaft during cement transportation, the middle part of the screw rotating shaft in the length direction is the length of the cylinder through the bearing holder. It is rotatably supported by an intermediate bearing fixed in the middle of the direction.
As a conventional intermediate bearing, for example, a plain bearing having a halved structure that is easy to maintain, such as that disclosed in Patent Document 1, is common. In the plain bearing of Patent Document 1, a cemented carbide with high wear resistance is provided on the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring, and grease is periodically supplied between the inner ring and the outer ring by a metering pump. By using, it is configured to reduce frictional resistance and frictional heat.

Japanese Patent Laid-Open No. 06-179517

However, since the intermediate bearing disclosed in Patent Document 1 is composed of a slide bearing, an expensive cemented carbide must be used, resulting in high bearing costs.
Also, in order to suppress the frictional resistance and frictional heat of the sliding bearing and prolong the service life of the intermediate bearing, it is necessary to install the grease supply unit on the vertical screw conveyor and inject grease frequently, increasing the initial cost. It was. Moreover, the amount of grease injected at one time is large, and the running cost is high.
Furthermore, the slide bearing has a large amount of grease leakage, and there is a possibility that the leaked grease is mixed into the cement being conveyed.

  Therefore, as a result of earnest research, the inventor has adopted a radial roller bearing in which a large number of rollers use a cage and are rotatably held between an inner ring and an outer ring instead of the conventional plain bearing. It was found that all the problems were solved, and the present invention was completed.

  This invention can reduce the cost of the bearing, does not require a grease supply unit in the vertical screw conveyor, and can reduce the number of times of grease injection and the amount of grease injected per time within a certain period, As a result, it is possible to reduce the maintenance cost, and further to provide an intermediate bearing for a vertical screw conveyor in which grease is difficult to be mixed into the granular material being conveyed in the cylinder.

  The invention according to claim 1 is the length of the rotating shaft among the screws housed in the cylinder for conveying the granular material and having the spiral blades around the outer peripheral surface of the rotating shaft that is long in the vertical direction. In the intermediate bearing for a vertical screw conveyor that supports a middle portion in the direction to be rotatable with respect to the cylindrical body, the intermediate bearing for the vertical screw conveyor is fixed to a middle portion in the length direction of the rotating shaft. A radial roller bearing in which a large number of rollers are rotatably sandwiched between an inner ring and an outer ring supported by the cylindrical body via an annular outer ring support provided in a frame-shaped bearing holder. An upper end surface of the roller bearing is covered with an annular upper bearing cover whose outer peripheral portion is fixed to the bearing holder in a state in which the rotating shaft is inserted into an inner space of the upper bearing cover. The lower end surface of the roller bearing is a vertical type whose outer peripheral portion is covered with an annular lower bearing cover fixed to the bearing holder in a state where the rotating shaft is inserted into the inner space of the lower bearing cover. This is an intermediate bearing for screw conveyors.

According to the first aspect of the present invention, since the radial roller bearing is adopted as the intermediate bearing, the expensive cemented carbide provided in the conventional sliding bearing becomes unnecessary, and the cost of the bearing can be reduced.
In addition, the friction resistance and frictional heat of the inner and outer rings are small compared to plain bearings. For example, a small amount (several milliliters) of grease is used several times a year using a hand-held grease gun. The number of injections and the amount of grease injected per time can be reduced. As a result, the maintenance cost of the intermediate bearing can be reduced. Further, since the number of grease injections and the amount of grease injection are small as described above, no grease supply unit is required for the vertical screw conveyor, and the equipment cost can be reduced. In addition, since the amount of grease injected is reduced, it is difficult for the grease to be mixed into the granular material being conveyed.
Further, since the upper bearing cover and the lower bearing cover are disposed so as to cover the upper end surface and the lower end surface of the radial roller bearing, the entire area of both ends in the axial direction of the radial roller bearing can be covered from the outside. . Thereby, it can prevent that the granular material which is conveying the cylinder penetrates into the bearing through the upper and lower end surfaces of the radial roller bearing.

The usage of the vertical screw conveyor is not limited. For example, it is possible to employ a vertical screw conveyor mounted on a particle carrier ship (such as a cement tanker) that transports particles such as cement or fly ash to the sea. Further, it may be a vertical screw conveyor for loading and unloading powder particles on silos and hoppers installed in various factories and plants.
The rotational speed of the rotating shaft is not limited. For example, in the case of a vertical screw conveyor for loading cement of a cement tanker from a hold, 100 to 500 rpm is preferable. If it is less than 100 rpm, the amount of cement transported per unit time is small, and it takes too much time to load cement in the hold. Moreover, if it exceeds 500 rpm, the blurring of a rotating shaft will become large, and it will be easy to generate | occur | produce damage to the bearing part of a vertical screw conveyor.
The shape of the spiral blade is arbitrary as long as it can be transported downward or upward within the cylinder by rotating with the rotation of the rotating shaft.
A radial roller bearing is a roller in which a large number of rollers are sandwiched between an inner ring and an outer ring using a circular retainer at a uniform angle and rotatable in the circumferential direction of the retainer.
The type of radial roller bearing is not limited. For example, a cylindrical roller bearing, a needle-shaped radial roller bearing, a tapered roller bearing self-aligning roller bearing, or the like can be employed. Further, a radial / thrust roller bearing that receives both a radial load and a thrust load at the same time may be used.

