Inside frame of compressor

Inside frame of a compressor including a frame body having a pass through hole for a crankshaft, legs formed by bending, and extending from, opposite ends of the frame body, respectively, and component fastening parts formed by extending from the legs in parallel to the frame body, respectively, wherein the component fastening parts have opposite inward extensions, and the frame body is formed such that component fastening to the component fastening parts is possible without interference with the frame body, thereby minimizing a size of the compressor and enhancing an assembly precision and strength.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to compressors for compressing a working fluid such as refrigerant to a required pressure, and more particularly, to an inside frame of a compressor inside of a shell of the compressor for mounting various components of the compressor thereon.

2. Background of the Related Art

The compressor compresses the working fluid, such as gas or a refrigerant, to a required pressure. In the compressors, there are turbo compressors, such as axial compressors, and centrifugal compressors, and displacement compressors, such as rotating compressors, and reciprocating compressors.

Of the compressors, the reciprocating compressor has a piston in a cylinder for reciprocating therein to draw gas or refrigerant into the cylinder, and compress, and discharge the gas or refrigerant.

FIG. 1illustrates a section of a related art reciprocating compressor.

Referring toFIG. 1, the related art reciprocating compressor (hereafter called as a compressor) is provided with a shell1having an upper case1aand a lower case1b, for holding various components, and a frame2supported on springs2S inside of the shell1for mounting various components of the compressor thereto.

There is a boss having a vertical pass through hole in a central part of the frame2, with a crankshaft5rotatably mounted therein.

The crankshaft5has an oil passage5a, for guiding oil L held in a bottom part of the shell1to an upper part of the shell, and spraying the oil onto the frame2. There is a pumping mechanism5dat a lower end of the crankshaft5for pumping the oil ‘L’ to the oil passage5a.

The crankshaft5rotates by a motor part having a stator3and a rotor4fixed to the crankshaft5for rotating by an electrical interaction with the stator3, under the frame.

There is a crank pin5bon top of the crankshaft5eccentric from a rotation center of the crankshaft5. There is a balance weight5copposite to the crank pin5b, for making a rotation speed of the crankshaft5uniform.

In the meantime, there is a cylinder6formed as one unit with the frame2at one side of an upper part of the shell, with a compression chamber formed therein. There is a piston7in the cylinder for compression of refrigerant or gas, connected to the crank pin5bat top of the crankshaft5with a connecting rod8.

There is a valve assembly9on the cylinder6for controlling flow of refrigerant into/out of the compression chamber. The valve assembly9is provided with a suction valve for drawing refrigerant, and a discharge valve for discharging compressed refrigerant.

The valve assembly9is mounted between the cylinder6and the head cover10, and there is a suction silencer11at one side of the head cover, connected to the valve assembly, for attenuating noise from the refrigerant.

The shell has one side having a suction pipe12fitted thereto for guiding the refrigerant from an outside of the compressor to the suction silencer11, and the other side having a discharge pipe13for discharging compressed refrigerant.

Though the frame2is cast together with the boss2a, the cylinder6, and the like, the frame2may be fabricated separate from the boss2aor the cylinder6and mounted on the frame depending on design conditions.

A structure of a related art frame for mounting the various components of the compressor will be described with reference toFIG. 2, wherein the boss, and the cylinder are fabricated separate from the frame.

Referring toFIG. 2, the frame is pressed or forged. The frame20is provided with an upper plate21having a boss hole in a central part for inserting a boss24therein, legs22bent downward, and extended from opposite ends of the upper plate21, and stator fastening parts23bent outward, and extended perpendicular from lower ends of the legs22parallel to the upper plate21.

Each of the stator fastening parts23has fastening holes23afor fastening the stator3thereto which is mounted on an underside of the stator fastening parts23with fastening means3a.

However, the related art frame has the following problems.

First, the stator fastening parts23of the frame20formed by outward bending, and extension from the legs16results in a long total length ‘L’ of the frame20, that impedes fabrication of a smaller compressor.

Second, the contact of an entire bottom surface of the flange24aformed at a top of the boss24with an edge of the boss hole is liable to cause the boss and the upper plate21to misalign so as to be out of a right angle, that impedes smooth rotation of the crankshaft inserted in the boss24.

