BRPI1103736A2 - dump chamber for refrigeration compressors and dump chamber closure process - Google Patents

Abstract

"DISCHARGE COVERING CAMERA FOR COOLING COMPRESSORS AND DISCHARGING CAMERA CLOSING PROCESS". The compressor comprises a block (2) with at least one discharge damper chamber (10,20) having an end bottom wall (14,24) provided with a blind and threaded axial hole (14a, 24a), a side wall surrounding (13,23) and an open end (11,21) defining an annular seat (12a, 22a) extended over the entire radial width of the surrounding sidewall (13,23). An annular gasket (30) comprises a peripheral annular portion (31) to be seated on the annular seat (12a, 22a), and a median bore (32). A cap (40) is seated on the gasket (30) and a set screw (50) has a head (51) seated on the cap (40), a rod (52) disposed through a middle hole (41). ) of the cap (40) and through the middle hole (32) of the gasket (30), and a threaded end (53) fixed in the blind axial hole (14a, 24a).

Description

Field of the Invention The present invention relates to a discharge chamber construction of the type formed integrally with the block of a reciprocating refrigeration compressor; inside a generally hermetic carcass. The invention is further directed to a method of closing said discharge damper construction. Invention History

As shown in figures 1 and 2 of the accompanying drawings, reciprocating hermetic compressors consist of a motor-compressor assembly mounted generally through suspension springs within a hermetically sealed housing 1. The motor-compressor assembly comprises a block 2 defining a compression cylinder 3 and an axle hub 4 for housing a crankshaft not shown. In general, the discharge of a compressor of the type herein has a discharge damping system comprising one or more discharge damping chambers 10, 20, usually defined in one piece in this block 2 and through which the compressed gas in the discharge cylinder. Compression 3 is passed through before being driven out of the compressor housing 1 by a compressor discharge pipe 5 carried by the hermetic housing 1.

In the illustrated construction, a first and a second baffle chamber 10, 20 are provided, interconnected by a conduit 6, internal to block 2 and having a diameter sufficient to accommodate, with radial clearance, an intermediate tube 7 having an inlet end ( connected to the compressor head to receive the gas being compressed by the latter, and an outlet end 7a open into the second damping chamber 20. The radial clearance between the intermediate tube 7 and the conduit 6 allows a The portion of the compressed gas fed to the second damping chamber 20 is returned to the first damping chamber 10, tending to equalize the pressure in said chambers.

The outlet pipe 5 has an inlet end open into the second outlet damper chamber 20, and an outlet end, attached to a outlet dowel (not shown), mounted through the hermetic housing 1 to connect the outlet. from the compressor to the high pressure side of a refrigeration system to which the compressor is connected.

The exhaust damping system is intended to attenuate the pulsation of the pumped gases from the compressor to the refrigeration system or, in the generic case, to the high pressure side of the circuit of which the compressor is part, as well as to reduce the radiated noise. by the compressor to the outside environment. The pulsation of the gases generates an excitation in the ducts and components to which the compressor discharge is coupled. This excitement, in turn, leads to the generation of always undesirable noise. A number of configurations are used for said exhaust damper system, but generally speaking, the principle comes down to having the gas flow through a well-defined sequence of pipes, volumes and localized constraints whose dimensions, arrangement and

particular characteristics depend on the application, compressor type and size, mass flow, working fluid, operating temperatures and conditions, noise bands to be attenuated, etc.

In a known construction, the exhaust muffler chambers 10, 20 are produced in the cylinder block 2 and each have a circumferential recess 12, 22 within a respective open end 11, 22, sized to define a seat. 12a, 22a for seating an annular sealing gasket 30 and a cap 40 resting on the sealing gasket 30 in the annular seat 12a, 22a at the circumferential recess 12, 22 to close each end 11, 21, of the two exhaust muffler chambers 10, 20. Each circumferential recess 12, 22 has annular seat 12a, 22a surrounded by a peripheral side wall 12b, 22b.

Each discharge damper chamber 10, 20 has a generally cylindrical tubular shape having a surrounding sidewall 13, 23 and a closed bottom end wall 14, 24 having a blind axial bore (14a, 24a), internally threaded.

In this known construction, the closure of each discharge damper chamber 10, 20 occurs with the sealing gasket 30 being seated in the annular seat 12a, 22a, in its circumferential recess 11, 21, followed by the fitting of its cap 40 over the sealing gasket 30. Each cap 40 is secured to block 2 by a respective cap screw 50, comprising a head 51 to be seated on cap 40, a rod 52

20 arranged through a central hole 41 of lid 40 and

through the hollow median region of the gasket 30 and a threaded end 53 to be secured within the blind axial bore 14a in the first baffle chamber 10 (Figure 5) and the blind axial bore 24a in the second baffle chamber 20 (see Figures 2, 4 and 5).

