Quantitative feeding device

Abstract

To improve shaft leakage prevention performance of a quantitative feeding device and extend service life.SOLUTION: A shaft seal part 15 which is filled with grease (lubricant) over the entire circumference in a partial space around rotating shafts 3, 4 in the shaft direction is formed between the inner peripheral surface of an annular bearing holder 6 that holds a bearing 5 and the outer peripheral surfaces of the rotating shafts 3, 4 with respect to the rotating shafts 3, 4 on both sides in the shaft direction of a drum 2 which temporarily stores to-be-transferred objects. As a result, even if to-be-transferred objects leak out from between an upper seat ring 7 and the drum 2, the flow of to-be-transferred objects in the shaft direction along the outer circumferential surfaces of the rotating shafts 3, 4 is blocked by the grease with which the shaft seal part 15 is filled, and furthermore, the grease in the shaft seal part 15 reduces wear on an X-ring 14 and an O-ring 13 that are arranged near the shaft seal part 15, thereby improving the performance of shaft leakage prevention.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a constant volume feeder that feeds a predetermined amount of a substance such as powder to a transport pipe or a subsequent process. [Background technology]

[0002] A known quantitative supply device used for supplying a fixed amount of powder or the like comprises a cylindrical casing having a supply port for the material to be transferred at its upper end and a discharge port for the material to be transferred at its lower end, and a cylindrical drum having both ends closed and an opening for receiving the material to be transferred, which is rotatably arranged around an axis perpendicular to the axis of the casing, and one of the rotating shafts extending axially from both ends of the drum and supported rotatably by bearings is driven to rotate, so that when the drum receives the material to be transferred and rotates integrally with the rotating shaft, the opening faces downward, and the material to be transferred falls from the opening and is discharged from the discharge port of the casing (see, for example, Patent Document 1).

[0003] In such constant volume feeders, in order to prevent the transported material from leaking axially outward along the outer circumferential surfaces of the rotating shafts on both sides of the drum (hereinafter referred to as "axial leakage"), a seat ring is incorporated that fits into the inner circumferential surface of the casing and slides against the outer circumferential surface of the drum, or an X-ring or O-ring is incorporated between the rotating shaft and the annular bearing holder that holds the bearing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-307189 Summary of the Invention [Problem to be solved by the invention]

[0005] However, even in constant volume feeders that have implemented the above-mentioned shaft leakage countermeasures, shaft leakage may not be sufficiently prevented due to wear on the contact surface of the seat ring with the drum or wear on the X-ring or O-ring, shortening the lifespan of the equipment. In particular, when the material being fed is small in particle size, such as lime powder, shaft leakage may occur within a short period of time after the start of use.

[0006] Therefore, an object of the present invention is to improve the axial leakage prevention performance of a constant volume feeder and to extend its life. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a cylindrical casing having a supply port at its upper end through which the object to be transferred is supplied and a discharge port at its lower end through which the object to be transferred is discharged, a cylindrical drum with both ends closed and rotatably disposed within the casing around an axis perpendicular to the axis of the casing, a rotary shaft extending in the axial direction from both ends of the drum, and bearings for rotatably supporting the rotary shaft, wherein the drum has an opening for receiving the object to be transferred supplied to the supply port of the casing, and the rotary shaft on one axial side of the drum is driven to rotate, thereby rotating the drum having received the object to be transferred. In this constant quantity supply device, when the drum rotates integrally with the rotating shafts on both axial sides and points the opening downward, the transferred material that falls from the opening is discharged from the discharge port of the casing. Of the rotating shafts on both axial sides of the drum, at least one of the rotating shafts that is driven to rotate in the axial direction is provided with an annular bearing holder that is arranged radially outside the rotating shaft and holds the bearing, and a shaft seal portion filled with lubricant is formed around the entire circumference of the space around a part of the axial direction of the rotating shaft between the inner surface of the bearing holder and the outer surface of the rotating shaft (Configuration 1).

