WO2011096226A1

WO2011096226A1 - Reciprocating compressor

Info

Publication number: WO2011096226A1
Application number: PCT/JP2011/000628
Authority: WO
Inventors: 利明塩原
Original assignee: サンデン株式会社
Priority date: 2010-02-08
Filing date: 2011-02-04
Publication date: 2011-08-11
Also published as: JP2011163177A

Abstract

Disclosed is a reciprocating compressor which raises the contact pressure of a gasket to ensure a seal, and which can improve compression efficiency. The reciprocating compressor is provided with a gasket (28) on which a communication hole (28a) which communicates with a cylinder bore (26) is formed interposed between a cylinder block and a cylinder head, and which has a seal section (28b) in which a lightening hole (28c) is formed cut into a predetermined position.

Description

Reciprocating compressor

The present invention relates to a reciprocating compressor, and more particularly to a hermetic reciprocating compressor that compresses a carbon dioxide refrigerant.

In this type of reciprocating compressor, a cylinder bore is formed integrally with a cylinder block, and a piston is reciprocally accommodated in the cylinder bore. In addition, a cylinder gasket for sealing the cylinder bore is provided, and a suction valve forming plate having a suction valve, a valve plate having a discharge valve, and a suction head and a discharge chamber are formed so as to close the opening of the cylinder bore. Is fixed. As the piston reciprocates, the suction valve and the discharge valve are opened and closed to perform a series of processes of refrigerant suction, compression, and discharge.

By the way, in such a reciprocating compressor, since the pressure fluctuates due to a series of processes of suction, compression, and discharge, when refrigerant gas accumulates in the space of each member, a pressure difference is generated and various seal members are used. As a result, there is a problem that the sealing performance necessary for compression cannot be ensured.
Accordingly, a configuration is disclosed in which a communication passage is formed in the suction valve forming plate so as to prevent the refrigerant gas from being accumulated, and the refrigerant gas leaked from the cylinder bore is guided to the suction passage (see Patent Document 1).

JP-A-10-196536

By the way, in such a reciprocating compressor, it is important to improve the surface pressure of the gasket in order to ensure sealing performance, and as one method for improving the surface pressure, the area of the gasket is further reduced. Is mentioned.
In this regard, in Patent Document 1, a through hole corresponding to the suction passage and the opening edge of the cylinder bore is provided in the gasket, which inevitably reduces the area of the gasket.

However, simply providing the suction passage and the through hole in this way cannot be said to sufficiently reduce the area, and there is a problem that the surface pressure is insufficient.
The present invention has been made to solve the above-described problems, and the object of the present invention is to provide a reciprocating type capable of improving the surface pressure of a gasket to ensure sealing performance and improving compression efficiency. It is to provide a compressor.

In order to achieve the above object, a reciprocating compressor according to claim 1 is a reciprocating compressor that compresses sucked working fluid and discharges the compressed working fluid, and includes a cylinder block and the cylinder. A cylinder bore formed in the block; a suction chamber for allowing a working fluid sucked into the cylinder bore to flow in from the outside in accordance with a reciprocating motion in the cylinder bore by a drive mechanism of a piston housed in the cylinder bore; A cylinder head formed with a discharge chamber for discharging the working fluid compressed in the cylinder bore to the outside in accordance with the reciprocating motion, and interposed between the cylinder block and the cylinder head, and a predetermined portion is thinned out. And a gasket having a seal portion in which a lightening hole is formed.

A reciprocating compressor according to a second aspect of the present invention is the reciprocating compressor according to the first aspect, wherein a suction hole that is inserted between the cylinder head and the gasket and communicates with the suction chamber and a discharge hole that communicates with the discharge chamber are formed. A valve plate provided, a second gasket interposed between the valve plate and the cylinder head and formed with a seal portion for sealing the periphery of the discharge chamber, and the gasket and the second gasket, respectively A fastening member that fastens and fixes the cylinder block, the valve plate, and the cylinder head that are interposed, and the hollow hole overlaps the second gasket when viewed in the fastening direction of the fastening member; It is characterized in that it is formed by removing a non-exposed portion.

The reciprocating compressor according to claim 3 is the reciprocating compressor according to

claim

1 or 2, wherein the seal portion of the gasket communicates the space formed in the inner peripheral portion of the lightening hole and the space of the outer peripheral portion of the gasket. A communication path is provided.
The reciprocating compressor according to claim 4 is the reciprocating compressor according to

claim

1 or 2, wherein a communication path that communicates the lightening hole and a space of the outer peripheral portion of the gasket is formed on one surface of the cylinder block facing the gasket. It is provided.

