JPH01249987A - Flat type blower - Google Patents

Abstract

PURPOSE:To enable a blower to be run without any troubles even in the start by forming a thrust dynamic pressure bearing between the upper surface of an impeller and a casing and between the lower side face of the impeller and the casing. CONSTITUTION:When current is supplied to a stator coil 27, a rotary drive force is given to a permanent magnet 24 and an impeller 10 starts to rotate so that gas to be handled is sucked into and discharged from a casing 3 while a stationary running condition is reached. Even if a thrust acts to press the impeller against the casing 3 side, the thrust is received by a spiral groove thrust dynamic pressure bearing on the lower side face consisting of the rotary side thrust receiving surface 14 on the lower surface of the impeller 10 and the fixed side thrust receiving surface 17 of a bearing plate. When the reversed thrust acts. it is received by a spiral groove thrust dynamic pressure bearing on the upper side face.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to a flat type, such as a whirlpool type or a centrifugal type, which handles toxic gases and is supported by a spiral groove dynamic pressure bearing and is capable of blowing air by high speed rotation. It is related to blowers.

[Conventional technology]

Generally, the impeller of a blower must be supported within a casing so that it can rotate while receiving radial and thrust loads. Conventionally, the impeller was fixed to the rotating shaft, the rotating shaft was passed through the wall of the casing, and a bearing was provided in the penetrating part, and the outside was sealed. It was supported by

[Problem to be solved by the invention]

However, in such conventional blowers, there are problems due to seal leakage, such as leakage of handled gas from the seal, or mixing of gas from the outside through the seal, or
There are problems such as vapors from bearing lubricating oil and sealing liquid getting mixed into the gas being handled, especially when the gas being handled is toxic and high temperature, and mixing with other gases is not allowed.
It was extremely difficult to blow air with high-speed rotation.

In addition, when driving a permanent magnet axial gap motor used for high-speed rotation, a strong magnetic force acts even when the motor is stopped, and with normal thrust bearings, there is a risk that the sliding surfaces and supporting parts will become plastically deformed, making it impossible to start. There were also problems with the tapered land, such as being bitten by the load and not being able to start.

The present invention solves the above-mentioned problems of the conventional ones, and provides a blower that can operate without trouble even when starting up, has good efficiency, and does not cause problems such as mixing of vapor from bearing or sealing liquid. This is the purpose.

[Means to solve the problem]

The present invention includes a blower impeller that is rotatably supported on a fixed shaft erected in a casing via a spiral groove radial dynamic pressure bearing, and a spiral groove upper surface side thrust movement is provided between the upper surface of the impeller and the casing. An upper thrust bearing plate forming a pressure bearing is provided, and a lower thrust bearing plate forming a spiral groove lower thrust dynamic pressure bearing is provided between the lower surface of the impeller and the casing, and a lower thrust bearing plate is provided between the lower surface of the impeller and the casing. A flat blower characterized in that a permanent magnet is arranged in an annular position, and a stator coil is provided in a casing and is arranged in a position facing the permanent magnet and provides rotational driving force to the permanent magnet. be.

[For production]

In the flat type blower of the present invention, when the stator coil is energized, a rotational driving force is applied to the permanent magnet, the impeller starts rotating, and a steady operating state is reached while drawing and discharging the handled gas into the casing. Even if a thrust that presses the impeller against the casing is applied, the thrust is absorbed by the spiral groove thrust dynamic pressure bearing on the lower surface, which consists of the rotating side thrust bearing surface on the lower surface of the impeller and the stationary side thrust bearing surface on the bearing plate. When thrust in the opposite direction acts, it is received by the spiral groove thrust dynamic pressure bearing on the upper surface, which consists of the rotating side thrust bearing surface on the upper surface of the impeller and the stationary side thrust bearing surface of the bearing plate, and the radial force is received by the sleeve and the thrust dynamic pressure bearing. The spiral groove radial dynamic pressure bearing on the sliding surface with the fixed shaft enables continuous operation of the blower. Since there is no rotating shaft penetrating the casing, there is no need for a rotating seal, and the problem of gas leaking through the seal is eliminated.In addition, both radial bearings and thrust bearings are spiral groove dynamic pressure bearings, which can handle gases. Since it is used as a gas for generating dynamic pressure, there is no need to supply lubricating fluid from the outside. Therefore, it is suitable for blowing toxic gases, and since no sealing or lubricating liquid is used, there is no problem of liquid vapor getting mixed into the gas being handled, and blowing work can be carried out efficiently and safely.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2. A blower casing is constituted by a back plate 1, an intermediate ring 2, and a casing 3. is formed.

