JP3372754B2 - Hermetic compressor and method for manufacturing hermetic case in hermetic compressor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic compressor which is, for example, a rotary compressor, and a method of manufacturing a hermetic case in which a compression mechanism portion and an electric motor portion are fixed .

[0002]

2. Description of the Related Art A rotary compressor used in, for example, a refrigeration cycle apparatus that constitutes an air conditioner or a refrigerator is a hermetic compressor in which a compression mechanism portion and an electric motor portion are housed in a hermetically sealed case.

The sealed case is composed of at least two parts, a case body and a lid body. The case body is a bottomed cylinder or a cylinder whose both ends are open, and the open end is closed by the lid.

A cylinder constituting the compression mechanism portion and a stator constituting the electric motor portion are fixed to the inner peripheral wall of the case body by means such as press fitting or shrink fitting. Therefore, it is indispensable to improve the roundness and cylindricity of the required dimensions for fitting the compression mechanism portion, which is an interior part, and the electric motor portion, which constitutes the closed case, particularly with respect to the inner diameter accuracy of the case body.

For these reasons, in forming the case body, a so-called expander method, which is a pipe expanding plastic working method, is mainly used as a means for obtaining higher precision.

This is as shown in FIG. First, as shown in FIG. 3A, a plurality of divided expansion operators S, called expanders, are inserted into the cylindrical inner peripheral wall M of the case. In this state, both side surfaces of the fan-shaped expanding actuator S are in contact with each other,
The overall cross-sectional shape is ring-shaped.

Then, not-shown conical expanding bodies are forcibly inserted into both side ends of the expanding operator S. The expanding actuators S expand in the radial direction, and their outer peripheral arcuate surfaces contact the inner peripheral wall M of the case body, and apply a expanding force.

As a result, the peripheral wall M of the case body bulges and deforms in the radial direction. The actual deformation amount Xb is several tens of μm to several tens.
Although it is 0 μm, it is schematically represented as an extreme deformation in the figure. However, since each expansion operator S is formed in a fan shape, a gap is formed between both side surfaces of each expansion operator S during this expansion. Since the portion of this gap cannot be urged to open and spread with respect to the case body, the gap facing portion of the case body remains as it is without being expanded and deformed.

The remaining portion of the expanded pipe is called a divided portion mark K. (Or, it is also called an expander trace or an expander split portion.) As shown in FIG.
A1 is the inscribed circle diameter as the case body. This is designed so that the outer diameter of the expanding actuator S matches the final inner diameter of the case body. However, the expansion amount (expanding amount) at the time of pipe expansion should be increased by the springback of the case body material. If it is not the required diameter, it cannot be achieved. The outer diameter line φB1 in the figure is the diameter of the peripheral wall M of the case body that is bulged and deformed.

[0010]

By the way, when the hermetic compressor thus formed is driven, the vibration caused by the compression work and the electromagnetic vibration of the electric motor section are transmitted from the compression mechanism section to the case body. And is emitted to the surroundings as noise.

As described above, since the compression mechanism portion and the electric motor portion are strongly fixed to the case body especially by the division mark, their support is unstable. To describe further, for example, in the electric motor portion, a plurality of cutout portions are formed on the outer peripheral surface thereof so as to form a passage for the refrigerant gas and a relief portion for caulking deformation of the electromagnetic steel plate.

If there are variations in the assembling and manufacturing, the divided portion traces may drop into the cutout portion or may ride on the outer peripheral surface of the electric motor portion other than the cutout portion. Therefore, there is a problem that vibration transmission becomes unstable and complicated, and the direction and frequency of the noise radiated by the case body vary, resulting in high noise.

Further, the compression mechanism portion, which is a collective assembly of precision parts, is assembled so as not to have a strong interference fit with the case body in order to prevent assembly deformation. However, since there are the above-mentioned divided portion marks, the two parts locally contact each other, and a local change occurs in a part of the precision component. Since all of these are conditions for noise generation, it is necessary to take necessary and sufficient noise reduction measures.

