Patent Application
20050238520
The invention concerns refrigeration or air conditioning compressor units of the hermetically sealed type wherein the compressor housing or “shell” encloses the compressor, its drive motor and accessories. The compressor housing has upper and lower cup shaped sections which sections are secured together, e.g., by welding along the peripheral mating joint formed by the mated contiguous opening portions of the shell sections after the compressor, motor, and accessories are mounted therein.
It is customary in the design and manufacture of hermetically sealed compressors to dimension and configure the shell sections to adequately accommodate, spacewise, the compressor, its motor, and the various auxiliary components such as the motor mounting, the suction feed system, the discharge loop, the discharge muffler, and the like. Often other design needs, such as diminishing the inherent property of the shell to transmit objectionable noise at objectionable frequencies, are compromised by paramount space considerations such as the dimensioning and configuration of the refrigeration or air conditioning system housing or cabinet into which the compressor unit is to be mounted. Also, the shell manufacturing techniques such as deep-draw press operations frequently necessitate certain shell configurations such as substantially straight, cylindrical side walls. Due to widely varying shell configurations, it is becoming increasingly difficult to align the shell sections for accurate and precise location, positioning and installation of fixtures such as junction boxes, intakes, exhausts, mounting brackets, feet, and the like. Similarly, alignment of the shell sections for mating and securing has become problematic.
The patent literature describes many different variations of compressor unit shell configurations, e.g., U.S. Pat. Nos. 4,239,461; 4,384,635; 4,396,360; 4,406,590; 4,412,791; 4,729,723; 5,281,105; 5,538,404; and 5,762,479. Many of these patents are directed to reducing objectionable noise transmitted by the shell. The objectionable noise is frequently originated or propagated in the shell either by the mechanical elements of the compressor such as the suction and discharge valves, or by the refrigerant flowing through the compressor, e.g., pulsations within the suction or discharge system. In this regard, it is recognized by those skilled in the art that the source of the noise, its mode of propagation within the shell, and its manner of transmission by the shell to the human ear are all extremely difficult to understand and predict, and of course, to control. The above referenced patents describe a myriad of shell shapes, both symmetric and asymmetric, in attempts to control the generation and propagation of vibration and noise, as well as to control the size of the assembled shell.
As compressor housings have become increasingly complex in shape, manufacturers find it increasingly difficult and expensive to securely and reliably orient the shells for accurate and precise positioning and installation of fixtures such as junction boxes, intakes, exhausts, ports, orifices, brackets, mountings, and the like, and also for the mating and securing of the shell sections. Improper location of fixtures caused by improper alignment of the shell sections can result in shell contact with internal compressor parts, resulting in unwanted noise, vibration, and friction. Improper alignment during the mating of the shell sections can compromise the integrity of the hermetic seal. It is therefore recognized by those skilled in the art that controllable, repeatable, precise and accurate alignment of the sections is desirable.
Known methods of alignment and positioning of shell sections are prone to error. Manufacturers currently engage in marking, pre-spot welding, and similar activities in order to locate, position, and install fixtures and to mate shell sections. Such labor-intensive measures do not produce inconsistent results, and are costly.
Therefore, what is needed is a precise, accurate and cost-effective method of aligning shell sections for fixture mounting and mating operations. Furthermore, what is also needed is a compressor unit housing or “shell” design which is easy to align for locating, positioning and installing of fixtures as well as for the mating of the shell sections.
In one embodiment of the present invention, the apparatus is a hermetic compressor housing unit comprising a shell having upper and lower sections which, when mated, form a generally cylindrical shell with substantially straight or linear sidewalls. Each shell section includes an open end (“opening”), a substantially cylindrical sidewall, and a closed end portion. Each shell section includes a generally circular or oval horizontal cross-sectional geometry defined by a major axis and a minor axis. The horizontal cross-sectional geometry includes a pair of substantially linear opposing portions disposed substantially perpendicular to and in proximity to the intersection of horizontal cross-sectional geometry with the minor axis. The pair of substantially linear opposing portions originate at the opening on the sidewall of the shell section and extend towards the closed end portion of the shell section. The substantially linear opposing portions can extend the entire length of the sidewall before being blended into the substantially circular or oval horizontal cross-sectional geometry at the closed end.
In another embodiment, the substantially linear opposing portions of a shell section are blended into the substantially circular or oval horizontal cross-sectional geometry before reaching the closed end portion. In this embodiment, the closed end portion and a portion of the sidewall can have a horizontal cross sectional geometry, e.g. circular, which differs from that of the horizontal cross sectional geometry of the sidewall at the opening, as a result of blending of the substantially linear opposing portions.
A further embodiment of the invention includes a method of aligning and assembling hermetic compressor shells having upper and a lower shell sections. The method includes comprises providing a hermetic compressor housing shell section having substantially straight sidewalls and a substantially circular or substantially oval horizontal cross-sectional geometry defined by a major axis and a minor axis. The method further provides applying force to at least two opposing points on the interior surface of the sidewalls in the direction of the major axis, such that the shell section becomes aligned along the major axis. In other embodiments, the method may further include the additional step of applying additional force to at least two points on the interior surface of the sidewalls in the direction of the minor axis, such that the shell section also becomes aligned along the minor axis.
After aligning the shell by application of force to at least two points on the interior surface of the sidewalls along the major axis or the major and minor axes, the method may further include the step of providing at least one fixture for installation on the shell section, and locating and positioning the at least one fixture based upon the alignment of the shell section. Proper locating and positioning of the fixture on the aligned shell section enables accurate and precise installation of the fixture to the shell section.
