JP2006144578A - Expander-integral type compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve reliability by preventing occurrence of abnormal abrasion and twisting by absorbing shaft deviation in a shaft coupling part for connecting a compressor and an expander in an expander-integral type compressor. <P>SOLUTION: Coupling ends of a drive shaft 45 in a compression part 42 and of a power recovering shaft 46 in an expander part are provided with small diameter parts 45a, 46a. A coil spring 47 of an elastic body is fitted to the small diameter parts 45a, 46a. The drive shaft 45 is coupled with the power recovering shaft 46. By so doing, the shaft deviation in the drive shaft 45 and the power recovering shaft 46 is accommodated by the coil spring 47. The drive shaft 45 and the power recovering shaft 46 are prevented from generating twisting in a bearing. Therefore, the highly reliable expander-integral type compressor can be offered. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an expander-integrated compressor capable of increasing efficiency by transmitting recovered energy in an expander to a compressor in a vapor compression refrigeration cycle used in a refrigerator, an air conditioner, or the like.

Conventionally, an expander-integrated compressor used in a refrigeration cycle is disclosed in Patent Document 1 and the like. As another application, an expander-integrated compressor including an expander driven by a Rankine cycle and a compressor of a refrigeration cycle is disclosed in Patent Document 2 and the like.
The configuration of a conventional expander-integrated compressor will be described with reference to FIGS. FIG. 7 is a configuration diagram of a conventional refrigeration cycle, where (a) is a refrigeration cycle, (b) is a refrigeration cycle using an expander, and (c) is a Mollier diagram of the refrigeration cycle.
The conventional refrigeration cycle of (a) is composed of a compressor 1, a radiator 2, an expansion valve 3, a heat absorber 4, and a motor 1a for driving the compressor 1, and the working fluid of the refrigeration cycle is a compressor. After being compressed to a high pressure by 1 and cooled by the radiator 2, the pressure is reduced by the expansion valve 3 and heated by the heat absorber 4 to normal temperature. This refrigeration cycle is indicated by ABCD on the Mollier diagram of (c), and the working fluid is decompressed with an enthalpy change from C to D by the expansion valve 3, so the energy of the high-pressure working fluid is effective. Could not be used.
On the other hand, in the refrigeration cycle using the expander of (b), the expander 5 is provided instead of the expansion valve 3, and the expander 5 and the compressor 1 are connected by the shaft 6, and in the conventional refrigeration cycle, The working fluid that has been depressurized by the enthalpy change at the expansion valve 3 rotates the expander 5 while the pressure is reduced by adiabatic expansion from the high pressure to the low pressure by the expander 5, and this rotational power drives the compressor 1 together with the motor 1a. To do. This refrigeration cycle is indicated by ABCD 'on the Mollier diagram of (c), and the energy of the motor 1a that drives the compressor by the amount of power recovered in the process of the adiabatic expansion CD' of the expander 5 is obtained. Since the energy that can be absorbed and absorbed by the heat absorber 4, that is, the energy that can be absorbed from the low heat source side of the refrigeration cycle, can be increased from DA to D′ A, the refrigeration cycle Can be made highly efficient. As described above, the expander-integrated compressor is configured by integrating the compressor 1 and the expander 5.
FIG. 8 is a cross-sectional view of a conventional expander-integrated compressor disclosed in Patent Document 1 for use in a refrigeration cycle. This expander-integrated compressor is connected to a compressor unit 11 that compresses the working fluid of the refrigeration cycle, and the compressor unit 11 and the shaft 12, and collects energy for adiabatic expansion of the working fluid of the refrigeration cycle. An expander unit 13 that drives the compressor unit 11 through 12 and a motor 14 that drives the compressor unit 11 through the shaft 12 are provided.
The compressor section 11 of the present expander-integrated compressor is of a so-called rotary type, and is a vane of a cylinder 16, a piston 17, an upper bearing member 18, a lower bearing member 19, and a vane groove (not shown) of the cylinder 16. (Not shown). The compressor unit 11 is fixed to the sealed container 15 by welding the upper bearing member 18 to the sealed container 15. The expander unit 13 is a so-called scroll type, and includes a fixed scroll 20, a turning scroll 21, an Oldham ring 22 that prevents the turning movement of the turning scroll 21, and a frame 23. The expander unit 13 is fixed to the sealed container 15 by welding the frame 23 to the sealed container 15.
The internal space of the sealed container 15 is separated by the frame 23 into a space 24 on the compressor unit 11 side and a space 25 on the expander unit 13 side. The closed vessel 15 includes a suction pipe 26 that supplies a low-pressure working fluid from the refrigeration cycle to the compressor unit 11, and a discharge pipe 27 that returns the high-pressure working fluid to the refrigeration cycle. And an outflow pipe 29 for returning the low-pressure working fluid to the refrigeration cycle.
FIG. 9 is a cross-sectional view of another conventional expander-integrated compressor disclosed in Patent Document 2. In FIG. This expander-integrated compressor includes an expander unit 31 that is driven by a Rankine cycle and a compressor unit 32 that drives the refrigeration cycle, and the refrigeration cycle is driven by the power obtained by the expander unit 31 in the Rankine cycle. The compressor unit 32 is driven. The present expander-integrated compressor is different from the expander-integrated compressor of Patent Document 1 in that the compressor section 32 is driven using the expander section 31 of the Rankine cycle and does not require a motor. However, in other respects, the basic configuration as an expander-integrated compressor is substantially the same.
The expander part 31 of the present expander-integrated compressor is a so-called scroll type, and the compressor part 32 is a so-called two-piston rotary type. The configuration of the expander unit 31 is substantially the same as that of the expander unit 13 of Patent Document 1. Moreover, the structure of the compressor part 32 is also substantially the same as the rotary compressor part 11 of patent document 1 except the point which is a 2 piston type. The shaft 33 of the expander unit 31 and the shaft 34 of the compressor unit 32 are connected via a joint 35.
JP 2003-138901 A Japanese Patent Laid-Open No. 10-266980