[0008] According to the above-mentioned configuration 1, even if the transferred material has a small particle diameter, the axial flow of the transferred material leaking from between the casing and the drum along the outer circumferential surface of the rotating shaft can be blocked by the lubricant filled in the space between the bearing holder and the rotating shaft, thereby effectively preventing shaft leakage. Furthermore, if a sealing member such as an X-ring or O-ring is incorporated near the shaft seal, the lubricant reduces wear on the sealing member, and the sealing action of the sealing member is stably maintained for a long period of time, thereby more reliably preventing shaft leakage.

[0009] In the above-mentioned configuration 1, it is desirable that a seal member be provided between the shaft seal and the end face of the drum to prevent both leakage of the transferred material from the drum side to the shaft seal and intrusion of the lubricant from the shaft seal into the drum side (configuration 2). In this way, it is possible to further improve the shaft leakage prevention performance and also to prevent the lubricant from mixing into the transferred material.

[0010] In addition, in the above configurations 1 or 2, it is preferable that the bearing be a sliding bearing that is in sliding contact with the outer circumferential surface of the rotating shaft over a length of at least ¼ of the distance from the end face of the drum to the rotating shaft support position (configuration 3). Furthermore, in any of the above configurations 1 to 3, it is preferable that the shaft seals be provided on the rotating shaft on both axial sides of the drum (configuration 4). By adopting configuration 3 or 4, the rotational operation of the rotating shaft is stabilized, making it possible to prevent rattling of the rotating shaft from becoming a cause of shaft leakage. [Effects of the Invention]

[0011] As described above, the quantitative supply device of the present invention is configured so that, for at least the rotating shaft that is rotated, among the rotating shafts extending axially from both ends of the cylindrical drum, a shaft seal filled with lubricant is formed between the inner surface of the annular bearing holder that holds the bearing and the outer surface of the rotating shaft, thereby blocking the axial flow of the transported material along the outer surface of the rotating shaft with lubricant, thereby effectively preventing shaft leakage and allowing for stable use over a long period of time. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a longitudinal sectional front view of a constant volume supply device according to an embodiment of the present invention; [Figure 2] Cross-sectional view along line II-II in Figure 1 [Figure 3] (a) is a perspective view of the drum and rotating shaft in Figure 1 (with the opening of the drum facing upward), and (b) is a right side view of (a). [Figure 4] FIG. 2 is an enlarged longitudinal front view of the drive side shaft seal portion of FIG. 1. [Figure 5] FIG. 2 is an enlarged longitudinal front view of the non-drive side shaft seal portion of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0013] 1 and 2, the constant-quantity feeder includes a cylindrical casing 1 arranged with its axis pointing up and down, a cylindrical drum 2 arranged within the casing 1 so as to be rotatable about an axis perpendicular to the axis of the casing 1, rotating shafts 3 and 4 extending axially from both ends of the drum 2, bearings 5 ​​that rotatably support the rotating shafts 3 and 4, and annular bearing holders 6 arranged radially outward of the rotating shafts 3 and 4 and that hold the bearings 5.

[0014] The casing 1 has a supply port 1a at its upper end through which the material is supplied, and a discharge port 1b at its lower end through which the material is discharged. The peripheries of the supply port 1a and the discharge port 1b are formed in a flange shape, so that the supply port 1a can be connected to a device such as a hopper that stores the material, and the discharge port 1b can be connected to a transport pipe or a device for the next process.

[0015] The axial center of the casing 1 is formed with bulges at positions facing each other in the radial direction to accommodate the drum 2. Rotating shafts 3 and 4 on both axial sides of the drum 2 protrude from through holes provided between the bulges.

[0016] 3(a), drum 2 is closed at both ends and has a substantially pentagonal opening 2a in a circumferential region for receiving the objects to be transferred. That is, when opening 2a is facing upward, it receives and temporarily stores the objects to be transferred that are supplied to and fall through supply port 1a of casing 1, and when opening 2a is facing downward, it allows the stored objects to fall from opening 2a.

[0017] Seat rings 7 that fit into the inner peripheral surface of the casing 1 and come into sliding contact with the outer peripheral surface of the drum 2 are installed between the supply port 1a and discharge port 1b of the casing 1 and the position where the drum 2 slides against them. Each seat ring 7 is connected to an adjustment mechanism 8 that is attached to the outer peripheral surface of the casing 1 and adjusts the pressing force of the seat ring 7 against the drum 2.

