JP2004316647A - Compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reciprocating compressor capable of reducing the number of faces to be machined and additional components, and simplifying the manufacture and assembly of the compressor. <P>SOLUTION: A motor 18 and a single body member 26 supported by the motor, i.e., a body member with a cylinder 30 and a head part 34 integrated with each other are disposed in a sealed casing 12. A piston 38 to be driven by a crank shaft 22 of the motor is fitted in the cylinder, and a discharge passage and a discharge valve assembly 50 are provided on the head part. The discharge valve assembly is shrink-fitted to the head part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a reciprocating compressor that is hermetically sealed and driven by a motor, and more particularly to a reciprocating compressor having an improved structure.

The hermetic reciprocating compressor is generally a closed casing having upper and lower shells, and an electric motor provided in the closed casing for driving a piston disposed in a compression cylinder provided in the closed casing. Is provided. Electric motors are usually stator and rotor,
And a crankshaft in which an eccentric part for driving the piston is formed at one end. The compression cylinder has a cylinder block that defines a compression chamber, and a piston is provided in the compression chamber so as to be able to reciprocate in a linear direction by a connecting rod disposed between the piston and an eccentric portion of a crankshaft. . A head section is usually mounted on the cylinder block, and a valve mechanism for controlling the discharge of compressed gas from the compression chamber is provided in the head section. A lot of noise and vibration are generated with the high speed operation of the compressor system. It is therefore desirable in the field of reciprocating compressors to reduce the amount of noise and vibration generated during compressor operation.

A reciprocating compressor that is widely used has a number of machined surfaces that require a seal or gasket and fasteners to attach the head to the cylinder block. Therefore, it would also be desirable in the field of reciprocating compressors to reduce machining surfaces and additional components, and to simplify compressor fabrication and assembly.
U.S. Pat. 5,934,305 U.S. Pat. 6,435,841

SUMMARY OF THE INVENTION The present invention seeks to provide a reciprocating compressor which addresses the above-mentioned problems and which reduces the machining surface and additional parts and simplifies the manufacture and assembly of the compressor.

The present invention provides a motor and a single body member supported by the motor in a closed casing, i.e., a single member such as a cylinder and a head portion that reduces the number of machining operations and the number of components required for assembling the compressor. The present invention relates to a reciprocating compressor provided with: A discharge passage is formed in the head portion, and a discharge valve assembly is tightly fitted.

Other uses of the present invention will become apparent from the following detailed description. While the following detailed description and specific examples illustrate preferred embodiments of the present invention, it is to be understood that they are for purposes of illustration only and are not intended to limit the scope of the present invention. It is.

The following description of the preferred embodiment is illustrative only and is not intended to limit the invention, its application, or applications. FIG. 1 shows a hermetic reciprocating compressor 10 according to the principles of the present invention. The reciprocating compressor 10 has a closed casing 12, which includes a lower shell 14 and an upper shell 16 hermetically connected to each other. The closed casing 12 is provided with a suction port passage 17. A motor 18 is arranged in the casing 12 and has a rotor (not shown), a stator 20 and a crankshaft 22 connected to the rotor in a known manner. The crankshaft 22 includes an eccentric part 24.

The motor 18 has a motor cover 25. A single body member 26 is arranged on the motor 18. This single body member 26 comprises a body portion 28 forming a cylinder 30,
And a bell-shaped housing portion 32. A head portion 34 is formed integrally with the body portion 28, and the head portion 34 communicates with the first discharge cavity 36a communicating with the cylinder 30 via the throttle 36c. It includes a second discharge cavity 36b. The dimensions of the first and second discharge cavities 36a, 36b are preferably set to optimize discharge pulsation or efficiency. Also, the throttle 36c is designed to further improve the discharge pulsation,
The dimensions can be set or insert members can be provided. Outlet 1 of second discharge cavity 36b
02 is connected to the discharge pipe 100. Discharge tube 100 is preferably one that snap-fits into outlet 102. In particular, as shown in FIG. 8, the discharge pipe 100 has the following pipe joint 104, that is, a retaining ring 106 that expands in a radial direction, and when pressed through the outlet 102, expands outward to prevent the pipe from coming out. Fitting 10 with retaining ring 106
4 can be provided. An airtight seal between the outlet 102 and the pipe fitting 104 is achieved by a flexible sealing member 105. A silencer 108 can be arbitrarily provided in the discharge pipe 100. The discharge pipe 100 is connected to a discharge port 110 provided in the closed casing 12.

