JPH0685863B2 - Magnet drive stirrer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a stirring device for stirring a substance inside a stirring tank in a sealed state, based on a magnet drive system,
Specifically, it relates to the improvement of the magnet drive part.

(B) Conventional technology In general, a stirring device used in an autoclave, etc., uses a partition to completely prevent the leakage of the contents from the stirring tank, especially under pressure conditions, in order to prevent the leakage inside the stirring tank and the driving part. A method of separating and driving magnetically between them is used.

Conventionally, the magnetic drive stirring device rotatably supports a shaft having stirring blades fixed inside a casing whose upper part is hermetically sealed, and also rotatably supports a holder interlocking with a drive device outside the casing. Further, a plurality of long magnets are fixed to the shaft and the holder in a row in the axial direction so as to face each other with a casing in between. The rotation of the holder is transmitted to the shaft via the magnetic force of the magnet.

Therefore, in the conventional stirrer, most of the gravity acting on the shaft is received by the bearing.

(C) Problems to be Solved by the Invention By the way, since the bearing is installed in a narrow space in the casing surrounding the shaft, it is unavoidable to use a bearing having a relatively small thrust load capacity.

On the other hand, recently, the types and sizes of agitation devices have been diversified with the development of fine chemicals, bioindustries, etc., and a large-sized device in which agitation blades are heavy and large gravity acts on the shaft is also demanded. There is.

For this reason, in the method of supporting the shaft gravity by the bearing, a large thrust load acts on the bearing and the life of the bearing is shortened. Especially, when continuous operation for a long time is required, the bearing is replaced during operation. However, there is a possibility that the reliability of the device may be reduced.

Therefore, an object of the present invention is to provide a magnet drive agitation device in which not only the rotation direction is supported by a magnet but also an axial force is supported, thereby eliminating the above-mentioned problems. .

(D) Means for Solving the Problem The present invention has been made in view of the above circumstances,
As shown in FIG. 2 and FIG. 2, each inner magnet 3 fixed to the shaft 2 and each outer magnet 6 fixed to the holder 5 are divided into a plurality of pieces so as to face each other with the casing 1 constituting the pressure partition wall facing each other. And then configure (3a, 3b
, 6a, 6b ...), and these magnet pieces 3a ..., 6a ... are arranged so as to have different poles from those adjacent to each other in the axial direction, so that not only in the rotating direction but also in the axial direction. A suction force is generated so as to be aligned, and gravity acting on the shaft is carried by the suction force in the axial direction. In particular, the inner magnet pieces 3a ... Are arranged with a predetermined amount of downward displacement relative to the outer magnet pieces 6a .. Preferably.

(E) Operation Based on the above configuration, when the holder 5 rotates together with the external magnet 6 based on the rotation from the drive device, the magnetic circuit formed through the casing 1 made of a non-magnetic material (see FIG. 2 (b)) The shaft 2 rotates integrally with the internal magnet 3, whereby the stirring blades connected to the shaft 2 rotate to stir the contents in the sealed stirring tank.

At this time, a relatively large gravity always acts on the internal members, that is, the stirring blades, the shaft 2, the internal magnet 3, etc., but since the magnets 3 and 6 are divided into a plurality of pieces, each magnet piece 3a ..., 6a ... A biasing force in a direction in which the parts are aligned with each other acts (see FIG. 1 (b)), and the biasing force acts so as to oppose the gravity.

(F) Example Hereinafter, an example according to the present invention will be described.