In the expander-integrated compressor disclosed in Patent Document 1, the compressor unit 11 and the expander unit 13 are connected by a common shaft 12. Moreover, the compressor part 11 and the expander part 13 are being fixed to the airtight container 15 by welding, respectively. Therefore, as an assembly order of the expander-integrated compressor, first, the compressor unit 11 and the expander unit 13 connected by the shaft 12 are assembled, and then the compressor unit 11 and the expander unit 13 are assembled. Each is fixed to the sealed container 15.
By the way, the shaft 12 is fitted to the upper bearing member 18 and the lower bearing member 19 on the compressor part 11 side, and to the bearings of the frame 23 on the expander part 13 side through a minute clearance. These clearances are usually about several micrometers to several tens of micrometers. In order to realize such a clearance, the relative positions of the compressor unit 11 and the expander unit 13 with respect to the shaft 12 must be within an error equivalent to the clearance.
However, the relative positions of the compressor unit 11 and the expander unit 13 are within several tens of micrometers due to welding positioning errors and thermal deformation caused by welding when welding to the sealed container 15. It is difficult to fit in the error.
Therefore, when the shafts of the compressor unit 11 and the expander unit 13 do not coincide with each other as a result of welding as described above, the shaft 12 is connected to the upper bearing member 18 and the lower bearing member 19 on the compressor unit 11 side. In addition, the bearing installed on the frame 23 of the expander unit 13 is inclined more than the clearance, and abnormal wear occurs due to contact between the shaft 12 and the bearing, or the shaft 12 is twisted by the bearing. The problem of not turning.
In addition, since the common shaft 12 is used in the compressor unit 11 and the expander unit 13, when the compressor unit 11 is assembled first, the compressor unit is connected to the shaft 12 when the expander unit 13 is assembled. The work must be performed in a state in which 11 is assembled, and it is difficult to adjust the clearance of the expander unit 13, resulting in poor workability.
Therefore, in the expander-integrated compressor disclosed in Patent Document 2, the power recovery shaft 33 of the expander unit 31 and the drive shaft 34 of the compressor unit 32 are connected by a joint 35. In this case, since the expander unit 31 and the compressor unit 32 can be separately assembled, the workability in the assembly of the expander unit 31 and the compressor unit 32 does not deteriorate.
Further, if the spline joint is used as the joint 35 and the power recovery shaft 33 and the drive shaft 34 are coupled to transmit power, the expander portion 31 and the compressor portion 32 are welded to the sealed container 35. Even when there is a position error and the axes of the power recovery shaft 33 and the drive shaft 34 do not completely coincide with each other, the joint 35 absorbs the deviation of the axes of the power recovery shaft 33 and the drive shaft 34 within the clearance range of the spline joint. Therefore, no contact or twisting of the power recovery shaft 33 or the drive shaft 34 with respect to the bearing occurs.
However, the clearance of the spline joint is very small, and if the range is exceeded, shaft misalignment cannot be absorbed. Therefore, as in the case of Patent Document 1, the power recovery shaft 33 and the drive shaft 34 and each bearing There arises a problem that abnormal wear occurs due to one piece contact between them, or that the power recovery shaft 33 and the drive shaft 34 are twisted by the bearings and do not rotate. Further, since the expander unit 31 and the compressor unit 32 use a volume type mechanism such as a scroll type or a rotary type, the torque of the power recovery shaft 33 is expanded or compressed while sucking the working fluid intermittently. And the load on the drive shaft 34 is changed. Then, by connecting the power recovery shaft 33 and the drive shaft 34 having different torque and load fluctuation timings via the joint 35, minute sliding occurs due to vibration within the clearance of the joint 35, and the joint 35 is worn due to wear. Reliability has been significantly reduced, such as destruction. At the same time, vibration around the shaft was generated because the timing of the fluctuations differed between the torque of the power recovery shaft 33 and the load of the drive shaft 34.

