JPH01249986A - Suspension type blower - Google Patents

Abstract

PURPOSE:To prevent lubricating oil for bearings and liquid for seals from being mixed with steam by interposing a thrust bearing plate provided with a spiral groove between upper and lower surface thrust plates to support a rotary shaft. CONSTITUTION:When a thrust is operated to urge an impeller 10 against the motor 4 side, the thrust is received by an upper surface thrust plate 14 in a bearing casing and a spiral groove thrust dynamic pressure bearing section of a thrust bearing carrier plate 15 on a rotary shaft 1. When the reversed thrust acts, a spiral groove thrust dynamic pressure bearing section on the upper surface of a lower surface thrust carrier plate 16 receives the thrust. A radial force is received by the spiral groove radial dynamic pressure bearing made of bearing sections 12, 13 and the inner surfaces of bearing members 22, 23 supported flexibly.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for blowing high-temperature gas and other gases used in molten carbonate fuel cell power generation systems, etc., which handle toxic gases that must not leak. It is related to the blower for

[Conventional technology]

Generally, in a blower for blowing air, the impeller of the blower, including the motor that drives the impeller, must be supported within a casing so that it can rotate while receiving a radial load and a thrust load.

Conventionally, the rotating shaft to which the impeller was fixed was passed through the wall of the casing, and the penetrating part was supported by a bearing and sealed on the outside, or a seal was provided on the penetrating part and the rotating shaft was supported by a bearing on the outside. .

[Problem to be solved by the invention]

However, in such conventional blowers, there are problems caused by seal leakage, such as leakage of the handled gas from the seal, or intrusion of gas from the outside through the seal, or problems with the handling of steam from bearing lubricating oil or sealing liquid. It is very difficult to blow air at high speed, especially when the gas being handled is high temperature and other gases cannot be mixed in. Lower-type blowers have production tolerances and errors that tend to cause vibrations due to core misalignment, and this tendency increases even more during high-speed operation, making them inefficient, impractical, and complicated to maintain.

The present invention solves these conventional problems and does not cause problems such as leakage of gas through the seal or contamination of vapor from bearing or sealing liquid, and does not have restrictions on the handling of high-temperature gases. The purpose of the present invention is to provide a blower that can be used without problems, is easy to maintain, is highly efficient, and can be operated safely.

[Means to solve the problem]

The present invention provides a motor casing in which a rotating shaft is rotatably suspended with a bearing in a bearing casing, a motor consisting of a rotor and a stator, and an impeller are sequentially provided on the rotating shaft extending outside the bearing casing, and the motor is covered. A blower casing containing the impeller therein is attached to the bearing casing, and a spiral groove is provided on the sliding surface of the rotating shaft and the bearing to form a spiral groove radial dynamic pressure bearing, and a spiral groove is formed in the bearing casing. An upper thrust plate and a lower thrust plate are provided, and a thrust bearing plate having a spiral groove provided on both thrust plates is disposed on the rotating shaft,
This is a high temperature gas blower characterized by forming a spiral groove thrust dynamic pressure bearing.

[For production]

The blower of the present invention has an impeller suspended from a rotating shaft enclosed in a bearing casing. When the motor 4 is energized, the motor rotor 2 starts rotating, and the impeller lO sucks in and discharges high-temperature gas to be handled. While doing so, a steady state of operation is reached. At that time, when a thrust that presses the impeller lO toward the motor 4 side is acting, the spiral groove thrust dynamic pressure bearing of the upper thrust bearing plate 1.4 in the bearing casing and the thrust bearing plate 15 on the rotating shaft l When a thrust in the opposite direction is applied, the thrust is received by the spiral groove thrust dynamic pressure bearing part on the upper surface of the lower thrust receiving plate 16, and the radial force is received by the sleeves IL and 13+ fitted to the rotating shaft 1, respectively. It is received by two spiral groove radial dynamic pressure bearings consisting of bearing parts 12 and 13 formed in the same manner and the inner surfaces of the flexibly supported bearing members 22 and 23.