A reciprocating compressor according to a fifth aspect of the present invention is the reciprocating compressor according to the third or fourth aspect, further comprising a suction valve forming plate interposed between the valve plate and the gasket and formed with a suction valve for opening and closing the suction hole. And one surface of the valve plate on the suction valve forming plate side is polished and formed smooth.

According to the reciprocating compressor of claim 1, the gasket having a communication hole interposed between the cylinder block and the cylinder head and communicating with the cylinder bore formed in the cylinder block is thinned at a predetermined position. Thus, a seal portion in which a lightening hole is formed is formed.
Thereby, since the area of the gasket is reduced, the surface pressure applied to the gasket is improved, the sealing performance of the gasket for sealing the periphery of the cylinder bore can be improved, and the compression efficiency can be improved.

According to the reciprocating compressor of claim 2, the second gasket for sealing the periphery of the discharge chamber is interposed between the valve plate and the cylinder head interposed between the cylinder head and the gasket and fastened. It is fixed by the member, and the lightening hole is formed by lightening a portion where the gasket and the second gasket do not overlap when viewed in the tightening direction of the fastening member, so that the area of the gasket is further reduced.

Accordingly, since the surface pressure applied to the gasket is further improved, the sealing performance around the cylinder bore can be further improved, and the compression efficiency can be improved.
In addition, since the seal portion of the gasket and the second gasket has the overlapping portion, the pressing force by the fastening member is transmitted to the cylinder block through the overlapping portion, so that the sealing performance of the gasket can be further improved and the compression efficiency can be improved. Can be improved.

According to the reciprocating compressor of claim 3, since the gasket seal portion is provided with the communication passage that connects the inner peripheral portion of the lightening hole and the space of the outer peripheral portion of the gasket, Even when air remains in the hole, the air is released to the space around the outer periphery of the gasket through the communication passage, so that the inner periphery of the light-ejecting hole and the outer periphery of the gasket are affected by pressure fluctuations due to suction pressure and discharge pressure or temperature changes around the gasket. Generation of a pressure difference between the parts can be suppressed, and adverse effects on surrounding components can be prevented. Therefore, it is possible to ensure the overall sealing performance and improve the compression efficiency.

According to the reciprocating compressor of the fourth aspect, since the communication passage is formed on the one surface of the cylinder block facing the gasket so as to connect the lightening hole and the outer peripheral space of the gasket. Even if air remains, by letting air escape to the outer space of the gasket through the communication path, it is possible to reduce the pressure due to suction pressure and discharge pressure or the temperature change around the gasket between the inner periphery of the hole and the outer periphery of the gasket. It is possible to suppress the occurrence of a pressure difference in the case, to prevent adverse effects on surrounding parts, to ensure the overall sealing performance, and to improve the compression efficiency.

According to the reciprocating compressor of claim 5, since one surface of the valve plate facing the suction valve forming plate inserted between the valve plate and the gasket is polished and formed smoothly, the valve The plate and the suction valve forming plate are sealed with a smooth metal surface. And since the inner peripheral part of the hollow hole formed in the gasket and the outer peripheral part of the gasket are communicated, the air of the thin hole can be released to the outer peripheral space, and the pressure is increased by the suction pressure and the discharge pressure. The pressure difference between the inner peripheral part of the lightening hole and the outer peripheral part of the gasket due to fluctuations or temperature changes around the gasket can be suppressed, and deformation of the suction valve forming plate corresponding to the lightening hole can be prevented. Performance can be ensured, and compression efficiency can be improved.

1 is a longitudinal sectional view of a reciprocating compressor according to an embodiment of the present invention. It is a principal part enlarged view of the compression mechanism of FIG. FIG. 3 is an exploded configuration diagram of FIG. 2. It is an enlarged view of the cylinder gasket of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a hermetic reciprocating compressor (hereinafter referred to as a compressor) 1 according to the present invention. The compressor 1 is classified into a positive displacement compressor called a reciprocating compressor or a piston compressor, and is used as, for example, a component of a refrigeration cycle (not shown) incorporated in a vending machine.
The refrigeration cycle includes a path through which a refrigerant as a working fluid of the compressor 1 circulates. For example, a carbon dioxide refrigerant that is a non-flammable natural refrigerant is used as the refrigerant.

