JPS61252889A - Multi-stage high pressure roots blower - Google Patents

Abstract

PURPOSE:To reduce a load on shaft seal parts and increase compressing efficiency by providing a multi-stage Roots blower with a centrally disposed compression chamber serving as a high pressure stage and compression chambers disposed at opposite sides of the chamber serving as a low pressure chambers, respectively. CONSTITUTION:A multi-stage Roots blower has a centrally disposed target-high- pressure reaching compression chamber 61 and primary stage compression chambers 64 disposed at opposite sides of the disposing direction of the chamber. There are disposed a second chamber 62 and a third chamber 63 between the primary stage compression chambers 64 and the target-high-pressure reaching compression chamber 61, respectively, differential pressures between the respective compression chambers and between the primary compression chambers 64 and the atmosphere being set at small values. As a result, a load on shaft seal labyrinth parts 23, 24, 25, 26, 27, 28 of a shaft for driving a Roots rotor 20 is reduced for improving seal performance of shaft seal parts.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a multi-stage high-pressure Roots blower, in which the compression chamber at the center in the arrangement direction is a compression chamber having a discharge port to reach a target high pressure, and each compression chamber is connected to This invention has a field of application in which it can provide an efficient high-compression pump with little pressure leakage by minimizing the burden on the shaft seals of the two lees.

(Prior art) A multi-stage high-pressure Roots blower in which compression chambers are arranged in multiple stages, and a Roots-type rotor in each chamber is rotated by two shafts that pass through each chamber in conjunction with a timing gear. When the arrangement of compression chambers is, for example, a royal arrangement, as shown in FIG. The side compression chamber is the final target high pressure compression chamber C equipped with a discharge port C', and the space between the compartments is an intermediate compression chamber, and a contactless seal is attached to the pongee seal ρ on the outer wall of the target high pressure compression chamber C. When used, the pressure difference between atmospheric pressure and the chamber is large, for example 3 to 4 kg/Cm2, so the shaft seal ρ
There was a large amount of compressed air leaking from the pump, resulting in a pump efficiency of about 20 to 30%. Therefore, in the past, expensive and complicated sealing materials that can withstand high sealing loads, such as double mechanical seals, have been used for the shaft seal ρ, but these products cause wear due to mechanical friction, so regular maintenance and inspections are required. There are inconveniences required.

(Problems to be Solved by the Present Invention) In the conventional multi-stage high-pressure Roots blower described above, the target high-pressure attainment compression chamber C is provided on one side in the arrangement direction of the plurality of compression chambers. It was determined that the problem was caused by a large difference between the atmospheric pressure and the pressure on the suction side of the compression chamber C. The object of the present invention is to solve the above-mentioned problem in which the shaft seal becomes defective due to the magnitude of this pressure difference.

(Means for Solving the Problems) In the first aspect of the present invention, compression chambers are arranged in multiple stages, and a set of Roots-type rotors in each chamber is passed through each chamber so as to be interlocked with each other by a timing gear. In a multi-stage high-pressure Roots blower that rotates with two shafts, the compression chamber at the center in the arrangement direction is the compression chamber that has a discharge port to reach the target high pressure, and the compression chambers on both sides of the arrangement direction have suction ports that are exposed to the atmosphere. The first stage compression chamber is open toward the other side. The main points of the invention are shown in the block diagram of FIG. The numerals given to each part of this block diagram are the same as the numerals given to the drawing of the embodiment shown in FIG.

A second invention of the present invention is based on the main part of the first invention, in which the compression chambers are arranged in multiple stages, and a set of Roots rotors in each chamber are interlocked by a timing gear. In a multi-stage high-pressure Roots blower that is rotated by two shafts that pass through each chamber, the compression chamber in the center in the arrangement direction is the compression chamber that has a discharge port to reach the target high pressure, and the compression chambers on both sides in the arrangement direction are The first stage compression chamber has a suction port open to the atmosphere, and the two shafts are sealed by a labyrinth seal between the adjacent compression chambers and at the shaft passage part of the outer wall of the first stage compression chamber of both sizes V. It is characterized by the fact that

(Example) Examples that include the first invention and the second invention of the present invention are shown in FIGS. 2 to 5.