Third, the low rigidity of the bent parts22aand22bof the frame is liable to cause breakage, or deformation due to stress concentration.

Fourth, in a case of deformation of the frame, relative positions of components mounted on the frame change, to make a performance of the compressor poor.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an inside frame of a compressor, which can minimize a size of the compressor.

Other object of the present invention is to provide an inside frame of a compressor, in which assembly precision of a boss which supports a crankshaft, and a frame body the boss is fixed thereto, is enhanced, for making crankshaft rotation smooth.

Another object of the present invention is to provide an inside frame of a compressor, deformation or breakage of which is prevented during operation of the compressor.

To achieve these objects and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, the inside frame of a compressor includes a frame body having a pass through hole for a crankshaft, legs formed by bending, and extending from, opposite ends of the frame body respectively, and component fastening parts formed by extending from the legs in parallel to the frame body, respectively, wherein the component fastening parts have opposite inward extensions, and the frame body is formed such that component fastening to the component fastening parts is possible without interference with the frame body.

The legs are bent in predetermined widths at middle parts of the opposite ends of the frame body respectively, and the component fastening parts are provided at width direction opposite sides of each of the legs. The component fastening part has fastening holes for fastening a component.

The frame body has parts over the fastening holes cut away for making the fastening holes visible from above.

The inside frame further includes a seating part bent outward from each of the legs for seating the component fastened to the component fastening parts thereon.

The seating part includes stoppers at outer edges thereof for preventing movement of the frame body, for preventing the component mounted on the inside frame from hitting an inside wall of the shell during operation of the compressor.

Preferably, the seating part is formed not longer than a side of the frame body at which the leg is formed.

The frame body includes a boss inserted in, and held at, the pass through hole, for rotatably supporting the crankshaft.

The boss includes a flange perpendicular to an axis direction of the crankshaft.

The frame body further includes an annular recess in a part the flange of the boss is seated thereon.

The boss is fixed with fixing holes formed in one the flange of the boss, and the annular recess, and projections formed in the other one of the flange and the annular boss.

Preferably, the projection includes a round part to have a curvature at a lower part thereof for preventing breakage or deformation of the projection.

The projection is cylindrical, and the round part has a radius of curvature greater than a 0.05 time of a diameter of the projection.

The flange of the boss or the annular recess includes a flange supporting part having predetermined width and height to form a step.

The projection may include a flange supporting part having predetermined width and height around a lower part thereof.

In formation of the projection, a predetermined pressure is applied to an opposite surface to a surface the projection is to be projected therefrom to sink the opposite surface to a predetermined depth.

The inside frame further includes at least one reinforcing rib at each bent part of the legs or the component fastening part.

The reinforcing rib is formed such that, by applying a predetermined pressure to one side of the bent part, one side having the pressure applied thereto is collapsed, and an opposite side is projected.

The reinforcing rib is formed by applying the predetermined pressure to an outward curved part of the bent part, to project the opposite side.

It is to be understood that both the foregoing description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention claimed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. In describing the embodiments, same parts will be given the same names and reference symbols, and repetitive description of which will be omitted.

In describing the reciprocating compressor having the inside frame of a compressor of the present invention applied thereto, since parts except the parts described hereafter are identical, description of the identical parts will be omitted for convenience sake. The embodiments of the inside frame of a compressor of the present invention will be described with reference to the attached drawingsFIGS. 3 to 7.

Of the attached drawings,FIGS. 3A,3B, and3C respectively illustrate a perspective view, and a developed view and a plan view, both having a boss detached therefrom, of an inside frame of a compressor in accordance with a preferred embodiment of the present invention.

Referring toFIGS. 3A and 3B, the inside frame30of a compressor in the compressor for mounting various components of the compressor thereon includes a frame body31, legs37at opposite sides of the frame body, and component fastening parts39.

The frame body31, fabricated with a steel plate of a thickness, has a vertical pass through hole33for a crankshaft which reciprocates a piston, linearly. There is a boss40inserted in the pass through hole33in the frame body for rotatably supporting the crankshaft.

