JPH051678A - Synchronously rotating scroll compressor - Google Patents

Abstract

PURPOSE:To operate a compressor in a wide range from high to low revolution by allowing the insides of paired motor shafts rotating paired scrolls to be the flow paths of operating fluid, and thereby automatically changing cooling capacity in response to the load of the motors. CONSTITUTION:A first rotating scroll 35a and a second rotating scroll 35b start rotating with a first and second motor rotor 32a and 32b rotated. This constitution thereby allows operating fluid to come in a suction space 50 through a suction port 37, and furthermore, allows operating fluid to pass through suction passages 38a and 38b formed out of scroll laps so as to be compressed while being turned out to be high pressure gas. Pressurized gas is discharged out of both of discharge ports 39a and 39b, so that fluid comes to spaces 41a and 41b within hermetic casings 30a and 3Ob through the through holes 4Oa and 4Ob of motor shafts 33a and 33b. Furthermore, fluid passes through operating sections 65a and 65b provided for bearing support plates 52a and 52b, and also through a plural number of flow paths 66a and 66b so as to be discharged outside out of discharge pipes 42a and 42b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a structure in which a pair of scroll members rotate together, and a motor is connected to each scroll member, and the scroll operation is performed by synchronously rotating the two motors. The present invention relates to a scroll compressor that compresses gas in a room and is used as a compressor for refrigeration, air conditioning, or general use.

[0002]

2. Description of the Related Art A conventional scroll compressor related to the present invention is disclosed in, for example, Japanese Patent Laid-Open No. 61-200391.
JP-A-1-200083 and JP-A-2-14978
No. 3, for example.

Of these, JP-A-61-200391 discloses a fixed scroll 1, an orbiting scroll 2, as shown in FIGS.
1 illustrates a vertically-installed scroll compressor including a rotary shaft 3 with a crankshaft, a casing, and the like. FIG. 4 and FIG. 5 are shown by dividing the main part into a partial cross-sectional view around the upper part of the rotary shaft 3 and a partial cross-sectional view around the lower part of the rotary shaft 3, which are shown in FIGS. 4 and 5. A motor (not shown) is arranged between the partial cross-sectional views. The inside of the rotary shaft 3 also serving as a motor shaft is hollow, and a cylindrical member 4 is further arranged in the hollow portion to form a double cylindrical space, and a metal fitting 5 having a cooling water 6 inlet / outlet on the lower end side of the rotary shaft 3 Place
The motor and the like are cooled by flowing the cooling water 6 so as to reciprocate in the double cylindrical space.

FIG. 6 shows a scroll compressor described in JP-A-1-200083. In this scroll compressor, a pair of scroll members 7 and 8 in a casing C are connected to motor shafts 9 and 10 which are rotatably supported in the casing C, respectively. It is adapted to be driven by the motor 11 and the second motor 12. Sensors 13 and 14 for detecting the rotation status of the two rotary shafts 9 and 10 are provided, and a third sensor is provided to reduce the rotational phase difference between both rotary shafts 9 and 10 based on the signals obtained by the sensors. A control device 16 for driving the motor 15 and the third motor 15 is provided. The space 17 in the casing C is a suction chamber, and the motor shaft 9 on one side is hollow and constitutes a discharge passage 18 having a discharge hole 18 ′ partially. The gas that has entered the casing C as indicated by the arrow A is sucked from the outer peripheral portion of the scroll and compressed toward the center, and the gas that has become high pressure has the motor shaft 9
It is configured to be discharged to the outside of the machine as shown by an arrow B through the inner flow path 18 and the discharge hole 18 '.

Next, FIG. 7 shows a scroll compressor described in JP-A-2-14983. In this scroll compressor, the pair of scroll members 7 and 8 are configured to be rotatable, one scroll 8 is connected to the motor shaft 19, and the other scroll 7 is connected to the holder 2
It is rotatably supported by 0. The rotation of the scroll 8 driven by the motor shaft 19 causes the Oldham mechanism 2 to rotate.
The other scroll 7 is also rotated via 0 '. The compression mechanism portion including the scroll members 7 and 8 and the motor 21 are integrally housed together with the lubricating oil 43 in the closed casing 22, and the lower space housing the motor 21 is a suction chamber space 23. Has become
The opposite space partitioned by the holder 20, the frame 25, etc. is the discharge chamber space 24. A frame 25 that rotatably supports the motor shaft has a flow path 25 ′ for suction gas, which communicates with a suction space 29 on the outer peripheral portion of the scroll. A rotary shaft 26 having a discharge flow path at the center of the other scroll member 7
This discharge flow path is open to the discharge space 24 at the end of the rotary shaft 26. The rotary shaft 26 is supported by the holder 20. Between the holder 20 and the other scroll member 7, there is a back pressure space 27 that guides and seals the discharge gas from the discharge space 24, and the gas force therein causes a back pressure space 27 inside the compression working chamber formed by both scroll members. It is designed to balance thrust gas power. The back pressure space 27
The suction space 29 outside the space is sealed by a protrusion 28 provided on the holder 20.

