TW201925618A - Single screw compressor and refrigeration cycle device with said single screw compressor - Google Patents

Abstract

This single screw compressor is provided with an affixation section for affixing the tooth section of a gate rotor and a gate rotor support. The affixation section is provided with a fitting section which is provided to the tooth section of the gate rotor, and a recess which is formed in a contact surface of the gate rotor support and into which the fitting section is fitted. The linear expansion coefficient of the fitting section is higher than that of the gate rotor support, and the thermal expansion of the fitting section caused by an increase in temperature during operation causes the fitting section to come into contact with and be fitted in the recess.

Description

Single screw compressor and refrigeration cycle device including the single screw compressor

The invention relates to a single-screw compressor and a refrigeration cycle device including the single-screw compressor. The single-screw compressor accommodates a screw rotor in a housing, and is formed by a disc-shaped gate rotor tooth portion and a screw rotor Screw grooves formed on the outer peripheral surface are fitted, and a compression chamber is formed in the housing.

In such a single screw compressor, the gate rotor is engaged with the screw rotor while being fixed to the gate rotor support and supported. Various fixed structures of the gate rotor and the gate rotor support are proposed. In Patent Document 1, the shaft portion of the gate rotor support is inserted into a through hole formed in the central portion of the gate rotor, and a pin is inserted to be arranged in contact with the gate rotor and The pin hole communicating with the gate rotor support, and the gate rotor and the gate rotor support are fixed.

Generally, the gate rotor is made of resin, and the gate rotor support is made of iron material, and the gate rotor is fixed and supported on the base portion of the gate rotor support.

In the single screw compressor configured in this way, the rotating shaft integrally provided to the screw rotor is rotated forward by the motor, whereby the screw rotor performs forward rotation. When the screw rotor rotates forward, with this rotation, refrigerant is sucked into the compression chamber from the low-pressure space in the casing. The compression chamber system has a reduced volume due to the movement of the gate rotor teeth in the screw groove, and compresses the refrigerant inside the compression chamber. Then, the compressed The refrigerant system is discharged from the compression chamber to the high-pressure space in the housing.

【Advanced Patent Literature】 【Patent Literature】

[Patent Document 1] Japanese Patent Laid-Open No. 2009-203817

When the fixed surface of the gate rotor to the gate rotor support is defined as the lower surface of the gate rotor, and the opposite surface is defined as the upper surface, the pressure in the compression chamber always acts on the upper surface of the gate rotor during operation, while the pressure in the low-pressure space Always acts under the gate rotor. In addition, the gate rotor is supported by the base portion of the gate rotor support, and the front end portion of the tooth portion of the gate rotor protrudes further outward than the base portion of the gate rotor support. below. In this way, the force from the top to the bottom acts on the teeth of the gate rotor. During operation, the teeth of the gate rotor are pressed toward the gate rotor support side by the differential pressure between the compression chamber and the low-pressure space.

On the other hand, when the operation is stopped, the rotation of the screw rotor is decelerated by the motor stop, whereby the flow of the refrigerant from the compression chamber to the high-pressure space gradually disappears. Then, when the screw rotor is stopped, the refrigerant flowing into the high-pressure space flows into the compression chamber and flows to the low-pressure space, and the flow of the refrigerant opposite to that during operation occurs, and the screw rotor reverses.

When the screw rotor is reversed, the volume in the compression chamber expands, so the refrigerant in the compression chamber expands, and the pressure gradually decreases, and the pressure in the compression chamber becomes lower than the pressure in the low-pressure space. Therefore, the force in the direction from the bottom to the top in the direction reverse to the forward rotation, even if the front end of the teeth of the gate rotor The force that deforms in the direction away from the gate rotor support acts on the teeth of the gate rotor. Therefore, the teeth of the gate rotor are bent and deformed, and this deformation is repeated every time the operation is stopped, so that the gate rotor has a problem of fatigue damage.

Patent Document 1 describes a fixed structure of a gate rotor and a gate rotor support, but it is not a fixed structure for preventing bending of a tooth portion of the gate rotor caused by reverse rotation of the screw rotor. Therefore, it is considered that in Patent Document 1, the fatigue damage of the gate rotor cannot be prevented.

