JP4300064B2 - Sealed motor blower - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hermetically sealed motor blower in which a blower that sends out a gas and a motor that drives the blower are integrally sealed, and particularly relates to cooling of a motor bearing.
[0002]
[Prior art]
There is known a hermetic motor pump or blower in which a pump or blower for feeding fluid and a motor for driving the fluid are housed in a sealed container. Such a pump may be called a wet motor pump. In this type of pump and the like, there is an advantage that it is not necessary to seal the shaft of the pump or the blower by sealing the motor and filling the inside of the motor with the handling fluid. Then, lubrication and cooling of the motor bearing are performed by the handling fluid in the motor. Such a pump is described in Patent Document 1 and Patent Document 2, for example.
[0003]
[Patent Document 1]
JP-A-11-324971 [Patent Document 2]
JP-A-8-298216
[Problems to be solved by the invention]
In such a hermetic motor pump or blower, a part of the fluid handled in the motor may be mixed into the fluid discharged by the pump or the like, and therefore the fluid from which foreign matters such as dust inside the motor are discharged. There was a case to be mixed.
[0005]
When the handling fluid is a gas, the gas is compressed by the blower and becomes high temperature at the blower outlet. When this is led into the motor, there is a case where efficient cooling cannot be performed due to the high temperature.
[0006]
In the sealed motor blower, the present invention prevents foreign matters from being mixed into the discharged gas and efficiently cools the motor.
[0007]
[Means for Solving the Problems]
The hermetic motor blower of the present invention has a branch pipe that divides the handling gas from the suction pipe of the blower, which has a pressure higher than the atmospheric pressure, and guides it to the bearing portion of the motor. The distal end of the branch pipe faces the outer peripheral side surface of the bearing housing that houses the bearing . The gas before the temperature rises by the blower can be efficiently cooled by introducing it to the bearing portion.
[0008]
Moreover, although the handling gas used for cooling is discharged | emitted from the inside of a motor, it is preferable to provide a discharge path so that it may be suck | inhaled by a blower at this time, and it may not merge with the gas discharged | emitted from the said blower. As a result, it is possible to prevent foreign matters from being mixed into the gas discharged from the blower.
[0009]
An orifice can be provided at the outlet of the branch pipe tip . The gas that has passed through the orifice expands adiabatically and the temperature decreases. Since the bearing is cooled by the low-temperature gas, the cooling can be efficiently performed with a small amount of gas.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a hermetic motor blower 10 of the present embodiment. The hermetic motor blower 10 includes a blower 12 that sucks and discharges a gas such as carbon dioxide, and a motor 14 that drives the blower 12.
[0011]
The blower 12 includes a centrifugal impeller 16 and a casing 18 for housing the centrifugal impeller 16. Further, the casing 18 is provided with a suction pipe 20 at a front portion of the impeller 16 and a discharge pipe 22 at a side portion. The rear side of the impeller 16 of the casing 18 is covered with a separate front plate 24, and a front bearing housing 26 that extends further rearward is fixed to the front plate 24. A front bearing 28 is accommodated in the front bearing housing, and the bearing 28 rotatably supports a shaft 30 with the impeller 16 fixed to the tip. A cylindrical container 32 is coupled to the rear of the casing 18 and a rear plate 34 is coupled to the rear thereof. The front plate 24 and the above-described front plate 24 form a container for housing the stator 36 and the rotor 38 of the motor 14 in a sealed state. ing. Further, the cylindrical container 32 is provided with a terminal box 40 to which a conducting wire for supplying power to the coil of the stator 36 is connected, and this part also has a sealed structure. The stator 36 is supported in the radial direction by a plurality of axially extending ribs 42 provided on the inner wall surface of the cylindrical container 32. A rear bearing housing 44 is fixed to the rear plate 34, and the vicinity of the rear end of the shaft 30 is supported by a rear bearing 46 housed therein. The rotor 38 is fixed to the shaft 30 and rotates together with the impeller 16 that is also fixed to the shaft 30.
[0012]
