JPS6359035B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is characterized in that an impeller in a casing vortex chamber is provided with a driven magnet disc, and a driving magnet disc is made to correspond to the driven magnet disc via a partition. A magnetic disk is attached to the rotating shaft of the drive machine, the impeller is rotatably supported by a shaft fixed to the partition wall, a thrust bearing is fitted between the impeller and the partition wall, and the impeller is rotatably supported by a shaft fixed to the partition wall. The present invention relates to a magnetic joint-driven pump in which an impeller is driven via a magnetic joint obtained by a magnetic disc.

BACKGROUND ART Conventionally, in this type of pump, a thrust bearing is of course fitted between an impeller and a partition wall to counteract the attraction force between the driven and driving magnet discs. In preparation for a stronger thrust toward the pump suction port being applied to the impeller during pump operation, a second thrust bearing was also provided on the suction port side.

However, since the second thrust bearing is located on the suction port side of the casing, it becomes a resistance to the flow of fluid, and the suction performance of the pump decreases accordingly.
When the impeller shifts toward the pump suction port due to wear of the second thrust bearing, the gap between both magnetic disks increases, and the transmitted torque decreases in inverse proportion to the square of the gap, resulting in pump startup failure, There is a problem in that the magnetic coupling may lose synchronization during operation.

As a solution to this problem, the applicant's earlier application (Japanese Patent Application No. 115884/1984)
The pump disclosed in Japanese Patent No. 59-5894 is provided with a driven magnet disk for an impeller in a casing vortex chamber, and a drive magnet disk is made to correspond to the magnet disk through a partition, and the drive magnet disk is driven. The impeller is rotatably supported by a shaft fixed to the bulkhead, a thrust bearing is fitted between the impeller and the bulkhead, and the driven magnet disc and the There is a magnetic joint driven pump in which the attractive force between the drive magnet discs is greater than the thrust toward the pump suction port that is applied to the impeller during pump operation.

According to such a pump, there is no need to provide a thrust bearing on the pump suction port side, so the flow resistance on the pump suction port side is reduced accordingly, the pump suction efficiency can be improved, and the distance between both magnetic plates can be reduced. Since the torque does not increase, a sufficient amount of torque is always transmitted between the two magnetic discs, which has the advantage of preventing pump startup failure and the phenomenon of out-of-sync of the magnetic coupling during operation.

Problems to be Solved by the Invention However, it has been found that there are further problems with such a pump.

That is, the shaft for supporting the impeller has a portion between the impeller and the partition into which the thrust bearing fits, and an impeller fitting portion adjacent to this portion, and the thrust bearing is connected to the shaft. The thrust bearing is held between the partition wall and a shoulder extending in the shaft radial direction at the boundary between the two parts, but it is difficult to center the thrust bearing with respect to the shaft. tends to be stable,
The problem is that force is concentrated on the peripheral edge of the shoulder of the shaft adjacent to the impeller fitting portion, and this peripheral edge may be damaged.

Means for Solving the Problems An object of the present invention is to provide a magnetic coupling-driven pump that has improved the above-mentioned problems.

Furthermore, the present invention is suitable for use in cases where the partition wall is made of synthetic resin, in cases where the pump rotates in reverse due to reverse phase operation, in cases where the pump rotates in reverse due to backflow of liquid from the discharge piping when the pump is stopped, or when the pump is subjected to vibration due to cavitation. It is an object of the present invention to provide a magnetic joint-driven pump that can securely, safely, and securely clamp a thrust bearing between a shaft shoulder and a partition wall even in the event of an abnormality.

The above object of the present invention is to provide a driven magnet disc for an impeller in a casing vortex chamber, a drive magnet disc that corresponds to the magnet disc via a partition wall, and a driving magnet disc that is connected to a rotating shaft of a drive machine. It is installed,
The impeller is rotatably supported by a shaft fixed to the partition wall, a thrust bearing is fitted between the impeller and the partition wall, and the attractive force between the driven magnet disk and the drive magnet disk drives the pump. When the thrust force applied to the impeller toward the pump suction port is greater than the thrust force applied to the pump suction port, the shaft has the thrust bearing fitting portion and the impeller fitting portion adjacent to the thrust bearing fitting portion, and the thrust bearing In a magnetic joint-driven pump that is held between the boundary shoulder of the two parts of the shaft and the partition wall, the shaft has a male threaded end portion formed thereon and is screwed into a female threaded hole provided in the partition wall. The shoulder of the shaft is a tapered shoulder that gradually becomes smaller in diameter toward the bulkhead, and the portion of the thrust bearing that should come into contact with the tapered shoulder also has a taper that matches the tapered shoulder. This is achieved by a magnetic coupling-driven pump featuring a

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

Pump casing 1 is connected to casing cover 2
1. Covered by a suction port cover 22 and a discharge port cover 23. Casing 1 is pump suction port 1
2. It is equipped with a vortex chamber 13 and a pump outlet in the outlet cover 23.