Therefore, the present invention solves the above-mentioned conventional problems, and can absorb the shaft misalignment at the connecting portion between the drive shaft and the power recovery shaft, and can prevent the occurrence of abnormal wear and twisting. An object is to provide an expander-integrated compressor.
It is another object of the present invention to provide a highly reliable expander-integrated compressor that can absorb fluctuations in load and torque and prevent breakage of a connecting portion.

The expander-integrated compressor according to the first aspect of the present invention includes an expansion chamber and a power recovery shaft, and rotates the power recovery shaft by expanding the working fluid sucked into the expansion chamber from a high pressure to a low pressure. An expander having an expander unit for obtaining power, a compression chamber and a drive shaft, and compressing the working fluid sucked into the compression chamber from a low pressure to a high pressure by rotating the drive shaft. An integrated compressor, wherein the power recovery shaft and the drive shaft are connected via an elastic body.
According to a second aspect of the present invention, in the expander-integrated compressor according to the first aspect, a spring is used as the elastic body.
According to a third aspect of the present invention, in the expander-integrated compressor according to the second aspect, the spring is a coil spring.
According to a fourth aspect of the present invention, in the expander-integrated compressor according to the second aspect, the spring is a torsion bar.
According to a fifth aspect of the present invention, in the expander-integrated compressor according to the first aspect, a resin-based or rubber-based material is used as the elastic body.
According to a sixth aspect of the present invention, in the expander-integrated compressor according to any one of the first, second, and fifth aspects, each connection end provided on the power recovery shaft and the drive shaft. Among them, the elastic body is disposed inside the concave portion provided at any one of the connecting end portions, and the convex portion provided at the other connecting end portion is fitted into the concave portion via the elastic body, The power recovery shaft and the drive shaft are connected.
According to a seventh aspect of the present invention, in the expander-integrated compressor according to any one of the first, second, fifth, and sixth aspects, the elastic modulus of the elastic body is set to the drive shaft or the like. The resonance frequency related to the vibration around the axis is set to be equal to the operation frequency.

As described above, according to the present invention, the elastic body absorbs the shaft misalignment of the power recovery shaft and the drive shaft, prevents abnormal wear and twisting at the connecting portion, and is a highly reliable expander-integrated compressor. Can be provided.
Further, it is possible to provide a highly reliable expander-integrated compressor that absorbs torque and load fluctuations, eliminates the problem of breakage and noise due to vibration of the connecting portion.