A piston 38 is provided in the cylinder 30, and the piston 38 is connected to a connecting rod 40 connected to the eccentric part 24 of the crankshaft 22. The single body member 26 is provided with a suction passage 42, which is connected to the inside of the cylinder 30 and the hollow portion 44 formed by the bell-shaped portion 32. As shown in FIGS. 2 and 3, the piston 38 is substantially cylindrical and includes a concave groove 46. This groove 46 communicates with the inlet passage 48 so that the suction gas flows through the suction passage 42, the groove 46 and the inlet passage 48 and into the cylinder 30 at the top of the piston 38 during the suction process of the compressor. Can flow in through a passage 47 covered by a suction reed valve 49 attached to the suction valve.

A discharge valve assembly 50 is arranged at the open end of the cylinder 30. The discharge valve assembly 50 has a valve plate 52, a discharge valve member 54, and a valve retainer 56. The valve plate 52 is substantially disk-shaped and has a pair of discharge ports 58. The valve plate 52 also includes a plurality of holes 6 for receiving fasteners for attaching the discharge valve member 54 and the valve retainer 56 to the valve plate 52.
Has zero. The discharge valve member 54 is a reed-type valve made of a flexible material, as shown in FIG. The discharge valve member 54 is disposed so as to face the arched surface 62 of the valve retainer 56, and the valve retainer 56 has a fastening tool that passes through a hole 60 provided in the valve plate 52 and a hole 66 provided in the discharge valve member 54. A plurality of holes 64 (only one of which is shown in FIG. 1) for receiving are provided. The discharge valve member 54 is provided with an arc-shaped cutout 68, which is disposed radially inward of a discharge port 58 provided in the valve plate 52, so that the discharge port 58 during the suction process of the compressor. To help control the flexibility of the discharge valve member 54 so that it disengages and curves out of the discharge port 58 during the compression process of the compressor. The arched surface 62 of the valve retainer 56 has a shape set to limit the opening movement of the discharge valve member 54, which is a reed valve, to optimize stress and performance.

Discharge valve assembly 50 has a valve plate 5 that is appropriately machined and toleranced to allow an interference fit between the outer diameters of valve plate 52 and retainer 56 and the inner diameter of cylinder 30.
By forming the second and retainers 56, they can be incorporated into the head portion 34 of the single body member 26. A diameter interference fit provides sealing and retention of the valve plate 52 and the retainer 56. During installation, the piston 38 is held in a predetermined position, for example, top dead center, and the discharge valve assembly 50 is cooled to a temperature low enough to thermally shrink to a diameter where it freely falls into the cylinder 30. Discharge valve assembly 50 is placed on piston 38 until it warms up and press fits into cylinder 30. The press fit holds the discharge valve assembly 50 and provides a seal between the diameter of the cylinder 30 and the discharge valve assembly 50. One way to position the piston 38 within the cylinder 30 during installation of the discharge valve assembly 50 as shown in FIG. 3 is to reverse load the bearing between the connecting rod 40 and the crankshaft 22 (by applying a force F). , Depending on the bearing gap, to position the piston 38 slightly above the normal top dead center position. During operation of the compressor, gas forces push piston 38 down, reversing the load on the bearings and extruding a cold piston-valve plate gap approximately equal to the sum of the bearing gaps in the operating drive.

An interference fit during installation also heats the cylinder to expand its internal diameter and cools the cylinder to room temperature prior to inserting the assembly into the cylinder, as opposed to cooling the discharge valve assembly. It should be noted that this can also be achieved by letting go. Also, a combination of the two methods (cylinder heating and discharge valve assembly cooling) is possible. Further, the sealing and holding between the valve plate 52 and the cylinder 30 can be enhanced by using a sealant or an adhesive such as, for example, LOCTITE (trade name).

Another embodiment would be to set the valve plate in a counterbore of a different diameter than the cylinder diameter. However, this method would require secondary machining to form the counterbore.

As shown in FIG. 2, a contoured column 70 is provided on the top surface of the piston 38, and the column 70 connects the discharge port 58 of the valve plate 58 when the piston 38 approaches the top dead center. It is designed to partially block. The contoured column 70 also includes the piston 3 in the top dead center position.
The gap between the valve 8 and the valve plate 52 is reduced, further increasing the efficiency of the compressor.

