CN101778999B - Screw compressor with integral bearing cover and discharge plenum divider - Google Patents

Abstract

The three-rotor screw compressor has a bearing cover and an integrated discharge case with a partition wall integrally formed with the bearing cover. The bearing cap closes the bearing chamber for each of the three rotor shafts, and the dividing wall divides the plenum chamber into two distinct chambers. By providing a dividing wall, noise and efficiency losses due to intermixing of the two discharge flows from the two separate compression chambers are excluded. By forming the partition wall integrally with the bearing cap, the leakage present in the prior art is eliminated.

Description

Screw compressors with integral bearing caps and discharge plenum dividers

technical field

The present application relates to screw compressors in which a partition separates the output of two discharge chambers and in which a bearing cover is integrally formed with the discharge box providing the partition wall.

Background technique

Screw compressors are known and generally comprise a plurality of rotating rotors, each having external threads. The rotor threads cooperate with threads on other rotors to define compression chambers. The captured fluid is compressed and passed toward a downstream location. One known type of screw compressor comprises three rotors and defines two compression chambers. The two compression chambers typically deliver compressed fluid into a common discharge plenum. The discharge of fluids into the common chamber may be slightly out of phase and may result in increased pulsation as well as unwanted loss and noise.

It is therefore known in the prior art to provide a dividing wall which separates the outputs from the two chambers until they reach a downstream location. Typically, the outlet housing includes two distinct flow paths. The outlet housing is connected to a discharge box that includes a dividing wall to define two flow passages.

Furthermore, bearing caps are typically provided to cover the bearings mounted in the outlet housings for each of the three rotors. In the prior art, the bearing cap is formed separately from the discharge box. The space between the dividing wall and the bearing cap allows interleaved flow between the two passages.

Contents of the invention

In the disclosed embodiment, the screw compressor is formed with three rotors. Each of the three rotors has a shaft mounted in a bearing. The bearing is fixed in the outlet housing. The outlet shell is fixed on the compressor case. The bearing cap is integrally formed with the discharge box, as is the partition wall. The outlet housing provides two separate discharge passages which communicate with two separate compression chambers. The two separate discharge passages allow fluid to flow downstream into two separate plenum chambers or flow passages. A separate plenum chamber is defined by a dividing wall and an integral bearing cap in the discharge box. Since the bearing cap and discharge box are formed as an integral part, there are no complicated surfaces between the two that must be sealed, and there are no leaks between the plenum chambers. In a sense, the bearing cap forms part of the partition wall.

These and other features of the invention will be best understood from the following detailed description and drawings, the following of which is a brief description of the drawings.

Description of drawings

Figure 1 is an exploded view of a prior art compressor.

Figure 2 shows the bearing cap features of a prior art compressor.

Figure 3 is an end view of the integral cover and compressor discharge box.

Figure 4 is a perspective view of one side of the compressor component of the present invention.

Figure 5 is a perspective view of the side opposite the compressor component of the present invention.

Detailed ways

A compressor 20 known from the prior art is shown in FIG. 1 . Compressor case 22 carries screw rotors 24 , 26 and 28 . As is well known, the screw rotors have threads which cooperate to compress and drive the refrigerant towards the discharge chamber 38 . Refrigerant enters through inlet 140 at the opposite end. Rotors 24 , 26 and 28 each have a shaft 30 mounted within a bearing assembly 32 . Bearing assembly 32 extends into cavity 34 in outlet housing 36 .

The outlet housing 36 includes a passage 40 that communicates with the discharge chamber and serves to pass compressed fluid downstream without allowing interleaved flow of fluid from the two chambers 38 .

Drain box 46 includes a chamber 50 in communication with passage 40 . The partition wall 48 separates the two chambers 50 so that the compressed fluids do not mix until downstream of the discharge tank 46 . At the end of the outlet housing 36, however, the dividing wall 48 and the bearing cap 42 are not generally on the same plane. Therefore, there is a space between the two separate parts that allows leakage. FIG. 2 shows a prior art cover 42 .

Figure 3 shows the discharge box 100 of the present invention. As shown, the partition wall 102 divides and divides the chamber 104 . However, the bearing cap 106 is integrally formed with this wall 102 .

Thus, as shown in FIG. 4 , the bearing cap 106 is incorporated into the partition wall 102 . There is no leakage between the wall 102 and the cover 106 because they are integrally formed. The two chambers 104 are thus kept separate by relatively simple formation of a one-piece component. In a sense, the bearing cap forms part of this wall.

FIG. 5 is a perspective view from the opposite side and shows chamber 104 separated by wall 102 . As can be appreciated from the several figures, the partition wall 102 is relatively thin compared to the bearing cap 106 . The partition wall 102 also extends over most of the axial length of the discharge box 100 . Near the end of the discharge box 100 adjoining the outlet housing 20 , the discharge dividing wall 102 merges to be thicker and a bearing cap 106 is provided.

Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that many modifications would come within the scope of this invention. For that reason, the appended claims should be studied to determine the true scope and content of this invention.

Claims (6)

1. compressor comprises:

At least three screw rotors, each in the described screw rotor has axostylus axostyle, and described compressor is used for transmitting compressed fluid each at least two independent discharge port of compressor casing;

Bearing, it is placed in the bearing chamber and supports in described three axostylus axostyles of described at least three screw rotors each; And,

The bearing cap surface, it is closed and is used for each described bearing chamber of described bearing, described bearing cap forms with the discharging case, described discharging case comprises partition wall, this partition wall is used for providing each independent discharge chamber that is communicated with described discharge port, make the fluid that in described compressor, compresses through described bearing cap, and pass independent discharge chamber and use, and described partition wall also forms with described discharging case to the downstream.

2. compressor according to claim 1 is characterized in that, described bearing chamber is positioned in the discharge case, and described discharge case is in abutting connection with described compressor case, and described discharging case is fixed on the described discharge case.

3. compressor according to claim 2 is characterized in that, described partition wall extends on relatively thin extension and becomes bigger to merge in the described bearing cap.

4. compressor according to claim 1 is characterized in that, described partition wall extends on relatively thin extension and becomes bigger to merge in the described bearing cap.

5. compressor according to claim 1 is characterized in that, described partition wall extends on most of axial length of described discharging case, and described bearing cap forms the end of contiguous described discharging case substantially.

6. compressor comprises:

At least three screw rotors, in the described screw rotor each has axostylus axostyle, described screw rotor cooperatively interacts limiting two compression chamber, and described compressor is used for transmitting compressed refrigerant one in two independent discharge port in the compressor casing from each of described two compression chamber;

Bearing, it is placed in the bearing chamber that forms in the discharge case, described discharge case is connected on the described compressor casing, each in the described axostylus axostyle of described at least three screw rotors of described bearing supporting, and described discharge port is communicated with vent pathway in the described discharge case; And

The bearing cap surface, its close be used for described bearing each described bearing chamber and be connected to described discharge case, described bearing cap forms with the discharging case, described discharging case comprise partition wall be used for providing with the described vent pathway that is formed at described discharge case in each independent discharge chamber that is communicated with, and described partition wall guarantees to be compressed in the fluid described bearing cap of process in the described compressor and the independent discharge chamber of passing in the described discharging case uses to the downstream, described partition wall extends on relatively thin extension and becomes bigger to merge in the described bearing cap, and described partition wall extends on most of axial length of described discharging case, and described bearing cap vicinity forms towards the end of the described discharging case of described discharge case, and described partition wall also forms with described discharging case.

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