The expander-integrated compressor according to the first embodiment of the present invention has an expansion chamber and a power recovery shaft, and rotates the power recovery shaft by expanding the working fluid sucked into the expansion chamber from high pressure to low pressure. An expander integrated type having an expander section for obtaining power, a compression chamber and a drive shaft, and a compressor section for compressing the working fluid sucked into the compression chamber from a low pressure to a high pressure by rotating the drive shaft The power recovery shaft and the drive shaft of the compressor are connected via an elastic body. According to the present embodiment, since the elastic body absorbs the axial deviation of the power recovery shaft and the drive shaft, it is possible to prevent the occurrence of abnormal wear and twisting.
The second embodiment of the present invention uses a spring as an elastic body in the expander-integrated compressor according to the first embodiment. According to the present embodiment, even when the torque to be transmitted is large, the shaft misalignment is absorbed, so that high reliability can be ensured.
In the third embodiment of the present invention, in the expander-integrated compressor according to the second embodiment, the spring is a coil spring. According to the present embodiment, it is possible to obtain a relatively large amount of deflection with a compact configuration, and it is possible to easily absorb the axial deviation.
In the fourth embodiment of the present invention, in the expander-integrated compressor according to the second embodiment, the spring is a torsion bar. According to the present embodiment, it is possible to absorb axial deviation even when the axis is displaced in the axial direction.
In the fifth embodiment of the present invention, the expander-integrated compressor according to the first embodiment uses a resin-based or rubber-based material as the elastic body. According to the present embodiment, an effect of absorbing the misalignment can be obtained and the cost can be reduced.
According to a sixth embodiment of the present invention, in the expander-integrated compressor according to the first, second, and fifth embodiments, any one of the connecting end portions provided on the power recovery shaft and the drive shaft. An elastic body is arranged inside the recess provided in one of the connection ends, and a convex portion provided in the other connection end is fitted into the recess via the elastic body to connect the power recovery shaft and the drive shaft. Is. According to the present embodiment, the elastic body can be formed into a free shape and can be formed with high accuracy, and the assembling property and the shaft misalignment absorbability can be improved and the cost can be reduced.
In the seventh embodiment of the present invention, in the expander-integrated compressor according to the first, second, fifth, and sixth embodiments, the elastic modulus of an elastic body is determined by vibration around an axis such as a drive shaft. The resonance frequency is set to be equal to the operation frequency. According to the present embodiment, the resonance system around the axis centered on the elastic body is generated due to the compressor part and the expander part when the expander-integrated compressor is operated at the rated rotational speed. It acts as a dynamic vibration absorber for surrounding vibrations, preventing destruction due to vibrations and reducing noise.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of an expander-integrated compressor according to a first embodiment of the present invention.
The expander-integrated compressor according to this embodiment includes a compressor unit 42, an expander unit 43, and an electric motor unit 44 inside the sealed container 41.
The sealed container 41 includes a cylindrical shell shell 41a, and an upper shell 41b and a lower shell 41c that are welded so as to close the upper and lower end surfaces thereof. The compressor section 42 is composed of a rotary type compression mechanism section and is driven by a drive shaft 45. The expander unit 43 includes a rotary type expansion mechanism unit, and drives the power recovery shaft 46. Note that the shaft of the power recovery shaft 46 is disposed so as to face the shaft of the drive shaft 45 so as to substantially coincide. The electric motor unit 44 includes a stator 44a and a rotor 44b. The stator 44 a is shrink-fitted to the body shell 41 a, and the rotor 44 b is fixed to the drive shaft 45.
Small-diameter portions 45 a and 46 a are provided at the connection end of the drive shaft 45 and the connection end of the power recovery shaft 46, respectively. And the coil spring 47 which is an elastic body has connected the drive shaft 45 and the power recovery shaft 46 by fitting to the small diameter parts 45a and 46a. The inner diameter of the coil spring 47 is set smaller than the outer diameter of the small diameter portions 45a and 46a so that the coil spring 47 and the small diameter portions 45a and 46a do not slip due to external force. The coil spring 47 is configured to have a sufficiently large elastic modulus in both the axial direction, the rotational direction, and the bending direction so that torque from the power recovery shaft 46 can be transmitted to the drive shaft 45 within a range of elastic deformation.

