JPH0889831A - Rotation structure of vertical planetary ball mill - Google Patents

Abstract

PURPOSE: To sufficiently develop revolution and rotation function by a simple structure by equally arranging the periphery of a revolution shaft to a plurality of mill pots and mounting an elastic strip on the entire periphery of the revolution shaft in a non-rotatable manner and bonding the outer peripheral surface of the elastic strip to the outer peripheral surface of the mill pot under pressure. CONSTITUTION: A revolution shaft 1 is vertically supported on a revolution shaft receiving base 11 to be rotated through the pulley 12 to which driving force is transmitted from an electromotor. An elastic strip 3 is fixed to the entire periphery of the upper part of the revolution shaft receiving base 11 and a revolution arm 24 is fixed to the upper part of the revolution shaft 1. The outer peripheral surface 21 of a mill pot 2 is bonded to the outer peripheral surface 31 of the elastic strip 3 under pressure to be restricted and, as the counter action of this restriction force, rotation action is induced in a rotation shaft receiving base 25. The matter M to be ground supplied from a receiving port 41 is distributed to each mill pot 2 through a branch passage 42 and treated along with grinding media B by grinding or modifying action due to rotation and revolution to be discharged to a recovery conveyor 45.

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 rotation structure of a vertical planetary ball mill.

[0002]

2. Description of the Related Art The general structure of a vertical planetary ball mill is that a plurality of mill pots that revolve around the rotation of a vertically-supported spindle are evenly distributed around a vertically-supported spindle (two symmetrically). If the number is three or more, they are arranged at equal distances from the main shaft), and the mill pot itself also rotates about 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 a pair of sprockets 101 and a transmission chain 102. The rotation shaft 103 attached to the mill pot 2a is rotatably attached to the mill 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 planetary sprocket 105 provided around the rotation shaft 103 are connected to the transmission chain 106.
To rotate the orbital shaft 103 while revolving around it, and roll the mill pot 2a fixed to the rotational shaft. When the crushing medium B and the object to be crushed M are housed in the mill pot 2a and the motor 100 is rotated, the mill pot 2a revolves around its own axis, and the crushing medium makes a unique motion due to centrifugal acceleration to crush the crushed material. That is, in the usual rolling ball mill, the balls of the crushing medium and the crushed material cause a cascading motion within one rolling cylinder, and the crushing and abrasion due to the gravity drop cause crushing and grinding. Ball mill revolves at high speed,
The centrifugal force due to the rotation and the Coriolis force work synergistically to improve the crushing rate remarkably and to obtain fine powder having an excellent particle size distribution in a short time. In particular, the crushing power by high-speed rotation is outstanding, and for example, a fine powder having an average particle size of several microns can be obtained by charging silica sand of several millimeters size and operating for only a few minutes. Since the example of this figure is a batch system, the typical configuration is to remove only the mill pot 2a and recover the fine powder in the mill pot after crushing is completed.

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

A feature of the planetary ball mill is that a powdery material which is an object 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 revolution or rotation and the Coriolis force causes a short time. The point is that powder particles can be easily crushed and processed. The equivalent centrifugal acceleration due to the synergistic centrifugal effect of the planetary ball mills shown in FIGS.
G), which is several tens of times (several tens of G) higher, and the equivalent centrifugal acceleration of the conventionally used rolling ball mill is only 1 G, and even the equivalent centrifugal acceleration of the vibrating ball mill remains at about 10 G, It can be understood that it is very heavy.

From this point of view, the vertical planetary ball mill shown here is a combination of a conductive chain and a sprocket,
Alternatively, since the rotation structure is formed by combining the V-pulley and the V-belt, the load on the chain and the V-belt increases sharply as the speed of rotation of the main spindle increases, causing elastic deformation and plastic deformation of the material, which causes the revolution. As a result, an error is added to the rotation action that should be tuned accurately, and a phenomenon occurs that the grinding conditions deviate from the planned grinding conditions. To absorb this fluctuation, it is necessary to adjust the tension of the transmission chain and the V-belt, but on the other hand, material aging and fatigue also progress, so accurate adjustment is technically difficult and the operating conditions are always uncertain. You have to worry about definite factors. That is, a physical upper limit is imposed on the increase in the number of revolutions of the apparatus, and even if it is suitable only for laboratory sample preparation, it is suitable for practical grinding equipment or modification of the substance itself, for example, mechanical alloying. However, it is a major obstacle in applying it to large-scale practical machines for mechanochemical purposes.