An impeller 3 having blades 31 is arranged in the vortex chamber 13 . This impeller 3 is provided with a driven magnet disk 4. As can be seen from the drawings, in this embodiment, the impeller 3 and the magnet holding case 41 of the driven magnet disk 4 are integrally formed, and a part of the magnet holding case 41 is also formed on the back plate of the impeller 3. It also serves as

A driving magnet disc 6 is arranged corresponding to the driven magnet disc 4 with a partition wall 5 made of a non-magnetic material interposed therebetween. The partition wall 5 is fitted onto the end of the casing 1 and fixed so as not to move by a bracket 7 coupled to the casing cover 21. A sealing O-ring 51 is provided between the partition wall 5 and the pump casing 1.
is fitted. The drive magnet disk 6 is fixed to a rotating shaft 81 of an electric motor 8, and the electric motor 8 is supported by a bracket 7.

A female threaded hole 52 is provided in the center of the partition wall 5 on the vortex chamber side, and a substantially horizontal shaft 9 is screwed into this female threaded hole with its tip male threaded portion 91. The impeller 3 is supported at 9. More specifically, the impeller 3 has a bearing bushing 32 in its center, and this bushing is fitted onto the shaft 9, whereby the entire impeller 3 is rotatably supported by the shaft 9. There is.

The bushing 32 has a flange 322 at the end on the partition wall 5 side, has a cylindrical shape as a whole, and has a fluid flow path 321 leading from the back side cavity 10 of the impeller 3 to the pump suction port side. This flow path 321 consists of a groove 3210 formed on the end surface of the flange 322 from the outer circumference of the flange toward the inner circumference, and a groove 3211 that communicates with each groove 3210 and is formed on the inner circumferential surface of the bushing in the direction of the center line of the bushing. It's on. The outer circumferential surface of the bushing 32 is provided with a flat portion 323 that abuts against a flat fitting hole portion (not shown) of the impeller 3 so that the bushing 32 does not rotate relative to the impeller 3.

For example, a nut 92 is attached to the free end of the shaft 9 as a device to prevent the impeller 3 from coming off to ensure safety.
can be screwed together.

A thrust bearing ring 50 is fitted between the impeller 3, more specifically, the flange 322 of its bushing 32 and the partition wall 5.

This thrust bearing ring 50 is fitted into a circular stepped portion 53 formed on the partition wall 5. A shoulder portion 93 at the boundary between a portion 94 of the shaft 9 where the bushing 32 of the impeller 3 is fitted and a portion 95 where the thrust bearing ring 50 is loosely fitted pushes the thrust bearing ring 50 toward the bulkhead 5 side. , sandwiching the ring 50 together with the partition wall.

Therefore, the ring 50 is easy to remove and install.

The shoulder portion 93 is a tapered shoulder portion that gradually becomes smaller in diameter toward the partition wall 5 side, and the portion of the ring 50 that comes into contact with it also has a taper 501 that fits the shoulder portion.
is attached.

In the driven magnet disk 4, a case 41 supports a magnetic yoke 42 and a magnet 43.
The drive magnet disk 6 includes a magnet 61 corresponding to the magnet 43 on a magnetic yoke 62. magnet 43
and 61 are made larger so as to make the attractive force between both magnet discs 4 and 6 stronger than the thrust toward the suction port 12 side that is applied to the impeller 3 during pump operation. The outer diameter of the entire disk 4 is larger than the outer diameter of the impeller portion, so that the outer peripheral portion 44 of the magnetic disk 4 forms the side wall of the vortex chamber 13 on the motor 8 side.

In this embodiment, the casing 1, the impeller 3
The magnet holding case 41 and the bushing 32 integrated therewith are all molded of fluororesin containing a filler, and the thrust bearing 50 and shaft 9 are made of a suitable metal, or made of alumina, silicon nitride, silicon carbide, etc. Although the parts are made of ceramic and the partition wall 5 is made of synthetic resin, these parts can be made of other materials as appropriate.

Note that 14 in the drawing is a drain outlet of the casing 1.

Therefore, a magnetic joint is obtained by the attractive force between the driving and driven magnetic discs 4 and 6, and when the driving magnetic disc 6 is rotated by the electric motor 8, the driven magnetic disc 4 is rotated via the joint, and thus The impeller 3 is also rotated to perform pump operation. As the pump operates, the impeller 3 receives thrust toward the suction port 12, but both magnetic discs 4 and 6
Since the suction force between them is greater than this thrust, the impeller 3 will not shift toward the suction port 12. Therefore, the distance between the two magnet disks does not increase, and no thrust bearing is required on the suction port 12 side. The shoulder portion 93 of the shaft abuts against the tapered portion 501 of the thrust bearing ring 50 to center the ring 50 with respect to the shaft 9. In addition, the shoulder portion 93
cooperates with the tapered portion 501 of the ring 50, with a wide contact area obtained by these tapered portions,
In addition, the ring 50 is reliably and safely held between the partition wall 5 and the partition wall 5 in a state where there is little risk of concentrated force being applied to one place. Moreover, in this case, the forward clamping of the ring 50 can be performed by screwing the shaft 9 and wedge-like tightening by the taper of the shaft shoulder 93. This is a preferable embodiment in which loosening does not occur even in the case of reverse rotation, in the case of reverse rotation of the pump due to the return of liquid from the discharge piping when the pump is stopped, or in the case of pump abnormality such as vibration due to cavitation. Note that the ring 50 can be held without loosening if the shoulder 93 and the tapered part of the ring 50 are made into rough surfaces.
The effect of preventing loosening of the shaft male thread has been improved.
It gets even better.