The operation of the expander-integrated compressor of this embodiment will be described.
In the expander-integrated compressor, the working fluid sucked into the compression chamber 42 a of the compressor unit 42 is compressed from a low pressure to a high pressure by rotating the drive shaft 45 by the electric motor unit 44. This high-pressure working fluid is introduced into the expansion chamber 43a of the expander unit 43 and expanded from a high pressure to a low-pressure working fluid to obtain rotational power to the power recovery shaft 46. Then, this rotational power is transmitted from the power recovery shaft 46 to the drive shaft 45 via the coil spring 47, and the compressor unit 42 is driven, whereby the recovered energy in the expander is used as the driving force of the compressor. .

Next, how to assemble the expander-integrated compressor of this embodiment will be described.
First, the compressor part 42 including the drive shaft 45 and the expander part 43 including the power recovery shaft 46 are assembled so as to satisfy a predetermined clearance in each mechanism part. Next, the rotor 44 b of the electric motor unit 44 is fixed to the drive shaft 45. Further, the stator 44 a of the electric motor unit 44 is shrink-fitted into the trunk shell 41 a of the sealed container 41. The compressor section 42 including the rotor 44b is welded to the shell shell 41a on which the stator 44a is shrink-fitted so that the air gap between the stator 44a and the rotor 44b is constant.
Next, the coil spring 47 is fitted into the small diameter portion 45 a at the end of the drive shaft 46. Then, with respect to the stator 44 a, the expander portion 43 including the power recovery shaft 46 is inserted from the side opposite to the compressor portion 42, and the small diameter portion 46 a at the end of the power recovery shaft 46 is fitted into the coil spring 47. And the expander part 43 is welded to the trunk | drum shell 41a. Finally, the upper shell 41b and the lower shell 41c are welded to the top and bottom of the trunk shell 41a, respectively.

Next, the effect by the above structure is demonstrated.
In the expander-integrated compressor of this embodiment, the drive shaft 45 and the power recovery shaft 46 are connected via the coil spring 47, so that the compressor portion 42 and the expander portion 43 are separately assembled in advance. It is possible. Therefore, assembly becomes easy and cost reduction can be achieved.
Further, since the drive shaft 45 and the power recovery shaft 46 are connected by the coil spring 47, the position where the compressor portion 42 and the expander portion 43 are welded to the shell shell 41a is caused by assembly errors or welding. Even if the drive shaft 45 and the power recovery shaft 46 are not on the same axis due to thermal deformation or the like, the coil spring 47 is deformed to connect the drive shaft 45 and the power recovery shaft 46 in a rotatable state. It becomes possible.
Since the coil spring 47 absorbs the axial deviation of the drive shaft 45 and the power recovery shaft 46, the drive shaft 45 and the power recovery shaft 46 are inclined with respect to the bearings of the compressor unit 42 and the expander unit 43, and Abnormal wear caused by an abnormally high sliding surface pressure and twisting of the drive shaft 45 can be prevented, and the reliability of the compressor can be improved.

On the other hand, the elastic modulus of the coil spring 47 is set so that the resonance frequency related to the vibration around the axes of the compressor section 42 and the drive shaft 45 is equal to the rated rotational speed (that is, the operating frequency) of the expander-integrated compressor. With this configuration, a resonance system around the axis centered on the coil spring 47 is generated when the expander-integrated compressor is operated at the rated rotational speed, and the shaft is caused by the compressor unit 42 and the expander unit 43. It acts as a dynamic vibration absorber for surrounding vibrations, and vibration noise generated from the expander-integrated compressor can be reduced.
In addition, since the drive shaft 45 and the power recovery shaft 46 are connected by the coil spring 47, the coil spring 47 can obtain a relatively large deflection amount with a compact configuration. Not only when the shaft of the recovery shaft 46 is relatively inclined, but also when the shaft is displaced in the axial direction, it becomes easy to absorb the displacement, so that the assembly accuracy is very poor or thermal deformation due to welding is caused. When it is large, the effect of improving the reliability becomes more remarkable.