In addition, the radial roller bearing is preferably a type in which the bearing is vertically divided into two along two dividing lines facing each other at an interval of 180 °, because assembly and maintenance on the rotating shaft are facilitated. Of course, a non-divided type may be used.
In the case of a half-split radial roller bearing, the inner ring and the outer ring face each other at an interval of 180 °, and each is split into two parts (natural split) along two split lines inclined in opposite directions with respect to the axis. It is preferable that the pair of left and right partial inner rings or the pair of left and right partial outer rings be used. In this way, if the inner ring and the outer ring are each divided in half, when the partial inner rings and the partial outer rings are connected to each other (the end faces are brought into contact with each other), the partial inner rings and the partial outer rings are fitted into each other. The alignment in the axial direction can be easily and reliably performed.

Also, when the inner rings are assembled by connecting the partial inner rings, the outer raceway surface appears on the outer peripheral surface of the inner ring, and when the outer rings are assembled by connecting the partial outer rings, The inner raceway surface appears. At this time, steps are generated on the butted end surfaces of both partial inner rings and the butted end surfaces of both partial outer rings. Therefore, when each roller passes through each step portion, an impact force having a predetermined magnitude acts on the roller and the inner and outer rings. However, the contact between each step of the inclined type inner and outer rings and each roller is not a line contact when half divided along two dividing lines parallel to the axis, as in the case of conventional intermediate bearings. This is a point contact. That is, each roller sequentially passes the dividing line on both raceway surfaces from one end to the other, so the impact force when each roller passes through each stepped portion is smaller than in the conventional product, Damage to the rollers, inner and outer rings is also reduced. Therefore, a smooth rolling state of the roller is ensured for a long time, and the life of the intermediate bearing can be extended.
The shape of the roller varies depending on the type of radial roller bearing.

  According to a second aspect of the present invention, in the middle portion of the rotating shaft in the length direction, the rotating shaft is inserted into the inner space of the upper bearing cover and the inner space of the lower bearing cover. A neck portion to be provided, and a portion of the rotating shaft on the upper side of the neck portion so as to cover the upper portion of the neck portion and the upper bearing cover from the circumferential direction of the radial roller bearing. An annular upper dustproof cover that closes the gap between the portion above the neck portion of the shaft and the outer ring support portion is provided in a cantilevered state, and the portion of the rotating shaft below the neck portion is An annular bottom that closes the gap between the portion below the neck portion of the rotary shaft and the outer ring support portion so as to cover the lower portion of the neck portion and the lower bearing cover from the circumferential direction of the radial roller bearing. Dust cover is a vertical screw intermediate bearing conveyor of claim 1, which is circumferentially provided in a cantilever state.

According to the second aspect of the present invention, the portion of the rotating shaft that is rotatably supported by the radial roller bearing is the neck portion having a smaller diameter than the normal portion of the rotating shaft. As a result, when the radial roller bearing is provided in the normal (outer diameter) portion of the rotating shaft, the clearance (powder conveying space) between the outer peripheral surface of the rotating shaft and the inner peripheral surface of the cylindrical body in this bearing installation portion Compared to the above, it is possible to prevent clogging of the granular material here. However, if the radial roller bearing is installed in the neck portion in this way, even if both end surfaces in the axial direction of the radial roller bearing are covered by the bearing covers, the portion between the upper and lower sides of the rotating shaft neck portion and the outer ring support portion The granular material being conveyed flows into each gap. As a result, due to the action of the pressure of the granular material, the granular material enters the internal space of the radial roller bearing through the gap between the inner peripheral surface of each bearing cover and the outer peripheral surface of the neck portion, and this is the radial roller bearing. There was a possibility of causing seizure of the granular material inside.
Therefore, an upper dustproof cover is provided in a cantilevered state at a portion above the neck portion of the rotating shaft, and a lower dustproof cover is provided in a cantilevered manner at a portion below the neck portion. Thereby, each clearance gap between the part above and below the neck part of the rotating shaft and the outer ring support part is closed by the corresponding dustproof cover, and as a result, the granular material being conveyed is removed from the circumferential direction of the radial roller bearing. Intrusion into the bearing can be prevented.