A fixed shaft 9 is erected and fixed in the center of the back plate 1 via a shaft fixing nut 4, and an impeller 10 having a sleeve 1) is rotatably supported on this fixed shaft 9.

That is, the impeller 10 includes a sleeve 1) made of a ceramic sintered body that is fixed in the rotational direction and the axial direction by means such as keying, polygonal cross-section shaft fixing, press-fitting, etc.
The fixed shaft 9 is fitted into the central hole of the sleeve 1). The inner diameter of the sleeve 1) is finished into a smooth cylindrical shape, and a herringbone-shaped spiral groove (not shown) is provided on the outer periphery of the fixed shaft 9, forming a spiral groove radial dynamic pressure bearing.

A flange 13 is formed at the lower end of the sleeve 1), the end surface of which is finished smoothly to form a rotating side thrust receiving surface 14, and a stationary side thrust made of a ceramic sintered body is provided at a portion opposite to this rotating side thrust receiving surface 14. A receiving plate 15 is provided. A spiral groove (not shown) is provided on the surface of the fixed-side thrust receiving plate 15 facing the flange 13 to form a fixed-side thrust receiving surface 17, and the rotating side thrust receiving surface 14 forms a rear surface. The side spiral groove forms a thrust dynamic pressure bearing.

When the impeller lO rotates in the normal rotation direction, the gas for generating dynamic pressure, that is, the gas to be handled, is forced into the spiral groove and blocked by the land, generating dynamic pressure and rotating the impeller 10 while receiving thrust. It is designed to support as much as possible.

The impeller 10 is rotatably supported at its center by a fixed shaft 9 made of a ceramic sintered body through a sleeve 1), and a core shaft 9 made of titanium alloy in the fixed shaft 9 is rotatably supported. ．． The upper thrust receiving plate 20 on the fixed side is attached using a tightening member 21. The end surface of the sleeve 1) on the suction port side is finished smoothly to form a rotating thrust receiving surface 22, and the surface of the stationary thrust receiving surface 20 opposing this is
A spiral groove is provided to form a fixed side thrust bearing surface 23, and together with the rotating side thrust bearing surface, a spiral groove thrust dynamic pressure bearing on the front side is formed.

The direction of the spiral groove on the fixed side thrust receiving surface 23 is such that when the impeller 10 rotates in the normal rotation direction, the gas for generating dynamic pressure is pushed in and dynamic pressure is generated. There is.

The fixed thrust receiving plate 15 on the lower surface side and the fixed thrust receiving plate 20 on the upper surface side are fixed in the rotational direction to the end surfaces of the back plate l and the fixed shaft 9, respectively, by means such as driving a pin. Rotation is prevented, or the fixed side thrust receiving plate 15 is oriented in the normal rotation direction on either the back surface of the fixed side thrust receiving plate 15 or the surface of the seat of the back plate 1 opposite thereto. The fixed shaft 9 of the fixed thrust receiving plate 20 is provided with a spiral groove oriented such that both surfaces stick to each other when turned, that is, the gas between the two surfaces is pushed out in the circumferential direction. a surface facing the end surface of
When the stationary side thrust receiving plate 20 is rotated in the normal rotation direction on either side of the opposite end surface of the fixed shaft 9, the two sides are attracted to each other, that is, there is a gap between the two sides. A spiral groove oriented so that a certain gas is pushed out in the circumferential direction of the end face of the fixed shaft 9 is provided, and the fixed side thrust receiving plate 1
5 and 20 may be fixed by the suction force of the spiral groove.

Further, a permanent magnet 24 is arranged in an annular manner on the back surface of the impeller 10. That is, the permanent magnet 24 may be integrally formed as an annular body, or a plurality of permanent magnet pieces may be arranged in an annular shape at intervals. An annular plate 25 made of a material with a high 13-inch ratio, such as a steel plate, is provided at the top. The surface side of the permanent magnet 24 is protected by a protective plate 26 made of a non-magnetic material, such as resin stainless steel, for prevention and protection.