As described above, according to the present embodiment, the elastic body absorbs the shaft misalignment of the drive shaft and the power recovery shaft and prevents the occurrence of abnormal wear and twisting, thus providing a highly reliable expander-integrated compressor. can do.
In addition, since the elastic body absorbs fluctuations in torque and load of the drive shaft and the power recovery shaft, vibrations are alleviated and destruction and noise are avoided, and a highly reliable expander-integrated compressor can be provided. .

FIG. 2 is a longitudinal sectional view of an expander-integrated compressor according to a second embodiment of the present invention.
The expander-integrated compressor of the present embodiment is the same as the expander-integrated compressor of the first embodiment, except that the elastic body connecting the drive shaft 45 and the power recovery shaft 46 is replaced with a torsion bar 48 from the coil spring 47. Except for the configuration described above, the configuration is exactly the same.
The cross section of the torsion bar 48 of this embodiment is square, and square holes 45b and 46b into which the torsion bar 48 is fitted are provided at the connecting ends of the drive shaft 45 and the power recovery shaft 46, respectively. The torsion bar 48 has a sufficiently large elastic modulus in both the axial direction, the rotational direction, and the bending direction so that the torque from the power recovery shaft 46 can be transmitted to the drive shaft 45 within a range of elastic deformation.
Further, vibrations around the axis of the rotating portion of the compressor unit 42 and the expander unit 43 of the expander-integrated compressor, and the rotating portion including the drive shaft 45, the power recovery shaft 46, the rotor 44b of the electric motor unit 44, and the like. The elastic modulus of the torsion bar 48 is set so that the resonance frequency becomes equal to the rated rotational speed of the expander-integrated compressor.

According to the expander-integrated compressor of the present embodiment, it is needless to say that the same axial deviation absorbing effect as that of the first embodiment can be obtained, and the reliability of the compressor can be improved.
Further, like the coil spring 47, the torsion bar 48 has an advantage that it can absorb the axial deviation even when the axis is displaced in the axial direction.
In addition, by setting the resonance frequency related to the vibration around the axis of the torsion bar 48 to be equal to the rated rotational speed of the expander-integrated compressor, the resonance system around the axis around the torsion bar 48 is It occurs when the expander-integrated compressor is operated at the rated speed, and acts as a dynamic vibration absorber for the vibration around the axis caused by the compressor section 42 and the expander section 43, and the expander-integrated compression Vibration noise generated from the machine can be reduced.

In the first embodiment and the present embodiment, when a spring such as a coil spring 47 or a torsion bar 48 is used as an elastic body for connecting the drive shaft 45 and the power recovery shaft 46, the transmitted torque is large. In addition, since the shaft misalignment is absorbed, high reliability can be secured. Further, even when a resin-based or rubber-based material is used as the elastic body, the effect of absorbing the axis deviation can be obtained and the cost can be reduced.
In the present embodiment, the torsion bar 48 has a square cross section. However, the present invention is not limited to this. If a fixing method capable of transmitting rotation to the drive shaft 45 and the power recovery shaft 46 is adopted, a circular cross section or the like is used. The configuration of