One advantage of the invention is that it provides a housing which is configured to accommodate many types of presently manufactured compressors, single or multiple cylinders, most preferably two cylinders, including their motors and the aforesaid auxiliary components, which compressors are typically employed in hermetic units. Another advantage of the invention is that it provides increased capacity for precise alignment of the shell sections. Yet another advantage is that the invention provides an improved shell design with substantially straight cylindrical side walls, which design is relatively inexpensive and easy to produce by conventional metal forming operations.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
The invention will be further understood from the following description and drawings which show a preferred embodiment of the present invention, wherein:
Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
The compressor shell or housing of the present invention preferably has a generally cylindrical shape, and is dimensioned to enclose a compressor, electric motor, and any corresponding auxiliary components such as a discharge muffler, suction line, motor cap or suction plenum having an inlet, and the like. A typical compressor having utility for the present invention is shown in U.S. Pat. No. 4,995,791, the disclosure of which is incorporated herein by reference.
Referring to the drawings, the compressor housing of the present invention includes two shell sections, an upper shell section 10 and a lower shell section 12, that are connected or secured together to form the housing. Each section 10, 12 is preferably formed by a metal drawing operation from low carbon sheet steel of a substantially uniform thickness, preferably from about 0.090 to about 0.160 in. It is to be understood that the sections 10, 12 can be formed by any suitable process and can have any suitable thickness. As shown in
As shown in
The horizontal cross-sectional geometry of the opening 16 each shell section 10, 12 further includes a pair of substantially linear opposing segments or portions 30 preferably disposed substantially perpendicular to and in proximity to the intersection of the horizontal cross-sectional geometry with the minor axis. However, the linear opposing portions could be disposed at an angle to the minor axis. The cross-sectional length along the major axis of each substantially linear opposing portion 30 is from about between 0.250 inches to about 3.0 inches wide and is preferably about 1.0 inch wide. The opposing portions 30 are preferably centered at the intersection of the minor axis and the horizontal cross-sectional geometry of the opening 16. As further shown in
In other embodiments, the shell may further include a pair of substantially linear opposing segments or portions disposed substantially perpendicular to and in proximity to the intersection of the horizontal cross-sectional geometry with the major axis. Such segments or portions may be supplement, or serve as an alternative to, linear segments or portions located in proximity to the intersection of the minor axis and the horizontal cross-sectional geometry.
In the embodiment shown in
In other embodiments, the substantially linear opposing portions 30 are blended into the general cross-sectional shape of the sidewall 18 before reaching the closed end portion 20. In this embodiment, the opening 16 and sidewall 18 of each shell 10, 12 have a substantially circular horizontal cross-sectional geometry defined by a major axis and a minor axis with substantially linear opposing portions 30. Furthermore, the remaining portion of the sidewall 18 and the closed end portion 20 may have a horizontal cross sectional geometry that is different from that of the opening 16, e.g. perfectly circular, as a result of the blending of the substantially linear opposing portions 30 sections.
The sidewall 18 of each shell section 10, 12 is preferably substantially straight or linear in an axial direction. The term “substantially straight” in this context permits a slight outward or inward bow on a substantially uniform radius should such a bow be desired at all. The origin of a slight outward bow may be located at any peripheral position around the sidewall 18 of the shell section, such that the radius is used to define the curvature, if any, of the sidewall 18. The length of the radius can be “substantially uniform” which means that the radius length for different small segments of a sidewall section can be changed for some specific purpose such as spatial requirements, without thereby deviating from the concept of giving a slight bow to the sidewall 18. In another embodiment, the sidewall 18 of each shell section 10, 12 may also be “stepped” inwardly or outwardly one or more times from the opening 16 toward the closed end portion 20 thereof, i.e., progressively or by steps of decreased or increased diameters. For example,
The present invention also includes methods of aligning and assembling hermetic compressor shells having an upper and a lower shell section with the substantially circular horizontal cross-sectional geometry previously described. The method can be preferably utilized in conjunction with the shell of the present invention. However, the method can also be used with shells having a horizontal cross-sectional geometries defined by a major axis and a minor axis.
The method comprises providing a hermetic compressor housing shell section having substantially straight sidewalls and having a horizontal cross-sectional geometry defined by a major axis and a minor axis, preferably the geometry shown in
Alternatively, as shown in
In other embodiments, the method may involve application of force to the exterior surface of the sidewalls. In this embodiment, force FA is applied, to at least two opposing points on the exterior surface of the sidewalls in the direction of the desired orientation of the major axis A-A, such that the shell section becomes aligned along the major axis. The application of the force causes the shell to rotate until the major axis of the shell is aligned with the force FA . The force FA can be applied to the exterior shell surface by any force applying means known to those skilled in the art that permit the shell to rotate. As in other embodiments, a characteristic of the force applying means is that as the force FA is increased, the rollers or wheels simultaneously contact and exert pressure on at least two points on the exterior surface of the sidewalls of the shell section forcing the shell section to rotate. When the shell section has rotated such that the rollers or wheels reach the intersection of the sidewall and the major axis A-A, the shell section is properly aligned. At this point, a sufficient level of force continues to be applied so as to maintain proper shell alignment and prevent the shell from changing position. Optionally, a second force, FB, can be applied to at least two points on the exterior surface of the sidewall in the direction of the desired orientation of the minor axis B-B, forcing the shell section to further rotate such that a second set of rollers or wheels rotate until reaching the intersection of the sidewall and the minor axis so that the shell section is also aligned along the minor axis. An exemplary force applying apparatus for practicing this method of alignment is illustrated in
With shell alignment completed and maintained, fixtures may now be located and positioned based upon the desired alignment of the shell section, and can be reliably, accurately, and precisely installed. Following installation of any necessary fixtures, aligned shells can be positioned relative to one another for mating and securing of shell sections into a single unit as shown in
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10428524 | May 2003 | US |
| Child | 11153184 | Jun 2005 | US |