〔Example〕

Embodiments of the present invention will be described using the drawings.

In the blower shown in FIG. 1, a motor 4 consisting of a motor rotor 2 provided on the rotating shaft l and a motor stator 3 provided opposite to the motor rotor 2 drives an impeller lO arranged on the rotating shaft l. In the blower rotatably disposed in the blower casing 5, a bearing member 22 is attached to the bearing casing 8.
A motor 4 consisting of a motor rotor 2 and a motor stator 3 and an impeller 10 are sequentially provided on the rotating shaft 1 which is suspended so as to be freely rotatable and extends outside the bearing casing, and the motor 4 is covered with the motor 4. A blower casing 5 housing the impeller therein is connected and attached to the bearing casing 8 via a casing 7, and a spiral groove is provided on the sliding surface of the rotating shaft l and the bearing 22 to form a spiral groove radial dynamic pressure bearing section 12. An upper thrust receiving plate 14 and a lower thrust receiving plate 16 are provided in the bearing casing 8, and a thrust bearing plate 15 having a spiral groove on both thrust plate surfaces is interposed and arranged on the rotating shaft l. This is a suspended blower with a spiral groove thrust dynamic pressure bearing.

In the bearing casing 8, the rotating shaft 1 is located in the center thereof, and the sleeve 1 made of ceramic sintered body is fitted onto the shaft.
2+ with 0 ring 22. The rotating shaft l is fitted with a bearing 22 that is flexibly supported by
The sleeve 12t made of a ceramic sintered body fitted into the rotary shaft 1 is elastically fixed with an O-ring interposed between the sleeve 12t and the rotating shaft 1, if necessary. A part of the high-pressure gas led from the discharge port 21 side through the ventilation duct 17 that connects between the motor stator 3 and the bearing casing 8 and the discharge 21 side of the blower casing 5 flows into the motor stator 3. and the motor rotor 2, and then passes through the radial dynamic pressure bearing 23 and returns to the blower casing 5 on the back of the impeller 10, while the high pressure gas in other parts cools the bearing parts in the bearing casing 8. It provides lubrication and, if necessary, captures the heat generated by the bearing and recirculates it to the suction port side of the blower casing 5 through the balance pipe 30. Further, the blower casing 5 also includes an impeller 10 at the lower end of the rotating shaft 1 extending in the center thereof, and a sleeve t3 connected to the impeller lO.
This is a support that is fitted and supported on a bearing member 23 that is flexibly supported by an O-ring 23° or the like via a +.

The rotating shaft 1 passes through the center of the blower casing 5 as a central axis, and a sleeve 12 with a spiral groove is provided on the outer periphery of the upper and lower parts of the rotating shaft 1. .

131 and bearing members 22 and 23 form a radial dynamic pressure bearing and are rotatably supported, and the rotor 2 and impeller 1 are rotatably supported.
0, and thrust bearing plates 14 and 16 are attached to the upper and lower surfaces of the thrust bearing plate 15 provided on the rear side of the motor rotor 2, respectively.
At the same time, the motor casing is provided with cooling fins 6 to serve as a blower for high-temperature gas.

The impeller 10 is made of a ceramic sintered body, and is integrated with the motor rotor 2 by a support ring boss 11 and a rotor receiving nut 20 made of a ceramic sintered body or a hard metal. The shaft is finished with a smooth cylindrical surface and the sleeve 12□
13. are fitted together to form two sets of spiral groove radial dynamic pressure bearings.