As a practical planetary ball mill developed in recent years to eliminate this unstable element, a system in which a sun gear and a planetary gear are meshed with each other in a rotation structure is generalized as a structure for maintaining the most stable operating condition. . FIG. 6 is one of the recent prior arts proposed to solve the problems of the prior arts of FIGS. 4 and 5 described above (Japanese Patent Laid-Open No. 3-337).
No. 670) A sun gear 114 is fixed to an upper portion of a bearing portion of a spindle 1c which is vertically supported, and a sturdy disc-shaped mill body 115 is fixed to the upper portion of the spindle so as to revolve and the inside of the disc-shaped body is revolved. A plurality of mill pots 2c evenly distributed are fitted into the planetary gears 116 fixed below the mill pots 2c.
Is meshed with the sun gear 114. With this configuration, the mill pot 2c, which revolves together with the main shaft in the mill body, is relatively forced to rotate in the mill body because it meshes with the stationary sun gear, and revolves around its own center axis while revolving. The function of performing rotation is also demonstrated. Since gears are basically meshed with each other, it is claimed that the rotation of the transmission chain and the V-belt due to the deformation (extension) of the rotation will not be lost, and that reliable steady operation without the need for tension adjustment can be maintained.

[0007]

In the planetary ball mill, the centrifugal force increases as the number of revolutions and revolutions of the planetary ball mill increases, and the crushing force and the modifying action also increase accordingly. However, as mentioned earlier, it is operating under much more severe conditions than other conventional models, so it had to be guaranteed within a certain limit to ensure safety. In particular, when the driving force transmission medium is subjected to an even greater burden than ever before, tension adjustment is indispensable for both the transmission chain and the V-belt, making accurate control more and more difficult. This and the entire structure are made up of a combination of many members, and the complexity of the function of each member bearing the severe load and exerting its function further aggravates the difficulty of control.

The gear meshing system, which has high rigidity and does not require any complicated adjustments to the physical fluctuations of the conductive medium, has a basic structure capable of withstanding high speed and was 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 gears, the combination of mechanical parts such as supporting the gears and constantly supplying an appropriate amount of lubricating oil becomes complicated,
In addition, the structure that maintains the overall rigidity must be reinforced and the weight must be set large. Therefore, even if we try to adopt it in a wide field by paying attention to the unique function of the planetary ball mill, in order to increase its capacity and scale it up to a practical level, we must assume extremely high equipment cost and operating cost. Inevitably, it becomes a big limitation in widely utilizing the excellent functions of the planetary ball mill itself, and it becomes large in size,
The more it is intended to be generalized, the more serious this constraint becomes a barrier and the problem is to be blocked.

Further, in the gear meshing system, the higher the speed of rotation, the more the sounds emitted from the mutual contact surfaces are amplified, and this tends to cause unacceptable workplace noise. Even if you use a relatively low noise synthetic resin gear, it is still an incomplete measure.
One of the challenges is that the more the soundproofing and safety measures are taken, such as covering the rotating part with a safety cover, the more complicated the maintenance work becomes, and the more both workability and environmental improvement are required.

In order to solve the above-mentioned problems, the present invention exerts stable revolution and rotation functions even if it is not a complicated and sturdy structure as in the prior art, and stable operating conditions are maintained. An object 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]

In the vertical planetary ball mill rotation structure according to the present invention, an elastic band 3 is non-rotatably mounted over the entire circumference of a revolving shaft 1 which is vertically supported, and the elastic band 3 is attached. The above-mentioned problem was solved by the outer peripheral surface 31 of No. 1 being constantly pressed against the outer peripheral surface 21 of the mill pot 2.

In the above-mentioned basic construction, it is most preferable that the elastic band 3 is specifically a pneumatic tire having an outer peripheral surface made of elastic rubber whose inner pressure can be adjusted.