As shown in FIG. 1, the compressor 1 includes a sealed container 2, and an electric motor 4 and a compression mechanism 6 to which the driving force of the electric motor 4 is transmitted are accommodated in the sealed container 2.
The electric motor 4 includes a stator 8 that generates a magnetic field by power feeding and a rotor 10 that rotates by the magnetic field generated by the stator 8. The rotor 10 is disposed coaxially inside the stator 8, and will be described later. The main shaft portion 24 is fixed by shrinkage fitting. Electric power is supplied to the stator 8 from the outside of the compressor 1 through an electrical component 12 fixed to the sealed container 2 and a lead wire (not shown).

As shown in FIG. 1, the stator 8 is bolted to the cylinder block 16 via a frame 36, and the frame 36 is fixed to the sealed container 2.
Specifically, the electric motor 4 and the compression mechanism 6 are supported by a pedestal portion 38 below the frame 36, and the frame 36 is fixed to the sealed container 2 by the pedestal portion 38. On the other hand, in the upper cylindrical portion 40 of the frame 36, the bearing 42 of the main shaft portion 24 is disposed on the inner peripheral surface 40a, and the thrust trace or thrust washer that receives the thrust load of the rotor 10 is disposed on the upper end surface 40b of the cylindrical portion 40. A bearing 44 such as is arranged.

The compression mechanism 6 includes a crankshaft 14, a cylinder block 16, a piston 18, a connecting rod 20, and the like. The crankshaft 14 includes an eccentric shaft portion 22 and a main shaft portion 24.
Specifically, as shown in FIGS. 2 and 3, a cylinder bore 26 is integrally formed in the cylinder block 16, and a cylinder gasket (gasket) 28 and a suction valve are formed in order from the cylinder block 16 side so as to close the opening of the cylinder bore 26. The plate 29, the valve plate 30, the head gasket (second gasket) 32, and the cylinder head 34 are pressed and fixed by bolts (fastening members) 35 through the through holes 31. Here, the cylinder gasket 28 and the head gasket 32 are formed by coating an elastic rubber member on a thinly stretched iron base material, and the thickness is, for example, 0.3 mm.

As shown in FIG. 2, the valve plate 30 includes a refrigerant suction hole 46 and a discharge hole 48. The suction hole 46 and the discharge hole 48 are a suction valve 50 formed on the suction valve forming plate 29, and a head of the valve plate 30. Each is opened and closed by a discharge valve 52 fixed to the gasket 32 side.
The cylinder head 34 includes a refrigerant suction chamber 54 and a discharge chamber 56. When the discharge valve 52 is opened in the compression stroke of the piston 18, the discharge chamber 56 communicates with the cylinder bore 26 through the discharge hole 48. On the other hand, when the suction valve 50 is opened in the suction process of the piston 18, the suction chamber 54 communicates with the cylinder bore 26 through the suction hole 46.

In the compression mechanism 6 configured as described above, a communication hole 28a communicating with the cylinder bore 26 formed in the cylinder block 16 is formed in the cylinder gasket 28, as shown in an exploded configuration diagram of FIG. A seal portion 28 b is formed for sealing the periphery of the cylinder bore 26 and sealing the periphery of the through hole 31 provided in the cylinder bore 26.
The seal portion 28b is formed by being thinned so that the pressure of the bolt 35 is evenly applied.
Specifically, the cylinder gasket 28 is formed with a lightening hole 28c so that when the cylinder gasket 28 and the head gasket 32 are overlapped, a portion that is not overlapped when viewed in the tightening direction of the bolt 35 is thinned. ing.

As shown in the enlarged view of the cylinder gasket 28 in FIG. 4, the lightening hole 28 c and the space 57 are communicated with a portion of the seal portion 28 b closer to the space 57 around the compression mechanism 6 than the lightening hole 28 c. A communication path 28d is provided.
Returning to FIG. 3, a communication hole 50 a that communicates with the discharge hole 48 provided in the valve plate 30 is formed in the suction valve 50 formed on the suction valve forming plate 29.

The one surface of the valve plate 30 on the side of the suction valve forming plate 29 is polished and smooth, and the suction valve forming plate 29 is in close contact with the valve plate 30 and sealed. Although not shown, a discharge valve 52 is fixed to the cylinder block 16 together with the suction valve forming plate 29 and the cylinder gasket 28 through the through hole 51 on the other surface of the valve plate 30 on the head gasket 32 side. .