[0006]

Since the above-mentioned conventional scroll compressor is constructed as described above, there are some problems as described below. For example, JP-A-61-200
According to the technique described in Japanese Patent No. 391, the cooling water 6 different from the working gas is caused to flow from the inside of the double cylindrical portion 4 penetrating the inside of the motor shaft 3 to flow outside the double cylindrical portion 4. Since it is configured to return, the motor can be effectively cooled from the inside under normal operating conditions. However, in order to always keep the motor temperature in a suitable state even when the load state changes drastically, an opening / closing valve such as a throttle valve is provided in the cooling water pipe to adjust its opening to the load, although not shown. There is a problem that it is necessary to control the amount of cooling water by opening and closing by opening and closing. In this way, the cooling water flow rate is controlled according to the load condition to keep the motor temperature in a good condition at all times.
That is, the above-mentioned prior art does not give sufficient consideration to automatically changing the cooling capacity of the motor according to the load condition and further cooling the motor with the working gas flowing in the scroll wrap.

Further, according to the technique described in Japanese Patent Laid-Open No. 1-208383, there is disclosed a structure of a discharge flow passage in a scroll compressor for rotating a pair of scrolls. In this case, however, one discharge flow passage is provided. It is formed only on the motor shaft 9, and is not configured to penetrate the entire length of the motor shaft. Therefore, the motor cannot be cooled by the working gas, and sufficient consideration is not given to cooling the motor when the load on the motor changes. Further, a reaction force due to the flow of high-pressure discharge gas acts on one motor shaft 9 on one scroll side, but a dynamic reaction force is generated because the other motor shaft does not have a passage. do not do. Therefore, thrust forces having different magnitudes act on the scrolls 7 and 8. As a result, the scroll member receives a thrust force on the tip end surface of the wrap. In such a state, if both scrolls are rotated synchronously at high speed, power loss due to friction will occur, and the laps will burn and become inoperable.
The balance of thrust force is a problem for high speed operation.
However, the above-mentioned publicly known example does not particularly mention that the thrust forces acting on the scrolls are balanced to rotate both scrolls synchronously at high speed.

Further, according to the technique disclosed in Japanese Patent Application Laid-Open No. 2-149783, in a scroll compressor in which both scrolls are rotated by one motor, a through hole is provided in the shaft of one scroll, and it further acts on the scroll. Techniques for balancing thrust forces are shown. That is, in order to obtain this thrust force, the back pressure space 27 is provided between the scroll 7 and the holder 20, and the discharge gas is introduced therein. However, back pressure space 2
Since 7 has a constant area and the pressure there is the discharge pressure, only a constant thrust force acts on the scroll 7. Therefore, if only the suction pressure changes and the thrust force in the compression chamber changes, the balance with the pressure in the back pressure space is lost, so there is a slight problem in that a suitable thrust force is always obtained. Furthermore, the back pressure space 27
In order to configure the above, the seal portion 28 is arranged on the rear surface of the end plate of the rotary scroll 7 so as to be separated from the suction pressure of the outer peripheral portion. However, since this sealing is performed between the scroll 7 that is the rotating member and the holder 20 that is the stationary member, gas leakage cannot be avoided. Since the leaked gas mixes with the suction gas, the flow rate of the suction gas is reduced and the performance of the compressor is deteriorated. On the contrary, in order to reduce the amount of leaked gas, it is necessary to increase the contact pressure of the seal portion 28, but the friction loss increases as the rotation speed increases due to the friction loss due to sliding, and the performance of the compressor deteriorates. There is a problem that occurs. Further, in this known example, one scroll is rotated by the motor and the other scroll is rotated by the Oldham mechanism 20 'arranged in a sandwich shape by the scroll members, so that the suction pressure is changed and the Oldham mechanism 20' is changed. There was a problem that friction loss increases when thrust force acts.

The present invention has been made to solve the various problems described above, and in a synchronous rotary scroll compressor in which two scrolls are rotated by two motors, cooling of the motors is performed according to the load state. The purpose is to automatically and properly achieve by working gas. Further, in a synchronous rotary scroll compressor that rotates each scroll by two motors, it is an object to always balance the thrust force acting on the scroll to achieve high-speed rotation with little mechanical loss. is there. Another object of the present invention is to obtain a synchronous rotary scroll compressor having a simple structure, a small size, a light weight, a small flow path resistance of discharge gas, high efficiency and low vibration even at high speed rotation.

[0010]

To achieve the above object, the synchronous rotary scroll compressor of the present invention has the structural features described in each of the claims.

[0011]

The first and second rotary scrolls are respectively the first
And by the second motor shaft, they are made to rotate in the same direction and at the same rotation speed in a state where they are eccentrically engaged with each other,
Thereby, the gas sucked from the outer peripheral portion of the scroll is moved to the central portion while being compressed in the compression working chamber formed between the wraps of both scrolls. Discharge is performed from the discharge hole of the portion, or in the case of the second aspect, from the discharge hole of the central portion of the first rotary scroll. The gas is sucked into the outer peripheral portion of the scroll through the suction flow passage formed in the outer peripheral portions of both rotating scrolls in the structure of claim 1, and in the second motor shaft in the structure of claim 2. It is performed from the through hole through the radial communication hole in the end plate of the second rotary scroll. In the structure of claim 1, the gas discharged from the discharge holes at the central portions of the both rotary scrolls is discharged to the outside of the machine through the through holes in the first and second motor shafts.
In the above configuration, the gas discharged from the discharge port at the center of the first rotary scroll is discharged to the outside of the machine through the through hole in the first motor shaft. In any case, the working gas flowing in these motor shafts provides a motor cooling effect commensurate with the load condition. The same thrust force acts on both motor shafts and rotary scrolls, and they are not pressed in one direction.