The neck portion is a portion having a smaller diameter than the normal portion of the rotating shaft.
Of the rotating shaft, the portion above the neck portion refers to a divided portion above the neck portion when the rotating shaft is divided in the length direction with reference to the neck portion.
Of the rotating shaft, the portion below the neck portion refers to a divided portion below the neck portion when the rotating shaft is divided in the length direction with reference to the neck portion. In addition, when the flange is arrange | positioned at the both ends of the length direction of a neck part, you may provide both dustproof covers in the cantilever state to these flanges.
The upper dust-proof cover and the lower dust-proof cover cover the gap between the upper part of the rotating shaft and the outer ring support part or the gap between the lower part of the rotating shaft and the outer ring support part. It is an annular member for preventing the granular material from entering the intermediate bearing from the gap between the side bearing cover and the neck portion.
As a material of the upper dustproof cover and the lower dustproof cover, for example, an annular plate material made of metal or plastic can be employed.
It is preferable that the distance between the tip of the upper and lower dust-proof covers supported on the cantilever and the outer ring support portion be as close as possible because entry of the granular material into the bearing can be minimized.

According to a third aspect of the present invention, a pair of annular trapezoidal grooves is formed on the inner peripheral surface of the upper bearing cover and the inner peripheral surface of the lower bearing cover. Each of the trapezoidal grooves is provided around the gap between the inner peripheral surface of the upper bearing cover and the outer peripheral surface of the rotary shaft, and the inner peripheral surface of the lower bearing cover and the outer peripheral surface of the rotary shaft. An intermediate bearing for a vertical screw conveyor according to claim 1 or 2, wherein annular seal members for sealing the gap between the vertical screw conveyor and the annular bearing member are respectively fitted.
It is.

  According to the third aspect of the present invention, the inner peripheral surface of each bearing cover and the outer periphery of the rotating shaft are provided on the inner peripheral surface of each bearing cover by a pair of annular seal members provided via a trapezoidal groove. The gap with the surface is sealed. As a result, the effect of preventing the rotation failure of the rollers, which is generated when foreign matters such as powder particles moving through the cylindrical body enter the internal space of the radial roller bearing, is enhanced compared to the case where the bearing cover is provided. be able to.

As the upper and lower bearing covers, for example, annular plate members made of metal or plastic can be employed.
As a material for the seal member, for example, felt, rubber or the like can be employed. The seal member may be a labyrinth. Among these, as the felt material, for example, wool, various synthetic resin fibers, and various synthetic resin fibers and wool can be used. For example, as the blending ratio of rayon and wool, those having rayon of 10 to 30% and wool of 70 to 90% can be employed. If the blended hair of this composition is employed, a felt sealing member having high sealing performance with excellent wear resistance and durability can be obtained.
The number of seal members used in each bearing cover may be one or two or more.
As a cross-sectional shape orthogonal to the length direction of the seal member, for example, a circle, an ellipse, a rectangle, a trapezoid, or the like can be adopted. In particular, a trapezoidal shape corresponding to the trapezoidal groove is preferable.

According to the first aspect of the present invention, since the radial roller bearing is adopted as the intermediate bearing, the expensive cemented carbide used in the conventional plain bearing is not required, and the cost of the bearing can be reduced. .
In addition, the friction resistance and heat of the inner and outer rings are small compared to plain bearings. For example, a small amount of grease can be used several times a year using a grease gun that can be held by the operator. The number of grease injections per time can be reduced. As a result, the maintenance cost of the intermediate bearing can be reduced, and the grease supply unit is not required for the vertical screw conveyor, so that the equipment cost can be reduced.
Further, since the amount of grease injected is reduced, it is difficult for the grease to leak from the intermediate bearing, and it is difficult for the grease to be mixed into the powder particles being conveyed.
Further, since the upper end surface and the lower end surface (both end surfaces in the axial direction) of the radial roller bearing are covered with the pair of bearing covers, the entire area of both end surfaces of the radial roller bearing can be covered from the outside. Thereby, it can prevent that the granular material which is conveying the cylinder penetrates into the bearing through the upper and lower end surfaces of the radial roller bearing.

In particular, according to the second aspect of the invention, the portion of the rotary shaft that is rotatably supported by the radial roller bearing is a neck portion having a smaller diameter than the normal portion of the rotary shaft. The gap with the inner peripheral surface of the rotary shaft becomes larger than when a radial roller bearing is provided in the normal portion of the rotating shaft, and clogging of the granular material can be prevented.
In addition, since the upper dustproof cover is provided in a cantilevered state on the upper part of the rotating shaft, the lower dustproof cover is provided in a cantilevered state on the lower part of the neck part. The gaps between the upper and lower parts of the rotating shaft neck and the outer ring support are closed by the corresponding dust-proof covers.As a result, the granular material being transported from the circumferential direction of the radial roller bearing Intrusion can be prevented.

  According to the invention of claim 3, the gap between the inner peripheral surface of the bearing cover and the outer peripheral surface of the rotary shaft is sealed by a pair of annular seal members provided around the inner peripheral surface of each bearing cover. Seal with a member. As a result, as compared with the case where each bearing cover is simply provided, the effect of preventing the roller rotation failure caused by the powder particles being transferred through the cylindrical body entering the radial roller bearing can be further enhanced. .