The single body member 26 has a bearing portion 72 that supports one end of the crankshaft 22. The single body member 26 also includes an opening 74 in the bell portion 32 spaced from the bearing portion 72 for receiving the crankshaft 22. A crankcase isolation seal 76 is arranged between the opening 74 and the crankshaft 22 to provide a large suction volume in the hollow portion 44 to reduce suction pulsation. The suction gas entering through the inlet passage 17 is sucked into the motor cover 25 from the upper end of the motor cover 25 and between the inside of the motor cover 25 and the outer surface of the stator 20. The suction gas then flows upward between the rotor and the stator 20 and flows into the space between the hollow portion 44 of the bell 32 of the body portion 28 and the stator 20. The free volume between the motor 18 and the bell 32 can be used as a suction silencer. The seal can be used to prevent oil from flowing down from the upper main bearing and the connecting rod bearing via the crankshaft and accompanying the suction gas. In addition, the above-described suction gas flow path prevents oil from accompanying the suction gas. The single body member 26, provided as a single mold forming the body portion 28 containing the cylinder 30 and the discharge cavity 36 in the head portion 34, greatly reduces the number of machined surfaces and seals or gaskets and bodies. Therefore, the omission of the fastener for mounting the head is achieved.

As shown in FIGS. 4 and 5, the closed casing 12 includes the motor 18 and the single body
It is of a size and shape that can be supported for two different applications. Oil temperature control is important for most hermetic compressors. If the oil is too hot, the lubricating properties will deteriorate and oil decomposition may occur. If the oil is too cold, lubrication properties of the oil will be significantly affected by refrigerant dilution, and will also adversely affect compressor reliability. The oil sump temperature is highly dependent on how the compressor is utilized. In applications with high superheat and high pressure ratio, the oil can be kept in a safe temperature range by cutting off as much heat as possible to the oil. This can be achieved by holding the compressor head outside the oil. For applications with low superheat and low pressure ratio, there is a benefit from blocking heat to the oil. This heat isolation can be enhanced by immersing the head and drive in oil.

Accordingly, the present invention provides for the motor 18 and the single body member 26 to have the motor located in the compressor oil sump as shown in FIG. 4 or the single body member 26 being located in the compressor oil sump as shown in FIG. The size and the shape of the closed casing 12 are set so as to be received in such a manner. The modification required to do this consists in using a crankshaft thrust bearing in connection with the oil pump inlet at the crankshaft end immersed in the oil sump. FIG. 9 shows FIG.
1 is a sectional view of a crankshaft thrust bearing for a compressor shown in FIG. The thrust bearing 120 particularly comprises a thrust washer 122 located between the end of the crankshaft 22 and the lower bearing housing 92. A bearing 123 is provided between the crankshaft 22 and the lower bearing housing 92.

FIG. 10 depicts an oil plug 124 provided within the upper end of the crankshaft 22 of the embodiment shown in FIG. The oil plug 124 has a vent passage 126 which allows gas to be discharged while preventing oil from being discharged from the upper end of the crankshaft 22 so as to control the oil circulation speed.

FIG. 11 illustrates a cross section of the crankshaft thrust bearing 130 for the compressor shown in FIG. The thrust bearing 130 particularly comprises a thrust washer 132 arranged between the lower end of the crankshaft and a retaining ring 134 mounted on the body part 28.
FIG. 12 illustrates an oil plug 136 provided in the upper end of the crankshaft 22 of the embodiment shown in FIG. The oil plug 136 has a vent passage 138, which allows gas to be discharged while preventing oil from being discharged from the upper end of the crankshaft 22 so as to control the oil circulation speed.
With respect to customary designs, many identical compressor components, including housings, motors, and single body components are utilized at high superheat and high pressure ratios or at low superheat and low pressure ratios. It can be used in compressors, whether or not they are used.

Referring to FIG. 1, the outer diameter of the stator 20 is a bell-shaped portion 32 of the single body member 26.
Is press-fitted into the inside diameter of The stator 20 is a structural member that carries a bearing load and a suspension system load. In another embodiment, as shown in FIG. 6, the stator 20 is fixed by an epoxy resin 80 filled in the hole of the bell-shaped portion 32. While the epoxy resin 80 is hardened, the stator 20 can be positioned by tack welding. In another embodiment, as shown in FIG. 13, the stator 20 is positioned using a bolt 150 that penetrates through the motor cover 25 and the stator 20 and screws into the bell-shaped portion 32, and the stator 20 is positioned. Is fixed to the surface of the bell-shaped portion 32. In yet another embodiment, the bell 32 is connected to the stator 20 by welding 151, as shown in FIG.