The present invention was developed in view of this problem, and its object is to provide a single-screw compressor and a refrigeration cycle device including the single-screw compressor. The single-screw compressor is a reaction of the screw rotor that occurs when the operation is stopped. When turning, it can prevent the fatigue damage of the gate rotor.

The single-screw compressor of the present invention includes: a screw rotor with a plurality of screw grooves formed on the outer peripheral surface; a disc-shaped gate rotor with a plurality of tooth portions meshing with the plurality of screw grooves on the outer peripheral portion; and a gate rotor The support has a contact surface with a plurality of teeth of the gate rotor; with the rotation of the screw rotor, the gate rotor and the gate rotor support rotate, and the refrigerant is compressed, the single screw compressor includes the teeth of the fixed gate rotor The fixing part with the gate rotor support; the fixing part includes: a fitting part, which is provided on the tooth part of the gate rotor; and a concave part, which is formed on the contact surface of the gate rotor support, and the fitting part is inserted; fitting The linear expansion coefficient of the part is larger than the linear expansion coefficient of the gate rotor support. By the thermal expansion of the fitting part according to the temperature increase during operation, the fitting part contacts the recess and fits.

According to the present invention, the fitting portion provided on the tooth portion of the gate rotor is thermally expanded during operation, and fits into the concave portion provided on the gate rotor support, thereby fixing the tooth portion of the gate rotor to the gate rotor support Composition. Therefore, when the screw rotor is reversed when the operation is stopped, the deformation of the teeth of the gate rotor can also be suppressed, and the fatigue damage of the gate rotor can be prevented.

1‧‧‧Housing

2‧‧‧screw rotor

2a‧‧‧Screw groove

3‧‧‧Gate rotor

4‧‧‧Gate rotor support

5‧‧‧ Stator

6‧‧‧Rotor

7‧‧‧Motor

8‧‧‧spindle

9a‧‧‧bearing

9b‧‧‧bearing

10‧‧‧Compression room

11‧‧‧Sliding groove

12‧‧‧ Internal volume ratio adjustable valve

13‧‧‧Central axis

14‧‧‧Central axis

15‧‧‧

20‧‧‧ Low pressure space

21‧‧‧Gate rotor support room

30‧‧‧tooth

31‧‧‧Through hole

32‧‧‧Through hole

33‧‧‧protrusion

40‧‧‧Base

40a‧‧‧Contact surface

41‧‧‧Shaft

42‧‧‧Shaft

43‧‧‧tooth

44‧‧‧recess

44a‧‧‧Bottom

50‧‧‧Fixed Department

60‧‧‧pin

61‧‧‧Shaft

62‧‧‧Head

62a‧‧‧Front face

70‧‧‧Refrigeration cycle device

71‧‧‧Single screw compressor

72‧‧‧Condenser

73‧‧‧pressure reducing device

74‧‧‧Evaporator

Fig. 1 is a schematic cross-sectional view of the main structure of a single screw compressor according to a first embodiment of the present invention.

Fig. 2 is a schematic longitudinal sectional view of a single screw compressor according to the first embodiment of the present invention.

Fig. 3 is a diagram showing the gate rotor of the single screw compressor according to the first embodiment of the present invention.

Fig. 4 is a diagram showing a gate rotor support of a single screw compressor according to a first embodiment of the present invention.

Fig. 5 is an enlarged cross-sectional view before expansion of the gate rotor and the fixed portion of the gate rotor support of the main portion of the single screw compressor according to the first embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view after expansion of the gate rotor and the fixed portion of the gate rotor support of the main portion of the single screw compressor according to the first embodiment of the present invention.

Fig. 7 is a diagram showing the gate rotor of the single screw compressor according to the first embodiment of the present invention.

Fig. 8 is an enlarged cross-sectional view before expansion of the gate rotor and the fixed portion of the gate rotor support of the main portion of the single screw compressor according to the second embodiment of the present invention.

Figure 9 is the main part of a single screw compressor according to a second embodiment of the present invention An enlarged cross-sectional view of the gate rotor and the fixed portion of the gate rotor support after expansion.

Fig. 10 is a diagram showing a refrigerant circuit of a refrigeration cycle apparatus according to a third embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described based on the drawings. In each figure, the same symbols are attached to the same symbols or equivalent, and are common throughout the entire patent specification. In addition, the forms of the constituent elements shown in the entire text of this patent specification are examples only, and are not limited to the forms described in the patent specification. In addition, the level of temperature and pressure is not determined by the relationship with the absolute value, but is relatively determined by the state and operation of the system and device.

In the following, a single-screw compressor with a screw rotor as a branch and two gate rotors meshed with a screw rotor to form two compression chambers as an example will be described as an embodiment.

First embodiment

Fig. 1 is a schematic cross-sectional view of the main structure of a single screw compressor according to a first embodiment of the present invention. Fig. 2 is a schematic longitudinal sectional view of a single screw compressor according to the first embodiment of the present invention.

As shown in FIG. 1, the single screw compressor includes a casing 1, a screw rotor 2, a motor 7, a rotating shaft 8 fixed to the motor 7 and driven by the motor 7 to rotate.

The casing 1 is formed into a cylindrical shape, and the screw rotor 2 is rotatably received in the casing 1. The screw rotor 2 is cylindrical, and a plurality of screw grooves 2a extending in a spiral shape from one end side to the other end side of the screw rotor 2 are formed on the outer peripheral portion. One end side of the screw rotor 2 becomes the refrigerant suction side, and the other end side becomes the refrigerant discharge side. The shell 1 is separated by a partition (not shown) into a low-pressure filled refrigerant The pressure space 20 is a high-pressure space filled with high-pressure refrigerant. One end of the screw rotor 2 communicates with the low-pressure space 20 and the other end communicates with the high-pressure space. In addition, at the center of the screw rotor 2, the rotating shaft 8 is integrally provided for rotation.

In the housing 1, two gate rotor support chambers 21 are formed so that the center axis 13 of the screw rotor 2 faces each other. In each gate rotor support chamber 21, the gate rotor 3 and the gate rotor support 4 supporting the gate rotor 3 are accommodated. The gate rotor 3 and the gate rotor support 4 housed in each gate rotor support chamber 21 are arranged to rotate 180 ° about the center axis 13 of the screw rotor 2.

The gate rotor support 4 is arranged such that its central axis 14 is substantially perpendicular to the central axis 13 of the screw rotor 2, and is rotatably supported by bearings 9a and 9b that are spaced apart in the direction of the central axis 14 and oppositely arranged.

The gate rotor 3 is disc-shaped, and has a plurality of teeth 30 on the outer periphery, and the teeth 30 mesh with the screw groove 2a of the screw rotor 2. Thereby, the compression chamber 10 is formed in the space surrounded by the screw groove 2a, the tooth portion 30 of the gate rotor 3, and the inner peripheral surface of the housing 1. Here, since there are two gate rotors 3, two compression chambers 10 are formed, and each compression chamber 10 has a 180 ° opposing positional relationship with respect to the central axis 13 of the screw rotor 2.

In addition, two slide grooves 11 extending in the direction of the rotating shaft 8 are formed on the inner wall surface of the housing 1 as shown in FIG. 1. These two slide grooves 11 are arranged to rotate 180 ° about the rotating shaft 8. Further, in this sliding groove 11, a rod-shaped internal volume ratio adjustable valve 12 having a crescent shape in cross section is accommodated in a sliding manner. On the end face on one side of the sliding direction of the internal volume ratio adjustable valve 12, a rod 15 connected to a direct-acting actuator (not shown) is fixed, and by driving the direct-acting actuator, the internal volume ratio is adjustable The valve 12 moves in the sliding groove 11. By controlling the rotation of the internal volume ratio adjustable valve 12 The position in the direction of the shaft 8 can adjust the discharge timing of the refrigerant sucked into the compression chamber 10. Specifically, for the purpose of adjusting the discharge timing to increase energy efficiency, the position of the internal volume ratio adjustable valve 12 is controlled.

The motor 7 system is composed of a stator 5 and a rotor 6. The stator 5 system is fixed inwardly in the housing 1, and the rotor 6 system is arranged inside the stator 5. The rotor 6 is fixed to the rotating shaft 8 like the screw rotor 2 and is arranged on the same axis as the screw rotor 2. When the motor 7 rotates, the rotating shaft 8 rotates, and the screw rotor 2 rotates forward. The motor 7 is configured to use an inverter (not shown), and the rotation speed of the rotating shaft 8 can be adjusted. With this, the single screw compressor can adjust the rotation speed of the motor 7 and change the operating capacity. In addition, the motor 7 is not limited to those whose speed can be adjusted by the inverter, but can also be a fixed speed.

