JP2904399B2 - Rotating structure of vertical planetary ball mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary ball mill, and more particularly to a rotating structure of a vertical planetary ball mill.

[0002]

2. Description of the Related Art The general structure of a vertical planetary ball mill is such that a plurality of mill pots that revolve under the rotation of a vertically supported spindle are evenly distributed around the vertically supported spindle (in the case of two, they are symmetrical). (If three or more, radially equidistant from the main shaft), and the mill pot itself rotates around its own rotation axis. Specifically, as shown in FIGS. 4A and 4B, the driving force of the motor 100 is transmitted to the main shaft 1a by the pair of sprockets 101 and the transmission chain 102. The rotation shaft 103 attached to the mill pot 2a is rotatably mounted on the mill main body fixed to the main shaft 1a. On the other hand, a sun sprocket 104 fixed so as not to rotate on the same axis as the main shaft 1a and a planet sprocket 105 provided around the rotation shaft 103 are connected to a conduction chain 106.
To rotate the rotating shaft 103 while revolving, and the mill pot 2a fixed to the rotating shaft is rolled. When the grinding medium B and the material to be crushed M are accommodated in the mill pot 2a and the motor 100 is rotated, the mill pot 2a rotates while revolving, and the grinding medium makes a specific motion by the centrifugal acceleration to pulverize the crushed material. That is, in a conventional rolling ball mill, a ball of a grinding medium and a crushing material cause a cascade motion in one rolling cylinder, and are crushed and crushed by the gravitational drop. The ball mill revolves at high speed,
The centrifugal force due to the rotation and the Coriolis force work synergistically to improve the pulverizing speed remarkably and to obtain fine powder having an excellent particle size distribution in a short time. In particular, the pulverizing power due to high-speed rotation is outstanding. For example, a fine powder having an average particle size of several microns can be obtained by charging only a few millimeters of silica sand and operating for only a few minutes. In the example of this figure, since it is a batch type, it is a typical configuration to remove only the mill pot 2a and collect the fine powder in the mill pot when the pulverization is completed.

On the other hand, FIGS. 5 (A), 5 (B) and 5 (C) show another type of vertical planetary ball mill, in which drive transmission is performed by two pairs of V pulleys 1 instead of the sprocket and the transmission chain of the previous example.
07, 108 and V belts 109, 11 wound therearound
0 is used to revolve the mill pot 2b while revolving on the supporting rotating disk 111. In this conventional example, the mill pot 2b is fixed on a supporting rotary plate 111 with a wire 112 and a screw 113, and is set to rotate and revolve with the plate.

[0004] The feature of the planetary ball mill is that a powdered material as a material to be crushed is charged into a mill pot together with a crushing medium, and a synergistic centrifugal effect of the centrifugal force due to the above-described revolving and rotating motions and the Coriolis force provides a short time. Is that the powder can be easily crushed and processed. The equivalent centrifugal acceleration due to the synergistic centrifugal effect of the planetary ball mill shown in FIGS.
G) several tens of times (several tens of G), the equivalent centrifugal acceleration of a conventionally used rolling ball mill is only 1 G, and even the equivalent centrifugal acceleration of a vibrating ball mill remains at about 10 G. It can be understood that a very large load is applied.

[0005] From this point of view, the vertical planetary ball mill shown here is a combination of a transmission chain and a sprocket,
Or, since the rotation structure is formed by the combination of the V pulley and the V belt, the higher the rotation speed of the main shaft, the more the load applied to the chain and the V belt increases, causing elastic deformation and plastic deformation of the material. As a result, an error is added to the rotation action to be tuned accurately, so that the crushing condition is not as expected. In order to absorb this fluctuation, it is necessary to adjust the tension of the conduction chain and V-belt, but on the other hand, aging and fatigue of the material also progress, so accurate adjustment is extremely difficult and the operating conditions are always improper. You have to worry about certain factors. In other words, a physical upper limit is imposed on the increase in the number of revolutions of the apparatus, and even if it is preferable only to prepare a laboratory sample, modification of a practical crushing apparatus or the substance itself, for example, mechanical alloying This is a major obstacle when applied to large-scale practical machines intended for mechanochemicals and the like.