On the other hand, if the assembly is completed with a very small amount of oil and fat adhered, the oil and fat will be dissolved in the refrigerant gas during the actual refrigeration cycle operation, which will adversely affect the compression efficiency. Therefore, conventionally, a degreasing step is performed after the compression mechanism part and the electric motor part are assembled in the case body, and the inside of the case body is washed to completely remove the oil and fat. As the cleaning agent, chlorofluorocarbon that does not attack the insulating coating such as the winding of the electric motor is used.

In other words, the internal cleaning after the completion of the assembling is performed by assembling the electric motor part or the like with the oil remaining on the inner peripheral surface of the case. In other words, even if the case body has a divided portion mark, the oil and fat content before removal serves as a lubricant, and defects such as galling do not occur, and productivity is not impaired.

However, from the concept of protecting the earth in recent years, the flon cleaning is to be completely abolished. A water-soluble cleaning agent is used as an alternative cleaning agent, but it has the property of attacking the insulation coating of the motor windings, so the inside of the case must be cleaned before the electric motor etc. is installed in the case. .

Eventually, the electric motor part or the like will be press-fitted into the inner peripheral wall of the case from which the oil and fat have been completely removed, and there is a risk of galling starting from the above-mentioned divided part mark. This galling not only hinders productivity such as occurrence of defective press-fitting, but also causes the galling pieces to remain in the compression mechanism portion, which impairs reliability.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a compression mechanism by using an expansion operator that forms a split portion mark that does not cause galling on the inner peripheral wall of the case body. Noise can be reduced even if the vibration generated from the motor and motor parts is transmitted to the sealed case.
Manufacture of hermetic type compressors and hermetically sealed cases in hermetic type compressors that reliably prevent galling during assembly, prevent local deformation, achieve highly accurate assembly, and improve reliability. It is intended to provide a method.

[0019]

[Means for Solving the Problems] In order to satisfy the above object
The present invention relates to a hermetic compressor including a hermetic case, a compression mechanism section and an electric motor section fixed to the inner peripheral wall of the hermetic case, wherein the case body has a plurality of arcs having an outer peripheral arc.
For expansion, it is formed by plastic working with the expansion actuator .
The diameter of the arc of the outer circumference of the actuator is the diameter of the inscribed circle so that the marks of multiple divisions generated by plastic working are located outside the inscribed circle.
It is formed larger.

[0020] The outer diameter of the compression mechanism section and the motor section is larger than the inscribed circle of the case body. Incidentally, the compression mechanism section and the motor section includes a notch which does not interfere with the dividing portion mark of the case body.

In order to satisfy the above object, the present invention is a closed case comprising a cylindrical case body and a lid body for closing an opening end of the case body. The case body is formed by plastic working. In a method of manufacturing a hermetic case in a hermetic compressor for molding, a cylindrical case body is divided into a plurality of pieces in the circumferential direction, and the diameter of an outer circumferential arc is set to be larger than the diameter of an inscribed circle of the case body. The process of inserting the opening actuator and expanding the opening actuator in the radial direction to bulge and deform the case body.
To form a plurality of division marks located outside the inscribed circle
And a step of performing .

By adopting the means for solving the invention as described above, even if the electromagnetic vibration or the vibration due to the pressure pulsation transmitted to the electromagnetic steel plate from the electric motor portion is transmitted to the case body through the joint portion with the case body. Since the outer peripheral surface is in surface contact with the inner peripheral wall of the case, the vibration transmission is stable, and the generated noise direction and frequency variation are reduced.

This reduction in variation limits the target frequency of the noise reduction item to be put in another portion, so that noise reduction is easy. Further, since the division mark does not come into strong contact with the compression mechanism part and the electric motor part, no galling occurs at the time of incorporation into the inner peripheral wall of the case, and therefore, there is no local deformation and the accuracy of the component parts can be maintained.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below.
The hermetic compressor is applied to, for example, a rotary compressor and will be described with reference to the drawings. Reference numeral 1 shown in FIG. 5 is a closed case. This hermetically sealed case 1 is manufactured by a manufacturing method described later, and has a case body 2 having upper and lower ends opened.
And lids 3 and 4 that close the upper and lower open ends of the case body 2, and the mating surfaces of the parts are completely sealed by, for example, welding means.