[0012]

First Embodiment of the Synchronous Rotary Scroll Compressor of the Present Invention
The embodiment has the configuration shown in FIG. That is, the first rotating scroll 35a and the second rotating scroll 35b are provided with the discharge ports 39a and 39b respectively at the center portions of the end plates, and the first rotating scroll 35a and the second rotating scroll 35a and the second rotating scroll 35b are opposed to the discharge ports 39a and 39b. The straight first motor shaft 33a and the second motor shaft 33b for rotating the respective rotary scrolls 35b are supported and arranged by respective bearings 53a, 53b and bearings 54a, 54b, and one end of each is sealed casing 30a. , The space 41 in 30b
a, 41b. Then, the motor shaft 33
Through holes 40a and 40b are provided in a and 33b,
The discharge ports 39a and 39b and the spaces 41a and 41b are configured to communicate with each other through the through holes 40a and 40b. Working fluid discharge pipes 42a and 42b are provided in the closed casings 30a and 30b, and an intake port 37 is provided in the central portion of the closed casing. In addition, a plurality of suction passages 3 are provided on the circumference of the convex portions of the outer peripheral portions 64a and 64b of the support plates 34a and 34b of the first and second rotary scrolls.
8a and 38b are provided so that the suction port 37 and the compression working chamber of the scroll communicate with each other. Both the first rotary scroll 35a and the second rotary scroll 35b are supported by mechanical dynamic pressure type thrust bearings 36a and 36b.

The synchronous rotary scroll compressor shown in FIG. 1 operates as follows. As the first and second motor rotors 32a and 32b rotate, both the first rotary scroll 35a and the second rotary scroll 35b rotate. As a result, the working fluid enters the suction pressure space 50 through the suction port 37, and further, the suction flow paths 38a, 3
It is compressed into a high pressure gas through a compression working chamber composed of a scroll wrap through 8b. High pressure gas is
The space 41 in the closed casing 30a, 30b is discharged from both the discharge ports 39a, 39b and passes through the through holes 40a, 40b in the respective motor shafts 33a, 33b.
a, 41b, and the discharge pipes 42a, 4b through the openings 65a, 65b provided in the bearing support plates 52a, 52b and the plurality of flow paths 66a, 66b provided in the outer peripheral portion of the motor.
It is discharged from 2b to the outside of the aircraft. In addition, the discharged gas having a high pressure is used for the space 41a in the closed casings 30a, 30b.
While flowing from 41b to the discharge pipes 42a, 42b, it radiates heat to the outside and cools the motor stators 31a, 31b and the motor rotors 32a, 32b. In addition, the discharge hole 39
Since the high-pressure gas discharged from a and 39b both give thrust forces of the same level to the rotary scrolls 35a and 35b, respectively, the first rotary scroll 35a and the second rotary scrolls 35a and 35b are opposed to the thrust force generated in the compression working chamber. Smooth the movement of the rotary scroll 35b.

The structure and operation of the synchronous rotary scroll compressor shown in FIG. 1 will be described in more detail below. Figure 1
, 30a, 30b are closed casings, 31a,
31b is a stator of the first motor and the second motor, 32a and 32b are rotors of the first motor and the second motor, respectively, and 45a and 45b are side casings having hermetic terminals 59a and 59b, respectively. Are respectively fixed to the closed casings 30a and 30b by fastening means such as bolts. Hermetic terminals 59a, 59
b is electrically connected to the windings of the stators of the first motor and the second motor, respectively, so that power can be supplied from the outside. The closed casing is separated from the inside by a closed space 44a, 44b.
Are provided, and the fins 57 are arranged inside thereof. Then, the cooling medium flows in through the respective openings 56a and 56b to more effectively cool the heat inside the closed casings 30a and 30b.

Sealed casings 30 arranged in two on the left and right
The a and 30b are connected to each other by fastening means such as bolts outside the rotary scrolls 35a and 35b. The closed casings 30a and 30b have almost the same structure except that the structure near the coupling portion is different. 33a,
33b are motor shafts of the first motor and the second motor, respectively, which are integrated with the respective motor rotors 32a, 32b by a coupling means such as shrink fitting. This motor shaft 3
One end of 3a, 33b is rotatably supported by bearings 53a, 53b fixed to bearing support plates 52a, 52b, and the other end is a slide bearing 54a, 54b fixed to the center of the hermetic casings 30a, 30b. Is rotatably supported by a cylindrical boss portion formed at the center of the scroll support plates 34a and 34b. Further, the motor shafts 33a and 33b have through holes 40a and 40b inside thereof.
And balance rings 55a, 55b, 55c and 55d for balancing the dynamics of the motor shafts are provided near both end surfaces of the motor rotors 32a and 32b. Motor shafts 33a and 33b and scroll support plates 34a and 34
b is connected by a spline joint or the like so that the rotational torques of the motor shafts 33a and 33b can be sufficiently transmitted to the disc-shaped scroll support plates 34a and 34b, respectively. The outer peripheral surface of the cylindrical boss portion formed on the motor side in the central portion of the scroll support plates 34a and 34b has the sliding bearing 5
It constitutes a sliding surface that faces 4a and 54b.

The outer peripheral portions 64a and 64b of the scroll support plates 34a and 34b constitute convex surface portions, and the convex surface portions of the outer peripheral portion of the other scroll support plate are disposed so as to be substantially in contact with each other in the thrust direction. Also,
A plurality of suction passages 38 are provided in the outer peripheral portions 64a and 64b.
a and 38b are formed in the radial direction. 35a, 35b
Are first and second rotary scrolls having discharge holes 39a and 39b in the center thereof, and are meshed with each other with their spiral wraps inside to form a compression working chamber. The center of the first rotary scroll 35a is aligned with the center of the first motor shaft 33a and is fixed to the first scroll support plate 34a with bolts. The center of the second rotary scroll 35b is the first motor shaft 3
The second motor shaft 33b is eccentric from the center of the third motor 3a by a certain distance, and is aligned with the center of the second motor shaft 33b and is fixed to the second scroll support plate 34b by bolts. As a result, the pair of scrolls 35a and 35b are eccentric to each other and can rotate in the same direction as the motor shafts 33a and 33b rotate. 51a, 5
Reference numeral 1b denotes a rotational phase compensating means, which is not shown in detail, but one rotary scroll is provided with a pair of stoppers at a position deviated to one side from the center thereof (a gap between the stoppers is an allowable width of the rotational phase difference) A protrusion provided at a position deviated from the center of the other rotary scroll is inserted between the pair of stoppers, and the first rotary scroll 35a and the second rotary scroll 35b of the first rotary scroll 35a and the second rotary scroll 35b are operated while the compressor is operating. It has a function of always regulating the rotational phase difference within a certain range.

While the compressor is in operation, a thrust force is generated in each scroll 35a, 35b due to the gas compression. Since the thrust force is received, each scroll support plate 34a,
Thrust bearings 36a and 36b are arranged in the casings 30a and 30b so as to face the back surface of the casing 34b. As the thrust bearings 36a and 36b, an annular flat plate having an oil film or a so-called dynamic pressure type groove bearing capable of generating dynamic pressure by rotation of a mating member can be used. Sealing elements 48a and 48b are formed on the back surfaces of the outer peripheral portions of the scroll support plates 34a and 34b, and the high pressure gas and the lubricating oil filled in the hermetic casing are radial bearings 54a and 54b and thrust bearings 36.
Leakage to the suction pressure space 50 side through a and 36b is prevented.

Next, the operation of the scroll compressor shown in FIG. 1 will be described. By receiving power from the hermetic terminals 59a and 59b, the stator 31a and the rotor 3
The first motor composed of 2a and the second motor composed of the stator 31b and the rotor 32b rotate simultaneously. As a result, the first rotary scroll 35a and the second rotary scroll 35a
The rotary scroll 35b rotates synchronously. With this,
Intake port 37 in which refrigerant gas is provided in a closed casing
To the suction pressure space 50, and further to the suction passages 38a, 3 provided in the scroll support plates 34a, 34b.
It is taken into the compression working chamber through 8b, and the pressure is increased as it moves toward the center. The high-pressure gas is discharged from the discharge holes 39a, 39b into the spaces 41a, 41b in the closed casings 30a, 30b through the through holes 40a, 40b provided in the motor shafts 33a, 33b. Then, when the gas fills the spaces 41a and 41b, the openings 65a provided in the bearing support plates 52a and 52b,
65b and a plurality of flow paths 66 provided on the outer peripheral portion of the motor
It is discharged from the discharge pipes 42a and 42b to the outside of the machine through a and 66b. When a rotational phase difference is generated between the two motors during compression operation and becomes larger than the allowable value, the rotational phase compensating means 51a and 51b function to maintain the rotational phase difference correctly, and thus the radial direction between the scroll wraps. The gap is properly maintained. In addition, the thrust bearing 36
Since a and 36b function and force acts so as to overcome the thrust gas force in the compression working chamber and bring the scroll wraps closer to each other, the axial gap between the scroll wraps is always kept small. Since the cooling medium is flowing inside the peripheral closed space 44 provided as a partition from the closed casings 30a and 30b, the heat generated by the motor is appropriately absorbed to effectively cool the entire compressor. . Balance ring 55
a and 55b are provided in order to balance the dynamics of the rotation systems such as the motor shafts 33a and 33b, and the unbalanced amount obtained by the rotation balance tester before assembling should be scraped off on this ring surface. You can

According to this embodiment, both motor shafts 33
Since the discharge gas passages 40a and 40b are formed in a and 33b, the load is increased and the heat generation amount of the motor is increased by increasing the rotation speed of the compressor, but the discharge gas flow rate is also increased. The cooling capacity as gas also increases, and as a result, the temperature of the motor can be kept substantially constant. In this way, the cooling capacity of the motor also changes depending on various operating conditions, so that the so-called discharge gas can have so-called self-controllability for cooling the motor. In addition, the motor shafts 33a, 33b
Since the same thrust force acts on the scroll members 35a and 35b, the scroll members 35a and 35b have the same thrust force.
Since the 5b is not pressed in one direction, the tip of the scroll wrap and the bottom of the wrap do not come into strong contact with each other. Further, since the motor shafts 33a and 33b have no crank portion, centrifugal force due to the eccentric mass does not act. Therefore, since the bearing load is also reduced and the mechanical friction loss can be kept small, the performance of the compressor as a whole can be kept high even at high speed rotation. Most of the motions of the moving parts are rotary motions centering on the rotation center of the motor, and since there are no reciprocating motion parts, low vibration can be achieved even at high speed operation. Further, since the discharge flow paths 40a and 40b are provided in both motor shafts,
Since it is possible to provide a sufficient flow passage area as compared with the discharge gas amount, the gas flow resistance is reduced. However,
Although not shown, the discharge gas passage may be formed in only one motor shaft without being formed in both motor shafts. In this case, on the closed casing side where the discharge flow path is not formed in the motor shaft, it is necessary to flow more cooling medium into the surrounding closed space 44a (or 44b).

FIG. 2 shows a second embodiment of the synchronous rotary scroll compressor of the present invention. In this embodiment, as shown in FIG. 2, the discharge port 3 is provided at the center of the end plate of the first rotary scroll 35a.
9 is provided, and the discharge port 39 is configured to communicate with the through hole 40a formed in the first motor shaft 33a. The discharge port is not provided in the second rotary scroll 35b, the working fluid flow passages 60 are radially provided in the end plate, and the central portion thereof is formed with the through hole 40b provided in the second motor shaft 33b. It is configured to communicate. Further, the other opening end of the flow path 60 of the working fluid provided in the end plate of the second rotary scroll 35b is provided with the convex portions of the outer peripheral portions 64a, 64b of the end plates of the first and second rotary scrolls 35a, 35b. It is configured to communicate with the suction chamber 61 configured by a scroll wrap. Furthermore, the closed casings 30a, 30
In b, pipes 42a and 67 communicating with the outside of the machine are provided. The pipe 67 is a suction pipe, and the second closed casing 3
The internal space of 0b is the suction pressure. The pipe 42 is a discharge pipe, and the internal space of the first closed casing 30a has a discharge pressure. The first rotary scroll 35a and the second
The rotary scroll 35b of the rotary scroll 35b allows the gas in the middle of compression inside the compression working chamber to be compressed in the annular intermediate pressure chambers 62a, 62a on the respective back surfaces.
It is supported by a thrust receiver of the type in which it is guided to b and received by gas pressure.

Next, the operation of the synchronous rotary scroll compressor of the type shown in FIG. 2 will be described. In this scroll compressor, the space 70 in the second closed casing 30b serves as a suction pressure space, and the suction gas entering from the suction pipe 67 passes through the opening 69 of the motor support plate 52b, and then the second suction
Through the through hole 71 in the motor shaft 33b, the radial flow passage 60 provided in the end plate of the second rotary scroll 35b, and is sucked into the suction chamber 61. The gas in the suction chamber 61 is further taken into the compression working chamber and compressed to a predetermined pressure. The high-pressure gas is discharged from the discharge hole 39, passes through the through hole 40 in the first motor shaft 33a, and is discharged into the space 41 in the first closed casing 30a. The gas in the space 41 is the bearing support plate 52a.
The gas is discharged from the discharge pipe 42 to the outside of the machine through an opening 65 provided in the air passage and a plurality of flow paths 66 provided in the outer peripheral portion of the first motor. As described above, in the second embodiment, the through hole 71 in the second motor shaft 33b serves as an intake passage, while the first hole
The through hole 40 in the motor shaft 33a serves as a discharge flow path. Therefore, the second motors (31b, 32b) and the second motor shaft 33 arranged in the second closed casing 30b.
b, the second rotary scroll 35b, etc. are suitably cooled by the suction gas. Also, the first closed casing 30a
Since the members arranged inside are cooled by the high-pressure discharge gas as in the cooling state shown in FIG. 1, the temperature level has no practical problem. Both rotating scrolls 35a, 3
Gas in the middle of compression is filled in the annular intermediate pressure chambers 62a and 62b by the communication holes 63a and 63b provided in the end plate of 5b, so that the first rotary scroll 35a and the second rotary scroll 35b are compressed by this gas pressure. A thrust force that opposes the gas force in the working chamber can be received. Further, since the space 80 formed outside the both rotary scrolls 35a and 35b also forms a closed space in an annular shape, the pressure is promptly balanced by the leak gas from the annular spaces (intermediate pressure chambers) 62a and 62b. Therefore, it is not necessary to provide a sealing means on the rear surface of the end plate.