The legs37are bent downward from opposite ends of the frame body31respectively, for supporting the frame body31. In more detail, the legs37are bent downward from middle parts of opposite ends of the frame body31, each with a predetermined width.

The component fastening parts39, parts for fastening components, such as a stator, extend inward from respective legs37opposite to each other, such that the component fastening parts139are parallel to the upper surface of the frame body31. In more detail, the component fastening part39extends inward from width direction opposite side parts of each of the legs37, and the component fastening part39has the fastening holes39afor fastening components.

It is preferable that, in order to make a part of the component fasting part39the fastening hole39aare formed therein visible from above, corners of the frame body31which comes over the fasting holes are cut away, so that, when a tool, such as a punch, accesses for fastening component, such as the stator, or forming a fastening hole in the component fastening part, the tool does not interfere with the frame body.

It is preferable that the inside frame of the compressor includes seating parts38each bent outward from each leg37for seating the component fastened to the component fastening part39, additionally. The seating part38is formed as one unit with the component fastening part39on the same plane with the component fastening part39.

It is preferable that the seating part38is parallel with an upper surface of the frame body31, and has a length not greater than a width of a frame body31side at which the leg37is formed.

It is preferable that the seating part38has stoppers38aextended outward from outer edges thereof in an outer direction of the leg37, for preventing the component mounted on the inside frame from hitting an inside wall of the shell due to vibration during operation of the compressor.

An unexplained reference symbol31adenotes an upper fastening hole for fastening a cylinder (not shown) or the like to the frame body31.

Next, the frame body31having the pass through hole33formed therein, and the boss40inserted in, and held at the pass through hole will be described, with reference toFIGS. 4,5A, and5B.

Referring toFIGS. 4,5A, and5B, the boss40is a length of cylinder, having a pass through hole42along an axis direction, for rotatably arranging the crankshaft therein.

The boss includes a thrust part43at a top end thereof for rotatably supporting an underside of the balance weight of the crankshaft, and a flange41at the top end thereof formed perpendicular to the axis of boss for seating the boss on an upper surface of the frame body, particularly, on an edge of the pass through hole.

It is preferable that the thrust part43is projected more than the upper surface of the frame body31slightly, for preventing parts, such as the balance weight of the crankshaft supported on the thrust part43from being brought into contact with the flange41or the frame body31.

The frame body31has an annular recess34lower than the upper surface of the frame body31around the pass through hole33the flange41of the boss is seated thereon.

For fixing the boss, the annular recess has a plurality of projections35of bars, and the flange41on the boss has a plurality of fixing holes41afor inserting the projections35.

The projections35may be formed by different methods, such as forging or pressing. There is a hole35asunken into a depth in a lower surface of the frame body31, i.e., in an opposite surface of the surface the projection35is projected therefrom by a pressure applied in a projection direction of the projection35in formation of the projection35.

The hole35ais formed for smoother formation of the projection35, i.e., the pressure applied for forming the hole35apushes the lower surface of the frame body31, to assist forming the projection31.

The formation of the holes35aunder the projections35liable to make strength of the annular recess weaker as a lower part of the projection35becomes relatively less thick. For preventing breakage of the projection35due to the weaker strength, it is preferable that the projection35has a round part35bat a lower part thereof.

The round part35breinforces a part that connects the lower part of the projection35to the annular recess34. It is preferable that the round part35bhas a radius ‘R’ of curvature greater than a 0.05 times of the diameter ‘D’ of the projection35, for reinforcing the part connecting the lower part of the projection35and the annular recess34with a thickness greater than a certain thickness.

Of course, the round part35bmay be formed in the lower part of the projection even in a case no hole35ais formed in the lower surface of the frame body31for smooth formation of the projection, for prevention of breakage of the projection35.

Though the embodiment suggests forming the projection35on the annular recess of the frame body31and the fixing hole41ain the flange41of the boss40, the projection35and the fixing hole41amay be formed, oppositely.

The projection35includes a flange supporting part34aaround the projection35, with a height from a surface of the annular recess34to form a step37. That is, the flange supporting part34ais formed at a height from the surface of the annular recess34, for seating a lower surface of the flange40of the boss40.