Further, in this structure, a crushing object receiving port 41 is opened at the center of the end of the orbiting shaft 1 which is vertically supported, and is branched to the crushing object charging port 22 which is opened on each top surface of the plurality of mill pots 2. It comprises a swivel feeder 4 for arranging the branches 42,
A configuration having a continuous operation function including a discharge chute 43 to which a discharge port 23 of a processed product that opens at the center of the bottom of the mill pot is connected is a very effective mode in terms of upsizing and practical use. In this case, a treated product line 52 connected to the discharge chute 43 and separated by the screen 51 and a return line 53 to the crushed material receiving port 41 of the planetary ball mill.
If the sorting device 5 consisting of the above is installed, it becomes an embodiment which leads to a more excellent effect.

[0014]

When the revolving shaft 1 which is vertically supported receives the driving force and rotates, a plurality of mill pots 2 which are evenly arranged around the revolving shaft 1 also rotate. The central axis of the mill pot 2 rotates on the same circumference about the revolution axis. On the other hand, the elastic band 3 fixed to the upper part of the bearing of the revolving shaft 1 is stationary irrespective of the revolving shaft, but its outer peripheral surface is pressure-bonded to the outer peripheral surface of the revolving mill pot 2. Is constrained by the surface of the elastic band 3 and relatively forced to rotate, and rotates about the central axis of the mill pot 2 itself. That is, the mill pot 2 exhibits the basic action of a planetary ball mill in which it revolves around its axis while revolving.

[0015]

The present invention is basically applicable to any type as long as it is a vertical planetary ball mill. For example, FIGS. 2 (A) and 2 (B) 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. 4 and 5. As described above, even in the case of a batch type relatively small-sized planetary ball mill for a laboratory, in order to restrain the mill pot 2 that revolves with the revolution shaft 1 from the outer periphery, the elastic band 3 arranged on the outer periphery of the revolution shaft 1 is stopped. If it is crimped to the mill pot 2 in this state, the mill pot 2 will be revolved and its rotation will be induced, and accurate and stable operating conditions will be guaranteed without being bothered by tension adjustment of the transmission chain and V-belt due to excessive rotational load. The advantage is that

However, an example in which the present invention is most effectively carried out is a case where the function of continuous operation as shown in FIG. 1 is given, and this embodiment is the first vertical planetary ball mill to be efficient. It has a structure that includes both the actual and actual qualifications as an actual machine that enables large-scale processing. In the figure, the revolution shaft 1 is vertically supported by a revolution bearing stand 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 the lower end of the revolution shaft 13. To rotate. 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 regardless of the rotation of the revolution shaft 1. A pneumatic tire made of elastic rubber, which can easily adjust the internal pressure as the elastic band 3, is suitable in this embodiment.

The revolution arm 24 is fixed to the upper part of the revolution shaft 1 and synchronizes with the rotation of the revolution shaft 1.
A plurality of mill pots 2, which are evenly arranged inside, also revolve around the revolution shaft 1. The mill pot 2 is rotatably supported by a rotation bearing 25 in a revolution arm 24, and the outer peripheral surface 31 of the elastic band 3 is pressure-bonded to the outer peripheral surface 21 of the mill pot 2 so as not to rotate, and thus revolves. At the same time, as a reaction of this restraining force, a rotation action is induced in the rotation bearing.

The object to be crushed M is fixed directly above the revolving shaft 1 and is continuously fed into the mill pot 2 from a slewing feeder 4 which rotates together with the shaft. In the example shown in the figure, the swirl feeder 4 has a crushed material receiving opening 41 on the central top surface and a branching branch 42 connected to the crushed material loading opening 22 opened on the top surface of the mill pot 2 revolving at the same speed. The crushable object M supplied at a constant rate from the crushable object receiving port 41 in the center of the swivel feeder 4 is
It is distributed to the mill pots 2 at substantially equal ratios through the branch branches 42, and is subjected to the crushing action and the reforming action by the rotation and the revolution together with the steel balls which are the crushing medium B loaded in the mill pot 2 in advance. Alternatively, depending on the purpose of the treatment, there is a case where the treatment is carried out by mutual collision or rubbing action of only the objects to be crushed without using a grinding medium, which is no different from the conventional planetary ball mill.

When the vertical type planetary ball mill is of a continuous type, special consideration must be given to the mechanism for discharging the processed product in practice. The object to be crushed M supplied from above into the mill pot 2
Receives a composite external force due to the secondary rotary motion unique to the device, and while oscillating near the outermost periphery of the revolution, it gradually descends by its own weight and approaches the bottom of the mill pot. The processed product discharge port 23 is opened at the center of the bottom of the mill pot, and the processed product m, which has been sufficiently processed, has sufficiently fine particles and a weak centrifugal force. The coarse particles that have not been sufficiently crushed are strongly subjected to the action of centrifugal force due to their large mass together with the crushing medium, and are entrained in the outermost direction of revolution in the mill pot 2.
It stays away from the central discharge port 23 and stays until it becomes finer.