In addition, since the shaft shoulder 93 to which force is applied is tapered, even if the shaft 9 is made of ceramic, which is susceptible to thermal shock, the bushing 32 and thrust bearing 5 may be damaged during abnormal operation such as idling.
Even when there is a sudden temperature rise due to sliding friction with zero, the shoulder portion 93 is not easily damaged.

Because the flow path 321 of the bushing 32 is straight and has relatively little resistance, and there is no thrust bearing on the pump suction port side, during pump operation, fluid that has entered the air space 10 on the back side of the impeller will flow through the bushing 3.
It flows smoothly through the flow path 321 of No. 2 to the pump suction port side. This passage 321 acts in the same way as a balance hole normally drilled in the back plate of an impeller, reducing the thrust on the pump suction port side. It acts as a fluid passage for cooling and lubricating the bearing 50.

Incidentally, since one side wall of the vortex chamber 13 is formed by the outer circumference of the driven magnet disk 4, the pump structure is simplified accordingly.

Even if it becomes necessary to cut the blades of the impeller 3 to make them shorter, such as when moving the pump to an area where the frequency of the pump motor power supply is higher and trying to use the pump with the same pump capacity,
Since the driven magnetic disc 4 is left in place, no opening is created in one side wall of the vortex chamber provided by the magnetic disc, so that a new opening is created for the fluid to escape from the vortex chamber 13. Never.

Effects of the Invention As described above, according to the present invention, the impeller in the casing vortex chamber is provided with a driven magnet disc, and the driving magnet disc is made to correspond to the driven magnet disc via the partition wall.
The drive magnet disc is attached to a rotating shaft of a drive machine, the impeller is rotatably supported by a shaft fixed to the partition wall, and a thrust bearing is fitted between the impeller and the partition wall, The attractive force between the driven magnet disc and the driving magnet disc is made larger than the thrust force toward the pump suction port that is applied to the impeller during pump operation, and the shaft is adjacent to the thrust bearing fitting part. and the impeller fitting portion,
In the magnetic joint driven pump, the thrust bearing is sandwiched between the boundary shoulder of the two portions of the shaft and the partition wall, the thrust bearing comprising:
It is easily centered with respect to the shaft, and
This has the advantage of being securely and securely held between the shaft shoulder and the bulkhead.

Furthermore, according to the present invention, when the partition wall is made of synthetic resin, when the pump rotates in reverse due to reverse phase operation, when the pump rotates in reverse due to backflow of liquid from the discharge piping when the pump is stopped, or when vibrations due to cavitation, etc. Even in the event of a pump abnormality, the thrust bearing can be held between the shaft shoulder and the bulkhead in a reliable, safe and desirable manner without loosening.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a partially cutaway sectional view, and FIGS. 2, 3, and 4 are a partially cutaway side view, flange side end view, and FIG. 4 of the bushing, respectively. The other end views, FIGS. 5 and 6, are a side view of the shaft and a sectional view of the thrust bearing ring, slightly enlarged from those shown in FIG. 1. DESCRIPTION OF SYMBOLS 1... Casing, 3... Impeller, 4... Driven magnet disk, 5... Partition wall, 6... Driving magnet disk, 8...
Electric motor, 9... Shaft, 12... Pump suction port, 13... Vortex chamber, 32... Bushing, 44...
...Outer peripheral portion, 50...Thrust bearing ring, 81
. . . Rotating shaft, 321 . . . Flow path, 501 .

Claims (1)

[Claims] 1. A driven magnet disk is provided on the impeller in the casing vortex chamber, a drive magnet disk is made to correspond to the magnet disk via a partition wall, and the drive magnet disk is attached to the rotating shaft of the drive machine, An impeller is rotatably supported by a shaft fixed to the partition wall, a thrust bearing is fitted between the impeller and the partition wall, and the attractive force between the driven magnet disk and the driving magnet disk is applied during pump operation. The thrust force applied to the impeller toward the pump suction port is greater than the thrust force applied to the pump suction port, and the shaft is fixed by screwing the tip male threaded portion formed therein into a female threaded hole provided in the partition wall, and the shaft is fixed to the thrust bearing. A magnetic joint drive type comprising a fitting part and the impeller fitting part adjacent to the fitting part, and the thrust bearing is sandwiched between the boundary shoulder of the two parts of the shaft and the partition wall. In the pump, the shoulder of the shaft is made into a tapered shoulder that gradually becomes smaller in diameter toward the partition wall, and the portion of the thrust bearing that should come into contact with the tapered shoulder is also tapered to match the tapered shoulder. A magnetic coupling-driven pump characterized by: