EP2778421B1

EP2778421B1 - Compressor

Info

Publication number: EP2778421B1
Application number: EP12846914.5A
Authority: EP
Inventors: Hirofumi Yoshida; Tsuyoshi Karino; Daisuke Funakoshi; Akira Hiwata; Hiroaki Nakai; Ryuichi Ohno; Noboru Iida; Shingo Oyagi
Original assignee: Panasonic Corp
Current assignee: Panasonic Corp
Priority date: 2011-11-08
Filing date: 2012-11-07
Publication date: 2016-06-08
Anticipated expiration: 2032-11-07
Also published as: WO2013069275A1; JPWO2013069275A1; JP6112489B2; EP2778421A1; CN103782039A; CN103782039B; EP2778421A4

Description

[TECHNICAL FIELD]

The present invention relates to a compressor used for an air conditioner, a freezing machine, a blower, a water heater and the like.

[BACKGROUND TECHNIQUE]

One example of a conventional configuration will be described with reference to Fig. 15. Fig. 15 is a longitudinal sectional view of a rotary type high pressure hermetic compressor.
A space formed by sandwich a cylinder 101 and a rolling piston 102 by an upper bearing 103 and a lower bearing 104 is partitioned by a vane (not shown), thereby forming a suction chamber 105 and a compression chamber 118. A compressing mechanism 107 and an electrical element 108 are accommodated in a hermetic container 109. The rolling piston 102 rotates in association with rotation of a drive shaft 106 and according to this, the compressing mechanism 107 carries out a compressing operation. The electrical element 108 gives a rotation force to the drive shaft 106.
A suction hole 110 which opens toward the suction chamber 105 is formed in the cylinder 101. A suction liner 113 is connected to the suction hole 110. A suction connection pipe 114 is connected to the suction liner 113. An accumulator 111 is connected to the suction connection pipe 114.
Low temperature and low pressure suction refrigerant gas which is separated into gas and liquid by the accumulator 111 is compressed by the compressing mechanism 107, and the suction refrigerant gas becomes high temperature and high pressure refrigerant gas. The compressed high temperature and high pressure refrigerant gas is discharged from the compressing mechanism 107 into the hermetic container 109. Oil mist included in the discharged high temperature and high pressure refrigerant gas is separated from the refrigerant gas in the hermetic container 109 and then, the refrigerant gas is discharged outside of the hermetic container 109 from a discharge pipe 112 provided at an upper portion of the hermetic container 109.
Fig. 16 is an enlarged sectional view of the compressing mechanism shown in Fig. 15.
The suction liner 113 is inserted, under pressure, into the suction hole 110 formed in the cylinder 101. An upstream side of the suction liner 113 is enlarged. The suction connection pipe 114 is inserted into the enlarged portion (enlarged pipe, hereinafter) of the suction liner 113. An end of the enlarged pipe of the suction liner 113 and the suction connection pipe 114 are brazed and sealed together with a suction outer pipe 115. The suction outer pipe 115 is brazed and fixed to the hermetic container 109.
A crescent-shaped chamber formed by the cylinder 101 and the rolling piston 102 is partitioned by a vane into the suction chamber 105 which is adjacent to the suction hole 110 and a compression chamber 116 which compresses while reducing volume of the chamber.
Low temperature and low pressure suction refrigerant gas flows from the suction connection pipe 114 into the suction chamber 105 through the suction liner 113 and the suction hole 110.
The interior of the hermetic container 109 is filled with high temperature and high pressure discharge gap. Therefore, an exterior of the compressing mechanism 107 and an outside of the suction liner 113 are exposed to high temperature and high pressure discharge refrigerant gas. The suction liner 113 is press-fitted into the suction hole 110. According to this, a divider 116 is formed between the suction liner 113 and the suction hole 110. By this divider 116, high pressure refrigerant gas does not flow into the suction hole 110.
However, temperature of the compressing mechanism 107 which is exposed to high temperature and high pressure refrigerant gas is high, and temperature of a wall surface of the suction hole 110 is also high. Hence, low temperature suction refrigerant gas is heated when it passes through the suction hole 110, density thereof is lowered, and volume efficiency and compressor efficiency of the compressor are deteriorated.
To solve this problem, there is proposed a high pressure domical compressor having a suction liner including a gas staying portion (Patent Document 1). Fig. 17 is an enlarged sectional view of essential portions of the high pressure domical compressor disclosed in Patent Document 1.
The suction liner 113 is mounted in the suction hole 110 formed in the cylinder 101. The suction liner 113 is composed of a fitting cylindrical portion 113a which is tightly fitted into the suction hole 110, and a small-diameter cylindrical portion 113b having a smaller diameter than an inner diameter of the suction hole 110. A gas staying portion P1 is provided between an outer peripheral surface of the small-diameter cylindrical portion 113b of the suction liner 113 and an inner peripheral surface of the suction hole 110, thereby restraining the low temperature and low pressure suction refrigerant gas from being heated by heat of the cylinder 101.

[PRIOR ART DOCUMENT]

[PATENT DOCUMENT]

[Patent Document 1] Japanese Utility Model Application Laid-open No.H5-993
US6158995 discloses another example of a compressor in a sealed container for use in a refrigerator or in an air conditioner.

[SUMMARY OF THE INVENTION]

[PROBLEM TO BE SOLVED BY THE INVENTION]

According to the configuration of Patent Document 1, however, an inner diameter of the suction hole 110 from a downstream side tip end of the suction liner 113 to a downstream side tip end of the suction hole 110 is greater than an inner diameter of the suction liner 113. Therefore, since a suction flow path is abruptly enlarged at the downstream side tip end of the suction liner 113, a pressure loss caused by the abrupt enlargement is generated in suction refrigerant gas which flows in the suction liner 113. As a result, pressure in the suction chamber is lowered, density of the suction refrigerant gas is reduced, and the volume efficiency and the compressor efficiency are deteriorated.
The present invention has been accomplished to solve the conventional problem, and it is an object of the invention to provide a compressor having high volume efficiency and compressor efficiency by restraining suction refrigerant gas from being heated in a suction pipe path extending from a suction liner to a suction chamber, and by suppressing a pressure loss caused by an abrupt enlarged portion.

[MEANS FOR SOLVING THE PROBLEM]

To solve the conventional problem, the present invention provides a compressor in which an electrical element and a compressing mechanism are accommodated in a hermetic container, the compressor comprises a suction hole through which refrigerant gas is introduced from an exterior of the hermetic container into a suction chamber of the compressing mechanism, and a suction liner inserted into the suction hole, wherein the suction hole includes a reduced-diameter portion located on a downstream side, and an increased-diameter portion located on an upstream side, a heat-insulating space is formed between the suction liner and the increased-diameter portion, and an inner diameter of the reduced-diameter portion is equal to an inner diameter of the suction liner.
According to this, the heat-insulating space is formed between the outer peripheral surface of the suction liner and the inner peripheral surface of the suction hole, and it is possible to restrain refrigerant gas flowing through the suction hole from being heated. A non-contact length up to the reduced-diameter portion is set shorter than a length of the reduced-diameter portion, and the inner diameter of the reduced-diameter portion and the inner diameter of the suction liner are set equal to each other. According to this, it is possible to suppress a pressure loss caused by the abruptly-enlarged portion, and to enhance volume efficiency and compressor efficiency.

[EFFECT OF THE INVENTION]

According to the compressor of the present invention, it is possible to suppress movement of heat to suction refrigerant gas and to minimize a pressure loss. Therefore, efficiency of the compressor can be enhanced.

[BRIEF DESCRIPTION OF THE DRAWINGS]

Fig. 1 is a longitudinal sectional view of a compressor in a first embodiment of the present invention;
Fig. 2 is an enlarged sectional view of a compressing mechanism in the first embodiment of the invention;
Fig. 3 is an enlarged sectional view showing a suction hole and its vicinity in the first embodiment of the invention;
Fig. 4 is a graph showing a pressure loss in the first embodiment of the invention;
Fig. 5 is an enlarged sectional view showing a downstream side tip end of a suction liner and its vicinity when a hole diameter ratio is 1 in the first embodiment of the invention;
Fig. 6 is an enlarged sectional view showing the downstream side tip end of the suction liner and its vicinity when the hole diameter ratio is 0.95 in the first embodiment of the invention;
Fig. 7 is an enlarged sectional view showing the downstream side tip end of the suction liner and its vicinity when the hole diameter ratio is 1.1 in the first embodiment of the invention;
Fig. 8 is an enlarged sectional view showing the downstream side tip end of the suction liner and its vicinity when an outer diameter of a small-diameter portion of the suction liner is smaller than an inner diameter of a reduced-diameter portion of a suction hole in the first embodiment of the invention;
Fig. 9 is an enlarged sectional view showing a suction hole and its vicinity in a second embodiment of the invention;
Fig. 10 is an enlarged sectional view showing a suction hole having a different shape and its vicinity in the second embodiment of the invention;
Fig. 11 is an enlarged sectional view showing a suction hole and its vicinity in a third embodiment of the invention;
Fig. 12 is an enlarged sectional view showing a suction hole having a different shape and its vicinity in the third embodiment of the invention;
Fig. 13 is an enlarged sectional view of a compressing mechanism in a fourth embodiment of the invention;
Fig. 14 is an enlarged sectional view showing a suction hole and its vicinity in a fifth embodiment of the invention;
Fig. 15 is a longitudinal sectional view of a conventional compressor;
Fig. 16 is an enlarged sectional view of a compressing mechanism in the conventional compressor; and
Fig. 17 is an enlarged sectional view showing a suction hole and its vicinity in a compressor described in Patent Document 1.

[EXPLANATION OF SYMBOLS]

1: hermetic container
2: electrical element
3: drive shaft
4: compressing mechanism
5: cylinder
6: rolling piston
7: upper bearing
8: lower bearing
9: suction chamber
10: compression chamber
12: suction hole
13: suction liner
13a: small-diameter portion
14a: suction connection pipe
15: suction outer pipe

[MODE FOR CARRYING OUT THE INVENTION]

According to a first aspect, the suction hole includes a reduced-diameter portion located on a downstream side, and an increased-diameter portion located on an upstream side, a heat-insulating space is formed between the suction liner and the increased-diameter portion, and an inner diameter of the reduced-diameter portion is equal to an inner diameter of the suction liner. According to this aspect, the heat-insulating space is formed between the outer peripheral surface of the suction liner and the inner peripheral surface of the suction hole, and it is possible to restrain refrigerant gas flowing through the suction hole from being heated. A non-contact length up to the reduced-diameter portion is set shorter than a length of the reduced-diameter portion, and the inner diameter of the reduced-diameter portion and the inner diameter of the suction liner are set equal to each other. According to this, it is possible to suppress a pressure loss caused by the abruptly-enlarged portion, and to enhance volume efficiency and compressor efficiency.
According to a second aspect, in the compressor of the first aspect, an outer diameter of the suction liner is made smaller than an inner diameter of the increased-diameter portion, thereby forming the heat-insulating space. According to this aspect, the heat-insulating space is formed by a gap between the suction liner and the increased-diameter portion, low heat conduction caused by refrigerant gas which stays in the heat-insulating space and low heat transfer caused by a plurality of heat media boundaries are combined together, and it is possible to largely suppress the movement of heat toward refrigerant gas in the suction liner.
According to a third aspect of the invention, in the compressor of the first or second aspect, the suction liner includes a small-diameter portion located on the downstream side, and a large-diameter portion located on the upstream side, and an outer diameter of the small-diameter portion is made smaller than an outer diameter of the large-diameter portion. According to this aspect, the same effect as that of the second aspect can be obtained. Further, in the assembling step of inserting the suction liner into the suction hole, since there is no contact resistance between the small-diameter portion of the suction liner and the suction hole, the suction liner can excellently be inserted, and it is possible to avoid a case where the number of assembling steps is increased and costs are increased.
According to a fourth aspect of the invention, in the compressor of any one of the first to third aspects, the inner diameter of the reduced-diameter portion is smaller than an outer diameter of a downstream side tip end of the suction liner. According to this aspect, the reduced-diameter portion provided downstream of the suction hole functions as a stopper, and it is possible to avoid an assembling problem that when the suction liner is inserted into the suction hole, the suction liner is inserted excessively deeply, the suction liner jumps out into the suction chamber and this prevents rotation of the rolling piston in the suction chamber and the rolling piston locks.
According to a fifth aspect of the invention, in the compressor of any one of the first to fourth aspects, an interior atmosphere of the hermetic container is an atmosphere of discharge pressure discharged by the compressing mechanism. This aspect is more effective for a configuration of a high pressure hermetic compressor.
According to a sixth aspect of the invention, in the compressor of any one of the first to fifth aspects, the suction liner is press-fitted into the increased-diameter portion to form a divider. As a dividing method, it is possible to use an O-ring or to press fit the suction liner to eliminate a gap. Especially when the suction liner is press-fitted to form the divider, the O-ring is unnecessary and since the number of parts is small, costs can be reduced. Therefore, according to the sixth aspect, it is possible to inexpensively heat refrigerant gas and to suppress a pressure loss.
According to a seventh aspect of the invention, in the compressor of any one of the first to sixth aspects, an upper bearing and a lower bearing sandwich a cylinder and a rolling piston to form a space, a vane partitions the space into the suction chamber and a compression chamber, and the rolling piston revolves, thereby carrying out a compression operation. According to this aspect, the vane is accommodated in the outer periphery of the cylindrical portion of the cylinder which forms the suction chamber and the compression chamber. Therefore, a certain amount of length is required between the cylindrical portion of the cylinder and the outermost peripheral portion of the cylinder, and a length of the suction hole into which the suction liner is inserted from the outermost peripheral portion of the cylinder up to the suction chamber becomes longer than that of other type of compressors. As a result, time during which refrigerant gas flows in the suction hole becomes relatively long, a heat-receiving amount is increased, and volume efficiency and compressor efficiency are prone to be deteriorated. Therefore, a heat insulating effect is enhanced.
According to an eighth aspect of the invention, in the compressor of the seventh aspect, the compressor further includes at least one more independent suction chamber and at least one more independent compression chamber, and the compressing mechanism includes a multi-cylinder configuring the plurality of independent suction chambers and the plurality of independent compression chambers. According to the compressor having the multi-cylinder, the compressing mechanism is prone to be getting larger in size in the axial direction due to its configuration that a plurality of cylinders are arranged. Therefore, as compared with a rotary compressor having a single cylinder, a height of cylinders is suppressed to a low level in general. On the other hand, to suppress a pressure loss, it is necessary to secure a large inner diameter of the suction liner. As a result, a distance between a wall surface of the suction hole of one of cylinders and upper and lower end surfaces of a cylinder which is adjacent to the former cylinder becomes short, and low temperature suction refrigerant gas which flows in the suction hole is prone to receive heat. According to such a multi-cylinder rotary compressor, a heat insulating effect of the invention is further enhanced.
According to a ninth aspect of the invention, in the compressor of any one of the first to eighth aspects, a suction connection pipe is connected to the suction liner, and the suction connection pipe and the suction liner are integrally formed together. The number of parts is reduced, and it is possible to enhance the efficiency and to reduce costs by the heat insulating effect.
Embodiments of the present invention will be described with reference to the drawings. The invention is not limited to the embodiments.

(First Embodiment)

Fig. 1 is a longitudinal sectional view of a compressor in a first embodiment of the present invention.
In Fig. 1, an electrical element 2 and a compressing mechanism 4 are accommodated in a hermetic container 1. The electrical element 2 and the compressing mechanism 4 are connected to each other through a drive shaft 3. An upper bearing 7 and a lower bearing 8 sandwich a cylinder 5 and a rolling piston 6 to form a space, and a vane(not shown) partitions the space , thereby forming a suction chamber 9 and a compression chamber 10. A crankshaft eccentric portion 11 which is integrally formed on the drive shaft 3 is accommodated in the cylinder 5, and the rolling piston 6 is rotatably attached to the crankshaft eccentric portion 11. The vane (not shown) is slidably provided on the cylinder 5. This vane is always in abutment against the rolling piston 6, thereby dividing the suction chamber 9 and the compression chamber 10 from each other. A suction hole 12 which is in communication with the suction chamber 9 is formed in the cylinder 5. The suction hole 12 is formed into a columnar space, one end of the suction hole 12 opens at an outer peripheral surface of the cylinder 5, and the other end of the suction hole 12 opens at the suction chamber 9, thereby introducing refrigerant gas from an exterior of the hermetic container 1 into the suction chamber 9.
The suction liner 13 is press-fitted into the suction hole 12, thereby forming a divider 18 between the suction liner 13 and the suction hole 12. By the divider 18, high temperature and high pressure refrigerant gas in the hermetic container 1 does not flow into the suction hole 12. A suction connection pipe 14a is inserted into the suction liner 13.
In this embodiment, an accumulator 14 is provided for preventing liquid of the compressor from being compressed. The accumulator 14 separates refrigerant gas into gas and liquid before the refrigerant gas is sucked into the hermetic container 1. The suction connection pipe 14a connects the accumulator 14 and the suction liner 13 to each other.
A suction outer pipe 15 is fixed to the hermetic container 1 by brazing or welding. An end of the suction liner 13 is connected to the suction connection pipe 14a together with an end of the suction outer pipe 15 by brazing or welding. If the electrical element 2 is biased and the drive shaft 3 thereof rotates, the crankshaft eccentric portion 11 eccentrically rotates in the cylinder 5, the rolling piston 6 revolves while abutting against the vane, and the rolling piston 6 continuously sucks and compresses refrigerant gas.
Fig. 2 is an enlarged sectional view of the compressing mechanism shown in Fig. 1, and Fig. 3 is an enlarged sectional view showing the suction hole and its vicinity in which the suction liner is incorporated.
The suction hole 12 includes a reduced-diameter portion 12a located on the downstream side, and an increased-diameter portion 12b located on the upstream side. An entire length of the suction hole 12 is defined as L_C, and most of the entire length (L_C-L_C1) is formed from the increased-diameter portion 12b having an inner diameter φd_C2, and only the length L_C1 on the side of the suction chamber 9 is the reduced-diameter portion 12a having an inner diameter φd_C1.
The suction liner 13 includes a small-diameter portion 13a located on the downstream side, a large-diameter portion 13b located on the upstream side, and an enlarged-pipe portion 13c located further upstream of the large-diameter portion 13b. The small-diameter portion 13a has an outer diameter φD_L1 and an inner diameter φd_L, and the large-diameter portion 13b has an outer diameter φD_L2 and an inner diameter φd_L. Therefore, the small-diameter portion 13a and the large-diameter portion 13b have the same inner diameters and different outer diameters and the small-diameter portion 13a and the large-diameter portion 13b form a stepped configuration.
The inner diameter φd_C1 of the most downstream side reduced-diameter portion 12a which is adjacent to the suction chamber 9 and the inner diameter φd_L of the suction liner 13 are equal to each other. Here, the fact that the inner diameter φd_C1 and the inner diameter φd_L are equal to each other is not limited to a case where a hole diameter ratio φd_C1/φd_L is 1, but this fact also includes a case where the hole diameter ratio φd_C1/φd_L is in a range from 0.95 to 1.1.
The upstream side inner diameter φd_C2 of the suction hole 12 is set slightly smaller than the outer diameter φD_L2 of the large-diameter portion 13b of the suction liner 13 before the suction liner 13 is press-fitted into the suction hole 12. By tightly fitting the suction liner 13 into the suction hole 12, the outer diameter φD_L2 of the large-diameter portion 13b of the suction liner 13 becomes equal to the inner diameter φd_C2, and the divider 18 is formed between the suction liner 13 and the suction hole 12. By this divider 18, an interior of the low pressure suction hole 12 and high pressure atmosphere to which the compressing mechanism 4 is exposed are isolated from each other.
A tip end of the small-diameter portion 13a of the suction liner 13 is inserted from the upstream side end of the suction hole 12 by a distance of L_L, and the outer diameter φD_L1 of the small-diameter portion 13a of the suction liner is made smaller than the inner diameter φd_C2 of the suction hole 12. According to this, a heat-insulating space 16 is formed between the small-diameter portion 13a of the suction liner and the suction hole 12. The heat-insulating space 16 is filled with low pressure suction refrigerant gas.
The suction pipe path is composed of the suction liner 13 and the suction hole 12.
Action and an effect of the compressor having the above-described configuration will be described below.