The head gasket 32 includes a communication hole 32 a communicating with a suction hole 46 formed in the valve plate 30 and a suction chamber 54 formed in the cylinder head 34, a discharge hole 48 formed in the valve plate 30, and the cylinder head 34. A communication hole 32b is formed in communication with the discharge chamber 56 formed at the bottom. A seal portion 32 c is formed that seals the periphery of the discharge chamber 56 provided in the cylinder head 34 and seals the periphery of the through hole 31 formed in the cylinder head 34.

As shown in FIGS. 1 and 2, a suction pipe 58 and a discharge pipe 60 are fixed to the sealed container 2, and one end of each of the suction and

discharge pipes

58 and 60 is a suction chamber 54 and a discharge chamber 56 of the cylinder head 34. And connected to each. The other ends of the suction pipe 58 and the discharge pipe 60 are connected to a refrigeration cycle via a suction muffler and a discharge muffler (not shown), and these mufflers reduce pulsation and noise of the refrigerant flowing between the compressor 1 and the refrigeration cycle. ing.

The connecting rod 20 is provided with a large end 62 to which the eccentric shaft portion 22 of the crankshaft 14 is rotatably connected at one end, and a small end 64 to which the piston 18 is reciprocally connected at the other end. It has been. The small end portion 64 is connected to the piston 18 by a piston pin 66, and the piston pin 66 is secured from the piston 18 by a fixing pin 68.

When the crankshaft 14 rotates in this state, the connecting rod 20 swings in conjunction with the eccentric rotation of the eccentric shaft portion 22 with the piston pin 66 as a fulcrum, and the piston 18 interlocks with the swinging motion of the connecting rod 20. It reciprocates in the cylinder bore 26.
The discharge pressure of the refrigerant mainly acts in the sealed container 2, and a small amount of lubricating oil for lubricating the sliding portions of the electric motor 4 and the compression mechanism 6, such as the

bearings

42 and 44, is applied to the inner bottom 2 a of the sealed container 2. Reserved.

An oil passage 70 is drilled in the crankshaft 14 from the substantially axial position of the lower end surface 22 a of the eccentric shaft portion 22 to the middle of the main shaft portion 24. An oil pipe 72 is fitted to the lower end of the oil passage 70, and the tip of the oil pipe 72 extends through an inclined portion 74 to an oil sump portion 76 having a concave shape in cross section as formed in the inner bottom portion 2 a in the sealed container 2. .

Hereinafter, the operation of the reciprocating compressor according to the present invention configured as described above will be described.
In the compressor 1, the rotor 10 fixed to the main shaft portion 24 is rotated by supplying power to the stator 8, and consequently the crankshaft 14 is rotated, and the piston 18 reciprocates in the cylinder bore 26 via the connecting rod 20. The reciprocating motion of the piston 18 causes the refrigerant to be sucked into the cylinder bore 26 from the refrigeration cycle, and the refrigerant is compressed by the cylinder bore 26 and further discharged to the refrigeration cycle.

Specifically, when the pressure in the cylinder bore 26 becomes equal to or lower than the suction pressure of the refrigerant, the suction valve 50 opens according to the difference between the pressure in the cylinder bore 26 and the pressure in the suction chamber 54. The refrigerant in the refrigeration cycle is guided to the suction chamber 54 through the suction pipe 58 and is sucked into the cylinder bore 26 through the suction hole 46.
Next, when the piston 18 operates in the direction of decreasing the volume of the cylinder bore 26 and the refrigerant in the cylinder bore 26 is compressed and the pressure in the cylinder bore 26 exceeds the discharge pressure of the refrigerant, the pressure in the cylinder bore 26 and the discharge chamber 56 are increased. The discharge valve 52 opens due to the difference from the internal pressure. The compressed refrigerant is guided to the discharge chamber 56 via the discharge hole 48 and discharged to the refrigeration cycle via the discharge pipe 60.

As described above, the refrigerant is compressed by the piston 18 reciprocating in the cylinder bore 26. As described above, the cylinder gasket 28 is thinned so that the pressure of the bolts 35 applied to the cylinder gasket 28 is uniform. A seal portion 28b is formed, and a lightening hole 28c is formed in which a portion other than the overlapping portion with the head gasket 32 is thinned. Accordingly, the area of the cylinder gasket 28 is reduced by the formed hole 28c, and the surface pressure received by the cylinder gasket 28 is improved, whereby the sealing performance can be improved and the compression efficiency can be improved. .