It is a principal part expanded sectional view of the intermediate bearing for vertical screw conveyors which concerns on Example 1 of this invention. It is a longitudinal cross-sectional view which shows the use condition of the intermediate bearing for vertical screw conveyors which concerns on Example 1 of this invention. It is a disassembled perspective view of the intermediate bearing for vertical screw conveyors which concerns on Example 1 of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view including a partially broken view showing a bearing cover of an intermediate bearing for a vertical screw conveyor according to Embodiment 1 of the present invention. It is a front view which shows the inner ring | wheel of the intermediate bearing for vertical screw conveyors concerning Example 2 of this invention. It is a front view which shows the outer ring | wheel of the intermediate bearing for vertical screw conveyors concerning Example 2 of this invention. It is a principal part expanded sectional view of the intermediate bearing for vertical screw conveyors which concerns on Example 3 of this invention. It is a top view of the upper dustproof cover and lower dustproof cover of the intermediate bearing for vertical screw conveyors concerning Example 3 of this invention. It is a longitudinal cross-sectional view of the upper dustproof cover and lower dustproof cover of the intermediate bearing for vertical screw conveyors which concerns on Example 3 of this invention.

  Examples of the present invention will be specifically described below. Here, an intermediate bearing for a vertical screw conveyor that is mounted on a cement tanker and loads cement from the hold is taken as an example.

In FIG. 1, reference numeral 10 denotes an intermediate bearing for a vertical screw conveyor (hereinafter referred to as an intermediate bearing) according to Embodiment 1 of the present invention. The intermediate bearing 10 is a screw 13 accommodated in a cylindrical body 12 of the vertical screw conveyor 11. The middle part (two parts of the upper part and the lower part) of the rotating shaft 14 that constitutes a part in the vertical direction is rotatably supported in the internal space of the cylindrical body 12.
Hereinafter, these components will be described in detail.
As shown in FIG. 2, the vertical screw conveyor 11 is mounted on a cement tanker 15 that transports cement (powder particles) manufactured at a cement manufacturing plant by sea, and loads the cement from its hold 16 to the outside of the ship.

  The cylinder 12 is obtained by cylindrically processing a steel plate or a stainless steel plate, and is erected vertically near the hold 16. A loading box 60 in which one cement inlet / outlet 12a is formed on the surface of the hold is provided at the lower end of the cylinder 12, and the other cement inlet / outlet 12b is formed at the upper end of the cylinder 12. Has been. In the internal space of the cylindrical body 12, a screw 13 having a spiral blade 17 and a rotating shaft 14 is interposed via an upper end bearing 18 provided at the center of the upper end plate of the cylindrical body 12 and the pair of intermediate bearings 10. And can be rotated freely. A dust seal is applied to the upper end bearing 18 and grease is also injected, so that the cement raw material does not enter the bearing in a normal state.

The screw 13 is divided substantially evenly in the length direction. That is, the rotating shaft 14 and the spiral blade 17 are each divided in the length direction. The spiral blade 17 is provided continuously from the upper end portion to the lower end portion of the rotary shaft 14 and is configured so that the cement loading operation can be performed smoothly.
The rotating shaft 14 protrudes from the upper end bearing 18 to the upper side of the cylindrical body 12, and an output shaft of the motor 20 is connected to the protruding portion via a belt-type power transmission structure 20a having a pulley and an endless belt. . When the output shaft of the motor 20 rotates at a predetermined speed in a predetermined direction, the screw 13 pivotally supported between the upper end bearing 18 and each intermediate bearing 10 via the belt-type power transmission structure 20 a is supplied from the hold 16. Rotate in the cement loading direction.
In addition, an air slide 61 that air-transports cement toward the loading box 60 is inclined at the bottom of the hold 16. Thus, the cement in the hold is pneumatically transported in the direction of the arrow in FIG. Thereafter, the transported cement passes through the communication pipe 62 and the loading / unloading port 12 a and is sent to the loading box 60, where it is unloaded by the vertical screw conveyor 11.

As shown in FIGS. 1 and 3, a pair of small-diameter neck portions 21 are disposed in each divided portion of the rotating shaft 14, and the neck portions 21 are connected to the pair of intermediate bearings 10 and the pair of bearing holders 22. By supporting (shaft-supporting) the cylinder body 12 rotatably via the shaft, blurring of the screw (rotating shaft 14) 13 during cement conveyance is suppressed. Each divided portion of the rotary shaft 14 and the neck portion 21 are connected by fastening the flanges 14a and 21a with bolts.
The pair of bearing holders 22 and the pair of intermediate bearings 10 are each divided into two equal parts so that assembly to the neck portion 21 and subsequent maintenance are easy.