A i, from the right in Figure 2, the first compression chamber ■, the second compression chamber ■
It is a 5-stage Roots blower housing in which a third compression chamber (■), a fourth compression chamber (■), and a fifth compression chamber (V) are connected.
A casing 3 provided with 3a) is arranged, and side walls (z-+) separating the inner space of the casing (3) are arranged on both sides thereof.
The casings (2) and (4) provided with (CI) are joined together, and side walls (1-1) and (5-1) are provided on both sides of the casings (2) and (4) to separate the inner spaces of the casings (2) and (4). End plates (6-1) and (7-) of casings (1) and (5)
, ) are installed, and the timing gear bar (8) is fixed to the housing (7). An installation leg (9) is provided on the peripheral wall component of the casing (3), and the component and the outer periphery of the side walls (L, ) and ('s-+) are connected by a connecting pin.

In the present invention, the third compression chamber (2) located at the center in the arrangement direction of the first compression chamber I to the fifth compression chamber V is defined as the target high pressure attainment compression chamber (61),
The second compression chambers (■) on both sides are designated as the second chamber (62), the fourth compression chamber (■) is designated as the third chamber (63), and both the outermost first compression chamber (■) and the fifth compression chamber (V) are used for initial stage compression. Room (6'4), (64
), and in addition to providing the discharge port (3a) in the casing (3) of the target high pressure attainment compression chamber (61) as described above, the connection pipe (51) allows the casing (3) of the fourth chamber (63) to A suction port (3b) connected to the discharge port (4a) provided in the fourth chamber (63) is provided, and the casing (
4) is provided with a suction port (4b) connected to the discharge port (2a) of the casing (2) of the second chamber (62) by a connecting vibrator (52), and further has a suction port (4b) connected to the discharge port (2a) of the casing (2) of the second chamber (62). )l2! () I+? G6; entering n r9b)
# a J < I F (53) - (F+';0 allows the casing (1), (
5), and the suction ports (1b), (5b) of the casings (1), (5) are connected to the atmosphere (see FIG. 1 above).

As shown in the cross-sectional view of Fig. 3.4, the casings (1) to (5) each have a set of Roots rotors (10-, ), (
10-, )-(10-2), (10-2)・(10-3
), (to-,)・(10-,), (io-,)・(1
0-6), (10-5,) are arranged, and the two pongees (15), (
15), the end plates (6-1), (7-1) constituted by each housing (6), (7), and the side wall (1) of the entire casing.
-, ) (2-, ), (4-+) (S-+) six shaft holes (17) to (22) and (17) to (22
) to connect each of the Roots type rotors, and one of the roots (15) (bottom in FIG. 2) protrudes outside the housing (6) to serve as a drive shaft for a motor.

The two shaft holes (15) and (15) have the respective shaft holes (17) to
On the outer periphery of the part passing through (22) and (17) to (22),
Labyrinth (23)-(28) and Labyrinth (23)
~(28) is provided.

Roots rotors (10-,) to (1) relative to the shaft (15)
0-s) and the formation of the labyrinths (z3) to (28) are the same for both the two shafts (15) and (15). FIG. 5 shows the installation and formation of one shaft (15). That is, the shaft (15) has a central Roots rotor (
1 (Lz) is integrally formed, and the other four rotors are fitted in such a way that they cannot rotate independently. Rotor (10-z)
, (10-) are provided with spacers (10-2a) and (10-na) that pass through the shaft holes of the side walls (L+) and (4-+), and labyrinths (23) and (26) are provided on the outer periphery thereof. , and the rotor (10-,), (10-s) has side walls (1-+), (
The spacer (10-na), (10
-1a) is provided integrally with a labyrinth (24) on its outer periphery.
, (27) are formed. Each of the rotors is pressed against both sides of the rotor (10-,) in order and tightened by the screws (29) and (30) screwed onto the shaft (15). the oak)
(29), (30) are end plates (6-+), (7-+
), and a labyrinth (2
5) and (28) are formed.

The shafts (15) and (15) are assembled as shown in FIG.

Roots type rotors (10-1) to (10-6) are two-lobed type,
Any trefoil type may be used.