Refrigerant gas flows from the suction connection pipe 14a through the suction liner 13 and the suction hole 12 and flows into the suction chamber 9. The suction hole 12 is closed by the rolling piston 6, and the refrigerant gas which flowed into the suction chamber 9 is trapped in the suction chamber 9. Thereafter, volume of the compression chamber 10 is reduced, and the refrigerant gas is compressed. In the suction pipe path formed from the suction liner 13 and the suction hole 12, heat from outside is received and a pressure loss is generated, and volume efficiency and compressor efficiency are deteriorated. To enhance the efficiency of the compressor, it is necessary to reduce the heat reception and the pressure loss.
In the case of a high pressure compressor in which an interior of the hermetic container 1 is filled with high pressure refrigerant gas, the compressing mechanism 4 including the cylinder 5 is in high temperature atmosphere and the cylinder 5 is in a high temperature state. On the other hand, low temperature and low pressure refrigerant gas flows through the suction liner 13 and the suction hole 12. Therefore, it is possible to enhance the efficiency of the compressor by suppressing movement of heat from the wall surface of the suction hole 12 to the refrigerant gas.
To realize this heat insulating function, the suction pipe path is provided with the heat-insulating space 16 in the first embodiment. In the first embodiment, as shown in Figs. 2 and 3, since the heat-insulating space 16 and the suction liner 13 are interposed between the wall surface of the suction hole 12 and the suction refrigerant gas, an amount of movement of heat is suppressed, and it is possible to enhance the volume efficiency and the compressor efficiency.
In addition, in the first embodiment, since the inner diameter φd_C1 of the most downstream side reduced-diameter portion 12a of the suction hole 12 and the inner diameter φd_L of the suction liner 13 are set equal to each other, a pressure loss caused by abrupt enlargement and abrupt reduction of a flow path is eliminated, and the efficiency can be enhanced.
Fig. 4 is a graph showing a pressure loss in the first embodiment.
Loss coefficients of an enlargement pressure loss and a reduction pressure loss are determined by a diameter ratio of a flow path. In the first embodiment, if enlargement or reduction flow from the inner diameter φd_L of the suction liner 13 to the inner diameter φd_C1 of the reduced-diameter portion 12a of the suction hole 12, and enlargement flow from the reduced-diameter portion 12a of the suction hole 12 to the suction chamber 9 are taken into consideration, a pressure loss in the flow path from the suction liner 13 to the suction chamber 9 is calculated as shown in Fig. 4 for example.
A vertical axis shows a pressure loss ratio of a configuration shown in Fig. 3 to a pressure loss in the conventional configuration. A lateral axis shows a hole diameter ratio φd_C1/φd_L between the reduced-diameter portion 12a of the suction hole 12 and the suction liner 13. When a hole diameter ratio is less than 1, a flow from the suction liner 13 to the reduced-diameter portion 12a of the suction hole 12 is reduction flow, and when a hole diameter ratio is greater than 1, the flow is an enlargement flow. The hole diameter ratio in the conventional configuration is generally 1.1.
A range of the hole diameter ratio at which a pressure loss can be reduced to the same level as the conventional configuration or lower than the conventional configuration in a state where the suction liner 13 is extended to a downstream portion of the suction hole 12 and movement of heat toward refrigerant gas is reduced is 0.95 to 1.1. If the hole diameter ratio falls within this range, it is possible to enhance the volume efficiency and the compressor efficiency of the compressor.
Figs. 5 to 8 are enlarged views showing a downstream side tip end of the suction liner 13 and its vicinity. Fig. 5 shows a case where the hole diameter ratio φd_C1/φd_L is 1, Fig. 6 shows a case where the hole diameter ratio φd_C1/φd_L is 0.95, and Fig. 7 shows a case where the hole diameter ratio φd_C1/φd_L is 1.1. Fig. 8 shows a case where the outer diameter of the suction liner small-diameter portion is smaller than the inner diameter of the reduced-diameter portion of the suction hole. The present invention is not limited to the configuration shown in Fig. 5, and if the inner diameter φd_L of the suction liner 13 falls within the ranges shown in Figs. 6 and 7, it is possible to suppress a pressure loss to the same level as the conventional configuration or lower than the conventional configuration, and the deterioration of efficiency caused by the pressure loss can be minimized.
There is an appropriate range also for the length L_C1 of the reduced-diameter portion 12a of the suction hole 12. Machining tolerance φL_MC of the length L_C1 of the reduced-diameter portion 12a of the suction hole 12 is a total of machining tolerance of the length (L_C-L_C1) of the increased-diameter portion 12b of the suction hole 12 and machining tolerance of an inner diameter of a cylindrical portion of the cylinder 5 which forms the compression chamber 10. To secure a size of the length L_C1 of the reduced-diameter portion 12a of the suction hole 12, a relation of L_C1>ΔL_MC is required. If machining tolerance of the length of the suction liner 13 is defined as ΔL_ML and assembling tolerance in an assembling step of inserting the suction liner 13 into the suction hole 12 is defined as ΔLA, in order to prevent the suction liner 13 and the reduced-diameter portion 12a of the suction hole 12 from coming into contact with each other in the axial direction, a relation of δL=L_C- (L_C1+L_L) >ΔL_ML+ΔLA is required. Here, δL is a non-contact length from the downstream side tip end of the suction liner 13 to the reduced-diameter portion 12a of the suction hole 12, and the non-contact length δL is shorter than the length L_C1 of the reduced-diameter portion 12a.
If the above two equations are summarized, it is necessary that an appropriate range of the length L_C1 of the reduced-diameter portion 12a of the suction hole 12 is ${ΔL}_{MC} < L_{C 1} < (L_{C} - L_{L}) - ({ΔL}_{ML} + {ΔL}_{A}) .$