Hereinafter, the intermediate bearing 10 including these bearing holders 22 will be described in detail with reference to FIGS. 1, 3, and 4. The pair of bearing holders 22 and the pair of intermediate bearings 10 have the same structure. Therefore, only the upper bearing holder 22 and the upper intermediate bearing 10 will be described here.
As shown in FIGS. 1 and 3, the bearing holder 22 is a thick cast frame made of metal, and includes a holder main body 23 that is detachably connected to the cylindrical body 12, and a partial holder 24 that is detachably attached to the holder main body 23. And have. The holder main body 23 is integrally extended in the radial direction of the bearing holder 22 from both ends of the semicircular main body side outer ring support portion 25 and the main body side outer ring support portion 25 in a plan view, and is fixed to the cylindrical body 12. And a pair of T-arm portions 26 having a substantially T-shape in plan view. The lateral frame portions 26a at the distal ends of both T-arm portions 26 are bolted to the cylinder 12 via a pair of bolt holes, respectively. The partial holder 24 includes a semicircular partial outer ring support portion 27 in a plan view and a pair of short connecting frame portions 28 extending from both ends of the partial outer ring support portion 27 in the radial direction of the bearing holder 22. It consists of. The partial holder 24 is assembled to the holder main body 23 with a pair of bolt holes formed in the base portion of the T-arm portion 26 and a pair of separate bolts formed in the connecting frame portion 28 so as to overlap these bolt holes. This is done by screwing the bolts continuously into the bolt holes.

The intermediate bearing 10 includes an inner ring 29 fitted to the outer peripheral surface of the neck portion 21, an outer ring 30 fitted to the bearing holder 22, and a large number of cylindrical rollers (rollers) interposed between the inner ring 29 and the outer ring 30. ) 31, a cylindrical roller bearing (radial roller bearing) having a retainer 32 that holds the cylindrical rollers 31 at a uniform interval (uniform angle) in the circumferential direction, and an upper bearing cover 33A and a lower bearing cover 33B. It is.
The inner ring 29 is composed of a pair of partial inner rings 29A that are half-divided vertically along two dividing lines that are parallel to the axis and opposed at intervals of 180 °. Further, semicircular fitting grooves 29a are formed on the outer peripheral surfaces of both end portions in the length direction of each partial inner ring 29A in plan view. Each fitting groove 29a is fitted with a semicircular partial clamp frame 34A in a plan view for fastening the partial inner rings 29A to each other.
At the time of assembling the inner ring 29, these partial inner rings 29 </ b> A are abutted with each other so that the neck portion 21 is sandwiched from the outside, and this state is maintained, and the end of the partial clamp frame 34 </ b> A is formed. Screw the bolts continuously into the bolt holes. As a result, the corresponding partial clamp frames 34A are integrated to form a pair of upper and lower clamp frames 34, and the inner ring 29 is assembled from the pair of left and right partial inner rings 29A by the tightening force by these clamp frames 34. At this time, the outer raceway surface a on which each cylindrical roller 31 rolls appears at a portion between the upper and lower clamp frames 34 on the outer peripheral surface of the inner ring 29.

The outer ring 30 is composed of a pair of partial outer rings 30A that are half-divided vertically along two dividing lines that are parallel to the axis and opposed at an interval of 180 °. Further, inner flanges 30a each having a short width are formed at both ends in the length direction of each partial outer ring 30A. Between the upper and lower inner flanges 30a, a storage space for a cage 32 in which a large number of cylindrical rollers 31 are rotatably connected is formed.
When the outer ring 30 is assembled, first, the corresponding partial outer ring 30A is fitted (fitted) to the main body side outer ring support portion 25 of the holder main body 23 of the bearing holder 22 and the partial side outer ring support portion 27 of the partial holder 24, respectively. . Thereafter, the abutting surfaces of the respective partial outer rings 30A are matched to cover the retainer 32 attached to the inner ring 29 described later from the outside, and the holder main body 23 and the partial holder 24 are bolted while maintaining this state. Thus, the outer ring 30 is assembled. At this time, the inner raceway surface b on which each cylindrical roller 31 rolls appears on the inner peripheral surface of the outer ring 30.

Each cylindrical roller 31 is a cylindrical roller, and rolls on the outer raceway surface a on the outer peripheral surface of the inner ring 29 and on the inner raceway surface b on the inner peripheral surface of the outer ring 30, while centering on the axis of the intermediate bearing 10. And rotate. Therefore, the length of each cylindrical roller 31 is shorter than the width between the upper and lower clamp frames 34 disposed on the inner ring 29.
The cage 32 is a semi-circular band in plan view, and is accommodated in a roller formed by penetrating the inner and outer peripheral surfaces at angular positions (22.5 ° intervals) equally divided into 16 in the circumferential direction. A total of 16 cylindrical rollers 31 are rotatably supported in the space. The axis of each cylindrical roller 31 is parallel to the axis of the cage 32. The cage 32 is composed of a pair of partial cages 32A that are each half-divided vertically along two dividing lines that are parallel to the axis and opposed at an interval of 180 °. Eight cylindrical rollers 31 are arranged in each partial holder 32A.
At the time of assembling the cage 32, the partial cages 32A are arranged on the outer raceway surface a of the inner ring 29, and then the respective butted surfaces are aligned, and the partial cages 32A are screwed together while maintaining this state. By doing so, the cage 32 is assembled.