The flange supporting part34amakes a contact area between the flange41and the frame body31to be minimum, and facilitating that the axis of the pass through hole42of the boss40is perpendicular to the upper surface of the frame body31accurately, and minimizing friction of the crankshaft in the boss40.

In the inside frame of the compressor in accordance with the first preferred embodiment of the present invention, though the flange supporting part34ahas a circular horizontal sectional area, the form is not limited to circle.

In addition to this, it is preferable that reinforcing ribs are formed in upper and lower parts of the legs37respectively, i.e., in a bent part connected to the frame body31, and in a bent part connected to the seating part39, respectively. A second embodiment of the present invention having the reinforcing ribs is illustrated inFIGS. 6 and 7.

Referring toFIGS. 6 and 7, the reinforcing ribs50in the bent parts of the inside frame30of the compressor are formed together with the inside frame. It is preferable that the reinforcing ribs50are formed in an extension direction of the legs37.

That is, reinforcing rib50is formed by applying a pressure to the bent parts in the upper and lower parts of the legs37with a punch of a required form. Though the punch may have a polygonal bar section, the section is not limited to the polygonal bar section.

Upon applying the pressure to the upper or lower bent part of the leg37with the punch of above form, the reinforcing ribs50are formed at a side opposite to a side having the pressure applied thereto, and collapsed recesses52are formed at the side having the pressure applied thereto with the punch.

The reinforcing ribs50prevent deformation or breakage of the inside frame of the compressor due to vibration or the like occurred in operation of the compressor.

A process for fabricating the inside frame of the compressor of the present invention, and operation thereof will be described, in detail.

The inside frame of a compressor of the present invention has a structure, in which the boss40is fabricated separate from the frame body31, and mounted on the frame body31. The inside frame30is pressed or forged with a sheet of steel plate, of which exemplary process will be described.

Referring toFIG. 3B, a sheet of plate cut in required length and width is cut into a designed form. The cut plate is bent to have a form having the legs37, the component fastening parts39, and the seating parts38. Of course, the cutting and bending may be carried out in one fabrication process.

Though the processes of cutting, bending, and hole making may be carried Out at the same time, or changing the order, it is preferable that a process on a surface of the inside frame30, such as the hole making of the fastening holes is progressed after completion of a form of the inside frame30.

For forming the fastening holes39ain the surface of the component fastening parts39for fastening the stator, it is required that the tool for forming the fastening hole39adoes not interfere with the frame body31. For this, it is required that corners of the frame body31are cut away such that the component fasting parts39are visible from above.

The frame body cut thus is joined with the boss40having the flange41with the fixing holes41aand the projections35.

The inside frame30of a compressor fabricated thus is mounted on an inside of the shell and joined with various components of the compressor. In the components mounted on the inside frame30, there are the piston with the cylinder fitted therein, the stator, the crankshaft, and the like. That is, the cylinder is mounted on the upper surface of the frame body31, the stator is fastened to the component fastening parts39, and the crankshaft is mounted passed through the boss40. As the rotor is pressed into, and fixed on, the crankshaft that interacts with the stator electro-magnetically, the compressor can carry out the function of compressing the low pressure refrigerant and discharging at a high pressure.

The inside frame of the compressor and a compressor therewith have the following advantages.

First, the inward extension of the fastening parts permits to reduce a volume of the inside frame, thereby reducing a size of the compressor.

Second, the cutting away of the corners of the frame body, for preventing interference with the frame body in formation of the fastening holes in the component fastening parts or fastening the component, such as the stator, enables easy formation of the fastening holes, and easy fastening of the components.

Third, the annular recess around the pass through hole in the frame body for seating the flange reduces a vertical length of the compressor, thereby reducing a size of the compressor.

Fourth, the pushing up of the lower surface of the frame body with a predetermined pressure for forming the projection from the annular recess permits an easy formation of the projection of a height.

Fifth, the flange supporting part for minimizing a contact area between the flange of the boss, and the flange body enhances a fitting precision between the frame body and the boss.

Sixth, the reinforcing ribs in the bent parts in the upper part and the lower part of the legs, and the round part in the lower part of the projection prevent deformation or breakage of the frame.