Further, the thrust bearing plate 15 provided on the rotating shaft l is fixed by a bearing holding pad 19, and the upper and lower surfaces are provided with rotation-side thrust bearing surfaces that are smooth and perpendicular to the axis. Upper thrust receiving plate 14 made of ceramic sintered body. A lower thrust receiving plate 16 is provided. A spiral groove is provided on the thrust receiving surface facing the thrust receiving plate 14, 16, and when the rotation side thrust receiving surface rotates in the normal rotation direction, gas for generating dynamic pressure flows along the groove. Dynamic pressure is generated, and it is preferable that the thrust bearing plates 14, 16 and the rotating side thrust bearing plate 15 form a spiral groove dynamic pressure thrust bearing.

The spiral grooves provided to form radial bearings and thrust bearings have a total waviness of 3μ or less and an average surface roughness Ra of 0.1μ or less. It is established at a depth of ~30 μm. The spiral groove may be processed by covering the surface corresponding to the land with a resin mask and performing shifted plast.

Note that the sleeves 121, 13I and the impeller 10 are
It is made of a ceramic sintered body and is supported by a radial dynamic pressure bearing and a thrust dynamic pressure bearing, each made of a ceramic sintered body, so that it can effectively generate a large dynamic pressure.

The motor rotor 2 has a rotor can to be sealed, and
The motor stator 3 also has a sealed stator can, and spiral groove thrust dynamic pressure bearings made of ceramic sintered body are provided on the front surface of the impeller 10 and the rear surface of the motor rotor 2, respectively, and the fixed shaft and the impeller are connected to each other. A conductive path leading to the spiral groove radial dynamic pressure bearing between the radial bearing portions 12, 10 and the motor rotor 2 is formed in communication with each other in each casing to form a safe rose type without gas leakage. It is guided to the thrust receiving plates 14 and 16, and generates dynamic pressure in the spiral groove radial dynamic pressure bearing and the spiral groove thrust dynamic pressure bearing. In addition, in FIG. 1, 17 is a ventilation duct for circulating gas from the discharge side of the blower to the motor side.
In FIG. 0, where a cooler is provided as necessary, a part of the gas guided through the ventilation duct 17 effectively cools the motor rotor 2 and motor stator 3 and cools the impeller 10. The flow returns to the blower casing 5 on the back side, and another part passes through the bearing casing 8 and passes through the balance pipe 30 to the blower casing suction port 9.
Reflux to the side.

In the figure, 9 is an inlet, 17 is a ventilation duct, 21 is an outlet,
22. 24 is a sealing member, 24 is an adjustment shim, 25 is a holding nut, 26 is a liner, 27, 28 is a bushing, 29 is a communication channel, and 31 is a mounting base.

The ceramic sintered body in the above description is preferably a hard and chemically stable one.SiC sintered body, 5
L3N* sintered body, A 1 gos sintered body, ZnO1 sintered body, etc. are used. Other impeller materials that can handle high-temperature gas include metal materials that can withstand high temperatures, such as Ti-^i gold alloy, Ti-Ti alloy, and stainless steel, and heat-resistant resins.

Further, although the spiral groove is shown as being provided on the fixed side bearing surface of the radial and thrust dynamic pressure bearing, the spiral groove may be provided on the rotating side.

When the impeller 10 is made of a ceramic sintered body, even if the gas to be handled is high temperature, it blocks heat transfer and prevents the motor, especially the motor rotor, from becoming high temperature, making it possible to handle high temperature gas. . However, as the material constituting the impeller 10, a metal material, resin, or composite material can be selected as appropriate depending on the state of the gas to be handled.

In the example shown in FIG. 3, the thrust bearing plate 15 is arranged between the motor casing 7 and the blower casing 5, and the upper thrust bearing plate 14 and the lower thrust plate surface are connected to the lower radial bearing member 2.
The motor stator 3 is connected from the ventilation duct 17, which utilizes the upper surface of the motor stator 3, and may be equipped with a cooler if necessary.
The gas guided to the side opposite to the impeller 10 of the motor rotor 2. After cooling the motor stator 3, a ventilation duct 3 is connected to a lower pressure part on the suction side (not shown).
3 and circulates to the suction port 9 side of the blower casing 5. Here, 32 is a conductive wire that leads electricity to the motor stator 3.