Further, branch pipes 48 and 50 branching from the suction pipe 20 and sending the handling gas to the vicinity of the front and rear bearings 28 and 46 are provided. In the present embodiment, the branch pipe is provided with a total of four branch pipes 48 for sending gas to the front bearing 28 and two branch pipes 50 for sending gas to the rear bearing 46. When these branch pipes need to be distinguished, they will be described as a front side branch pipe 48 and a rear side branch pipe 50. The distal ends of the branch pipes 48 and 50 are arranged to face the outer peripheral side surfaces of the portions where the bearings of the front and rear bearing housings 26 and 44 are located. Details of this part are shown in FIG. An orifice plug 54 having a pore 52 is screwed to the tip of the branch pipe 48, and the pore 52 functions as an orifice. On the outer peripheral surface of the front bearing housing 26, flanges 56 are provided on both sides so as to sandwich the tip of the branch pipe 48 with a gap therebetween. Further, the gas guided by the branch pipe 48 is supplied to one flange 56 by the motor. An introduction hole 58 leading to 14 is provided. Another orifice plug 60 is provided in the middle of the branch pipe 48 (see FIG. 1). This is because the differential pressure before and after the single-stage orifice becomes too large. The configuration of the rear branch pipe 50 tip, the rear bearing housing 44, and the like are substantially the same as the configuration of the front side shown in FIG.
[0013]
The rear plate 34 is connected to a discharge pipe 62 for discharging the gas sent into a container in which the motor 14 is housed by branch pipes 48, 50 and the like. The discharge pipe 62 is provided with a restriction orifice 64 that restricts the discharged flow rate.
[0014]
The handling gas is sucked from the suction pipe 20 by the rotation of the impeller 16 and sent to the discharge pipe 22. This flow is the main system, and the handling gas is sent to a predetermined facility downstream. The handling gas before being sucked into the blower 12 of the main system has a higher pressure than the atmospheric pressure, and the front and rear bearings are branched by branching pipes 48 and 50 branched from the intake pipe 20 by this pressure. 28 and 46 are sent to the vicinity. When this gas passes through the orifices near the ends of the branch pipes 48 and 50, the gas adiabatically expands and the temperature decreases. By reducing the temperature, the bearing portion can be efficiently cooled with a small amount of gas.
[0015]
The gas having cooled the bearing portion, particularly the gas supplied to the front side, passes between the cylindrical container 32 and the stator 36 and between the stator 36 and the rotor 38 to cool them. Then, it merges with the gas supplied to the rear side and is discharged from the discharge pipe 62. Since the exhausted gas may contain foreign substances by the motor 14 or the like, it is discarded without returning to the main system. Since the branched handling gas is discarded in this way, it is desirable that the amount to be branched is small. As described above, in the present embodiment, since the temperature of the gas branched by adiabatic expansion is lowered, sufficient cooling can be performed with a small amount of gas.
[0016]
As described above, in the present embodiment, two of the four branch pipes are piped to the front side, and the other two are piped to the rear side. However, the number of branch pipes is not limited to this, and the front side rear The number need not be the same. Since the thermal load is large on the front side, more branch pipes may be provided on the front side. Further, in this embodiment, the orifice near the tip of the branch pipe has a two-stage configuration, but it can be made one stage depending on the required cooling performance or the like.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a hermetic motor blower of an embodiment.
FIG. 2 is a view showing details of the vicinity of a branch pipe tip and a bearing portion.
[Explanation of symbols]
10 Sealed Motor Blower, 12 Blower, 14 Motor, 16 Impeller, 18 Casing, 20 Suction Pipe, 26 Front Bearing Housing, 28 Front Bearing, 30 Shaft, 44 Rear Bearing Housing, 46 Rear Bearing, 48, 50 Branch Pipe, 54, 60 Orifice plug, 62 discharge pipe.

Claims (3)

A sealed motor blower in which a blower for discharging gas and a motor for driving the blower are integrally sealed,
High pressure compared to the atmospheric pressure, is branched from the suction pipe of the blower, it has a branch pipe for guiding the handling gas bearing near the motor,
The tip of the branch pipe is opposed to the outer peripheral side surface of the bearing housing that houses the bearing.
Sealed motor blower.   2. The hermetic motor blower according to claim 1, further comprising a discharge passage for discharging the handling gas guided by the branch pipe to the outside of the motor, wherein the discharge passage sucks the discharged gas into the blower. Also, a hermetically sealed motor blower that prevents merging with the handling gas discharged from the blower. The hermetic motor blower according to claim 1, wherein an orifice is provided at an outlet of a tip of the branch pipe.

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