The structure and operation of the second embodiment will be described in more detail with reference to FIG. The following description focuses on the parts that differ from the first embodiment. Reference numerals 30a and 30b denote closed casings in which two motors are arranged as in the first embodiment. First rotating scroll 3
5a and the second rotary scroll 35b form a shaft portion that is combined with the main bearings 54a and 54b on the side opposite to the surface on which the wrap is formed. The inner side of the shaft portion is combined with one end of each of the motor shafts 33a and 33b, and is associated with each motor shaft so that the rotational torque of each motor can be transmitted to each scroll. I am fit. Although not shown, rotation phase compensating means similar to those shown in FIG. 1 are engaged with each other on the scroll wrap side, and the two motors rotate in the same direction and the first and second motors rotate. The rotary scrolls 35a and 35b can also rotate in synchronization with each other. Annular protrusions 64a and 64b are formed on the outer peripheral portions of the rotary scrolls 35a and 35b.
The a and 64b are lightly contacted with each other and assembled so as to be slidable. The space 80 formed outside the rotary scrolls 35a and 35b is formed by the convex portions 64a and 64b.
It is isolated from the suction chamber 61 formed inside the scroll. The second rotary scroll 35b has a radial flow path 60 formed inside the end plate thereof, and communicates with a through hole 40b provided in the second motor shaft 33b at the center of the second rotary scroll 35b. There is. The other end of the flow path 60 is
It communicates with a suction chamber 61 formed inside the rotary scrolls 35a and 35b. First rotary scroll 35a
Has a discharge hole 39 formed in the center thereof, and the discharge hole 39 is provided in the first motor shaft 33a through the through hole 40.
It is arranged to communicate with. Further, intermediate pressure chambers 62a and 62b formed in a ring shape are provided on the back surfaces of both the rotary scrolls 35a and 35b.
A plurality of communication holes 63 provided on the end plates 5a and 35b
The compression working chamber and the intermediate pressure chambers 62a, 6 by a and 63b.
It communicates with 2b.

Next, the operation of the embodiment shown in FIG. 2 will be described. When the respective motors receive electric power from the outside through the hermetic terminals 59a and 59b, the motor shaft 3
3a and 33b rotate in the same direction. Then, in synchronization with this, the first rotary scroll 35a and the second rotary scroll 35b also rotate. These rotary scrolls 35
As a and 35b rotate, the working gas enters the space 70 in the second closed casing 30b from the suction pipe 67 and is filled therewith. Further, the gas is the shaft 33b of the second motor.
It reaches the back surface of the second rotary scroll 35b through a through hole 71 therein, flows into the suction chamber 61 from the radial flow passage 60 in the end plate of the second rotary scroll 35b, and is taken into the compression working chamber. The compression working chamber includes a rotary scroll 35a,
As the volume of the gas 35 is reduced and the volume of the gas is moved to the center of the motor 35b, the working gas is pressurized and discharged from the discharge hole 39 to the through hole 40 in the first motor shaft 33a. The high-pressure gas fills the space 41 in the first closed casing 30a and is finally discharged to the outside of the machine through the discharge pipe 42. Further, the intermediate pressure chambers 62a and 62b formed in the annular shape on the back surfaces of the first rotary scroll 35a and the second rotary scroll 35b are filled with gas in the compression working chamber by the communication holes 63a and 63b. The gas leaked from the annular intermediate pressure chambers 62a and 62b is stored in the outer space 8
However, since the pressure levels of the intermediate pressure chambers 62a and 62b and the space 80 become equal, the gas level is eliminated and the pressure level is stabilized. Furthermore, the first rotary scroll 35a and the second rotary scroll 35
It is not necessary to provide a seal member on the back surface of b, and the structure is simple. The pressure of the gas in the intermediate pressure chambers 62a and 62b is
The pressure level is between the suction pressure and the discharge pressure,
A force capable of counteracting the thrust load acting in the compression working chamber can be generated. Therefore, strong contact with the mating members (casing 30a, 30b) is prevented at the back surface of the rotary scroll, so that a smooth rotary motion can be achieved. Further, according to the present embodiment, the inside of the second closed casing 30b serves as an intake gas space, so that the members arranged inside the second closed casing 30b are appropriately cooled by the gas. In particular, the second rotary scroll 3
Since the suction gas flows on the back surface of 5b, the main bearing portion of the scroll, which is difficult to cool by the conventional structure as well as the second motor, can be cooled very effectively.

FIG. 3 shows a third embodiment of the synchronous rotary scroll compressor of the present invention. This embodiment has a basic configuration similar to that of the first embodiment, but as shown in FIG. 3, the pressure in the first closed casing 30a and the pressure in the second closed casing 30b are adjusted to each other. In order to balance the space 76a in the first closed casing 30a and the space 76b in the second closed casing 30b, a communication hole (pressure equalizing hole) 78 is formed between the closed casing (30a, 30b) and the frame. It is provided between (77a, 77b). Similarly, regarding the oil level, an oil leveling hole 79 is provided in the outer peripheral portion of the frame to balance the left and right casings. The pressure-equalizing hole 78 allows the first closed casing 30a.
Since the internal pressure and the internal pressure of the second closed casing 30b are equal, the thrust forces due to the high-pressure gas acting on the first rotary scroll 35a and the second rotary scroll 35b are equal.