Since the cylinder gasket 28 has a seal portion 28b that overlaps the head gasket 32, the cylinder gasket 28, the suction valve forming plate 29, the valve plate 30, the head gasket 32, and the cylinder head 34 are pressed and fixed with bolts 35. Sometimes, the seal portion 28 b of the cylinder gasket 28 and the seal portion 32 c of the head gasket 32 overlap with each other via the suction valve forming plate 29 and the valve plate 30. As a result, the pressing force by the bolts 35 is reliably transmitted to the cylinder block and the surface pressure of the cylinder gasket 28 can be improved, so that the sealing performance of the cylinder gasket 28 can be further improved and the compression efficiency can be improved. it can.

Further, since the communication hole 28d communicating with the space 57 is provided in the lightening hole 28c, air can be extracted from the communication path 28d to the space 57 even when air remains in the lightening hole 28c during assembly. In particular, the space 57 and the inner peripheral portion of the lightening hole 28c may be affected by fluctuations in pressure due to suction pressure or discharge pressure that are higher than other refrigerants by using carbon dioxide refrigerant, or temperature changes around the cylinder gasket 28. This prevents the pressure difference from occurring. As a result, even if the suction pressure or discharge pressure of the refrigerant acts or a temperature change occurs around the cylinder gasket 28, the portion corresponding to the lightening hole 28c of the suction valve forming plate 29 is prevented from being deformed by the pressure difference. It is possible to prevent the sealing performance between the suction valve forming plate 29 and the valve plate 30 from being lowered, and to improve the sealing performance by ensuring the surface pressure of the cylinder gasket 28. And compression efficiency can be improved.

Although the description of the embodiment is finished as described above, the present invention is not limited to the above-described embodiment.
For example, in the above-described embodiment, the communication passage 28d is formed in the cylinder gasket 28. However, it is sufficient that the air in the lightening hole 28c can be extracted into the space 57, and one surface of the cylinder block 16 on the side facing the cylinder gasket 28 or the intake valve A communication path that communicates from the lightening hole 28 c to the space 57 may be formed on one surface of the forming plate 29.

Moreover, although the said embodiment demonstrated the electric reciprocating compressor as an example, it is not restricted to an electric drive.
In the above embodiment, the hermetic reciprocating compressor has been described as an example. However, the present invention is also applicable to an open reciprocating compressor.

1 Compressor 26 Cylinder bore 28 Cylinder gasket (gasket)

28a Communicating hole

28b Seal portion 28c Meat removal hole 28d Communicating passage 29 Suction valve forming plate 30 Valve plate 32 Head gasket (second gasket)
32c Seal part 34 Cylinder head

Claims

A reciprocating compressor that compresses a sucked working fluid and discharges the compressed working fluid,
A cylinder block;
A cylinder bore formed in the cylinder block;
A suction chamber for allowing a working fluid sucked into the cylinder bore to flow in from the outside in accordance with a reciprocating motion in the cylinder bore by a drive mechanism of a piston housed in the cylinder bore;
A cylinder head formed with a discharge chamber for discharging the working fluid compressed in the cylinder bore with the reciprocating motion of the piston;
A gasket that is interposed between the cylinder block and the cylinder head and has a seal portion in which a predetermined portion is thinned to form a thinning hole;
A reciprocating compressor characterized by comprising:
A valve plate interposed between the cylinder head and the gasket and having a suction hole communicating with the suction chamber and a discharge hole communicating with the discharge chamber;
A second gasket interposed between the valve plate and the cylinder head and formed with a seal portion for sealing the periphery of the discharge chamber;
A fastening member that fastens and fastens the cylinder block, the valve plate, and the cylinder head in which the gasket and the second gasket are respectively interposed;
2. The reciprocating compressor according to claim 1, wherein the lightening hole is formed by lightening a portion that does not overlap the second gasket when viewed in a fastening direction of the fastening member.
The communication part which connects the space formed in the inner peripheral part of the said hollowing hole, and the space of the outer peripheral part of the said gasket is provided in the seal part of the said gasket, The Claim 1 or characterized by the above-mentioned. 2. A reciprocating compressor according to 2.
The one side of the cylinder block facing the gasket is provided with a communication path that communicates the lightening hole and the space of the outer peripheral portion of the gasket. A reciprocating compressor.
A suction valve forming plate interposed between the valve plate and the gasket and formed with a suction valve for opening and closing the suction hole;
The reciprocating compressor according to claim 3 or 4, wherein one surface of the valve plate on the suction valve forming plate side is polished and smooth.