If the length L_C1 is in this range, it is possible to avoid such a state that the downstream side tip end of the suction liner 13 and the reduced-diameter portion 12a of the suction hole 12 come into contact with each other, heat is conducted from the cylinder 5 to the suction liner 13 and suction refrigerant gas is heated.
However, if the hole diameter ratio φd_C1/φd_L of the inner diameter φd_C1 of the reduced-diameter portion 12a of the suction hole 12 and the inner diameter φd_L of the suction liner 13 is within the above-described appropriate range between 0.95 and 1.1, and if the outer diameter φD_L1 of the small-diameter portion 13a of the suction liner 13 is smaller than the inner diameter φd_C1 of the reduced-diameter portion 12a of the suction hole 12 as in the configuration shown in Fig. 8, since there is a gap δD1 exists between the downstream side tip end of the suction liner 13 and the reduced-diameter portion 12a of the suction hole 12, the reduced-diameter portion 12a of the suction hole 12 and the suction liner 13 do not come into contact with each other. Hence, there is no problem unless the downstream side tip end of the suction liner 13 projects toward the suction chamber 9. That is, it is only necessary that the relation ΔL_MC<L_C1 is satisfied.
By the configuration shown in Fig. 8, it is possible to largely secure the gap δD2 between the outer diameter φD_L1 of the small-diameter portion 13a of the suction liner 13 and the inner diameter φd_C2 of the increased-diameter portion 12b of the suction hole 12, and to enhance the heat insulating properties. Further, if the gap δD1 between the outer diameter φD_L1 of the small-diameter portion 13a of the suction liner 13 and the inner diameter φd_C1 of the reduced-diameter portion 12a of the suction hole 12 is set small, circulation between the heat-insulating space of the gap δD2 and main flow passing through the suction liner 13 is suppressed, and heat diffusion toward the suction refrigerant gas is minimized.
According to the configuration shown in Fig. 8, since the non-contact length δL is zero, the non-contact length δL is smaller than the length L_C1 of the reduced-diameter portion 12a.
Even if the step and the volume of the compressing mechanism 4, and refrigerant are changed, the relation shown in Fig. 4 is generally established. Therefore, the appropriate range of the hole diameter ratio φd_C1/φd_L can be applied to small compressors used for dehumidifiers and the like to large compressors used for large air conditioning equipment. Further, the hole diameter ratio φd_C1/φd_L can be applied also to various operating fluid such as HFC refrigerant and natural refrigerant.
The configuration of the present invention intends to enhance the efficiency by suppressing heat reception of suction refrigerant gas while minimizing a pressure loss in the suction pipe path. Hence, the configuration of the invention can be applied to compressors of various compressing types, and it is possible to enhance the efficiency also in rotary compressors, scroll compressors, reciprocating compressors and screw compressors.
In the rotary compressor, it is necessary to accommodate a vane in the outer periphery of the cylindrical portion of the cylinder 5 which forms the suction chamber 9 and the compression chamber 10. Hence, a certain distance is required between the cylindrical portion of the cylinder 5 and the outermost peripheral portion of the cylinder 5, and a length of the suction hole 12 into which the suction liner 13 is inserted from the outermost peripheral portion of the cylinder 5 to the suction chamber 9 becomes longer than those of other type compressors. As a result, time during which low temperature suction refrigerant gas flows through the suction hole 12 becomes relatively long, an amount of received heat increases, and the volume efficiency and the compressor efficiency are prone to be deteriorated. Therefore, the high efficiency effect obtained by the configuration of the present invention is especially large.
In a multi-cylinder rotary compressor, the compressing mechanism 4 configures a plurality of independent suction chambers 9 and compression chambers 10. The multi-cylinder rotary compressor is generally designed small in size by lowering a height of the cylinder 5 as compared with a cylinder 5 of a single cylinder rotary compressor. On the other hand, to suppress a pressure loss in the suction pipe path, it is necessary to secure a large inner diameter φd_L of the suction liner 13. As a result, a distance between the wall surface of the suction hole 12 and upper and lower end surfaces of the cylinder 5 which is adjacent to the wall surface becomes short, and low temperature suction refrigerant gas which flows through the suction hole 12 is prone to receive heat. Therefore, in the multi-cylinder rotary compressor, the heat insulating effect obtained by the configuration of the invention becomes higher.
Although the first embodiment has been described based on the case where the high pressure compressor having the hermetic container 1 filled with high pressure refrigerant gas is employed, even if a low pressure compressor having the hermetic container 1 filled with low pressure refrigerant gas is employed, heat is transferred from high temperature and high pressure refrigerant gas compressed by the compression chamber 10 to the compressing mechanism 4 and temperature of the cylinder 5 also becomes high. Therefore, although the low pressure compressor is smaller than the high pressure compressor, the heat insulating effect can be expected.
The suction liner 13 is of the stepped configuration having the outer diameter φD_L1 and the outer diameter φD_L2, and the inner diameters can also be stepped. Therefore, the suction liner 13 can be formed into a press molded product without using cutting work and thus, costs can be reduced, but since a pressure loss is easily generated at the stepped portion of the inner diameters of the suction liner 13, it is necessary to form the suction liner 13 into a smoothly tapered shape so that the pressure loss can be minimized.