An electric compressor body 5 is housed in the closed case 1. The electric compressor main body 5 includes a rotating shaft 6 whose axis is oriented in the vertical direction, an electric motor portion 7 on the upper side, and a compression mechanism portion 8 on the lower side.

The electric motor section 7 is provided with a stator 9 which is press-fitted and fixed to the case body 2 of the hermetically sealed case 1, and an outer peripheral surface of the electric motor section 7 and the inner peripheral surface of the stator 9 with a small gap therebetween. The rotor 10 is fitted on the rotary shaft 6.

The rotary shaft 6 is integrally provided with an eccentric portion 6a at a position corresponding to the compression mechanism portion 8, and a roller 11 is fitted around the outer periphery of the eccentric portion. The eccentric portion 6a and the roller 11 are housed in a cylinder 13 that is fitted into the case body 2 of the closed case 1 via a frame 12. On the upper surface of the cylinder 13, the main bearing member 14
However, the sub bearing 15 is provided on the lower surface.

The inner peripheral surface of the cylinder 13 and the main bearing 1
The space surrounded by 4 and the sub bearing 15 is called a cylinder chamber 16. The roller 11 and the eccentric portion 6a are housed in the cylinder chamber 16 so as to be eccentrically rotatable. Roller 1 above
The outer peripheral surface of No. 1 is set so as to always come into line contact with the inner peripheral surface of the cylinder chamber 16.

Although not specifically shown, the cylinder 1
A blade is attached to the roller 3 in a state of being elastically pressed and urged, and the tip end thereof elastically abuts the outer peripheral surface of the roller 11. Therefore, the inside of the cylinder chamber 16 is divided into two chambers by this blade.

A suction port 17 is provided so as to penetrate from the inner peripheral surface of the cylinder 13 to the outer peripheral surface thereof, and the suction pipe 1 which communicates with an evaporator which is an external refrigeration cycle device.
8 is connected through the sealed case 1.

On the other hand, the main bearing 14 is provided with a discharge valve mechanism (not shown), which communicates with the inside of the cylinder chamber 16. Further, a discharge pipe 19 that communicates with a condenser that is an external refrigeration cycle device is connected to the upper lid 3 of the closed case 1.

With the rotation of the rotary shaft 6, however, the refrigerant gas as the compressed gas is sucked into the cylinder chamber 16 from the suction pipe 18 through the suction port 17. In the cylinder chamber 16, the roller 11 is eccentrically rotated together with the eccentric portion 6a of the rotary shaft 6, and the blade tip portion is slidably contacted with the roller peripheral surface to divide the cylinder chamber.

The gas sucked into the cylinder chamber 16 is gradually compressed as the volume of the divided cylinder chamber is reduced, and finally becomes high pressure. When the pressure rises to a predetermined pressure, the divided high pressure side cylinder chamber 16 communicates with the discharge valve mechanism, and the discharge valve mechanism is opened to discharge the high pressure gas from the cylinder chamber into the closed case 1. And
Once the high pressure gas is filled in the sealed case, the discharge pipe 1
It is discharged from 9.

Next, a method of manufacturing the case body 2 which constitutes the closed case 1 will be described. Figure 2 (A)
As shown in FIG. 3, a rectangular steel plate 2 having a predetermined width dimension and a longitudinal dimension is prepared, and both ends thereof are curled in a curl shape as shown in FIG. Then, as shown in FIG. 6C, both side edges are abutted to form a circular cross section. The contact edge portion is completely fixed by, for example, welding means. In this way, the cylindrical case body 2 having both open ends is formed.

As shown in FIG. 1, expansion actuators 20 ... Also referred to as expanders, which are divided into eight parts, are inserted into the cylindrical inner peripheral wall 2a of the case. Each expansion operator 20 has an arc-shaped cross section, and both side surfaces thereof are expanded in a fan shape. Appropriate chamfering is performed on the inner diameter side and the outer diameter side of both side surfaces.

While being inserted into the case inner peripheral wall 2a, both side surfaces of the expanding actuator 20 are in close contact with each other and have a substantially ring-shaped cross section. The radius of curvature on the inner diameter side of each expansion operator 20 may be set to an appropriate dimension that forms a perfect circle when inserted into the case body 2.

