JP2005256614A - Multi-cylinder type rotary compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-cylinder type rotary compressor improvable in compressing performance ensuring the smooth motion of blades in the multi-cylinder type rotary compressor provided with a compression mechanism part for always performing compressing operation, and a compression mechanism part capable of performing cylinder cut off operation. <P>SOLUTION: A motor part 3 and the first and second compression mechanism parts 2A, 2B are stored in a sealed casing 1. The respective compression mechanism parts are provided with cylinders 8A, 8B provided with cylinder chambers 14a, 14b storing eccentric rollers 13a, 13b; blades 15a, 15b with the tip edges abutting on the peripheral surfaces of the rollers to bisect the cylinder chambers; discharge passages 50A, 50B for guiding compressed gas to be discharged into the sealed casing; and discharge valve devices 70A, 70B. The second compression mechanism part separates the blades from the peripheral surface of the roller to allow cylinder cut off operation when load is small, and the first compression mechanism part always performs compressing operation. The respective compression mechanism parts are differentiated in at least one of the size of clearance between the respective components, the discharge passages and the discharge valve devices. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a multi-cylinder rotary compressor provided with a second compression mechanism that can perform a cylinder resting operation, for example, with respect to a first compression mechanism that performs a constant compression operation.

In a compression mechanism of a general rotary compressor, an eccentric roller is accommodated in a cylinder chamber of a cylinder, and a blade chamber is provided in the cylinder so that the blade is slidably accommodated. The leading edge of the blade is pressed and urged by a compression spring so as to elastically contact the peripheral surface of the eccentric roller, and the cylinder chamber is divided into two chambers by the blade. One chamber side is a suction chamber, and the other chamber side is a compression chamber equipped with a discharge valve device.
In recent years, a two-cylinder rotary compressor provided with two sets of the compression mechanism section above and below is being standardized. If such a compressor can be provided with a compression mechanism part that always performs a compression action and a compression mechanism part that can be switched between compression and stop if necessary, the specifications are advantageously expanded.

For example, in [Patent Document 1], two cylinder chambers are provided, and if necessary, the blades of either one of the cylinder chambers are forcibly separated from the rollers, and the cylinder chamber is pressurized and compressed. A two-cylinder rotary compressor characterized in that it is provided with high-pressure introduction means for interrupting is disclosed.
JP-A-1-247786

  By the way, in a rotary compressor having a compression mechanism part that always performs a compression action and a compression mechanism part that enables switching between compression and stop, full capacity operation that operates all the compression mechanism parts and compression that always performs a compression action. It is important to smoothly switch the operation of the ability reduction operation that operates only the mechanism part and to improve the compression performance at each operation.

  The present invention has been made on the basis of the above circumstances, and the purpose of the present invention is to smoothly switch between operations on the premise that a compression mechanism portion that always performs a compression operation and a compression mechanism portion that can perform a cylinder resting operation are provided. An object of the present invention is to provide a multi-cylinder rotary compressor that can be performed and can improve the compression performance during each operation.

  In order to satisfy the above object, a multi-cylinder rotary compressor according to the present invention includes an electric motor part and a plurality of compression mechanism parts connected to the electric motor part in a sealed case, and each compression mechanism part is A cylinder provided with a cylinder chamber in which the roller is eccentrically rotatable, a blade provided in each cylinder, the tip edge of which is in contact with the circumferential surface of the roller, and halves the cylinder chamber along the rotation direction of the roller; A discharge passage for discharging and guiding the gas compressed in the chamber into the sealed case; and a discharge valve device provided in the discharge passage for controlling opening and closing of the discharge passage, and at least one compression mechanism when the load is small The compressor is equipped with a compression mechanism that enables a cylinder resting operation that stops the compression operation in the cylinder chamber by separating the blade from the peripheral surface of the roller, and performs a compression operation at all times In 構部 and cylinder deactivation operation is the compression mechanism unit capable, the size of the gap between the components, of the discharge passage and the discharge valve system was different from the one constituting at least one.

  According to the multi-cylinder rotary compressor of the present invention, it is possible to smoothly perform operation switching on the premise that a compression mechanism portion that performs constant compression operation and a compression mechanism portion that can perform idle cylinder operation are provided. There are effects such as improvement.

Hereinafter, embodiments of the multi-cylinder rotary compressor of the present invention are applied to a two-cylinder rotary compressor and described with reference to the drawings.
FIG. 1 is a diagram illustrating a cross-sectional structure of a two-cylinder rotary compressor T and a configuration of a refrigeration cycle R including the two-cylinder rotary compressor T.
First, a description will be given of a two-cylinder rotary compressor T. Reference numeral 1 denotes a hermetic case, and a lower portion in the hermetic case 1 has a plurality of compression mechanism parts described later, here, a first compression mechanism part 2A and a second compression mechanism part. A compression mechanism assembly 2 including a compression mechanism portion 2B is provided, and an electric motor portion 3 is provided on the compression mechanism assembly 2. The electric motor unit 3 and the first and second compression mechanism units 2A and 2B constituting the compression mechanism assembly 2 are connected to each other via a rotating shaft 4.

The electric motor unit 3 includes a stator 5 that is fixed to the inner surface of the sealed case 1 and a rotor 6 that is disposed inside the stator 5 with a predetermined gap and in which the rotating shaft 4 is inserted. The The electric motor unit 3 is connected to an inverter 30 that varies the operating frequency, and is electrically connected to a control unit 40 that controls the electric motor unit 3 via the inverter 30.
The first and second compression mechanism portions 2A and 2B include a first cylinder 8A and a second cylinder 8B, which are disposed below the rotation shaft 4 with an intermediate partition plate 7 interposed therebetween. ing. The first and second cylinders 8A and 8B are set to have different outer shape dimensions and the same inner diameter dimensions. The outer diameter of the first cylinder 8A is slightly larger than the inner diameter of the sealed case 1 and is press-fitted into the inner peripheral surface of the sealed case 1 and then positioned and fixed by welding from the outside of the sealed case 1. The

A main bearing 9 is superimposed on the upper surface portion of the first cylinder 8A, and is fixed to the cylinder 8A via a mounting bolt 10 together with a valve cover a. The auxiliary bearing 11 is superimposed on the lower surface portion of the second cylinder 8B, and is fixed to the first cylinder 8A via the mounting bolt 12 together with the valve cover b.
On the other hand, the rotary shaft 4 is pivotally supported by the main bearing 9 and the sub-bearing 11 at a midway portion and a lower end portion. Furthermore, the rotary shaft 4 penetrates through the first and second cylinders 8A and 8B and is integrally provided with two eccentric portions 4a and 4b formed with a phase difference of about 180 °. The eccentric portions 4a and 4b have the same diameter as each other, and are assembled so as to be located in the inner diameter portions of the cylinders 8A and 8B. Eccentric rollers 13a and 13b having the same diameter are fitted to the peripheral surfaces of the eccentric parts 4a and 4b.

  The first cylinder 8A and the second cylinder 8B are divided into upper and lower surfaces by the intermediate partition plate 7, the main bearing 9 and the auxiliary bearing 11, and a first cylinder chamber 14a and a second cylinder are provided inside each of them. A chamber 14b is formed. The cylinder chambers 14a and 14b are formed to have the same diameter and height, and the eccentric rollers 13a and 13b are accommodated in the cylinder chambers 14a and 14b so as to be eccentrically rotatable.

FIG. 2 is an exploded perspective view showing a part of each of the first compression mechanism 2A and the second compression mechanism 2B.
Each cylinder 8A, 8B is provided with blade chambers 22a, 22b communicating with the cylinder chambers 14a, 14b. Blades 15a and 15b are accommodated in the respective blade chambers 22a and 22b so as to protrude and retract with respect to the cylinder chambers 14a and 14b. The blade 15b is shown in FIG.