This known type of construction utilizes the circumferential recess 12, 22, to allow easy and correct positioning of the gasket 30 and the cap 40 at the open end 11, 21 of each damper chamber.

30 discharge 10, 20 considering that the sealing gasket 30,

The mid-hollow annular configuration has its radial indexing guaranteed by the peripheral sidewall 12b, 22b of each circumferential recess 12, 22. Although the radial indexing of the cap 40 with respect to the open end 35, 21, of each discharge chamber 10, 20, also be obtained by the peripheral sidewall 12b, 22b of each circumferential recess 12, 22, its indexed mounting can be obtained by means of the securing screw 50 itself. Thus, the provision of the recess 12, 22, results from the need for radial indexing of the shaped gasket 30

ring, moderately leaked.

Because of the need for each circumferential recess 12, 22 to be provided, the discharge muffler chambers 10, 20 of this known construction have the total height of the peripheral sidewall 12b, 22b greater than that required for the definition of the exhaust volume because the upper part of said peripheral sidewall is defined by the depth of the circumferential recess 12, 22, more precisely by the height of its peripheral sidewall 12b, 22b. This higher height for the discharge muffler chambers 10, 20 ultimately requires an increase in compressor casing sizing to ensure a minimum distance between the open end 11, 21 of said discharge muffler chambers 10, 20, and adjacent portions. of housing 1

20 of the compressor.

In addition, the provision of the circumferential recess 12, 22 in the discharge muffler chambers 10, 20 results in a weakening in this region of the cylinder block, which is defined by the peripheral sidewall 12b, 22b of each circumferential recess. 12, 22. These fragile regions of the surrounding sidewall 13,

23, of each discharge damper chamber 10, 20, generally defined by the material of block 2 itself, are vulnerable to breakage, leading to scrapping of block 2.

3 0 during machining or even during handling and

use.

Another negative aspect of this prior construction relates to the compressor assembly process, which requires the sequential steps of: seating each sealing gasket 30 on its circumferential recess 12, 22; seating each cap 40 on a respective sealing gasket 30 already mounted; and mounting the set screw 50 through the central hole 41 of the cap 40 with the fixing of its threaded end 53 within the blind axial hole 14a, 24a in the bottom end wall 14, 24 of each discharge damper 10 20 holding the lid 40 in position and compressing the sealing gasket 30 against the circumferential recess 12, 22.

Thus, it is a general object of the present invention to provide a discharge damper of the type incorporated in the block itself of a refrigeration compressor and having a total height corresponding to that of the volume required for its operation as a noise damper, allowing a reduction in the design of the compressor casing, respecting the required minimum distances between the casing and the adjacent compressor block portions.

Another object of the present invention is to provide a chamber of the above type which decreases the fragility of the cylinder block during its obtainment, handling and operation in

20 compressor.

Still another object of the present invention is to provide a chamber of the above type which permits easy indexing of the mounting of the lid and its gasket at the open end of the respective discharge damper chamber.

Still another objective is to provide a new method of closing a discharge chamber as defined above, which would suppress the formation of a sealing gasket indexing means at the extreme

30 open of each discharge chamber.

Summary of the invention

These and other objects are achieved with a refrigeration compressor discharge chamber of the type comprising: a housing housing a block carrying at least one tubular shaped gas discharge chamber having a closed bottom end wall and having a blind threaded axial bore, a surrounding sidewall and an open end having an annular seat; an annular gasket, seated on said annular seat; a cover provided with a middle hole and seated over the sealing gasket; and a set screw having a head seated on the cap, a stem protruding from the head and terminating at a threaded end that is fixed within said blind axial hole. According to the present invention said annular seat extends over the entire radial width of the surrounding side wall of the discharge damper in the region of its open end, wherein the sealing gasket comprises a peripheral annular portion seated on the annular seat. and a median hole to be pierced by the fixing screw shank. The construction proposed by the invention allows a reduction in the discharge damper height to be achieved simultaneously by eliminating the peripheral sidewall of the recess of the previous constructions, thereby reducing the compressor housing dimensions and reducing the block fragility in the open end region of the discharge damper. Due to the elimination of the peripheral sidewall of the recess, ie the recess itself, the surrounding sidewall of the discharge damper may be reduced in thickness, allowing the necessary internal volume to be maintained with a corresponding reduction in the height of the discharge damper. discharge and the material required to form the block.