However, the radius of curvature of the expanding actuator 20 on the outer diameter side must be set as follows.
That is, when the radius of the outer circumferential arc of the expanding actuator 20 is Rc, its diameter R: 2Rc is larger than the diameter φA of the inscribed circle. (2Rc> φA) forming such a step is inserted into the case body peripheral wall 2a in combination for opening use actuator 20, and the step of forcibly widened along each radially outwards. Case inner peripheral wall 2
a spreads in the range of several tens of μm to several hundreds of μm.

Since the diameter R: 2Rc of the outer circumferential arc of the expanding actuator 20 is made larger than the diameter φA of the inscribed circle,
Split portion traces 21 projecting toward the outer diameter side are formed in both side portions of the operator in the range where the projection amount Xa is in the range of several tens μm to several hundreds μm.

A circle is formed which connects the central portions of the outer peripheral arcs of the expanding actuator 20 in which the division marks 21 are not formed,
This diameter is the inscribed circle φA and the inner diameter φB of the case body 2.

In the case body 2 thus completed, the stator 9 constituting the electric motor portion 7 shown in FIG. 5 is again shown.
Alternatively, the frame 12 or the like forming the compression mechanism portion 8 is press-fitted. The outer diameters of the stator 9 and the frame 12 are slightly larger than the inscribed circle φA of the case body 2, and the stator 9 and the frame 12 are firmly fixed to the case body 2 by press fitting or shrink fitting. To do.

At this time, the inside of the case body 2 has already been degreased and washed with a water-soluble cleaning agent under the condition of CFC regulation, and very little oil and fat is left on the inner peripheral wall 2a.

Since, for example, when the stator 9 is press-fitted into the completely degreased case body 2, a divided portion mark 21 protruding outward from the inscribed circle φA is formed on the inner peripheral wall 2a of the case, The circumferential surface of the stator 9 does not come into contact with the division mark 21, and therefore galling does not occur.

Since the inscribed circle φA and the inner diameter φB of the case body 2 are substantially coincident with each other, and the outer diameter of the stator 9 is slightly larger than the inscribed circle φA, the stator 9 is the peripheral wall 2 of the case body.
It is press-fitted and fixed to a in a surface contact state. Also,
The cylinder receiver 12 constituting the compression mechanism portion 8 is also press-fitted and fixed to the inner peripheral wall 2a of the case in exactly the same state.

As shown in FIG. 3, in particular, in the case of the stator 9, four flat cutouts 9a are provided on the peripheral surface thereof at equal intervals. On the other hand, the expanding actuator 21 is divided into eight parts, and eight divided part marks 21 are formed. Therefore, the notches 9a must be press-fitted into every other divided part marks 21. become.

Since the divided portion mark 21 projects outward from the inscribed circle φA, a space portion having a sufficient capacity is formed between the divided portion trace 21 and the cutout portion 9a, which can be secured as a passage for the refrigerant gas. .

Further, as shown in FIG. 4, the expanding actuator 2
With 0 being expanded to the maximum extent, a gap is created between the respective actuators. As described above, the division mark 21 protrudes outward from the inscribed circle φA, but the gap between the expansion actuators is not biased so as to face the apex of the actual division mark. Therefore, when this apex portion is enlarged, a concave portion having a certain radius of curvature is formed. Alternatively, it has a flat shape, and at least the apex portion does not project.

When the hermetic compressor is driven in accordance with the refrigerating cycle operation, however, the electromagnetic vibration from the electric motor section 7 or the vibration due to the pressure pulsation transmitted to the electromagnetic steel sheet is passed through the joint with the case body 2 to close the case. Even if it is transmitted to No. 1, since the outer peripheral surface is in surface contact with the inner peripheral wall 2a of the case, the vibration transmission is stabilized, and the generated noise direction and frequency variations are reduced.

Furthermore, since the division mark 21 does not come into strong contact with the compression mechanism portion 8 and the electric motor portion 7, no galling occurs when it is assembled in the case body 2, and therefore there is no local deformation and the accuracy of the components is high. Can be maintained.