In the example shown in FIG. 4, the thrust bearing plate 15 is disposed oppositely by utilizing the upper surface of the upper radial bearing member 22, and the upper thrust bearing plate 15
It is clamped at 4.

In the example shown in FIG. 5, the motor rotor 2 is sandwiched between the rotor bearing nuts 20 and 20, and the thrust bearing plate 1 is
5 is fixed with a bearing holding nut 19, and is placed in the bearing casing 8 between the upper thrust receiving plate 14 and the lower thrust receiving plate 16 for support.

〔Effect of the invention〕

The present invention provides a motor casing in which a rotating shaft is rotatably suspended with a bearing in a bearing casing, a motor consisting of a rotor and a stator, and an impeller are sequentially provided on the rotating shaft extending outside the bearing casing, and the motor is covered. A blower casing containing the impeller therein is attached to the bearing casing, and a spiral groove is provided on the sliding surface of the rotating shaft and the bearing to form a spiral groove radial dynamic pressure bearing, and a spiral groove is formed in the bearing casing. An upper thrust plate and a lower thrust plate are provided, and a thrust bearing plate having a spiral groove provided on both thrust plate surfaces is interposed and disposed on the rotating shaft,
By forming a spiral groove thrust dynamic pressure bearing,
Since there is no shaft penetrating the casing, there is no need for a rotating seal, preventing leakage of gas through the seal or incorporation of gas from the outside, and radial and thrust bearings use gas as the fluid for generating dynamic pressure. Since it is a spiral groove dynamic pressure bearing, it does not require lubricating oil, which prevents accidents such as lubricating oil vapor or sealing liquid vapor from entering the handling gas, and also suppresses the occurrence of vibration phenomena, ensuring stable continuous operation. This makes it possible to ensure efficient operation without degrading the motor's magnetic properties, handle high-temperature gas without any problems, significantly improve efficiency, and facilitate heat control for maintenance and safety. This has an extremely great practical effect, making it possible to create an advantageous and safe blower.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIG. 2 is a plan view,
3 to 5 are longitudinal cross-sectional views of other embodiments, respectively. l... Rotating shaft, 2... Motor rotor, 3... Motor stator, 4... Motor, 5... Prower casing, 7... Motor casing, 8... Bearing casing , 9... Suction port, 10... Impeller, 11... Boss, 12.13... Radial bearing part, 12□131.
...Sleeve, 14...Top thrust receiving plate, 15...
・Thrust bearing plate, 16...Lower thrust bearing plate, 20
...Rotor support napft, 22.23...Bearing member.

Claims (3)

[Claims] (1) A rotating shaft is rotatably suspended with a bearing in a bearing casing, a motor consisting of a rotor and a stator, and an impeller are sequentially provided on the rotating shaft extending outside the bearing casing, and a motor casing covers the motor. A blower casing housing the impeller therein is attached to the bearing casing, and a spiral groove is provided on the sliding surface of the rotating shaft and the bearing to form a spiral groove radial dynamic pressure bearing, and an upper surface is provided in the bearing casing. A hanging device comprising a thrust plate and a lower thrust plate, which are disposed on the rotating shaft with a thrust bearing plate having a spiral groove provided on both thrust plate surfaces to form a spiral groove thrust dynamic pressure bearing. type blower. (2) The bearing casing has a sintered ceramic sleeve fitted to the rotating shaft in the center thereof and fitted into the flexibly supported bearing, and the inside of the bearing casing is arranged as a blower casing. The hanging blower according to claim 1, wherein the blower is connected to the motor casing in a communicating state and forms part of a circulation flow path communicating with the blower suction side through a balance pipe. (3) The blower casing is provided with an impeller at the lower end of the rotating shaft extending in the center thereof, and is fitted and supported on a bearing flexibly supported via a sleeve connected to the impeller. hanging type blower.