As shown in FIG. 1, the motor 18 includes a motor cover 25 that can be press-fit on the stator 20. The motor cover 25 has a recess 25A (for example, as shown in FIG. 7), that is, a gap that engages with the stator 20 and allows the flow of the suction gas between the motor cover 25 and the stator 20. An indentation 25A can be provided. In another embodiment, the motor cover 25 is plug-welded to the stator 20. Plug welding is combined with press fitting,
Alternatively, as shown in FIG. 6, it can be used together with the positioning by the epoxy resin filling gap 86. During the curing of the epoxy resin, void shims can be used to remove them later to form voids for the inhaled gas. Further, the motor cover 25 can be attached to the stator 20 by bolts 150 as shown in FIG. 13 or can be connected by welding 152 as shown in FIG.

In yet another embodiment, a two-part motor cover housing having a motor cover 90 and a lower bearing housing 92 is used, as shown in FIG. The motor cover 90 is press-fitted, glued, bolted, and / or welded to the stator 20 as described above. The lower bearing housing 92 is moved laterally to position the lower bearing relative to the lower end of the crankshaft 22 and then plug welded to the motor cover 90. Lower bearing housing 9
By the two separate connections, the crankshaft 22 and the rotor can be correctly positioned with respect to the stator 20, and the air gap between the rotor and the stator 20 can be correctly set to obtain efficient motor operation. .

During operation, oil is supplied to the thrust bearing and internal lubricating oil passages 140, as is known in the art.
Is sucked upward through the crankshaft 22 provided with the shaft. The crankshaft 22 is provided with radial passages 142, 144 for supplying lubricating oil to the passage in the connecting rod 40 and to the upper crankshaft bearing. The cylinder 30 receives splash lubrication with the lubricating oil from the connecting rod 40.

The description of the embodiments described above is merely illustrative, and all modifications that do not depart from the gist of the present invention are intended to be within the scope of the present invention. Such modifications should not be deemed to depart from the scope of the present invention.

1 is a partial longitudinal perspective view of a reciprocating compressor according to the principles of the present invention. FIG. 3 is a partially longitudinal exploded perspective view showing a piston and a discharge valve device according to the principle of the present invention. FIG. 4 is a partially longitudinal exploded perspective view showing a method of assembling a valve plate assembly according to the principles of the present invention. 1 is a partially longitudinal perspective view showing a compressor in a vertical configuration with a motor housing immersed in oil in accordance with the principles of the present invention. FIG. 4 is a partially longitudinal perspective view showing the compressor supported in an airtight shell in an inverted posture in which a head portion of the compressor is arranged in an oil sump. FIG. 3 is a cross-sectional view showing a state where a compressor body and a motor cover are connected to a motor stator according to the principle of the present invention. FIG. 4 is a cross-sectional view showing a connection state between a motor stator, a motor cover, and a lower bearing housing according to the principle of the present invention. It is a disassembled perspective view which shows the discharge pipe joint snap-fitted. FIG. 5 is a sectional view illustrating a thrust bearing used in the compressor of FIG. 4. FIG. 5 is a cross-sectional view illustrating an oil plug provided in an upper end portion of a crankshaft used in the compressor of FIG. 4. It is sectional drawing which shows the thrust bearing utilized in the compressor of FIG. FIG. 6 is a cross-sectional view illustrating an oil plug provided in an upper end portion of a crankshaft used in the compressor of FIG. 5. FIG. 10 is a cross-sectional view showing the connection of a compressor body and a motor cover to a motor stator according to another embodiment of the present invention. FIG. 11 is a cross-sectional view showing a compressor body and a motor cover connected to a motor stator according to still another embodiment of the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 10 Hermetic reciprocating compressor 12 Hermetic casing 14 Lower shell 16 Upper shell 18 Motor 20 Stator 22 Crankshaft 25 Motor cover 26 Single body member 28 Body part 30 Cylinder 34 Head part 36a, 36b Discharge cavity 38 Piston 42 Suction passage 50 Discharge valve assembly 52 Valve plate 54 Discharge valve member 56 Valve retainer 58 Discharge port 70 Column 72 Bearing part 74 Opening 80 Epoxy resin 90 Motor cover 92 Lower bearing housing 150 Bolt

