JPS6332200A - Turbo-blower - Google Patents

Abstract

PURPOSE:To improve blasting efficiency by making a spiral ventilation flue which connects the outer peripheral part of an impeller adjacent to the cover installing part of a casing to a discharge port, run nearly one round in the circumferential direction, and gradually increasing its sectional area. CONSTITUTION:A cover 10 which encloses an impeller 7 is installed on the outer periphery of the end plate 23 of a casing 22. On the cover installing part of the end plate 23, a spiral ventilation flue 21 which connects the outer peripheral part of an adjacent impeller 7 to discharge port 27 provided on the outer peripheral part of the casing 22 in the tangential direction, is formed making nearly one round in the circumferential direction. And, its sectional area is gradually increased toward the discharge port 27 in the ventilating direction. Thereby, ventilation resistance and a pressure loss accompanying the turn of a high pressure air in the ventilating direction, can be reduced, improving blasting efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to Which the Invention Pertains] The present invention relates to a turbo blower that is capable of improving the efficiency of the feeding section.

[Prior art and its problems]

A conventional example of a turbo blower will be explained based on FIG.

This figure shows a multi-stage blower, in which both end plates 3 and 4 of a cylindrical caning 2 forming a discharge passage 1 are connected to a rotating shaft 6 via a bearing 5.
is supported, and a plurality of turbo-type impellers 7 are fixed to an end G of a rotating shaft 6 protruding from one end plate 3, which takes in air from the center and discharges air from the outer circumference in the radial direction. The impellers 7 each have separate covers 8. ? , 10, and the first stage cover 8 has a suction port 8a arranged at the center of the end surface. 2nd stage 3 and 3rd stage covers 9. A plurality of rectifying guides 11 are provided radially on the outer end face of each IO, and a suction port 9 a + 10 a is provided at the center of the end face. Adjacent covers 8, 9 and 10 are connected by fitting their outer peripheral ends into each other, and the final stage cover 10 is attached to the outer periphery of the end plate 3. The impeller 7 is attached to the annular holding plate 1 by screwing a holding bolt 12 into the end face of the rotating shaft 6.
3 and spacer tubes 14 and 15 to the inner ring end surface of the bearing 5, and an annular drawing plate 16 is provided at the axial tip of the rectifying guide 11 between its inner periphery and the outer periphery of the spacing tube 14. They are integrally formed with a gap g between them.

The blower sucks air through the suction port 8a by the action of the impeller 7 as the rotary shaft 6 rotates, and the air pressurized by the first stage impeller 7 and discharged from the outer circumferential portion flows into the adjacent rectifying guide 1.
1, it is sent toward the center. This air is sucked in through the suction port 9a of the second stage cover 9 by the action of the impeller 7, is further pressurized, and this pressurization is repeated until it becomes high-pressure air, passes through the discharge passage 1, and is heated to the casing 2. It is sent out from a discharge port 17 provided on the outer periphery.

In such a structure, the high-pressure air sent into the discharge passage 1 from the outer periphery of the final stage impeller 7 suddenly turns around 1800° near the outer periphery of the end plate 3, resulting in a large pressure loss, which reduces the blowing efficiency. The disadvantage was that it decreased.

[Purpose of the invention]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned drawbacks, it is an object of the present invention to provide a turbo blower that can improve air blowing efficiency.

[Summary of the Invention] In order to achieve the above-mentioned object, the present invention installs a cover that surrounds a cylindrical gauging impeller by dividing the outer periphery of the adjacent impeller and the casing by one discharging port. The communicating spiral ventilation passage is formed by making approximately one turn in the circumferential direction and gradually increasing the cross-sectional area.

[Embodiments of the invention]

FIG. 1 and FIG. 2 show an embodiment of this invention.
Components designated by the same reference numerals as in FIG. 3 are the same parts. In this figure, a rotating shaft 6 is supported by both end plates 23 and 24 of a cylindrical casing 22, and an impeller 7 is attached to the outer periphery of one end plate 23.
A cover 10 is attached to surround the. When attaching the cover to the end plate 23, the spiral air passage 21 that connects the outer periphery of the adjacent impeller 7 and the discharge port 27 provided tangentially on the outer periphery of the casing 22 goes around the circumferential direction almost once. The cross-sectional area of the ventilation passage 21 gradually increases in the ventilation direction toward the discharge port 27. An opening 21a is provided on the outer circumferential side through which the discharged high-pressure air is introduced into the ventilation passage 211 while being rotated.This opening 21a is covered with a cover 10 attached to the outer circumference of the end plate 23, and The high-pressure air turning section is formed obliquely at an appropriate angle α to avoid sudden turning.This inclined surface may be a curved surface.The casing 2
2 and the end plate 23 are integrally formed by casting or the like.

According to the embodiment, the high-pressure air discharged from the outer periphery of the impeller 7 is sequentially fed into the ventilation passage 21 whose cross-sectional area gradually increases in the ventilation direction and merges therewith while making approximately one circumference in the circumferential direction, thereby reducing ventilation resistance. In addition, since the turning angle of the high-pressure air discharged radially from the impeller 7 is approximately 90°, the pressure loss caused by the turning is reduced by almost half compared to that described in the conventional example, and the blowing efficiency is improved. Can be done. Since the opening 21a of the ventilation passage 21 is larger than the outer periphery, the casing 22 and the end plate 23 are integrally formed by casting, so that it is possible to easily remove the molding sand.

〔Effect of the invention〕

According to the present invention, in the turbo blower, the cover surrounding the cylindrical gauging impeller is installed in the circumferential direction of the spiral air passage that communicates the outer periphery of the adjacent impeller with the discharge port provided in the casing. (Since the earthen pot is formed so as to go around it and gradually increase the cross-sectional area, it is possible to reduce ventilation resistance and pressure loss due to rotation of the ventilation direction of high-pressure air, thereby improving ventilation efficiency.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIG. 2 is a longitudinal sectional view taken along the line -■ in FIG. 1, and FIG. 3 is a longitudinal sectional view of a conventional example. 6... Rotating shaft, 7... Impeller, 10... Cover,
10a... Suction port, 21... Ventilation path, 22...
Casing, 23.24... End plate, 27... Discharge port. Be person - #d Shito Yamaguchi Yuu

Claims (1)

[Claims] 1) A rotating shaft is supported by both end plates of a cylindrical casing having a discharge port, a turbo-type impeller is attached to the end of the rotating shaft protruding from the end plate, and a cover is attached to the casing to surround this impeller. In a turbo blower having a suction port provided in the center of the casing, a spiral air passage communicating the discharge port with the outer circumferential portion of the impeller adjacent to the cover attachment portion of the casing is arranged around one circumference in the circumferential direction and has a cross-sectional area that gradually increases. A turbo blower characterized by being formed by