[0018] 3(a) and 3(b), the drum 2 has circular recovery ports 2b on both end faces, and a J-shaped blade 2c, as viewed from the axial direction, is provided on the outer surface of the periphery of each recovery port 2b. As a result, the transferred material that leaks out from between the lower end of the upper seat ring 7 and the outer peripheral surface of the drum 2 is scraped up by the blades 2c on both sides and collected into the drum 2 through the recovery ports 2b.

[0019] The rotating shaft 3 on one axial side of the drum 2 (the right side in Figure 1) has a tip end portion having a key groove 3a connected to a driving device such as a motor (not shown) by a key, and is driven to rotate integrally with the drum 2 and the rotating shaft 4 on the other side (the left side in Figure 1) by the driving device.

[0020] As shown in Figure 1, an annular bonnet 9 is arranged between the bearing holder 6 on the side connected to the drive unit (drive side) and the casing 1, and this bonnet 9 is bolted to the casing 1, with the bearing holder 6 being bolted to the bonnet 9 together with a distance piece 10 arranged on the axial outside of it. Meanwhile, the bearing holder 6 on the opposite side from the drive unit (non-drive side) is bolted directly to the casing 1 together with a lid 11 arranged on the axial outside of it. In addition, thrust washers 12 are incorporated between the stepped surface in the axial center of the drive-side rotating shaft 3 and the distance piece 10, and between the end face of the non-drive-side rotating shaft 4 and the lid 11, respectively.

[0021] 1, 4, and 5, one O-ring 13 and two X-rings 14 facing each other across the O-ring 13 are arranged between the inner circumferential surfaces of the bearing holders 6 on both sides and the outer circumferential surfaces of the rotating shafts 3, 4. A shaft seal 15 filled with grease as a lubricant is formed over the entire circumference of the space around the rotating shafts 3, 4 between the O-ring 13 and the positions where each X-ring 14 is arranged.

[0022] Grease filled into shaft seal 15 on the drive side is supplied from grease nipple 16 provided on bonnet 9 via grease supply passages 9a, 6a in bonnet 9 and bearing holder 6. Then, by periodically supplying new grease with plug 17 provided on bonnet 9 removed, the grease in shaft seal 15 is replaced, and the grease that had been filled into shaft seal 15 up until then is discharged via grease drain passages 6b, 9b in bearing holder 6 and bonnet 9.

[0023] The grease filled in the shaft seal 15 on the non-drive side is supplied and discharged in the same way as on the drive side. However, on the non-drive side, there is no bonnet 9, so two grease nipples 16 and two plugs 17 are provided directly on the bearing holder 6, and the lubricating oil supplied to the shaft seal 15 from each grease nipple 16 via the grease supply passage 6a of the bearing holder 6 is discharged directly from the grease drain passage 6b of the bearing holder 6.

[0024] Between the outer circumferential surface of the driving-side rotating shaft 3 and the inner circumferential surface of the bonnet 9, there is provided a dust seal 18 as a sealing member that prevents both leakage of transferred materials from the drum 2 side to the shaft seal 15 and intrusion of grease from the shaft seal 15 to the drum 2 side, and a seal retainer 19 that is screwed to the inner circumferential surface of the bonnet 9 and holds down the dust seal 18. In addition, between the outer circumferential surface of the non-driving-side rotating shaft 4 and the inner circumferential surface of the through-hole in the casing 1, there is provided a dust seal 18 similar to that on the driving side, and a seal retainer 20 that holds down the dust seal 18.

[0025] The bearings 5 ​​supporting the rotating shafts 3, 4 are cylindrical sliding bearings with a flange at one end, and the inner end face of the flange is in close contact with the outer end face of the bearing holder 6, and is assembled in such a way that it is in sliding contact with the outer circumferential surfaces of the rotating shafts 3, 4 over a length that is at least ¼ of the distance from the end face of the drum 2 to the support positions of the rotating shafts 3, 4.