  The blade chambers 22a and 22b are integrally connected to the blade housing grooves 23a and 23b in which both side surfaces of the blades 15a and 15b are slidably movable and the ends of the blade housing grooves 23a and 23b. It consists of vertical hole parts 24a and 24b in which the rear end part is accommodated. The first cylinder 8A is provided with a lateral hole 25 that communicates the outer peripheral surface with the blade chamber 22a, and the spring member 26 is accommodated therein. The spring member 26 is interposed between the rear end surface of the blade 15a and the inner peripheral surface of the sealing case 1, and applies an elastic force (back pressure) to the blade 15a so that the tip edge contacts the eccentric roller 13a. It is a compression spring.

  No member other than the blade 15b is accommodated in the blade chamber 22b on the second cylinder 8B side. However, depending on the setting environment of the blade chamber 22b and the action of the pressure switching mechanism K as will be described later, The tip edge of 15b contacts the eccentric roller 13b. Since the leading edges of the blades 15a and 15b are formed in a semicircular shape in plan view, they can be in line contact with the peripheral walls of the eccentric rollers 13a and 13b regardless of the rotation angle of the eccentric roller 13a. When the eccentric rollers 13a and 13b rotate eccentrically along the inner peripheral walls of the cylinder chambers 14a and 14b, the blades 15a and 15b reciprocate along the blade housing grooves 23a and 23b, and the blade rear end portion has a vertical hole portion 24a, It is possible to advance and retreat from 24b.

A part of the outer shape of the second cylinder 8B is exposed in the sealed case 1 because of the relationship between the outer dimension of the second cylinder 8B and the outer diameter of the intermediate partition plate 7 and the auxiliary bearing 11. The exposed portion of the sealed case 1 is designed to correspond to the blade chamber 22b, and the blade chamber 22b and the rear end portion of the blade 15b are directly subjected to the pressure in the case.
In particular, since the second cylinder 8B and the blade chamber 22b are structures, there is no influence even if they are subjected to pressure in the case, but the blade 15b is slidably accommodated in the blade chamber 22b and has a rear end portion. Is located in the vertical hole portion 24b of the blade chamber 22b, and thus receives the pressure inside the case directly.

The tip of the blade 15b faces the second cylinder chamber 14b, and the blade tip receives the pressure in the cylinder chamber 14b. Eventually, the blade 15b is configured to move in a direction from a higher pressure to a lower pressure in accordance with the magnitude of the pressure received by the front end and the rear end.
Each cylinder 8A, 8B is provided with a mounting hole or screw hole through which the mounting bolts 10, 12 are inserted or screwed, and a plurality of arc-shaped gas passage holes 27 only for the first cylinder 8A. .

Next, the refrigeration cycle R provided with such a two-cylinder rotary compressor T will be described.
As shown in FIG. 1 again, a discharge pipe 18 is connected to the upper end of the sealed case 1. The discharge pipe 18 is connected to the accumulator 17 via a condenser 19, an expansion mechanism 20 and an evaporator 21. Suction pipes 16 a and 16 b for the compressor T are connected to the bottom of the accumulator 17. One suction pipe 16a penetrates the sealed case 1 and the side of the first cylinder 8A, and communicates directly with the first cylinder chamber 14a. The other suction pipe 16b passes through the side of the second cylinder 8B through the sealed case 1 and communicates directly with the second cylinder chamber 14b.

  Further, a branch pipe P is provided which branches from the middle part of the discharge pipe 18 communicating with the compressor T and the condenser 19 and joins the middle part of the suction pipe 16b connected to the second cylinder chamber 14b. It is done. A first opening / closing valve 28 is provided in the middle of the branch pipe P, and a second opening / closing valve 29 is provided upstream of the branch portion of the branch pipe P in the suction pipe 16b. The first on-off valve 28 and the second on-off valve 29 are electromagnetic valves, respectively, and are controlled to open and close according to an electrical signal from the control unit 40.

  In this way, the pressure switching mechanism K is configured by the suction pipe 16b, the branch pipe P, the first on-off valve 28, and the second on-off valve 29 connected to the second cylinder chamber 14b. In accordance with the switching operation of the pressure switching mechanism K, the suction pressure or the discharge pressure is guided to the cylinder chamber 14b of the second cylinder 8B.

Next, the operation of the above-described rotary-type hermetic compressor T and the refrigeration cycle apparatus R provided with this compressor will be described.
(1) When normal operation (full capacity operation) is selected:
The control unit 40 controls the first switching valve 28 of the pressure switching mechanism K to be closed and the second switching valve 29 to be opened, and sends an operation signal to the motor unit 3 through the inverter 30. The rotating shaft 4 is driven to rotate, and the eccentric rollers 13a and 13b rotate eccentrically in the cylinder chambers 14a and 14b.

In the first cylinder 8A constituting the first compression mechanism portion 2A, the blade 15a is always elastically pressed and biased by the spring member 26, so that the tip edge of the blade 15a is in sliding contact with the peripheral wall of the eccentric roller 13a. The first cylinder chamber 14a is divided into a suction chamber and a compression chamber.
When the position of the inner circumferential surface of the eccentric roller 13a in contact with the blade housing groove 23a coincides with the blade housing groove 23a, the space capacity of the cylinder chamber 14a is maximized. The refrigerant gas is sucked into the cylinder chamber 14a from the accumulator 17 through the suction pipe 16a and is filled.

  Along with the eccentric rotation of the eccentric roller 13a, the rolling contact position of the eccentric roller with respect to the inner peripheral surface of the first cylinder chamber 14a is moved, and the volume of the compression chamber partitioned by the cylinder chamber is reduced. The introduced gas is gradually compressed. The rotating shaft 4 is continuously rotated, the compression chamber capacity in the cylinder chamber 14a is further reduced, the gas is compressed, and when the pressure rises to a predetermined pressure, a discharge valve (not shown) is opened. The high-pressure gas is discharged into the sealed case 1 through the valve cover a and is filled. And it discharges from the discharge pipe 18 of an airtight case upper part.

  On the other hand, since the first on-off valve 28 constituting the pressure switching mechanism K is closed, the discharge pressure (high pressure) is not guided to the second cylinder chamber 14b. The low-pressure evaporative refrigerant evaporated by the evaporator 21 and gas-liquid separated by the accumulator 17 is guided to the second cylinder chamber 14b through the opened second on-off valve 29. The cylinder chamber 14b is in a suction pressure (low pressure) atmosphere, while the blade chamber 22b is exposed in the sealed case 1 and is under a discharge pressure (high pressure). When the blade 15b is used as a reference, the tip end portion is under a low pressure condition, the rear end portion is under a high pressure condition, and a differential pressure exists at the front and rear end portions.

  Under the influence of the differential pressure, the tip of the blade 15b is pressed and urged so as to be in sliding contact with the eccentric roller 13b. That is, the same compression action is performed in the second cylinder chamber 14b as the blade 15a on the first cylinder chamber 14a side is pressed and urged by the spring member 26 to perform the compression action. Eventually, in the two-cylinder rotary compressor T, full capacity operation is performed in which the compression action is performed in both the first cylinder chamber 14a and the second cylinder chamber 14b.

  The high-pressure gas discharged from the sealed case 1 through the discharge pipe 18 is led to the condenser 19 to be condensed and liquefied, adiabatically expanded by the expansion mechanism 20, and the evaporator 21 takes away latent heat of evaporation from the heat exchange air and cools it. It works. Then, the evaporated refrigerant is guided to the accumulator 17 and separated into gas and liquid, and is again sucked into the first and second compression mechanism portions 2A and 2B of the compressor T from the suction pipes 16a and 16b. Circulate.

(2) When special operation (half-capacity operation) is selected:
When the special operation (operation that halves the compression capacity) is selected, the control unit 40 switches and sets the first switching valve 28 of the pressure switching mechanism K to be opened and the second switching valve 29 to be closed. In the first cylinder chamber 14a, the normal compression action is performed as described above, and the high-pressure gas discharged into the sealed case 1 is filled to become a high pressure in the case. A part of the high-pressure gas discharged from the discharge pipe 18 is diverted to the branch pipe P, and the second cylinder constituting the second compression mechanism portion 2A via the opened first on-off valve 28 and the suction pipe 16b. It is introduced into the chamber 14b.

  While the second cylinder chamber 14b is in a discharge pressure (high pressure) atmosphere, the blade chamber 22b remains in the same situation as the high pressure in the case. Therefore, the blade 15b is affected by the high pressure at both the front and rear ends, and there is no differential pressure at the front and rear ends. The blade 15b does not move at a position away from the outer peripheral surface of the roller 13b and maintains a stopped state, and no compression action is performed in the second cylinder chamber 14b. Eventually, only the compression action in the first cylinder chamber 14a is effective, and an operation with half the capacity is performed.

Since the inside of the second cylinder chamber 14b is at a high pressure, there is no leakage of compressed gas from the sealed case 1 into the second cylinder chamber 14b, and no loss is caused thereby. Therefore, it is possible to operate with half the capacity without lowering the compression efficiency.
In this way, the capacity can be varied with a simple configuration that omits the spring member that biases the blade in at least one of the plurality of compression mechanism portions, which is advantageous in terms of cost and excellent in productivity. A highly efficient two-cylinder rotary compressor can be provided.
Here, in the first compression mechanism 2A that always performs the compression operation and the second compression mechanism 2B that can perform the cylinder resting operation, the size of the gap between the components, the discharge passages 55A and 55B, and the discharge It is characterized in that at least one of the configurations of the valve devices 70A and 70B is different.

The configuration will be specifically described below.
Capability variation by operation of only the first compression mechanism portion 2A is possible by pulling the blade 15b constituting the second compression mechanism portion 2B away from the eccentric roller 13b and causing the second cylinder chamber 14b to perform a cylinder-free operation. . Therefore, the clearance between the groove width of the blade housing grooves 23a and 23b and the plate thickness of the blades 15a and 15b and / or the clearance between the height of the cylinders 8A and 8B and the height of the blades 15a and 15b is secured to some extent, and the movement of the blade is controlled. It needs to be smooth.

In particular, as described above, in the compressor T including the second compression mechanism portion 2B capable of the cylinder resting operation without using the spring member 26 that presses and biases the blade 15a, the gap is increased to some extent. Thus, switching from special operation, which is a cylinder-free operation, to full capacity operation can be performed smoothly.
However, if the clearance is secured to be the same in the first compression mechanism portion 2A and the second compression mechanism portion 2B, the leakage amount of the compressed gas increases in the first compression mechanism portion 2A on the side where the cylinder resting operation is not performed. As a result, the compression performance is reduced.
Therefore, in the present embodiment, the size of the gap is basically different between the first compression mechanism 2A that always performs the compression operation and the second compression mechanism 2B that can perform the cylinder resting operation. .
That is, the gap in the first compression mechanism 2A that is always operated is matched with the conventional gap, and the gap in the second compression mechanism 2B on the side where the cylinder is rested is set as the gap in the first compression mechanism 2A. By making it larger than this, operation switching can be performed smoothly and performance degradation can be suppressed.

FIG. 3A illustrates the side gap Sa of the blade, which is the difference in the plate thickness dimension of the blades 15a and 15b with respect to the width dimension of the blade housing grooves 23a and 23b. FIG. 3B illustrates the blade height direction gap Sb, which is the difference in height between the blades 15a and 15b with respect to the height of the cylinder chambers 14a and 14b.
At least one of the gaps Sa and Sb is set so that the second compression mechanism 2B capable of cylinder resting operation is larger than the first compression mechanism 2A that always performs compression operation. As described above, in the first compression mechanism section 2A, the gap in the compression mechanism section of this type of conventional compressor is the same as that in the second compression mechanism section 2B.

Actually, when the amount of gas leakage during compression with respect to changes in the side surface gap Sa of the blades 15a and 15b and the height direction gap Sb of the blades 15a and 15b is measured, gas leakage occurs as the gaps Sa and Sb increase. The result is an increase in quantity. When the compression performance was measured after changing the gaps Sa and Sb, it was found that the compression performance tends to decrease as the gap increases.
Therefore, the second compression mechanism unit 2B that performs the cylinder resting operation is set by setting the side surface gap Sa of the blade 15a and the blade height direction clearance Sb in the first compression mechanism unit 2A that always performs the compression operation. The side clearance Sa of the blade 15b and the height clearance Sb of the blade are set to be larger than those of the first compression mechanism portion 2A, so that the leakage loss is reduced by half and the deterioration of the compression performance is minimized.

  In addition, with respect to the first compression mechanism portion 2A that always performs the compression operation, as a setting of the gaps in the components of the second compression mechanism portion 2B that can perform the cylinder resting operation, the cylinders 8A and 8B in FIG. There is a setting of the clearance Sc between the height dimension and the height dimension of the eccentric rollers 13a and 13b, and a setting of a clearance Sd between the inner diameters of the cylinders 8A and 8B and the outer diameter of the eccentric rollers 13a and 13b in FIG. Either one of the gaps Sc and Sd is set so that the second compression mechanism 2B capable of cylinder resting operation is larger than the first compression mechanism 2A that always performs compression operation.

  While the second compression mechanism unit 2B is in the cylinder resting operation, the eccentric roller 13b is in a so-called idling state. On the other hand, although not particularly illustrated, an oil reservoir for collecting lubricating oil is formed at the inner bottom of the sealed case 1, and the second compression mechanism 2B is immersed in the lubricating oil in the oil reservoir. . When the eccentric roller 13b idles, the lubricating oil is stirred, so that a sliding resistance is generated between the eccentric roller and the inner wall of the cylinder 8B due to the centrifugal force of the eccentric roller.

  Therefore, the clearance Sc between the height dimension of the cylinder 8B and the height dimension of the eccentric roller 13b in the second compression mechanism section 2B capable of cylinder resting operation or the clearance formed by the inner diameter of the cylinder 8B and the outer diameter of the eccentric roller 13b. If Sd is too small, the sliding resistance increases, so that the gaps Sc and Sd of the second compression mechanism 2B are made larger than those of the first compression mechanism 2A. Thereby, the sliding loss of the eccentric roller 13b that rotates idly during the idle cylinder operation of the second compression mechanism portion 2B can be minimized.

In FIG. 4A, the horizontal axis represents the height clearance ratio, and the vertical axis represents the coefficient of performance (COP). The height clearance ratio is obtained from (height clearance of the second compression mechanism 2B on the cylinder resting operation side / height clearance of the first compression mechanism 2A on the constant compression operation side). The height clearance refers to the difference between the height of the cylinders 8A and 8B and the height of the eccentric rollers 13a and 13b.
Here, when the predetermined width is set as the optimum range of the height clearance ratio from the state where the coefficient of performance is maximized, the optimum range is that the height clearance ratio is in the range of 1.2 to 1.8. I understand.

FIG. 4B shows the change in the coefficient of performance during the cylinder resting operation, with the side clearance ratio on the horizontal axis and the coefficient of performance (COP) on the vertical axis. The side clearance ratio is obtained from (the side clearance of the second compression mechanism 2B on the side where the cylinder is rested / the side clearance of the first compression mechanism 2A on the side where the constant compression is performed). The side clearance refers to the difference formed between the inner diameters of the cylinders 8A and 8B and the outer diameters of the eccentric rollers 13a and 13b.
As in the previous example, when the predetermined width is set as the optimum range of the side clearance ratio from the state where the coefficient of performance is maximized, this optimum range is such that the side clearance ratio is in the range of 1.2 to 1.8. I know that there is.

A configuration that satisfies the object of the present invention may be as described below.
5A is a cross-sectional view of the discharge passage 50A provided in the main bearing 9 in the first compression mechanism portion 2A, a plan view of the cylinder chamber 14a provided with the discharge notch 52a, and opening and closing at the end of the discharge passage 50A. It is a figure which shows the shape structure of 55 A of discharge valves provided freely. 5B is a cross-sectional view of the discharge passage 50B provided in the auxiliary bearing 11 in the second compression mechanism portion 2B, a plan view of the cylinder chamber 14b provided with the discharge notch 52b, and opening and closing at the end of the discharge passage 50B. It is a figure which shows the shape structure of the discharge valve 55B provided freely.

When the second compression mechanism section 2B performs the cylinder resting operation and only the first compression mechanism section 2A performs the compression operation, the first compression mechanism section 2A performs the low frequency operation. At this time, since the circulation amount of the refrigerant becomes extremely small, it is effective to reduce the dead volume (dead volume) formed by the discharge passage 50A and the discharge notch 52a. The compression efficiency in the first compression mechanism portion 2A on the other side can be maximized, which helps to reduce the running cost.
On the other hand, since the second compression mechanism 2B that performs the cylinder resting operation is mainly operated at a high frequency, the rate of performance degradation due to overcompression is greater than the performance degradation due to dead volume, so that the discharge passage 50B and the discharge notch should be large to some extent.

Therefore, specifically, the length of the discharge passage 50A in the first compression mechanism portion 2A is t1, the inner diameter of the discharge passage 50A is φD1, the radius of the discharge notch 52a is R1, and the discharge in the second compression mechanism portion 2B. When the length of the passage 50B is t2, the inner diameter of the discharge passage 50B is φD2, and the radius of the discharge notch 52b is R2,
φD1 <φD2, t1 <t2, R1 <R2,
Set to at least one of the following.
After all, the size of the discharge passage 50A, 50B,
2nd compression mechanism part 2B> 1st compression mechanism part 2A
Will be set to the relationship.

Further, because of the difference in operating conditions between the first compression mechanism 2A that is mainly operated at a low frequency and the second compression mechanism 2B that is mainly operated at a high frequency, the spring of the discharge valve of each compression mechanism Different constants are also effective for improving performance.
That is, the length of the discharge valve 55A used in the second compression mechanism 2B is N1, the length of the discharge valve 55A used in the first compression mechanism 2A is N1, the thickness is T1, and the width is L1. If the dimension is N2, the thickness dimension is T2, and the width dimension is L2,
N1 <N2, T1 <T2, L1 <L2,
Set to at least one of the following.
The above is the spring constant of the discharge valve 55A.
2nd compression mechanism part 2B> 1st compression mechanism part 2A
It will be set to the relationship.
Thereby, the responsiveness of the discharge valve of the first compression mechanism portion 2A that is mainly operated at a low frequency is improved, and the efficiency is improved. On the other hand, the second compression mechanism portion 2B that is mainly operated at a high frequency has a high spring constant to some extent, and can prevent a decrease in reliability.

Furthermore, the same effect can be derived from the difference in the shape structure of the valve seat portions 60a and 60b that constitute the discharge valve devices 70A and 70B together with the discharge valves 55A and 55B. That is, the cross-sectional shape of the valve seat portion 60a provided in the first compression mechanism portion 2A may be curved in an R shape, and the cross section of the valve seat portion 60b provided in the second compression mechanism portion 2B may be formed in a flat shape. .
In particular, when only the first compression mechanism portion 2A performs the low frequency operation alone, the refrigerant circulation amount is extremely reduced. Therefore, by making the cross-sectional shape of the valve seat portion 60a into an R shape with good responsiveness to the discharge valve 55A, the sealing performance is improved and the compression efficiency is improved.

On the other hand, a decrease in the durability of the discharge valve 55A itself can be considered by reducing the collision area of the discharge valve 55A. In this regard, the strength of the discharge valve 55A used in the first compression mechanism portion 2A is increased. This can be avoided by increasing the strength of the discharge valve 55B used in the second compression mechanism 2B.
In FIG. 6, the horizontal axis represents the refrigeration capacity, and the vertical axis represents the coefficient of performance (COP). Then, the second compression mechanism portion 2B capable of the cylinder resting operation of the present invention and the first compression mechanism portion 2A that always performs the compression operation are provided, and the compressor R having the capacity adjustment structure described above is changed in a solid line. A two-cylinder structure that is shown as E, and is simply shown as a one-dot chain line change F, showing a conventional compressor only having a compression mechanism capable of cylinder resting operation and a compression mechanism that always performs compression operation. The compressor provided is shown as a broken line change G.

  The range a in the figure is the operation region of only one cylinder of the compressor provided with the compression mechanism unit capable of the present invention and the conventional cylinder-cylinder operation, and the range b is the operation region of two cylinders simultaneously. In the range b, the F coefficient is higher than the E change of the present invention. In the a range, the E change of the present invention is higher than the F change and the G change. From an average over all the a range and b range, it can be seen that the E change of the present invention has the highest coefficient of performance and is a two-cylinder rotary compressor with good operating efficiency.