On the inner surface of the back plate l, a stator coil 27 is made of a non-magnetic material, etc., at a position facing the permanent magnet 24. tJi2
It is protected and deployed by 8.

The stator coil 27 is a DC brushless motor.

It is a stator coil of a Hall motor or an inverter AC motor, and both change the magnetic field to create a permanent magnet 2.
4 to provide rotational driving force.

The impeller 10 is usually made of metal, but if the gas to be handled is high temperature, it can be made of Ti alloy or ceramic sintered body, and if the handled gas is corrosive, it can be made of Ti alloy, ceramic sintered body, or plastic depending on the use. It is preferable to use a durable material.

Sleeve 1) The material of the ceramic sintered body of the fixed side thrust receiving plate 15.20 is SiC+ 5i3Nt+A1
．． O, ZrO, etc. are used.

In either the spiral groove radial dynamic pressure bearing or the spiral groove thrust dynamic pressure bearing, the depth of the spiral groove is preferably about 5 to 30 μm.

In the figure, 5 is a mounting bolt, 12 is a seal member, and 16 is a casing mounting leg, which are provided as necessary.

〔Effect of the invention〕

The present invention includes a blower impeller rotatably supported on a fixed shaft erected within a casing via a spiral groove radial dynamic pressure bearing, and since the impeller is directly driven by a stator coil, the impeller penetrates the casing. Since there is no shaft, there is no need for a rotating seal, and it prevents the leakage of the handled gas through the seal or the mixing of gas from the outside.In addition, the spiral groove motion uses the handled gas as the fluid for generating dynamic pressure using radial bearings and thrust bearings. Since it is a pressure bearing, it does not require special lubricating oil, and can prevent accidents such as lubricating oil vapor or sealing liquid vapor getting mixed into the handling gas, and there is no risk of plastic deformation due to load when starting the blower. It is a compact, high-performance blower that can be operated safely, performs efficient air blowing work, and has extremely great practical effects.

[Brief explanation of the drawing]

The drawings relate to embodiments of the present invention, and FIG. 1 is a vertical sectional front view taken along the line 1-1 in FIG. 2, FIG. 1 A is an enlarged vertical sectional view of a part thereof, and FIG. . l... Back (reverse, 2... Intermediate ring, 3... Casing, 4... Shaft fixing nand, 6... Inlet, 7...
・Discharge port, 8... vortex chamber, 9... fixed shaft, 91...
・Core shaft, lO... impeller, 1)... sleeve, 1
2... Seal member, 13... Flange, 14...
Rotating side thrust receiving surface, 15... Fixed side thrust receiving plate,
17... Fixed side thrust receiving surface, 20... Fixed side thrust receiving plate, 22... Rotating side thrust receiving surface, 23...
Fixed side thrust receiving surface, 24...Permanent magnet, 25...
Annular plate, 26... protection plate, 27... stator coil, 28... protection plate.

Claims (3)

[Claims] (1) A blower impeller is rotatably supported via a spiral groove radial dynamic pressure bearing on a fixed shaft erected in the casing, and a spiral groove upper surface side thrust dynamic pressure is provided between the upper surface of the impeller and the casing. An upper thrust receiving plate forming a bearing is provided, and a lower thrust receiving plate forming a spiral groove lower thrust dynamic pressure bearing is provided between the lower surface of the impeller and the casing, and a lower thrust receiving plate is provided on the lower surface of the impeller. , a permanent magnet arranged in an annular position;
A flat blower characterized in that a stator coil is disposed within a casing and is disposed at a position facing the permanent magnet and provides rotational driving force to the permanent magnet. (2) The impeller is rotatably supported at its center by a fixed shaft made of ceramic sintered body through a sleeve, and a tightening member is attached to a core shaft made of titanium alloy in the fixed shaft. 2. The flat blower according to claim 1, further comprising upper and lower thrust receiving plates. (3) The flat blower according to claim 1 or 2, wherein the impeller is made of a ceramic sintered body and has permanent magnets arranged at intervals in an annular plate, and is fixed with a protective plate.