FIG. 6 shows the result of actual measurement of the noise value of the hermetic compressor of the present invention and the hermetic compressor of the conventional structure driven. As shown in FIG. 2B, in the hermetic compressor having the conventional configuration, the peak variation of the noise level at each operating frequency was relatively large. However, as shown in FIG. It can be understood that in the hermetic compressor, the noise level peak variation at each operating frequency is smaller than that of the conventional configuration, and noise reduction can be obtained.

[0050] Incidentally, as a condition for setting the outer circumferential arc of the spreader for actuator 20, in the above embodiment has been larger than the diameter φA of the inscribed circle, is not limited thereto, the outer circumference arc Even if the division mark 21 is set so as not to contact the inscribed circle of the case body 2 by a plurality of circular arc aggregates having different dimensions, the same effect can be obtained.

[0051]

[0052]

[0053]

As described above , according to the present invention, even if the compression mechanism portion and the electric motor portion are press-fitted into the inner peripheral wall of the case from which all the oil and fat inside has been removed, no galling occurs and local deformation occurs. To prevent the occurrence of
The reliability can be improved.

Since the electric motor portion is in surface contact with the case body, the vibration transmission is stabilized and the generated noise direction and the variation in frequency are reduced, while the case body is reinforced by the electric motor portion, so that the vibration damping effect is obtained. Is increased, and thus noise can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view of a case body of a hermetically sealed case and an expanding divider for manufacturing the case body according to an embodiment of the present invention.

FIG. 2A to FIG. 2C are views for sequentially explaining the molding process of the case body according to the embodiment.

FIG. 3 is a cross-sectional plan view showing a state in which a stator of an electric motor unit is press-fitted into a peripheral wall of a case body according to the first embodiment.

FIG. 4 is an enlarged view of a split portion trace by the expansion operator of the embodiment.

FIG. 5 is a vertical cross-sectional view of the hermetic compressor including the hermetic case molded in the manufacturing process according to the embodiment.

FIG. 6A is a noise characteristic diagram when the hermetic compressor having the structure of the present invention is driven. FIG. 3B is a noise characteristic diagram when a hermetic compressor having a conventional structure is driven.

FIG. 7A is a cross-sectional plan view of a case body of a conventional hermetically sealed case and an expanding splitting member for manufacturing the case body. (B) is a cross-sectional plan view of a case body of a conventional molded closed case.

[Explanation of symbols]

1 ... hermetically sealed case, 8 ... compression mechanism section, 7 ... motor part, 2 ... Case body, 2a ... the peripheral wall of the case body, 3, 4 ... Lid, 21 ... Trace of division, 9a ... notch, 20 ... Spreading actuator.

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) F04B 39/12 B21D 39/20 F01C 29/00

Claims (4)

(57) [Claims] 1. A hermetic-type compressor comprising a hermetic case, a compression mechanism section and an electric motor section fixed to the inner peripheral wall of the hermetic case, wherein the hermetic case is compressed into an inscribed circle from an opening at one end. It is composed of a case body into which the mechanism section and the electric motor section are inserted and fixed, and a lid body that closes the opening end of the case body, and the case body has a plurality of expansion operators having an outer peripheral arc.
Molded by plastic working with the outside of the expansion actuator.
The diameter of the circular arc is larger than the diameter of the inscribed circle so that the marks of multiple divisions generated by plastic working are located outside the inscribed circle.
A hermetic compressor characterized by being formed into a hollow shape . 2. The outer diameters of the compression mechanism section and the electric motor section are:
The hermetic compressor according to claim 1, wherein the hermetic compressor is larger than an inscribed circle of the case body. 3. The hermetic compressor according to claim 2, wherein the compression mechanism section and the electric motor section are provided with notches that do not interfere with the traces of the divided portions of the case body. 4. A method for manufacturing a hermetically sealed case in a hermetic compressor, which is a hermetically sealed case including a cylindrical case body and a lid body that closes an open end of the case body. In the cylindrical case body, the step of inserting the expanding actuator, which is divided into a plurality of pieces in the circumferential direction and whose outer circumferential arc has a diameter larger than the diameter of the inscribed circle of the case body, Expand the opening actuator in the radial direction to bulge the case body.
It is the shape, the manufacturing method of the sealed casing in the hermetic compressor and characterized by including a step of forming a plurality of divided portions marks positioned outside the inscribed circle.