FIG. 3 is a longitudinal sectional view of an expander-integrated compressor according to a third embodiment of the present invention.
The expander-integrated compressor of the present embodiment is the same as the expander-integrated compressor of the first embodiment, with the configuration in which the shapes of the connecting end portions of the drive shaft 45 and the power recovery shaft 46 are changed, and these are coupled. Except for the configuration in which the elastic body is replaced with the resin material 49 from the coil spring 47, the configuration is exactly the same.
In this embodiment, a concave square hole 45 c is provided at the connecting end of the drive shaft 45, and a convex prismatic part 46 c is provided at the connecting end of the power recovery shaft 46. And the square hole 45c and the square column part 46c are mutually fitted through the resin material 49 which is an elastic body, and the drive shaft 45 and the power recovery shaft 46 are connected.
4 is a cross-sectional view of the fitting portion in the ZZ ′ cross section of FIG. The cross section of the square hole 45c and the square column part 46c is a square, and the square hole 45c is larger than the square column part 46c. Between them, a resin material 49 which is an elastic body is arranged. The resin material 49 has a sufficiently large elastic modulus in both the axial direction, the rotational direction, and the bending direction so that the torque from the power recovery shaft 46 can be transmitted to the drive shaft 45 in the range of elastic deformation.
Further, vibrations around the axis of the rotating portion of the compressor unit 42 and the expander unit 43 of the expander-integrated compressor, and the rotating portion including the drive shaft 45, the power recovery shaft 46, the rotor 44b of the electric motor unit 44, and the like. The elastic modulus of the resin material 49 is set so that the resonance frequency becomes equal to the rated rotational speed of the expander-integrated compressor.

The expander-integrated compressor of the present embodiment can provide an axial displacement absorbing effect as in the first and second embodiments, and can improve the reliability of the expander.
Further, since the resin material 49 is used, the cost can be reduced.
In addition, although the prismatic part 46c of the power recovery shaft 46 is fitted to the square hole 45c of the drive shaft 45 via the resin material 49, the resin material can be formed in a shape that is more flexible than a spring or the like. Therefore, it can be accurately formed in the shape of the gap between the square hole 45c and the prism portion 46c, and the assembly becomes easy.
By the way, in this embodiment, since the rectangular column part 46c of the power recovery shaft 46 is fitted into the square hole 45c of the drive shaft 45, an oil supply hole provided in the axial direction inside the drive shaft 45 is provided. 45d and an oil supply hole 46d provided in the axial direction inside the power recovery shaft 46 can be communicated with each other, and the oil accumulated in the lower shell 41c of the sealed container 41 is caused to pass through the hole 45d and the hole 46d. It is possible to pump up to the expander unit 43 disposed on the upper side of the sealed container 41 and supply it to the expander unit 43. Therefore, it is possible to improve the reliability of the expander.
In this embodiment, the drive shaft 45 is provided with the square hole 45c, and the power recovery shaft 46 is provided with the square column part 46c. However, the square hole 45c and the square column part 46c are not necessarily required to be fitted to each other. Needless to say, if the power can be transmitted from the power recovery shaft 46 to the drive shaft 45 without slipping, the same effect can be obtained with other shapes.
Further, in this embodiment, the drive shaft 45 is provided with the square hole 45c and the power recovery shaft 46 is provided with the square column portion 46c. Conversely, the drive shaft 45 is provided with a square column portion and the power recovery shaft 46 is square. It goes without saying that the same effect can be obtained even when the hole is provided.
Further, even when a rubber-based material is used in place of the resin material 49, it is possible to improve the assemblability and the ability to absorb misalignment and to reduce the cost.

FIG. 5 is a longitudinal sectional view of an expander-integrated compressor according to a fourth embodiment of the present invention.
The expander-integrated compressor of the present embodiment has the same configuration as that of the expander-integrated compressor of the third embodiment, except that the elastic body is replaced with the disc spring 50a.
In the present embodiment, a square hole 45 c is provided at the connection end of the drive shaft 45, and a prismatic part 46 c is provided at the connection end of the power recovery shaft 46. The square hole 45c and the rectangular column part 46c are fitted to each other via a disc spring 50a, which is an elastic body, so that the drive shaft 45 and the power recovery shaft 46 are connected.
FIG. 6A is a cross-sectional view of the fitting portion in the ZZ ′ cross section of FIG. The cross section of the square hole 45c and the square column part 46c is a square, and the square hole 45c is larger than the square column part 46c. Between these, a disc spring 50a, which is an elastic body, is disposed. In the present embodiment, a total of four disc springs 50a are arranged, one by one, between a pair of opposed planes of the square hole 45c and the prismatic portion 46c.
The disc spring 50a has a sufficiently large elastic modulus in both the axial direction, the rotational direction, and the bending direction so that torque from the power recovery shaft 46 can be transmitted to the drive shaft 45 within a range of elastic deformation. Further, vibrations around the axis of the rotating portion of the compressor unit 42 and the expander unit 43 of the expander-integrated compressor, and the rotating portion including the drive shaft 45, the power recovery shaft 46, the rotor 44b of the electric motor unit 44, and the like. The combined elastic modulus of the disc spring 50a is set so that the resonance frequency becomes equal to the rated rotational speed of the expander-integrated compressor.