The third embodiment will be described in more detail with reference to FIG. This figure also shows a cross section of the synchronous rotary scroll compressor. The following description will focus on the points different from the first embodiment. From the center of the closed casing (30a, 30b) to the frames 77a, 77
b is fixed, and a first rotary scroll 35a and a second rotary scroll 35b are arranged so as to be sandwiched and rotatable with respect to these frames. At multiple locations on the outer periphery of the frames 77a and 77b,
A pressure equalizing hole 78 for communicating the discharge spaces 76a and 76b in the closed casing, and an oil leveling hole 79 for balancing the oil surfaces of the lubricating oils 43a and 43b are provided. The motor shafts 33a, 33b include bearings 54a, 54b and bearing support plates 52a, 5 provided at the central portions of the frames 77a, 77b.
It is rotatably supported by bearings 53a and 53b fixed to 2b, and through holes 40a and 40b are formed therein, respectively. Further, the motor shafts 33a and 33b are provided with flow passages 75a and 75b, respectively, which intersect the through holes 40a and 40b and extend in the radial direction on the way. The flow paths 75a and 75b are formed by the motor and the frame 77, respectively.
The discharge spaces 76a and 76b between the a and 77b are opened. Although not shown, the motor stators 31a and 31b and the closed casings 30a and 30
A communication groove extending in the axial direction is formed between the groove and b.
The discharge pipes 42a and 42b are provided open to the spaces 41a and 41b on the end surface side of the motor shaft. An intake port 27 that communicates with the space between the frames 77a and 77b is provided so as to penetrate the casing and the frame.

Next, the operation of the embodiment shown in FIG. 3 will be described. As the first and second rotary scrolls 35a and 35b rotate while meshing with each other, the refrigerant gas flows from the suction port 37 through the suction flow passage 38 into the compression working chamber. The gas compressed in the compression working chamber is discharged through the discharge hole 3
9a, 39b to the through hole 4 in the motor shaft 33a, 33b
It is discharged through the spaces 0a and 40b into the spaces 41a and 41b in the closed casings 30a and 30b. At this time, gas is also discharged to the discharge spaces 76a and 76b from the radial flow paths 75a and 75b that cross the through holes 40a and 40b. However, since the centrifugal force that accompanies the rotation of the shaft acts on the fluid in the flow paths 75a and 75b, the lubricating oil mixed with the suction gas is efficiently separated from the gas by the flow paths 75a and 75b. . Therefore, the discharge spaces 76a and 76b are filled with discharge gas rich in oil. The filled gas further separates oil in the spaces 76a and 76b, and reaches the spaces 41a and 41b through the gap between the stator and the rotor of the motor and the communication groove provided in the outer peripheral portion of the stator. here,
It merges with the other discharge gas flowing straight through the through holes 40a, 40b, and together, the discharge pipes 42a, 4 respectively.
It is discharged from the machine 2b. During this time, the motor is effectively cooled by the high pressure refrigerant gas from the inside of the shaft and its surface. Further, since the gas pressures in the spaces inside the closed casings 30a and 30b are sufficiently equalized by providing the pressure equalizing holes 78, the first rotating scroll 35a and the second rotating scroll 35a are rotated via the motor shafts 33a and 33b, respectively. Scroll 35
The thrust force of the gas acting on b is almost the same on the left and right. Thus, no imbalance due to gas force occurs in the first and second rotary scrolls, so that high-speed operation can be achieved very smoothly. Further, since the oil equalizing pipe 79 is provided so as to communicate with the lubricating oil, the amounts of the left and right lubricating oils 43a and 43b are always the same, and the oil supply conditions from the oil supply holes 58a and 58b to the bearing surface are always the same. Get better

[0027]

According to the present invention, a through hole is provided in a pair of motor shafts for rotating a pair of scrolls, and a working fluid flow path is provided in the through hole. The cooling capacity of the motor can be changed automatically, and the motor can be operated in a wide range from low speed rotation to high speed rotation under constant temperature conditions. Further, since the refrigerant gas flows in the motor shaft, it is possible to suitably cool the main bearing or members in the vicinity thereof, which has been a problem in the prior art. Further, since the same thrust force acts on both the motor shafts and the rotary scroll members, the pair of rotary scroll members are not pressed in one direction. There is no contact, and mechanical loss due to friction does not increase even when operating at a very high rotational speed, and high-speed operation can be achieved with high performance. Further, by configuring as in the present invention, it is possible to combine the entire compressor as a synchronous rotary compressor with a simple structure and in a compact and lightweight manner. Furthermore, since the space inside the closed casing can be effectively used as a space for oil separation, the oil separation efficiency is improved, and the amount of lubricating oil taken out of the machine due to the flow of discharge gas can be minimized. it can. Furthermore, a straight motor shaft is used so that both rotary scroll members rotate synchronously, and each rotary member has a center of gravity on the rotation axis and is a complete rotation type centered on this axis. There is no eccentric member like the crankshaft, and there is no imbalance due to rotation. Therefore, high-speed rotation can be achieved with low vibration. Further, since the rotating shaft does not need the balance weight as in the conventional crankshaft, the centrifugal force caused by the balance weight does not act on the bearing, and the load acting on the bearing and the sliding portion is reduced. Further, the rotation preventing means for the orbiting scroll, which has been conventionally required, becomes unnecessary. In this way, the load is reduced and the number of parts can be reduced, so that the performance of the compressor as a whole is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view showing the upper part of the main part of the prior art.