The construction proposed by the invention further allows the closing process of the damping chamber to be done by radially indexing the lid and the sealing gasket provided by the set screw stem itself, when mounting the latter threaded end into the blind axial hole provided. at the bottom of the discharge damper chamber. 3 5 Brief Description of the Drawings

In the following the invention will be described with reference to the accompanying drawings, given by way of example and in which:

Figure 1 illustrates, in a perspective view, a block defining the piston hub, the shaft hub for receiving a crank shaft and two discharge muffler chambers, prior to mounting the respective gaskets and caps and constructed accordingly. with the prior art;

Fig. 2 is a partial cross-sectional view of the block shown in Fig. 1 and mounted within a compressor casing, said section having been taken along line II-II in the preceding figure, illustrating one of the discharge damp chambers constructed of according to the prior art and having the gasket and lid already mounted at their open end; Figure 3 illustrates, in a perspective view, a block defining the piston hub, the shaft hub for receiving a crank shaft and two discharge muffler chambers, prior to mounting the respective gaskets and caps and constructed accordingly. with the present invention;

Figure 4 is a partial cross-sectional view of the block shown in Figure 3 and mounted within a compressor casing, said section having been taken along line IV-IV in the previous figure, illustrating a

25 of the discharge dampers, constructed according to

with the present invention and having the gasket and lid already mounted at their open end; and Figure 5 is a cross-sectional view of the block shown in Figure 3, said section having been taken along line VV in said previous figure and illustrating the two discharge chambers, with the gasket and lid already assembled, according to the present invention. Detailed Description of the Invention

The present invention will be described for a compressor of

generally hermetic refrigeration of the type already described in the introduction to this report and shown in Figures 1 and 2 and comprising a housing 1 housing a block 2 carrying at least one tubular-shaped discharge chamber 10, 20 having a bottom end wall 14, 24 closed and having a blind axial hole 14a, 24a and threaded, a surrounding side wall 13, 23 and an open end 11, 21, having an annular seat 12a, 22a.

The same reference numerals in the accompanying drawing figures represent equal parts in the prior art representative construction and the object construction of the present invention.

According to the illustrated embodiment, the block 2 incorporates, generally in one piece, obtained by casting, two discharge baffles 10, 20, with the bottom end wall 14, 24, defined by the block 2 itself.

According to the invention, the annular seat 12a, 22a extends over the entire radial width of the surrounding sidewall 13, 23 of each discharge damper chamber 10, 20 in the region of its open end 11, 21. This new construction for annular seat 12a, 22a allows for complete elimination of peripheral sidewall 12b, 22b from circumferential recess 12, 22 of prior art constructions.

By eliminating said prior art peripheral sidewall 12b, 22b, it is possible to suppress the height of said peripheral sidewall 12b, 22b from the total height of the surrounding sidewall 13, 23 of each discharge damper chamber 10, 20. Thereby, a corresponding reduction in the contour of the housing 1 can be obtained in the region adjacent to said discharge baffles 10, 20.

Another advantage of the new construction for annular seat 12a, 22a results from the fact that its radial width is defined by the radial thickness of the surrounding sidewall 13, 23 in the region of annular seat 12a, 22a, allowing the radial wall thickness surrounding side 13, 23 is dimensioned to simultaneously define the required structure of the discharge damper chamber 10, 20, and the minimum radial width required for the definition of the annular seat 12a, 22a. As previously described, the discharge damper construction 10, 20 further comprises a sealing gasket 30 constructed of any suitable material well known in the art, having a peripheral annular portion 31 to be seated on the annular seat 12a, 22a when closing the discharge damper chamber 10, 20 and having a median hole 32.

In the preferred embodiment illustrated, the median bore 32 of the gasket 30 is defined in a median annular portion 33 radially spaced from the peripheral annular portion 31 and incorporated therein by a plurality of radial bridges 34.

Still according to the illustrated construction, the gasket 30 has its peripheral annular 31 and median annular portions 33 and their radial bridges 34 coplanar to each other and obtained in one piece.

The venting chamber 10, 20 further comprises

a lid 40 provided with a preferably central middle hole 41 and to be seated on the sealing gasket 30, more particularly on the peripheral annular portion 31 of the latter. The closure of each discharge damper chamber 10, 20 further includes the provision of a set screw 50 having a head 51, to be seated on the lid 40, a stem 52 protruding from the head 51 and to be fitted through the hole 41 of cap 40 and ending in a

30 The threaded end 53 to be secured within the axial hole

14a, 24a of the bottom end wall 14, 24 of each discharge damper chamber 10, 20.

The above described construction and object of the present invention allows the closure process of each discharge damper chamber 10, 20 to be carried out by the steps defined below after formation of the discharge damper chamber (s) 10, 20, with their annular seat 12a, 22a extended throughout the radial width of the surrounding sidewall 13, 23 of the discharge damper chamber 10, 20, in the region of its open end 11, 21, thereby eliminating the provision of the peripheral sidewall 12b, 22b, required in prior art constructions in which the open end 11, 21 of each discharge damper chamber 10, 20 is provided with the circumferential recess 12, 22.