(Second Embodiment)

Fig. 9 is an enlarged sectional view showing a suction hole and its vicinity of a compressor of a second embodiment of the invention. Other configurations which are not illustrated in the drawing are the same as those of the first embodiment and thus, description thereof will be omitted.
In Fig. 9, a step between the reduced-diameter portion 12a of the suction hole 12 and the upstream side increased-diameter portion 12b of the suction hole 12 are tapered and forming an angle α. This angle α is formed by drilling the increased-diameter portion 12b of the suction hole 12. In the case of a general drill, the angle α is 118°.
According to this configuration also, the same effects as those of the first embodiment can be obtained of course. In addition, since it is possible to drill the increased-diameter portion 12b of the suction hole 12, the machining time can be reduced and it is possible to contribute to enhancement of workability.
Fig. 10 is an enlarged sectional view showing a suction hole having a different shape and its vicinity in the second embodiment of the invention. Even in the configuration shown in Fig. 10 in which the reduced-diameter portion 12a of the suction hole 12 is only tapered, the same effects can be obtained.
In this case also, the non-contact length δL is shorter than the length L_C1 of the reduced-diameter portion 12a.

(Third Embodiment)

Fig. 11 is an enlarged sectional view showing a suction hole of a compressor and its vicinity in a third embodiment of the invention. Other configurations which are not illustrated in the drawing are the same as those of the first embodiment and thus, description thereof will be omitted.
As shown in Fig. 11, the outer diameter φD_L2 of the large-diameter portion 13b of the suction liner 13 is set slightly smaller than the inner diameter φd_C2 of the increased-diameter portion 12b of the suction hole 12, and an O-ring 17 inserted in an upstream side of the suction hole 12 divides a high pressure and a low pressure from each other. In this embodiment, the O-ring 17 configures the divider.
According to this configuration, since the high temperature cylinder 5 and the high temperature suction liner 13 do not come into direct contact with each other, heating of low temperature and low pressure suction refrigerant gas which flows through the suction liner 13 is further suppressed, and it is possible to further enhance volume efficiency and compressor efficiency.
As compared with the press-fitting configuration of the suction liner 13, the high pressure and the low pressure are divided from each other more stably. In the press-fitting configuration, there is a possibility that rotation failure of the compressing mechanism may be caused due to wear powder and chipping but according to this embodiment, rotation failure of the compressing mechanism does not occur. Therefore, it is possible to provide a compressor having stable performance and high reliability.
Fig. 12 is an enlarged sectional view showing a suction hole having a different shape and its vicinity in the third embodiment of the invention. It is unnecessary that the suction liner 13 has a stepped shape having the small-diameter portion 13a and may have a straight shape as shown in Fig. 12, and the same effect can be obtained.
In this case also, the non-contact length δL is shorter than the length L_C1 of the reduced-diameter portion 12a.
The configuration that the step formed between the reduced-diameter portion 12a and the increased-diameter portion 12b in the second embodiment is tapered such that the angle α is formed may be applied to the third embodiment shown in Figs. 11 and 12.

(Fourth Embodiment)

Fig. 13 is an enlarged sectional view of a compressing mechanism in a fourth embodiment of the present invention. The suction liner 13 is integrally formed on the suction connection pipe 14a of the accumulator 14. Other configurations which are not illustrated in the drawing are the same as those of the first embodiment and thus, description thereof will be omitted. Due to this integral configuration, the number of parts is reduced, and it is possible to enhance the efficiency and to reduce the costs by the heat insulating effect.
In the fourth embodiment also, the non-contact length δL is shorter than the length L_C1 of the reduced-diameter portion 12a.
The configuration in the second embodiment that the step formed between the reduced-diameter portion 12a and the increased-diameter portion 12b is tapered such that the angle α is formed may be applied to the fourth embodiment shown in Fig. 13.
The divider configured by the O-ring 17 in the third embodiment may be applied to the fourth embodiment shown in Fig. 13.
The straight suction liner 13 in the third embodiment may be applied to the fourth embodiment shown in Fig. 13.