[0006] As a practical planetary ball mill recently developed to remove this unstable element, a system in which a sun gear and a planetary gear mesh with each other is generally used as a structure that maintains the most stable operating conditions in a rotating structure. . FIG. 6 shows one of the recent prior arts proposed to solve the problems of the prior arts in FIGS. 4 and 5 described above.
No. 670) A sun gear 114 is fixed above a bearing portion of a vertically supported main shaft 1c, and a rigid disk-shaped mill main body 115 is fixedly mounted on the upper portion of the main shaft to revolve. A plurality of millpots 2c equally distributed into the planetary gears 116 are fitted therein, and are fixed below the millpots 2c.
Are meshed with the sun gear 114 described above. With this configuration, the mill pot 2c that revolves with the main shaft in the mill main body is relatively forced to rotate in the mill main body because it meshes with the stationary sun gear, and revolves around its own central axis while revolving. The function of also performing rotation is exhibited. Since the meshing of the gears is fundamental, it is stated that the rotation action is not lost due to deformation (elongation) such as a conduction chain or a V-belt, and that a reliable steady operation without the necessity of tension adjustment can be maintained.

[0007]

In a planetary ball mill, the centrifugal force increases as the number of revolutions and rotations increases, and the crushing force and the reforming action also increase accordingly. However, as described above, since the vehicle is operated under much harsher conditions than other conventional models, it was necessary to guarantee safety within certain limits. In particular, if the transmission medium for the driving force is subjected to a greater load than before, the tension adjustment is indispensable for both the conduction chain and the V-belt, and it becomes more difficult to control accurately. This and the overall structure are made up of a combination of many components, and the complexity of the function of each component to withstand severe loads and perform its function further exacerbates the difficulty of control.

The gear meshing method which has high rigidity and does not require complicated adjustment for the physical fluctuation of the conductive medium is a basic structure which can withstand high speed, and has been effective in solving the problems of the prior art. However, in order to support the high-speed meshing between the sun gear and the planetary gear, the combination of mechanical parts such as supporting the gear and always supplying an appropriate amount of lubricating oil becomes complicated,
In addition, the structure that maintains the overall rigidity must be reinforced firmly, and the weight must be set large. Therefore, even if the special features of the planetary ball mill are focused on and adopted in a wide range of fields, in order to increase the capability and scale up to a practical level, extremely high equipment costs and operating costs must be assumed. Inevitably, this is a major constraint on widely utilizing the excellent functions of the planetary ball mill itself,
This restriction becomes a major obstacle to the general purpose, and becomes a problem to be blocked.

[0009] Furthermore, in the gear meshing method, the sound generated from the mutual contact surface is amplified as the rotation speed becomes higher, which is likely to cause unbearable workplace noise. The use of relatively low noise synthetic resin gears is still only an incomplete measure,
One of the issues is that the more the noise reduction measures and safety measures are taken, such as covering the rotating parts with a safety cover, the more complicated maintenance work is added.

In order to solve the above-mentioned problems, the present invention provides stable revolving and rotating functions even without a complicated and sturdy structure as in the prior art, and maintains stable operating conditions. An object of the present invention is to provide a rotation structure of a vertical planetary ball mill that can be easily put into practical use and increased in size.

[0011]

The rotation structure of the vertical planetary ball mill according to the present invention is such that an elastic band 3 is non-rotatably mounted around the entire circumference of a vertically supported revolving shaft 1. The above-mentioned problem was solved by the outer peripheral surface 31 being constantly pressed against the outer peripheral surface 21 of the mill pot 2.

In the basic configuration described above, the most preferred embodiment is that the elastic band 3 is an air tire having an outer peripheral surface made of an elastic rubber whose internal pressure can be adjusted.

Further, in this configuration, a crushed material receiving port 41 is opened at the center at the tip of the vertically supported revolving shaft 1, and branched to a crushed material loading inlet 22 opened on each top surface of the plurality of mill pots 2. A revolving feeder 4 for arranging the branches 42;
A configuration having a continuous operation function provided with a discharge chute 43 connected to a processed product discharge port 23 opened at the center of the bottom of the mill pot is a very effective mode for increasing the size and practical use. In this case, the processing system 52 connected to the discharge chute 43 and separated by the screen 51 and the return system 53 to the crushed material receiving port 41 of the planetary ball mill.
If the sorting device 5 is interposed, an embodiment that leads to a more excellent effect is provided.