[0026] This quantitative supply device has the above-mentioned configuration, and when the rotating shaft 3 on one axial side of the drum 2 is rotated by the drive device, the drum 2, which has received the transferred material, rotates integrally with the rotating shafts 3 and 4 on both axial sides, and faces the opening 2a downward, the transferred material that falls from the opening 2a is discharged from the discharge port 1b of the casing 1.

[0027] Here, there is a risk that some of the material being transferred, supplied from a hopper or the like to the supply port 1a of the casing 1, will not enter the opening 2a of the drum 2 and will leak out from between the lower end of the upper seat ring 7 and the outer peripheral surface of the drum 2. However, the axial flow of the material being transferred along the outer peripheral surfaces of the rotating shafts 3 and 4 is blocked by a dust seal 18, an O-ring 13, two X-rings 14, and two shaft seals 15 filled with grease, so that axial leakage can be reliably prevented even if the particle diameter of the material being transferred is small.

[0028] The dust seal 18 has the function of preventing the leakage of the transported material from the drum 2 side to the shaft seal portion 15, and also of preventing grease from entering from the shaft seal portion 15 to the drum 2 side, so that it is also possible to prevent grease from getting mixed into the transported material.

[0029] In addition, the grease filled in the shaft seal portion 15 reduces wear on the O-ring 13 and the X-ring 14, thereby ensuring that the sealing action of these sealing members is maintained stably for a long period of time, thereby contributing to improved shaft leakage prevention performance.

[0030] Furthermore, in this constant volume feeder, the bearings 5 ​​supporting the rotating shafts 3, 4 are sliding bearings that come into sliding contact with the outer surfaces of the rotating shafts 3, 4 over a relatively long area, so the rotational movement of the rotating shafts 3, 4 is stable and there is little risk of shaft leakage caused by rattling of the rotating shafts 3, 4.

[0031] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0032] For example, it is desirable to provide grease-filled shaft seals on both axial sides of the drum as in the embodiment, but they may be provided only on the driving shaft.

[0033] Furthermore, the grease filled in the shaft seal portion can be replaced with other lubricants, and the dust seal can be replaced with other sealing materials. [Explanation of symbols]

[0034] 1 casing 1a Supply port 1b Outlet 2 drums 2a aperture 3rd and 4th rotation axes 5 bearings 6 Bearing holder 9. Bonnet 11 Lid 13 O-ring 14 x Rings 15 Shaft seal 16 Grease nipple 17 Plug 18 Dust seal (sealing material) 19, 20 Seal holder

Claims

1. The transfer device comprises a cylindrical casing having a supply port at an upper end through which the object is supplied and a discharge port at a lower end through which the object is discharged, a cylindrical drum arranged within the casing so as to be rotatable about an axis perpendicular to the axis of the casing and having both ends closed, a rotating shaft extending in the axial direction from both ends of the drum, and bearings for rotatably supporting the rotating shaft, the drum having an opening for receiving the object supplied to the supply port of the casing, In this quantitative supply device, when the rotary shaft on one side of the drum in the axial direction is rotated and the drum receiving the object rotates integrally with the rotary shafts on both sides of the axial direction and faces the opening downward, the object falls from the opening and is discharged from the discharge port of the casing, A constant-volume supply device characterized in that, of the rotating shafts on both axial sides of the drum, at least one of the rotating shafts that is driven in rotation is provided with an annular bearing holder arranged radially outward of the rotating shaft to hold the bearing, and a shaft seal portion filled with lubricant is formed around the entire circumference of the space around part of the axial direction of the rotating shaft between the inner surface of the bearing holder and the outer surface of the rotating shaft.

2. A quantitative supply device as described in claim 1, characterized in that a seal member is provided between the shaft seal portion and the end face of the drum to prevent both leakage of the transported material from the drum side to the shaft seal portion and intrusion of the lubricant from the shaft seal portion to the drum side.

3. 3. The constant-volume supply device according to claim 1, wherein the bearing is a sliding bearing that is in sliding contact with the outer circumferential surface of the rotating shaft over a length that is at least 1 / 4 of the distance from the end face of the drum to a supporting position of the rotating shaft.

4. 3. The constant volume supply device according to claim 1, wherein the shaft seals are provided on both axial sides of the rotary shaft of the drum.

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