(Fifth Embodiment)

Fig. 14 is an enlarged sectional view showing a suction hole of a compressor and its vicinity in a fifth embodiment of the invention. Other configurations which are not illustrated in the drawing are the same as those of the first embodiment and thus, description thereof will be omitted.
As shown in Fig. 14, the suction liner 13 has a straight shape having no small-diameter portion 13a, and an enlarged portion 12c having an inner diameter φdc3 greater than the inner diameter φd_C2 of the increased-diameter portion 12b is provided between the reduced-diameter portion 12a and the increased-diameter portion 12b of the suction hole 12.
In this configuration, the heat-insulating space 16 formed between the suction liner 13 and the suction hole 12 is formed from the enlarged portion 12c, and the same effect as that of the configuration of the first embodiment can be obtained.
This embodiment is effective especially when a thickness of the suction liner 13 is thin and sufficient strength can not be kept in the stepped configuration.
In the fifth embodiment also, the non-contact length δL is shorter than the length L_C1 of the reduced-diameter portion 12a.
The configuration in the second embodiment that the step formed between the reduced-diameter portion 12a and the increased-diameter portion 12b is tapered such that the angle α is formed may be applied to the fifth embodiment shown in Fig. 14. The divider configured by the O-ring 17 in the third embodiment may be applied to the fifth embodiment shown in Fig. 14.
The integral configuration between the suction liner 13 and the suction connection pipe 14a in the fourth embodiment may be applied to the fifth embodiment shown in Fig. 14.
In all of the above-described first to fifth embodiments, as operating refrigerant, it is possible to employ HCFC-based refrigerant such as R12, HFC-based refrigerant such as R410An and natural refrigerant such as carbon dioxide. It is also possible to employ refrigerant having hydrofluoroolefin (HFO) having a carbon-carbon double bond as basic component, single refrigerant having HFO-1234yf, and mixture refrigerant in which this refrigerant, R32 (HFC-32) and R125 (HFC-125) are mixed.
Since the HFO refrigerant is low pressure refrigerant, specific volume is large and flow velocity in the suction liner 13 is relatively fast. Therefore, a pressure loss is prone to be generated. When such refrigerant is used, the present invention is more effective.

[INDUSTRIAL APPLICABILITY]

The compressor of the present invention can be applied to air conditioners and heat pump water heaters using HFC-based refrigerant, HCFC-based refrigerant and HFO-based refrigerant, and to air conditioners and heat pump water heaters using carbon dioxide of natural refrigerant.

Claims

A compressor in which an electrical element and a compressing mechanism are accommodated in a hermetic container, the compressor includes a suction hole (12) through which refrigerant gas is introduced from an exterior of the hermetic container into a suction chamber of the compressing mechanism, and a suction liner (13) inserted into the suction hole, wherein the suction hole (12) includes a reduced-diameter portion (12a) located on a downstream side, and an increased-diameter portion (12b) located on an upstream side,
characterised in that a heat-insulating space (16) is formed between the suction liner and the increased-diameter portion, and
an inner diameter of the reduced-diameter portion is equal to an inner diameter of the suction liner.
The compressor according to claim 1, wherein an outer diameter of the suction liner is made smaller than an inner diameter of the increased-diameter portion, thereby forming the heat-insulating space.
The compressor according to claim 1 or 2, wherein the suction liner includes a small-diameter portion located on the downstream side, and a large-diameter portion located on the upstream side, and an outer diameter of the small-diameter portion is made smaller than an outer diameter of the large-diameter portion.
The compressor according to any one of claims 1 to 3, wherein the inner diameter of the reduced-diameter portion is smaller than an outer diameter of a downstream side tip end of the suction liner.
The compressor according to any one of claims 1 to 4, wherein an interior atmosphere of the hermetic container is an atmosphere of discharge pressure discharged by the compressing mechanism.
The compressor according to any one of claims 1 to 5, wherein the suction liner is press-fitted into the increased-diameter portion to form a divider.
The compressor according to any one of claims 1 to 6, wherein an upper (7) and a lower bearing (8) sandwich a cylinder (5) and a rolling piston (6) to form a space, a vane partitions the space into the suction chamber and a compression chamber, and the rolling piston revolves, thereby carrying out a compression operation.
The compressor according to claim 7, further comprising at least one more independent suction chamber and at least one more independent compression chamber, wherein the compressing mechanism includes a multi-cylinder configuring the plurality of independent suction chambers and the plurality of independent compression chambers.
The compressor according to any one of claims 1 to 8, wherein a suction connection pipe is connected to the suction liner, and the suction connection pipe and the suction liner are integrally formed together.