[0014]

When the vertically supported revolving shaft 1 is rotated by receiving a driving force, the plurality of mill pots 2 uniformly arranged around the revolving shaft 1 also rotate. The center axis of the mill pot 2 rotates on the same circumference around the revolution axis. On the other hand, the elastic band 3 fixed on the upper part of the bearing of the revolving shaft 1 is stationary irrespective of the revolving shaft, but the outer peripheral surface thereof is pressed against the outer peripheral surface of the revolving mill pot 2. Due to the restraining action of the surface of the elastic band 3, is relatively forced to rotate by itself, and rotates about the center axis of the mill pot 2 itself. That is, the mill pot 2 exhibits a basic planetary ball mill function of revolving while rotating.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is basically applicable to any type of vertical planetary ball mill as long as it is a vertical type. For example, FIGS. 2A and 2B show a modified embodiment in which the present invention is applied to the same model as the conventional batch type vertical planetary ball mill cited in FIGS. In order to restrain the mill pot 2 revolving with the revolving shaft 1 from the outer periphery of the batch type relatively small laboratory planetary ball mill for laboratory use, the elastic band 3 arranged on the outer periphery of the revolving shaft 1 is stationary. If the mill pot 2 is press-fitted to the mill pot 2 in a state, the mill pot 2 is revolved and the rotation action is induced, and accurate and stable operating conditions are guaranteed without troublesome adjustment of the tension of the conduction chain and the V-belt due to an excessive rotation load. The excellent advantage of this is obtained.

However, an example in which the present invention is most effectively implemented is a case where a function of continuous operation as shown in FIG. 1 is provided. According to this embodiment, the vertical planetary ball mill has the first efficiency. It has a structure that qualifies as a real machine that can perform large-scale processing. In the figure, a revolving shaft 1 is vertically supported by a revolving bearing base 11 fixed to a frame (not shown), and a driving force from an electric motor (not shown) is transmitted to a pulley 12 fixed to a lower end of the revolving shaft 1 so as to be inside the revolving bearing 13. Rotate with. The elastic band 3 is fixed to the upper part of the revolution bearing base 11 over the entire circumference, and is fixed in a stationary state irrespective of the rotation of the revolution shaft 1. An air tire made of an elastic rubber, which can easily adjust the internal pressure, is used as the elastic band 3 in this embodiment.

A revolving arm 24 is fixed above the revolving shaft 1 and synchronizes with the rotation of the revolving shaft 1.
The plurality of mill pots 2 evenly arranged in the orbit also revolve around the revolving shaft 1. The mill pot 2 is rotatably supported by a rotation bearing 25 in the revolving arm 24, and the outer peripheral surface 21 of the elastic band 3 is constrained so as not to rotate by being pressed against the outer peripheral surface 21, so that the mill pot 2 revolves. At the same time, a rotation action is induced in the rotation bearing as a reaction of the restraining force.

The crushed material M is fixed immediately above the revolving shaft 1 and is continuously supplied into the mill pot 2 from a revolving feeder 4 rotating with the shaft. In the example shown in the figure, the revolving feeder 4 has an opening 41 for receiving the crushed material at the center top surface and a branch 42 connected to the crushed material loading opening 22 opened at the top surface of the mill pot 2 revolving at the same speed. The crushed material M supplied at a constant rate from the crushed material receiving port 41 at the center of the revolving feeder 4,
It is distributed to each of the mill pots 2 at a substantially equal rate through the branch 42 and receives a grinding action and a reforming action by rotation and revolving together with a steel ball as a grinding medium B previously charged in the mill pot 2. Alternatively, depending on the purpose of the processing, the processing may be performed by the mutual collision and the rubbing action of only the crushed objects without using the grinding medium, which is the same as the conventional planetary ball mill.

When the vertical planetary ball mill is of a continuous type, it is necessary to give special consideration to the mechanism for discharging the processed product. Crushed material M supplied from above into the mill pot 2
Under the combined external force due to the secondary rotation movement unique to the device, it gradually descends by its own weight while floating around the outermost periphery of the revolution and approaches the bottom of the mill pot. A treated product discharge port 23 is opened at the center of the bottom of the mill pot, and the treated product m which has been sufficiently treated is discharged from the center because the particles are sufficiently fine and the effect of centrifugal force is weak. However, the coarse particles that have not been sufficiently pulverized are strongly subjected to the action of centrifugal force due to their large mass together with the pulverization medium, and are entrained in the outermost circumferential direction of the revolution in the mill pot 2,
It stays away from the central outlet 23 until it becomes finer.

The processed product discharge port 23 opened at the bottom of the mill pot 2 is connected to a discharge chute 43 fixed to the frame of the apparatus, and further discharged from a collection port 44 at the bottom of the chute onto a collection conveyor 45, not shown. Move to collection section.