As shown in FIG. 3, the magnetic drive stirring device 10 has a casing 1 made of a non-magnetic material that withstands a predetermined pressure such as stainless steel, and the casing 1 has a cap 11 and a cap nut 12 on the upper portion thereof. Is fixed and sealed, and the housing 13 is fixed to the bottom of
The housing 13 may be hermetically attached to the stirring tank 15. A shaft 2 is rotatably supported inside the casing 1 and the housing 13 by bearings 16 and 17, and the shaft 2 is divided at an intermediate portion thereof and integrated through a thrust ring 19. And the ring 19 abuts on the bearing 17, supporting the gravity acting on the shaft 2 and adjusting the axial position. Furthermore, shaft 2
A pin 21 in which a shaft rotation speed detection magnet 20 is embedded is fixed to the upper end of the, and a magnetic rotation sensor 22 is installed in the cap 11 part, and the rotation sensor 22 can detect the magnet 20. Thus, the rotation of the shaft 2 can be detected outside the casing 1. A stirring shaft 25 having various stirring blades 25a is fixed to the lower portion of the shaft 2 by a coupling 23 so as not to rotate. On the other hand, the holder 5 is rotatably supported outside the casing 1 via ball bearings 26, 26.
The ball bearing 26 located outside the casing can support a large thrust force, and the support 27 and the nut 29 are positioned in place. Furthermore,
A pulley 30 is formed integrally with the holder 5, and V
A predetermined torque is transmitted from a driving device such as a motor via the belt. The housing 13 has a cooler jacket 36
Is welded, water is circulated in a cooler chamber 37 constituted by the housing 13 and a jacket 36, and a bearing is
Absorbs heat generated at 17. The cooler room 37 is
The arrangement of the magnet according to the present invention significantly reduces the thrust force from the shaft 2 acting on the bearing 17, and can be omitted.

As will be described in detail with reference to FIGS. 1 and 2, a sleeve 31 made of a magnetic material is fitted on the shaft 2, and the outer peripheral surface of the sleeve 31 has a predetermined axial length every 30 degrees. The magnets 3 are arranged in a row across each magnet 3
Spacer made of non-magnetic material between the circumferential direction of
32 are provided, and these magnets 3 and spacers are further provided.
A cylindrical liner 33 made of a non-magnetic material is fitted around the outer circumference of 32 to form an internal magnet unit I. On the other hand, a sleeve 35 made of a magnetic material is also formed on the inner peripheral surface of the holder 5.
Are fitted and the outer magnets 6 are fixed to the inner peripheral surface of the sleeve 35 at intervals of 30 degrees so as to correspond to the inner magnets 3 ,. Therefore, the internal magnet unit I and the external magnet unit O form a magnetic circuit in the rotating direction with the casing 1 interposed therebetween, as shown in FIG.

The inner magnet 3 and the outer magnet 6 are divided into a large number in the axial direction, and the divided magnet pieces 3a, 3b ..., 6a, 6b ... Are adjacent to each other with a spacer 37. The magnets are arranged so that the N and S poles are reversed. Furthermore, internal magnet pieces 3a, 3
b ... are displaced in advance downward by a predetermined amount c with respect to the external magnet pieces 6a, 6b. Therefore, as shown in FIG. 1 (b), the divided magnet pieces 3a, 3b ..., 6a, 6
A magnetic circuit is formed such that the inner magnet pieces 3a ... Are pulled up toward the outer magnet pieces 6a.

Since the present embodiment is configured as described above, the housing
13 is hermetically attached to the stirring tank 15, and a belt is attached to the pulley 30 of the holder 5 to interlock with the driving device. In this state, in the stirring device 10, the inside of the stirring tank 15 is completely separated from the outside by the casing 1, the housing 13 and the cap 11, and the stirring shaft 25 extends into the stirring tank 15.
It is possible to apply a predetermined high pressure in the stirring tank 15. Then, when the pulley 30 and the holder 5 integrated with the pulley 30 are rotated based on the drive of the driving device, the outer magnet unit O integrated with the holder 5 absorbs the inner magnet unit I with the casing 1 interposed therebetween and integrally rotates. As a result, the shaft 2 inside the casing 1 rotates. Then, the stirring shaft 25 integrally rotates via the coupling 23,
The predetermined stirring blade 25a is rotated to stir the contents in the stirring tank 15. The rotation of the shaft 2 is monitored by the sensor 22 detecting the rotation of the rotation speed detecting magnet 20 embedded in the pin 21.