The closing process itself comprises the consecutive steps of: engaging the cap 40 through its middle hole 41 about the stem 52 of the set screw 50, keeping the head 51 of the latter located on the outer side of the cap 40; providing the sealing gasket 30 as defined above and fitting it through its middle hole 32 around the stem 52 of the set screw 50, already carrying the cap 40; and assembling the set screw assembly 50, cap 40 and gasket 30 into the discharge damper chamber 10, 20 by seating the peripheral annular portion 31 of the gasket 30 against the annular seat 20 12a, 22a and securing the end. 53 of the retaining screw 50 in the blind axial hole 14a, 24a, so as to compress the lid 40 against the sealing gasket 30, closing the open end 11, 21 of the discharge damper chamber 10, 20. The elimination of the recess 12, 22 further permits the production of sealing joints 30 and lids 40 with greater dimensional tolerances and greater concentricity errors between the blind axial hole region 14a, 24a, and the open end center 11, 21, of the discharge chambers 10, 20, as there is no longer a need for said components to be fitted within the circumferential recess 12, 22, but only seated on the annular seat 12a, 22a and radially indexed by the shank 52 of the set screw 5 0. The elimination of the circumferential recess 12, 22 further allows the optimization of the compressor casing 1 with the use of larger bending radii in the region of the casing 1 adjacent to said discharge baffles 10, 20, with significant improvement of noise, maintaining the carcass thickness, or reducing the carcass thickness, without prejudice to its acoustic characteristics and its minimum recommended distance to the compressor-motor assembly.

Claims (6)

1.- Refrigeration compressor discharge chamber of a type comprising: a housing (1) housing a block (2) carrying at least one tubular-shaped discharge chamber (10, 20) having an extreme wall of bottom (14, 24) closed and having a blind (14a, 24a) and threaded axial hole, a surrounding side wall (13, 23) and an open end (11, 21), having an annular seat (12a, 22a); an annular gasket (30) seated on said annular seat (12a, 22a); a lid (40) provided with a middle hole (41) and seated on the sealing gasket (30); and a set screw (50) having a head (51) seated on the cap (40), a rod (52) protruding from the head (51) and ending at a threaded end (53) that is fixed within the said blind axial bore (14a, 24a), characterized in that said annular seat (12a, 22a) extends over the entire radial width of the surrounding side wall (13, 23) of the discharge damper (10,20), in the region of its open end (11, 21), wherein the gasket (30) comprises a peripheral annular portion (31) seated on the annular seat (12a, 22a) and a median hole (32) to be by the rod (52) of the set screw (50). Chamber according to Claim 1, characterized in that the median bore (32) of the gasket (30) is defined in a median annular portion (33) radially spaced from the peripheral annular portion (31) and it is incorporated by means of a plurality of radial bridges (34). Chamber according to claim 2, characterized in that the sealing gasket (30) has its peripheral (31) and middle annular (33) annular portions and their coplanar radial bridges (34) obtained in a single piece. 4.- Process for closing a discharge compressor damper for a refrigeration compressor of a type comprising: a housing (1) housing a block (2) carrying at least one tube-shaped discharge damper (10, 20); having a closed bottom end wall (14, 24) and having a threaded blind (14a, 24a) axial hole, a surrounding side wall (13, 23) and an open end (11, 21) having an annular seat ( 12a, 22a); an annular gasket (30) seated on said annular seat (12a, 22a); a cap (40) provided with a middle hole (41) and seated on the sealing gasket (30); and a set screw (50) having a head (51) seated on the cap (40), a rod (52) protruding from the head (51) and ending at a threaded end (53) that is fixed within the said blind axial hole (14a, 24a), characterized in that it comprises the steps of: - forming the discharge damping chamber (10, 20), with its annular seat (12a, 22a) extended over the entire radial width of the side wall surrounding (13,23) of the discharge damper chamber (10,20) in the region of its open end (11,21); - fitting the cap (40) through its middle hole (41) around the rod (52) of the fixing screw (50); - providing a sealing gasket (30) with a peripheral annular portion (31) and a median hole (32) and engaging the sealing gasket (30) through its middle hole (32) around the stem (52 ) of the fixing screw (50), already loading the cover (40); and - mounting the set screw (50), cap (40) and gasket (30) assembly to the discharge damper chamber (10, 20), the peripheral annular portion (31) of the gasket (30) resting against the annular seat (12a, 22a) and securing the end (53) of the set screw (50) in the blind axial hole (14a, 24a) so as to compress the cap (40) against the gasket (30) closing the open end (11, 21) of the discharge damper chamber (10, 20). 5. The method of claim 4 wherein the middle bore (32) of the gasket (30) is defined in a median annular portion (33) radially spaced from the peripheral annular portion (31) and it is incorporated by means of a plurality of radial bridges (34). 6. A method according to claim 5 wherein the sealing gasket (30) has its peripheral (31) and middle annular (33) annular portions and their coplanar radial bridges (34) obtained in a single piece.