With the expander-integrated compressor according to the present embodiment, the reliability of the expander that can obtain the effect of absorbing the shaft misalignment can be improved as in the first and second embodiments.
Furthermore, since the disc spring 50a is used, it is less likely to be affected by chlorofluorocarbon or supercritical carbon dioxide as the working fluid than when the resin material 49 is used, and higher reliability can be obtained.
Further, it is easy to assemble, and the cost can be reduced.
Further, by using the disc springs 50a in an overlapping manner, the number of springs can be adjusted to change the spring constant, so that the resonance frequency as a dynamic vibration absorber can be finely adjusted, and vibration noise can be further reduced. It is.
In addition, the elastic body in this embodiment is not necessarily the disc spring 50a, and the configuration using the coil spring 50b as shown in FIG. 6B or the configuration using the leaf spring 50c as shown in FIG. 6C. The same effect can be obtained.

  The expander of the present invention can be used as a prime mover or a generator that obtains rotational power from a compressible gas.

1 is a longitudinal sectional view of an expander-integrated compressor according to a first embodiment of the present invention. Vertical section of an expander-integrated compressor according to a second embodiment of the present invention Vertical section of an expander-integrated compressor in a third embodiment of the present invention Sectional drawing of the fitting part in the ZZ 'cross section of FIG. Vertical section of an expander-integrated compressor in a fourth embodiment of the present invention Sectional drawing of the fitting part in the ZZ 'cross section of FIG. Configuration diagram of conventional refrigeration cycle Vertical section of a conventional expander-integrated compressor Vertical sectional view of another conventional expander-integrated compressor

Explanation of symbols

41 Sealed container 42 Compressor portion 42a Compression chamber 43 Expander portion 43a Expansion chamber 44 Motor portion 45 Drive shaft 45a Small diameter portion 45b Square hole 45c Square hole 45d hole 46 Power recovery shaft 46a Small diameter portion 46b Square hole 46c Square column portion 46d Hole 47 Coil spring 48 Torsion bar 49 Resin material 50a Belleville spring 50b Coil spring 50c Leaf spring

Claims (7)

An expansion unit having an expansion chamber and a power recovery shaft, and obtaining rotational power of the power recovery shaft by expanding the working fluid sucked into the expansion chamber from a high pressure to a low pressure;
An expander-integrated compressor having a compression chamber and a drive shaft, and comprising a compressor section that compresses the working fluid sucked into the compression chamber from a low pressure to a high pressure by rotating the drive shaft;
An expander-integrated compressor, wherein the power recovery shaft and the drive shaft are connected via an elastic body.   The expander-integrated compressor according to claim 1, wherein a spring is used as the elastic body.   The expander-integrated compressor according to claim 2, wherein the spring is a coil spring.   The expander-integrated compressor according to claim 2, wherein the spring is a torsion bar.   The expander-integrated compressor according to claim 1, wherein a resin-based or rubber-based material is used as the elastic body.   The elastic body is disposed in a recess provided in one of the connection ends of the connection ends provided in the power recovery shaft and the drive shaft, and provided in the other connection end. 6. The expansion according to claim 1, wherein a convex portion is fitted into the concave portion via the elastic body, and the power recovery shaft and the drive shaft are connected. Machine-integrated compressor. The elastic modulus of the elastic body is set such that a resonance frequency related to vibration around an axis of the drive shaft or the like is equal to an operating frequency. The expander-integrated compressor according to claim 6.

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