Even when the continuous operation is basically performed, the operation of the apparatus is stopped at the end of work. At that time, the grinding medium B and the uncrushed material M in the mill pot 2 released from the centrifugal force are subjected to the processed product outlet at the bottom. There is a concern that it will fall out of 23 due to its own weight. In order to prevent this, it is possible to adopt a configuration in which a screen is stretched at the processed product discharge port 23 of the mill pot 2. However, always interposing the screen requires providing a strong resistance in view of the movement of the powder. Therefore, it is not always a good idea to ensure a smooth flow of processed products. For this purpose, as shown in FIG. 3, the lower part of the sieve is separated from the collecting conveyor 45 through the screen 51 into the processing line 52, and the upper part of the sieve is separated into the return line 53. The system preferably includes a sorting device 5 connected to the crushed material receiving port 41 at the center of the revolving feeder 4 in order to return the unmilled crushed material M or the crushed medium B flowing out of the mill pot back to the mill pot. is there.

[0022]

As described above, the present invention has a relatively simple structure, and therefore has a structure capable of sufficiently exhibiting revolving and rotating functions while being relatively light in weight. This is advantageous in that the field of application of the vertical planetary ball mill is greatly expanded. During operation, it is free from the complicated and skillful maintenance work of tension adjustment as in the prior art, and the quality of the processed product is stabilized and the reliability is improved. Further, as compared with the gear meshing method, the required dynamic energy is small, the structure is simplified and the weight is reduced, and the noise pollution is released. Conversely, since the size can be increased more easily than in the past, it is directly linked to the rationalization of production, and a wide variety of embodiments can be realized as treatment of various substances. In other words, it is expected to make a great contribution to the development and practical production of new functional materials, such as mechanical alloying and mechanochemicals, which have attracted attention in recent years, not only for crushing.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

FIGS. 2A and 2B are front views showing another example of the second embodiment.

FIG. 3 is a flowchart showing a sorting device as still another embodiment.

FIG. 4 is a front view (A) of the prior art and a cross section (B) of the same mill pot.

FIG. 5 is a perspective view (A), a front view (B) of another prior art,
It is a top view (C).

FIG. 6 is a vertical sectional front view of still another conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 orbital shaft 2 mill pot 3 elastic band 4 revolving feeder 5 sorting device 11 revolving bearing stand 12 pulley 13 revolving bearing 21 outer peripheral surface 22 crushed material inlet 23 processed product outlet 24 revolving arm 25 rotating bearing 31 outer peripheral surface 41 crushed material receiving port 42 Branch branch 43 Discharge chute 44 Recovery port 45 Recovery conveyor 51 Screen 52 Process route 53 Return route M Crushed material m Processed product

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-94748 (JP, A) JP-A-5-146698 (JP, A) JP-A-2-117035 (JP, U) JP-A-4-1748 102239 (JP, U) Table 3-3-503859 (JP, A) (58) Fields surveyed (Int. Cl. ⁶ , DB name) B02C 17/00-17/24

Claims (4)

(57) [Claims] 1. A plurality of mill pots 2 are arranged by uniformly distributing the circumference of a revolving shaft 1 rotated by receiving a driving force, and the mill pot 2 revolves and also rotates about its own central axis. In a planetary ball mill, an elastic band 3 is mounted so as not to rotate over the entire periphery of a vertically supported orbiting shaft 1, and the outer peripheral surface 31 of the elastic band 3 is attached to the outer peripheral surface 2 of the mill pot 2.
A rotating structure of a vertical planetary ball mill characterized by being constantly pressed to 1. 2. The rotating structure of a vertical planetary ball mill according to claim 1, wherein the elastic band 3 is an air tire having an outer peripheral surface made of an elastic rubber whose internal pressure can be adjusted. 3. The crushed material loading port 22 according to claim 1 or 2, wherein a crushed material receiving port 41 is opened at the center at the tip of the vertically supported revolving shaft 1, and opened on each top surface of the plurality of mill pots 2. A swivel feeder 4 having a branch branch 42 disposed therein, and an outlet 23 for the processed product opened at the center of the bottom of the mill pot.
The rotation structure of a vertical planetary ball mill characterized by continuous operation provided with a discharge chute 43 connected to the ball mill. 4. A sorting apparatus 5 according to claim 3, comprising a treated product path 52 connected to a discharge chute 43 and separated by a screen 51 and a return path 53 to the crushed material receiving port 41 of the planetary ball mill. The vertical structure of a vertical planetary ball mill.