  As shown in FIGS. 1 and 4, each of the bearing covers 33 </ b> A and 33 </ b> B is a thick annular plate having a central portion arranged outwardly in a step shape. On the inner peripheral surface of each bearing cover 33A, 33B, a pair of annular seal members 35 that seal the gap between the inner peripheral surface and the outer peripheral surface of the rotary shaft 14 are arranged in the axial direction of each bearing cover 33A, 33B. Are spaced apart from each other. Each seal member 35 is composed of a pair of semi-circular partial seal members 35A in plan view.

Each partial seal member 35A is made of felt made of a mixture of 30% rayon and 70% wool. Since the blended hair having such a composition is employed, it has a high sealing performance with excellent wear resistance and durability. Further, since the seal member 35 has a double seal structure, the function of preventing cement from entering the internal space of the intermediate bearing 10 can be enhanced as compared with the case of a single seal member 35. Each seal member 35 has a trapezoidal cross section so that it does not easily protrude from a pair of upper and lower seal grooves 33a formed on the inner peripheral surface of each bearing cover 33A, 33B when the screw rotates.
The upper and lower bearing covers 33A and 33B are each composed of a pair of partial covers 33C that are half-divided vertically along two dividing lines that are parallel to the axis and opposed at an interval of 180 °. . These partial covers 33C are detachably screwed to the outer end surface of the main body side outer ring support portion 25 of the holder main body 23 and the outer end surface of the partial side outer ring support portion 27 of the partial holder 24, respectively.

Next, a method for loading cement from the hold 16 to the outside of the ship using the intermediate bearing 10 for a vertical screw conveyor according to Embodiment 1 of the present invention will be described with reference to FIGS.
The air slide 61 is operated in the hold, and the output shaft of the motor 20 is rotated in a predetermined direction in the vertical screw conveyor 11, and the screw 13 is moved 100 in the cement loading direction via the belt-type power transmission structure 20a. Rotate at ~ 500 rpm. As a result, the cement accumulated in the hold 16 is pneumatically transported in the direction of the arrow in FIG. 2 by the air slide 61 and flows into the loading box 60 of the vertical screw conveyor 11 through the communication pipe 62 and the inlet / outlet 12a. As the screw 13 rotates, it passes through the inside of the cylinder 12 and is unloaded from the hold 16.
At this time, each neck part 21 of the rotating shaft 14 is rotatably supported by the pair of upper and lower intermediate bearings 10, and the screw 13 is prevented from shaking. In each intermediate bearing 10, each cylindrical roller 31 rotates around the axis of the rotating shaft 14 while rolling on the inner and outer raceways a and b.

As described above, since the radial roller bearing is adopted as the intermediate bearing 10, the expensive cemented carbide used in the conventional sliding bearing becomes unnecessary, and the cost of the intermediate bearing 10 can be reduced.
Further, by adopting the cylindrical roller bearing, the friction resistance and frictional heat of the inner and outer rings 29 and 30 are smaller than that of the sliding bearing. For example, a vertical gun that uses a grease gun that can be held by the operator several times a year or about 1000 hours. Even after the mold screw conveyor 11 is used, even a few milliliters of grease can be sufficiently used at one time, so that the number of times of grease injection in a certain period and the amount of grease injected per time can be reduced. As a result, the maintenance cost of the intermediate bearing 10 can be reduced. In addition, the vertical screw conveyor 11 does not require a grease supply unit, and the equipment cost can be further reduced.

Furthermore, since the pair of bearing covers 33 are disposed at both ends of the intermediate bearing 10 in the axial direction, the entire area of both end faces of the intermediate bearing 10 can be covered from the outside. Thereby, it can prevent that the cement which is conveying the cylindrical body 12 penetrate | invades in a bearing through the upper-lower-end surface of the intermediate bearing 10. FIG.
Furthermore, since the gap between the inner peripheral surface of both bearing covers 33A and 33B and the outer peripheral surface of the rotating shaft 14 is sealed by the annular seal member 35, both bearing covers 33A and 33B are provided. As compared with the above, it is possible to further enhance the effect of preventing the rotation failure of the cylindrical roller 31 caused by the cement being transferred through the cylindrical body 12 entering the intermediate bearing 10.