Claims (28)

A motor having a crankshaft,
A single body member comprising: a piston interlockingly connected to the crankshaft; a body part forming a cylinder for reciprocatingly receiving the piston; and a head part forming a discharge passage communicating with the cylinder. A single body member wherein the part and the head part are formed as a single member,
With compressor. A motor having a crankshaft,
A piston linked to the crankshaft,
A cylinder for receiving this piston in a reciprocating manner,
A head portion forming a discharge passage communicating with the cylinder, and a discharge valve assembly tightly fitted to the cylinder;
With compressor.   The compressor according to claim 1, wherein the single body member has a suction passage therein. The compressor according to claim 1, wherein said single body member includes a discharge chamber communicating with said discharge passage. The said single body member has a bearing part which supports one end part of the said crankshaft.
Compressor. The compressor according to claim 1, further comprising a discharge valve assembly disposed within a head portion of said single body member.   7. The compressor according to claim 6, wherein said discharge valve assembly is tightly fitted in said head portion. The discharge valve assembly includes a valve plate disposed on the top of the cylinder, a valve member disposed in contact with the valve plate, and a retainer disposed in contact with the valve member. Item 2
Or the compressor of 6.   9. The compressor according to claim 8, wherein said valve member is a flexible reed valve. The compressor according to claim 1 or 2, wherein the crankshaft passes through an opening formed in the single body member, and an isolation seal is disposed between the crankshaft and the opening. The body portion of the single body member includes a hollow portion that receives a part of the motor, and the single body member forms a suction passage communicating with a space between the hollow portion and the motor. The compressor of claim 1 wherein: A compressor shell having a first end portion and a second end portion connected to each other at an intermediate portion, wherein the motor and a single body member are mounted within the compressor shell within the first shell. The compressor according to claim 1, wherein a single body member is positioned and located on one end portion or the second end portion side. 2. The compressor according to claim 1, wherein said body portion of said single body member has a hollow portion for receiving a stator of said motor. 14. The compressor according to claim 13, wherein the body portion of the single body member is press-fitted to a stator of the motor. 14. The compressor according to claim 13, wherein the body portion of the single body member is fixed to the stator of the motor with an adhesive. 14. The compressor according to claim 13, wherein the body portion of the single body member is bolted to a stator of the motor. The compressor according to claim 1, wherein the motor has a motor cover attached to a stator of the motor. A stator provided on the motor, and a motor cover connected to the stator;
2. The compressor according to claim 1, further comprising a suction gas passage formed between the motor cover and the stator.   19. The compressor according to claim 17, wherein the motor cover is press-fitted to the stator.   19. The compressor according to claim 17, wherein the motor cover is fixed to the stator with an adhesive. 19. The compressor according to claim 17, wherein said motor cover comprises a cover body connected to said stator, and a lower bearing housing mounted on said cover body to support a lower motor bearing. 3. The compressor according to claim 1, wherein the piston has at least one column on a top surface thereof, and the column is received in a discharge port communicating with the discharge passage. The discharge valve assembly has a valve plate and holds the interference fit in the following manner: holding the piston in a predetermined position within the cylinder;
Heat shrink the valve plate, insert the valve plate from the open end of the cylinder until it comes into contact with the piston,
3. The compressor according to claim 2, wherein the compressor is made by a method in which the valve plate is left to warm and expanded so as to press-fit the cylinder. 24. The compressor of claim 23, wherein the method includes providing a discharge valve between the valve plate and a retainer attached thereto. The method thermally shrinks the retainer attached to the valve plate, inserts the retainer with the valve plate into the cylinder, leaves the retainer warm and press-fits the cylinder. 24. The compressor of claim 23, further comprising the step of expanding. 24. The compressor according to claim 23, wherein the step of holding the piston in a predetermined position within the cylinder comprises reversing a bearing of a connecting rod connected to the piston. The discharge valve assembly has a valve plate and holds the interference fit in the following manner: holding the piston in a predetermined position within the cylinder;
Thermal expansion of the cylinder, insert the valve plate from the open end of the cylinder until it contacts the piston,
3. The compressor according to claim 2, wherein said valve plate is formed by a method in which said valve plate is left to cool and contracted so as to press-fit with said cylinder. A discharge valve assembly disposed in the cylinder, the discharge valve assembly having at least one discharge port; and a column disposed on a top surface of the piston so as to be received by the discharge port. The compressor according to claim 1.

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