Also, non-contact dry lip seals may be used in place of the labyrinths (23) to (28).

Each suction port and each discharge port is provided with a cannula for circulating cooling water.
41) are connected to the suction port pipes (13) to (5-3) and the discharge port pipes (L,) to (5-,), respectively. The aforementioned connecting pipe (51) connects the discharge port pipe ('L4) and the suction port pipe (3).
-, ) and (52) are the discharge port pipe (z-< ) and the suction port ￥
1' (4-*), (53) and (53) are the discharge port pipes (
L, ), suction port pipe (2-3) and discharge port! (5-,) and the suction port pipe (2-,).

Although some of the suction port pipe and discharge port pipe are not shown, they are the same as those shown.

In the above, the pressure of the first stage compression chamber (64) (64) is approximately 0.6 kg/
Cl112° Pressure in second chamber (62) approx. 2
, Okg7Cm2 Pressure of the third chamber (63)
Approximately 4.0 kg/Cm2 target high pressure attainment compression chamber (64),
The volumes of the casings (1) to (5) and the compression capacities of the roots-type rotors (10-,) to (10-s) are set respectively so that the pressure of (64) is 7,000 kg7 am''.Labyrinth (23) The maximum outer diameter of ~(28) is 50
1. The length should be 20mm.

(Operations and effects of the second invention) The structure of the first invention and the second invention of the present invention is as clarified by the description of the above embodiments, and there are five compression chambers, and the compression chambers I and (2) are the same. First stage compression chamber (64), (64
), the pressure difference between the target high pressure compression chamber (61), the second chamber (61), the third chamber, the second chamber and the first stage compression chamber (64), and the third chamber and the first stage compression chamber (64). This reduces pressure leakage.

Therefore, as in the second aspect of the invention, it becomes possible to seal the shaft using a labyrinth type seal that is free from failure and easy to manufacture.

The first invention of the present invention and the invention of fjS2 which is based on the main part of the first invention have the effect of improving the performance of a multi-stage high-pressure Roots blower and providing it at low cost.

[Brief explanation of drawings]

Fig. 1 is a detailed schematic diagram of the present invention, Fig. 2 is a vertical sectional side view, Fig. 3 is a front view taken along the line A-A of Fig. 2, and Fig. 4 is a front view cut along the line B-B of Fig. 2. FIG. 5 is a vertical sectional side view showing the pongee (15), the rotor, and the labyrinth. FIG. 6 is a schematic diagram of a conventional multi-stage high-pressure Roots blower, similar to FIG. 1. 1-V → 1st to 5th compression chambers (1) to (5) → Casing (10-1) to (10-5) → Roots 2 rotor (15)
, (15) → shaft (51L (52L (53) → connecting pipe (61) → target high pressure attainment compression chamber (62) → second
Chamber (63) → 3rd chamber (64), (64) → First-stage compression chamber Applicant Ann Shit Co., Ltd. 6i 10,
159 Fig. 4 62151 Axis 9

Claims (2)

[Claims] (1) In a multi-stage high-pressure Roots blower, compression chambers are arranged in multiple stages, and a Roots-type rotor in each chamber is rotated by two shafts that pass through each chamber in conjunction with a timing gear. The compression chamber at the center in the arrangement direction is the target high-pressure compression chamber with a discharge port, and the compression chambers on both sides in the arrangement direction are the first-stage compression chambers with suction ports facing the outside air. A roots blower for multistage compression, characterized in that the compression ratio is increased sequentially toward a compression chamber that reaches a target high pressure. (2) In a multi-stage high-pressure Roots blower, the compression chambers are arranged in multiple stages, and one set of Roots-type rotors in each chamber are rotated by two shafts that pass through each chamber in conjunction with a timing gear. The compression chamber at the center in the arrangement direction is the target high-pressure compression chamber with a discharge port, and the compression chambers on both sides in the arrangement direction are the first-stage compression chambers with suction ports facing the outside air. The compression ratio is gradually increased toward the compression chambers that reach the target high pressure, and the two shafts are connected by labyrinth seals between the adjacent compression chambers and in the shaft passages on the outer walls of the first stage compression chambers on both sides. A multi-stage high-pressure Roots blower featuring a sealed seal.