Next, an intermediate bearing for a vertical screw conveyor according to Embodiment 2 of the present invention will be described with reference to FIGS.
As shown in FIGS. 5 and 6, the feature of the intermediate bearing 10 </ b> A of the second embodiment of the present invention is that it is opposed to the inner ring 29 of the first embodiment at intervals of 180 °, and each has an angle θ with respect to the axis. An inner ring 50 composed of a pair of left and right partial inner rings 50A that are half-divided (naturally divided) along two dividing lines L1 that are inclined only is adopted, and instead of the outer ring 30 of the first embodiment, the inner rings 50 face each other at intervals of 180 °. Thus, an outer ring 51 composed of a pair of left and right partial outer rings 51A divided in half along two dividing lines L2 inclined in a horizontal V shape with respect to the axis is employed.

If the inner ring 50 and the outer ring 51 are each divided in half, stepped portions appear on the butted end surfaces of both partial inner rings 50A and the butted end surfaces of both partial outer rings 51A. Therefore, when each cylindrical roller 31 passes through each stepped portion, a predetermined magnitude of impact force acts on the cylindrical roller 31 and the inner and outer rings 50 and 51. However, the contact between the stepped portions of the outer rings 50 and 51 and the cylindrical rollers 31 with the dividing lines L1 and L2 being inclined is divided into two parts parallel to the axis as in the case of the intermediate bearing 10 of the first embodiment. It is not a line contact when it is divided in half along the line, but a substantially point contact. That is, since each cylindrical roller 31 sequentially passes through the dividing lines L1 and L2 on both raceway surfaces a and b from one end to the other end, the impact force when each cylindrical roller 31 passes through each stepped portion is an example. 1 and the damage to the cylindrical rollers 31 and the inner and outer rings 50 and 51 due to this impact is reduced. Therefore, a smooth rolling state of the cylindrical roller 31 is ensured for a long time, and the life of the intermediate bearing 10A can be extended.
Other configurations, operations, and effects are substantially the same as those of the first embodiment, and thus description thereof is omitted.

Next, with reference to FIGS. 7-9, the intermediate bearing for vertical screw conveyors concerning Example 3 of this invention is demonstrated.
As shown in FIGS. 7 to 9, the feature of the intermediate bearing 10 </ b> B of the third embodiment of the present invention is that the divided portion 14 </ b> A on the upper side of the neck portion 21 of the rotating shaft 14, specifically, the divided portion 14 </ b> A on the upper side. On the outer peripheral surface of the flange 21a on the upper side of the neck portion 21 that is directly connected to the neck portion 21, a clearance S1 between the divided portion 14A above the neck portion 21 of the rotating shaft 14 and the main body side outer ring support portion 25 and the partial side outer ring support portion 27. An annular upper dustproof cover 60 that covers the outer periphery of the rotary shaft 14 is provided in a cantilevered manner, and the divided portion 14B of the rotary shaft 14 below the neck portion 21, specifically, the flange 21 a below the neck portion 21 is provided. On the outer peripheral surface, an annular lower dustproof cover 61 that can close the gap S2 between the divided portion 14B below the neck portion 21 of the rotating shaft 14 and the main body side outer ring support portion 25 and the partial side outer ring support portion 27 is cantilevered. Points that are installed in the state A.
Both dust covers 60 and 61 are made of steel. Further, when the dust covers 60 and 61 are provided around the upper and lower flanges 21a of the neck portion 21, the upper and lower divided portions 14A and 14B have a larger diameter than the bolt-connected flange 21a. Using the edges of the divided portions 14A and 14B as a guide, the dust covers 60 and 61 can be easily positioned.

The upper dust cover 60 covers the gap S1 between the upper divided portion 14A and the outer ring support portions 25 and 27, thereby covering the upper portion of the neck portion 21 and the upper bearing cover 33A from the circumferential direction of the intermediate bearing 10B. Can do. Further, the lower dust-proof cover 61 closes the gap S2 between the lower divided portion 14B and the outer ring support portions 25 and 27, so that the lower bearing cover 33B of the neck portion 21 and the lower bearing cover 33B can be connected to the intermediate bearing 10B. It can be covered from the circumferential direction.
The upper dustproof cover 60 and the lower dustproof cover 61 are vertically divided into two parts, such as an upper part dustproof cover 60A and a lower part dustproof cover 61A, so that assembly of the neck portion 21 to the flange 21a and subsequent maintenance are easy. It is divided (FIGS. 8 and 9). Both partial dustproof covers 61A and 61B are connected by screwing bolts 63 into a pair of nut pieces 62 fixed to both ends of the partial dustproof covers 61A and 61B in the length direction. Further, the inner peripheral surfaces of the leading edge portions of the dustproof covers 60 and 61 are formed on the inner peripheral surfaces of the bearing covers 33A and 33B in order to close gaps between these inner peripheral surfaces and the outer peripheral surfaces of the corresponding bearing covers 33A and 33B. An annular seal ring 64 is fixed over the circumference. Each seal ring 64 is spot welded at a predetermined pitch in the circumferential direction of the corresponding bearing cover 33A, 33B in order to prevent distortion of the seal ring 64. Further, these seal rings 64 are also divided into two equal parts in a vertical division into a pair of partial seal rings 64A (FIGS. 8 and 9).