FIG. 5 is a vertical cross-sectional view showing the lower part of the main part of the prior art.

FIG. 6 is a vertical sectional view showing another conventional technique.

FIG. 7 is a longitudinal sectional view showing still another conventional technique.

[Explanation of symbols]

30a, 30b ... Hermetically sealed casings 31a, 32a ... First motor stator and rotor 31b, 32b ... Second motor stator and rotor 33a ... First motor shaft 33b ... Second motor shaft 35a ... First rotation Scroll 35b ... Second rotary scroll 36a, 36b ... Thrust receiver 37 ... Suction port 39, 39a, 39b ... Discharge hole 40, 40a, 4
0b, 71 ... Through holes 42, 42a, 42b ... Discharge pipes 43a, 43b ...
Lubricating oil 50 ... Suction pressure space 52a, 52b ...
Bearing support plates 53a, 53b ... Rolling bearings 54a, 54b ...
Plain bearings 55a to 55d ... Balance rings 57a, 57b ...
Fins 60 ... Radial flow path 61 ... Suction chambers 62a, 62b ... Annular intermediate pressure chambers 63a, 63b ...
Communication hole 67 ... Suction piping 75a, 75b ...
Radial discharge passages 77a, 77b ... Frame 78 ... Pressure equalizing hole 79 ... Oil equalizing hole

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazutaka Suto             502 Kintatemachi, Tsuchiura City, Ibaraki Japan             Tate Seisakusho Mechanical Research Center

Claims (5)

[Claims] 1. A first rotary scroll rotated by a motor shaft of a first motor, and a second rotary scroll rotated by a motor shaft of a second motor, each rotary scroll being at the center. It consists of an end plate with a discharge hole in it and an upright spiral wrap, and both rotary scrolls are combined in a state where the spiral wraps are eccentric to each other and the spiral wraps mesh with each other. By rotating the first motor shaft and the second motor shaft in the same rotation speed in the same direction, gas is sucked from the scroll outer peripheral portion, compressed, and discharged from the discharge holes in the central portions of both scrolls. A through hole is provided in each of the motor shafts for rotating the rotary scroll, and the first motor shaft is arranged at the center of the first rotary scroll. The second motor shaft is provided in the center of the second rotary scroll, and the through holes in the respective motor shafts communicate with the discharge holes in the center of the respective rotary scrolls. A synchronous rotary scroll compressor, wherein the through hole in the motor shaft forms a discharge gas flow path. 2. A first rotary scroll rotated by a motor shaft of a first motor and a second rotary scroll rotated by a motor shaft of a second motor, each rotary scroll being an end plate. And the upright spiral wrap. A discharge hole is provided in the center of the end plate of the first rotating scroll, and both rotating scrolls eccentric their rotation axes with respect to each other to mesh the spiral wrap with each other. In this state, both rotary scrolls are respectively rotated by the first motor shaft and the second motor shaft at the same rotational speed in the same direction, so that gas is sucked from the outer peripheral portion of the scroll and compressed to generate the first gas. It is designed to discharge from the discharge hole at the center of the end plate of the rotating scroll, and an axial through hole is provided in each motor shaft that rotates each rotating scroll. , The first motor shaft is arranged so as to face the discharge hole so that the through hole in the first motor shaft communicates with the discharge hole in the central portion of the end plate of the first rotary scroll. A radial communication hole is provided in the end plate of the rotary scroll, one end of which is open to the outer periphery of the scroll and the other end of which is a central part and which is open to the through hole in the second motor shaft, and which drives the second rotary scroll. The through hole in the motor shaft forms an intake gas flow path, and the through hole in the first motor shaft driving the first rotary scroll forms a discharge gas flow path. Synchronous rotary scroll compressor. 3. A first motor and a second motor are housed in respective hermetically sealed spaces in a hermetically sealed casing.
2. The synchronous rotary scroll compressor according to claim 1, further comprising: a communication hole provided in the hermetic casing for communicating the hermetically-sealed space for housing the motor and the hermetically-sealed space for housing the second motor. 4. The synchronous rotary scroll compressor according to claim 1, wherein a mechanical thrust receiver is provided for each rotary scroll to counter the thrust force of the compressed gas that tends to separate the two rotary scrolls. 5. The synchronous rotation according to claim 1, wherein a back pressure space for introducing an intermediate pressure is provided on the back side of each rotary scroll in order to counter the thrust force of the compressed gas that tends to separate the two rotary scrolls. Shaped scroll compressor.