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

Even when the continuous operation is basically used, the operation of the apparatus is stopped at the end of the work. At that time, the grinding medium B in the mill pot 2 released from the centrifugal force and the unground crushed material M are processed product discharge ports at the bottom. There is a concern that it will fall from 23 due to its own weight. In order to prevent this, a configuration may be adopted in which a screen is stretched over the processed product discharge port 23 of the mill pot 2. However, the presence of the screen at all times provides a strong resistance in view of the movement of the powder. Therefore, it cannot always be said that it is a good measure for ensuring a smooth flow of processed products. For that purpose, as shown in FIG. 3, the lower part of the screen is separated into the processed product path 52 and the upper part of the screen is separated into the return system path 53 from the recovery conveyor 45 through the screen 51. The system path preferably comprises a sorting device 5 connected to the crushed object receiving port 41 at the center of the swivel feeder 4 in order to send the uncrushed crushed object M and the crushing medium B flowing out of the mill pot back into the mill pot. is there.

[0022]

As described above, the present invention has a relatively simple structure, and therefore has a structure that can sufficiently exhibit the functions of revolution and rotation while being relatively lightweight. This is advantageous in that it has the effect of greatly expanding the field of application of the vertical planetary ball mill. During operation, maintenance work, which requires skill due to the complexity of tension adjustment as in the past, is released, and the quality of processed products is stable and reliability is high. Further, 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. In other words, the size can be increased more easily than in the past, which directly leads to the rationalization of production and enables a wide variety of embodiments for treating various substances. In other words, it is expected that it will not only be used for mere crushing, but will also make a significant contribution to the development and field production of new functional materials such as mechanical alloying and mechanochemicals, which have been attracting attention in recent years.

[Brief description of drawings]

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

FIG. 2 is a front view showing another embodiment 2 according to (A) and (B).

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

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

FIG. 5 is a perspective view (A), a front view (B), and FIG.
It is a top view (C).

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

[Explanation of symbols]

 1 Revolving shaft 2 Millpot 3 Elastic band 4 Swivel feeder 5 Sorting device 11 Revolving bearing stand 12 Pulley 13 Revolving bearing 21 Outer peripheral surface 22 Crushed object inlet 23 Processed product discharge port 24 Revolving arm 25 Outer circumferential bearing 31 Outer peripheral surface 41 Crushed object receiving port 42 Branch branch 43 Discharge chute 44 Recovery port 45 Recovery conveyor 51 Screen 52 Process line 53 Return line M M crushed product m Processed product

Claims (4)

[Claims] 1. A plurality of mill pots 2 are arranged by evenly distributing the circumference of an orbiting shaft 1 which rotates by receiving a driving force, and the mill pots 2 revolve and also rotate about their own central axes. In a planetary ball mill, an elastic band 3 is non-rotatably mounted over the entire circumference of a revolving shaft 1 which is vertically supported, and an outer peripheral surface 31 of the elastic band 3 is an outer peripheral surface 2 of a mill pot 2.
1. The vertical rotation structure of the vertical planetary ball mill characterized by being constantly crimped to 1. 2. The rotation 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 elastic rubber whose internal pressure can be adjusted. 3. The object to be crushed 22 according to claim 1 or 2, wherein a crushed object receiving port 41 is opened at a center of a tip end of the orbiting shaft 1 which is vertically supported, and the crushed object inlet 22 is opened at each top surface of a plurality of mill pots 2. A discharge outlet 23 for processing products, which is provided with a swivel feeder 4 in which a branching branch 42 is disposed, and which is opened at the center of the bottom of the mill pot.
A vertical planetary ball mill rotation structure characterized by continuous operation with a discharge chute 43 connected to each other. 4. The sorting device 5 according to claim 3, comprising a treated product passage 52 connected to the discharge chute 43 and separated by a screen 51, and a return passage 53 to the crushed material receiving port 41 of the planetary ball mill. The rotation structure of the vertical planetary ball mill characterized by being equipped.