At this time, as shown in FIG.
At each boundary of 3a ..., 6a ..., a biasing force that pulls up the shaft 2 is generated so that the inner magnet pieces 3a ... Which are displaced downward are aligned with the outer magnet pieces 6a.
As a result, an upward pulling force that resists the gravity of the stirring shaft 25 acts on the shaft 2, and the thrust force of the thrust ring 19 contacting and acting on the bearing 17 is reduced to reduce the bearing.
17 reduce wear. The above-mentioned pulling force acting on the shaft 2 is carried by the holder 5 through the magnets 3 and 6, but the holder 5 is supported by the ball bearings 26 and 26 supported outside the casing 1 and having a large thrust load capacity. Is carried and held in the correct position at all times.

Further, in the above-described embodiment, the inner magnet pieces 3a ... Are displaced in advance downward by a predetermined amount c with respect to the outer magnet pieces 6a .. However, this is aligned with the inner magnet pieces 3a. Are arranged so that the upward displacement force of the shaft 2 is gradually increased by the downward displacement of the inner magnet 3 caused by the wear of the bearing 17, and the wear of the bearing 17 is gradually reduced so that the wear does not progress beyond a predetermined amount. You may.

Further, in the above-mentioned embodiment, the thrust force acting on the shaft 2 is also carried by the bearing 17 by using the thrust ring 19, but all the axial force acting on the shaft 2 is carried by the magnets 3, 6. , The thrust ring 17 and the like may be deleted.

(G) Effect of the Invention As described above, according to the present invention, each magnet 6 provided on the shaft 2 and the holder 5 is divided into a plurality of pieces in the axial direction, and these magnet pieces 3a ..., 6a ... Since it is arranged so as to have a pole different from that of the axially adjacent ones, and is configured to generate a suction force so as to be aligned not only in the rotational direction but also in the axial direction, it acts on the shaft 2. Gravity can be counteracted and the thrust load on the bearing can be reduced or eliminated to significantly extend bearing life and improve the reliability of the agitator. Further, based on this, it becomes possible to apply large gravity and high-speed rotation to the shaft 2, and diversification of needs such as a large device and a device requiring high-speed rotation and a device requiring continuous rotation for a long time. Accordingly, various stirring devices can be provided with high reliability.

[Brief description of drawings]

FIG. 1 (a) is a vertical cross-sectional view of a magnet drive portion of a stirring device according to the present invention, FIG. 1 (b) is a view showing its magnetic circuit, and FIG. FIG. 2 (b) is a diagram showing the magnetic circuit.
And FIG. 3 is a vertical cross-sectional view of the stirring apparatus showing an embodiment of the present invention. 1 ... Casing, 2 ... Shaft, 3 ... Inner magnet, 3a, 3b ... Magnet piece, 5 ... Holder, 6 ...
… External magnets, 6a, 6b …… Magnet pieces, 10 …… Stirring device, 15 …… Stirring tank, 25 …… Stirring shaft, I …… Internal magnet unit, O …… External magnet unit.

Claims (2)

[Claims] 1. A shaft which can be connected to a stirring blade is rotatably supported inside a casing whose one end is closed, and a holder which can be interlocked with a driving device is rotatably supported outside the casing. A magnet drive stirrer comprising magnets fixed to a shaft and a holder in a row in the axial direction so as to face each other with a casing interposed therebetween, and the casing is hermetically mounted in a stirring tank. Each magnet provided facing the holder is divided into a plurality of magnets in the axial direction, and these magnet pieces are arranged so as to have different poles from those adjacent to each other in the axial direction. And exerting a suction force so that they are aligned with each other in the axial direction, and act on the shaft by the suction force in the axial direction. Gravity formed by carrying a magnet drive stirrer. 2. The magnet piece divided in the axial direction is arranged by displacing an inner magnet piece fixed to a shaft downward by a predetermined amount with respect to an outer magnet piece fixed to a holder. The magnetic drive stirrer according to item 1.