When the portion of the rotary shaft 14 rotatably supported by the intermediate bearing 10B is a neck portion 21 having a smaller diameter than the normal portion of the rotary shaft 14, the outer peripheral surface of the rotary shaft 14 in the bearing installation portion of the vertical screw conveyor 11 And the inner peripheral surface of the cylindrical body 12 (cement conveyance space) are larger than when the intermediate bearing 10B is provided in the normal (outer diameter) portion of the rotating shaft 14. As a result, it is possible to prevent clogging of cement at the bearing installation portion.
However, if the intermediate bearing 10B is installed in the neck portion 21, even if both end surfaces in the axial direction of the intermediate bearing 10B are covered with the bearing covers 33A and 33B, the upper and lower portions 14A, 14A, The cement being conveyed flows into the gaps S1 and S2 between 14B and the outer ring support portions 25 and 27. Therefore, due to the action of the pressure of the granular material, cement enters the internal space of the intermediate bearing 10B from the gap between the inner peripheral surface of each bearing cover 33A, 33B and the outer peripheral surface of the neck portion 21, and this causes Cement seizure easily occurs in the intermediate bearing 10B.

  However, in Example 3, since the upper dustproof cover 60 is provided around the upper portion 14A and the lower dustproof cover 61 is provided around the lower portion 14B in a cantilever state, the upper and lower portions 14A, 14B and The gaps S1 and S2 between the outer ring support portions 25 and 27 are closed by the corresponding dustproof covers 50A and 50B. As a result, it is possible to almost completely prevent cement being conveyed from entering the intermediate bearing 10B from the circumferential direction of the intermediate bearing 10B.

  The present invention is useful as an intermediate bearing for a vertical screw conveyor for transferring various powder particles in the vertical direction.

10, 10A, 10B Intermediate bearing for vertical screw conveyor,
13 screw,
14 rotation axis,
14A The upper part of the neck part,
14B The part below the neck,
17 Spiral feather,
21 neck,
29,50 inner ring,
30, 51 outer ring,
31 Cylindrical rollers
33 bearing cover,
35 Seal member 60 Upper dust cover,
61 Lower dust cover,
S1, S2 gaps.

Claims (3)

Of the screw accommodated in the cylindrical body for conveying the granular material and having a spiral blade provided around the outer peripheral surface of the rotary shaft that is long in the vertical direction, the middle portion in the length direction of the rotary shaft is the cylindrical body. In an intermediate bearing for a vertical screw conveyor that is rotatably supported with respect to
The intermediate bearing for the vertical screw conveyor is supported by the cylindrical body via an inner ring fixed to a middle portion in the length direction of the rotating shaft and an annular outer ring support portion provided in a frame-shaped bearing holder. A radial roller bearing that holds a large number of rollers rotatably between the outer ring and
The upper end surface of the radial roller bearing is covered with an annular upper bearing cover whose outer peripheral portion is fixed to the bearing holder in a state where the rotating shaft is inserted into the inner space of the upper bearing cover,
The lower end surface of the radial roller bearing is covered with an annular lower bearing cover whose outer peripheral portion is fixed to the bearing holder in a state where the rotating shaft is inserted into the inner space of the lower bearing cover. Intermediate bearing for vertical screw conveyor. A neck portion that is smaller in diameter than the rotation shaft and inserted into the inner space of the upper bearing cover and the inner space of the lower bearing cover is provided in the middle portion of the rotation shaft in the length direction,
Of the rotating shaft, the portion above the neck portion is located above the neck portion of the rotating shaft so as to cover the upper portion of the neck portion and the upper bearing cover from the circumferential direction of the radial roller bearing. An annular upper dustproof cover that closes the gap between the outer ring support portion and the outer ring support portion is provided in a cantilevered state,
A portion of the rotating shaft below the neck portion is provided below the neck portion of the rotating shaft so as to cover the lower portion of the neck portion and the lower bearing cover from the circumferential direction of the radial roller bearing. The intermediate bearing for a vertical screw conveyor according to claim 1, wherein an annular lower dustproof cover that closes a gap between a side portion and the outer ring support portion is provided in a cantilevered manner. On the inner peripheral surface of the upper bearing cover and the inner peripheral surface of the lower bearing cover, a pair of annular trapezoidal grooves are provided around the entire circumference of these inner peripheral surfaces, respectively.
All the trapezoidal grooves seal the gap between the inner peripheral surface of the upper bearing cover and the outer peripheral surface of the rotary shaft and the gap between the inner peripheral surface of the lower bearing cover and the outer peripheral surface of the rotary shaft. The intermediate bearing for a vertical screw conveyor according to claim 1 or 2, wherein an annular seal member is inserted.

Images