JPH051741Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a blower that rotates in an atmosphere containing liquid mist above the liquid surface of a liquid tank, or a low-pressure blower without a gasket in which a liquid pump and a blower rotate together. In particular, the present invention relates to a liquid mist prevention structure for preventing liquid mist from entering the blower.

[Conventional technology]

An example of this type of blower is widely used as an air-hydraulic supply source for an air-hydraulic servo system that uses air pressure to detect position and operates hydraulically.

This blower, motor, and oil pump direct connection structure is simple. Since the blade wheel of a blower rotates at high speed, sealing it with a seal would have a disadvantage in terms of service life, so sealing between the shaft of the rotating blade wheel and the fixed part is generally performed. There is. Therefore, a problem arises in that oil mist is sucked into the blower from the rotating shaft through the above-mentioned gap.

A known example of a gasket-less low-pressure blower that rotates in a gas phase containing oil mist forms an annular chamber surrounding a coupling chamber containing a rotating shaft, and introduces a portion of the discharged air into the annular chamber to blow the rotating shaft. and seal the inside of the blower. In this case, there is also a configuration in which the annular chamber is divided by a plurality of partition walls to prevent excessive loss of discharged air. The coupling chamber is provided with a hole communicating with the oil tank, so that leaked oil from the shaft seal of the oil pump is returned to the tank. Therefore, the coupling chamber is filled with oil mist due to minute liquid leaks from the shaft and the atmosphere inside the tank.

[The problem that the idea aims to solve]

In the above-mentioned known configuration, if no partition wall is formed in the annular chamber, oil mist can be prevented from entering the vicinity of the suction side of the blower, but a large amount of air flows back from the vicinity of the discharge side to the vicinity of the suction side, reducing blower efficiency. let When an annular chamber is divided by multiple partition walls, the positive pressure of the air near the discharge side does not reach the divided annular chamber near the suction side, resulting in a negative pressure in a part of the annular chamber, and liquid mist flows into the blower. It enters from near the suction side. Therefore, the oil mist reaches the pneumatic detection end, and the oil adheres to the object to be measured. If a filter is used, the filter will become clogged and the number of cleaning operations will increase.

An object of the present invention is to provide a structure for preventing oil mist from being sucked into the blower having the above-mentioned annular chamber with a partition wall.

[Means to solve the problem]

In order to solve the above-mentioned problems, the blower liquid mist prevention structure according to the present invention forms notches in at least part of the partition wall to enable gas flow between the divided annular chambers.

With the above configuration, the required amount of positive pressure air maintains a positive pressure in all the annular chambers to prevent inhalation of liquid mist.

[Effect]

With the configuration of the present invention, the adjustment of the notch in the partition wall is extremely simple and accurate, and the entire annular chamber can be positively pressurized to prevent the infiltration of liquid mist without impairing the efficiency of the blower. If the positive pressure in the annular chamber is too high, the blower efficiency will decrease, so it is possible to adjust liquid mist prevention and blower efficiency depending on the application.

〔Example〕

Embodiments and drawings illustrating the present invention will be described.

In this embodiment, oil is used as the liquid, and the rotating shaft of the blower is integrated with a coupling with the motor and a coupling with the oil pump.

The blower according to the present invention shown in FIGS. 1 and 2 has a configuration in which an electric motor 1, air blowers 2, 11 are directly connected, and a hydraulic pump 6 is connected by a coupling 8, but other configurations are also possible. The fixed part 11 of the blower forms a housing 15. When the impeller 2 of the blower rotates, air is sucked in from the suction port 16 shown in FIG. 2, compressed through the air chambers 5 and 4, and discharged from the discharge port 17. The suction side passage 5 becomes a negative pressure, and the discharge side passage 4 becomes a positive pressure. The blower is on the tank 18, and the pump 6 is suspended in the tank.
The center of the housing 15 communicates with the gas phase inside the tank.

A coupling chamber 9 formed in the center of the housing 15 communicates with the gas phase of the tank through a passage 7, and allows leakage oil from the pump shaft seal to return into the tank.
Therefore, the coupling chamber 9 is always filled with oil mist. (The coupling ring does not require lubrication.) An annular chamber 3 is formed on the outside of the coupling ring 8 that includes the rotating shaft of the blower.
is divided by a plurality of partition walls 12. Pressurized air flows from the positive pressure passage 4 through the gap 13 between the impeller 2 and the housing 15, and flows from the annular chamber 3 through the gap 10 into the coupling chamber 9. Annular chamber 3 and partition wall 1
2 is known, and in the case of only the annular chamber 3, an excessive amount of air flows in the environmental chamber from the vicinity of the discharge side to the vicinity of the suction side, which impairs the efficiency of the blower. If several partition walls 12 are provided to prevent this, positive pressure will not reach the annular chamber near the suction side, and the air will flow from the coupling chamber 9 to the suction air passage 5 via the spacer 10, the annular chamber 3, and the spacer 13. There was a drawback that oil mist was sucked in.

According to the present invention, a notch 20 is formed in at least a part of the partition wall 12 of the annular chamber 3. The air positive pressure flows from the air discharge side passage 4 through the gap 13, the annular chamber 3, and the notch 20 in the partition wall 12, filling all the annular chambers 3, and flows through the gap 10 to the coupling chamber 9. The oil is discharged to the outside of the housing 15 through the air escape hole 14 formed in , and is also discharged into the tank through the oil escape hole 7 . In this way, oil mist is prevented from being sucked into the blower.

If the notch 20 is too large, a large amount of air will be supplied from the discharge side to the annular chamber 3, which is effective in preventing oil mist but impairs blower efficiency. If the notch 20 is too small, the positive pressure will not reach the suction-side annular chamber, and a portion of the annular chamber will have a negative pressure, causing suction of oil mist.
The cutout 20 of the present invention is easily adjustable and can be easily adjusted according to the efficiency and mist suction requirements. As shown in FIG. 2, no notch 20 is formed in the partition wall 12' closest to the discharge port to prevent a decrease in efficiency.

Although the illustrated example has a configuration in which the oil pump shaft and the blower shaft are connected by a coupling, the present invention can be applied without the above-described configuration as long as the coupling chamber 9 is in an atmosphere of liquid mist such as oil.

[Effect of idea]

The blower liquid mist intrusion prevention device according to the present invention can demonstrate stable blower performance due to the direct connection structure of the motor, blower, and pump, can easily and effectively prevent the suction of liquid mist, and has a long life due to the non-contact sealing method. .

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a blower to which the present invention is applied;
FIG. 2 is a sectional view showing the structure of the present invention taken along line A--A in FIG. 1. 1... Motor, 2... Blower impeller, 3... Annular chamber, 4, 5... Air passage, 6... Oil pump, 7,
14...Escape passage, 8...Cup ring, 9...
Coupling room, 10, 13... between, 11...
Blower fixing part, 12... Partition wall, 15... Housing, 16... Suction port, 17... Discharge port, 20...
...Notch.

Claims (1)

[Claims for Utility Model Registration] (1) One end of the rotating shaft rotates in a gaseous atmosphere containing liquid mist, and an annular chamber is provided between the rotating shaft and the rotary blade chamber without using a packing. In a blower that is sealed and has an annular chamber divided by a plurality of partition walls in the radial direction, a notch is formed in at least some of the partition walls to enable gas flow between the divided annular chambers. The characteristic feature of the blower is its liquid mist prevention structure. (2) A liquid mist prevention structure for a blower according to claim 1, wherein the oil pump and the blower are coupled via a coupling or directly, and the coupled portion is exposed to a gas phase atmosphere containing liquid mist.