In the embodiment of the present invention, a two-cylinder type having two compression mechanism portions, that is, a first compression mechanism portion 2A that always performs a compression operation and a second compression mechanism portion 2B that can perform a cylinder deactivation operation. Although the rotary compressor has been described, it is needless to say that the present invention is not limited to this and can be applied to a three-cylinder type, a four-cylinder type or a multi-cylinder type rotary compressor.
In short, it has a plurality of compression mechanisms, and when the load is small, at least one compression mechanism allows the blades to be separated from the peripheral surface of the roller and can perform a cylinder-resting operation that stops the compression operation in the cylinder chamber A multi-cylinder rotary compressor provided with the compression mechanism section described above may be used.

The longitudinal cross-sectional view and refrigeration cycle block diagram of the rotary type hermetic compressor based on embodiment of this invention. The perspective view which decomposed | disassembled each part of the 1st compression mechanism part and 2nd compression mechanism part based on the embodiment. The figure explaining the clearance gap between mutually different components based on the embodiment. The characteristic figure of a height clearance ratio and a coefficient of performance, and the characteristic figure of a side clearance ratio and a coefficient of performance based on the embodiment. Sectional drawing of the discharge passage in the 1st, 2nd compression mechanism part based on the embodiment, the top view of a part of main bearing, and the figure which shows the shape structure of a discharge valve. The characteristic view of the refrigerating capacity and a coefficient of performance for comparing the compressor of this invention and the compressor of another structure based on the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Sealing case, 3 ... Electric motor part, 2A ... 1st compression mechanism part, 2B ... 2nd compression mechanism part, 13a, 13b ... Eccentric roller, 14a ... 1st cylinder chamber, 14b ... 2nd cylinder chamber , 8A ... first cylinder, 8B ... second cylinder, 15a, 15b ... blade, 50A, 50B ... discharge passage, 70A, 70B ... discharge valve device.

Claims (4)

In the sealed case, the motor part and a plurality of compression mechanism parts connected to the motor part are accommodated,
Each of the compression mechanism sections includes a cylinder having a cylinder chamber in which the roller is eccentrically rotatable, and a tip edge provided in each cylinder abuts on the circumferential surface of the roller, along the rotation direction of the roller. A blade that bisects the cylinder chamber, a discharge passage that discharges and guides the gas compressed in the cylinder chamber into the sealed case, and a discharge valve device that is provided in the discharge passage and controls opening and closing of the discharge passage,
Multi-cylinder rotary compression with a compression mechanism that enables a cylinder resting operation in which the blade is separated from the peripheral surface of the roller and stops the compression operation in the cylinder chamber when the load is small In the machine
In the compression mechanism part that performs the compression operation at all times and the compression mechanism part that can perform the cylinder resting operation, the size of the gap between the components, the configuration of at least one of the discharge passage and the discharge valve device are made different. A multi-cylinder rotary compressor characterized by that. In the compression mechanism part that performs the constant compression operation and the compression mechanism part that can perform the cylinder resting operation, among the side gap of the blade, the height direction gap of the blade, the height direction gap of the roller, and the radial direction gap of the roller, At least one size,
Compression mechanism section capable of idle cylinder operation> The multi-cylinder rotary compressor according to claim 1, wherein the compression mechanism section performs a constant compression operation. In the compression mechanism part that performs the constant compression operation and the compression mechanism part that can perform the cylinder resting operation, the size of the discharge passage is set as follows:
Compression mechanism section capable of idle cylinder operation> The multi-cylinder rotary compressor according to claim 1, wherein the compression mechanism section performs a constant compression operation. In the compression mechanism portion that performs the compression operation at all times and the compression mechanism portion that can perform the idle cylinder operation, the spring constant of the discharge valve that constitutes the discharge valve device,
Compression mechanism section capable of idle cylinder operation> The multi-cylinder rotary compressor according to claim 1, wherein the compression mechanism section performs a constant compression operation.

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