Next, the characteristic configuration of the first embodiment will be described. The first embodiment of the present invention is characterized by including a fixing portion 50 (see FIG. 2) for fixing the tooth portion 30 of the gate rotor 3 and the gate rotor support 4. In addition, by including the fixing portion 50, it is possible to prevent the gate rotor 3 from being fatigued and damaged due to bending and deformation of the tooth portion 30 of the gate rotor 3 when the operation is stopped.

The fixing part 50 is made of materials different from the gate rotor 3 and the gate rotor support 4, and according to the difference in linear expansion coefficient, the two are fixed by thermal expansion during operation. That is, during operation, the gas system sucked into the compression chamber 10 is compressed and its temperature rises. Therefore, with this temperature increase, the temperature of each of the gate rotor 3 and the gate rotor support 4 also rises more than the normal temperature during the stop. Because of this temperature rise, the gate rotor 3 and the gate rotor support 4 thermally expand. In the following, the structure of each of the gate rotor 3 and the gate rotor support 4 will be described using FIGS. 3 to 6, and following this description, the fixed portion 50 will be described.

FIG. 3 is a view showing the gate rotor of the single screw compressor according to the first embodiment of the present invention. FIG. 3 (a) is a plan view, and FIG. 3 (b) is an A-A sectional view of FIG. 3 (a). FIG. 4 is a diagram showing the gate rotor support of the single screw compressor according to the first embodiment of the present invention, FIG. 4 (a) is a plan view, and FIG. 4 (b) is AA section of FIG. 4 (a) Figure. Fig. 5 is an enlarged cross-sectional view before expansion of the gate rotor and the fixed portion of the gate rotor support of the main portion of the single screw compressor according to the first embodiment of the present invention.

As described above, the gate rotor 3 has a disc shape, and has a plurality of teeth 30 on the outer peripheral surface, and a through hole 31 in the center. In addition, through holes 32 are formed in each of the tooth portions 30. The through hole 32 is formed outside the diameter R of the circle connecting the roots of the teeth 30 of the gate rotor 3. FIG. 3 shows an example in which there are 11 tooth portions 30 of the gate rotor 3 and the through-holes 32 are provided in all the tooth portions 30 of the gate rotor 3, but not necessarily all of them.

Then, as shown in FIG. 5, the pin 60 is pressed into the through hole 32 from the lower surface side of the gate rotor 3. The pin 60 is made of the same material as the gate rotor 3, and has a structure in which a shaft portion 61 and a cylindrical head portion 62 having a larger diameter than the shaft portion 61 are integrally formed. The shaft portion 61 is inserted into the through hole 32被 fixed to the tooth 30.

The gate rotor support 4 has: a substantially disc-shaped base 40 having a planar contact surface 40a on which the gate rotor 3 is arranged; and a shaft 41 and a shaft 42 on both sides of the base 40 The central axis of the portion 40 extends. The base 40 has the same number of teeth 43 corresponding to the teeth 30 of the gate rotor 3 on the outer periphery. Furthermore, a cylindrical recess 44 into which the head 62 of the pin 60 is inserted is formed in the contact surface 40 a constituting the tooth portion 43.

The gate rotor 3 and the gate rotor support 4 formed in this way As shown in FIG. 5, the shaft portion 42 of the gate rotor support 4 is inserted into the through hole 31 of the gate rotor 3 and fitted, and the gate rotor 3 is in contact with and supported by the base portion 40. The gate rotor support 4 is composed of an iron material, and is supported by the gate rotor 3 in contact with the base portion 40 to reinforce the rigidity of the gate rotor 3 made of resin.

Furthermore, the head 62 of the pin 60 fixed to the gate rotor 3 is inserted into the recess 44. The pin 60 and the recessed portion 44 are processed so that the head 62 of the pin 60 is inserted into the recessed portion 44 and their respective central axes coincide. , With a uniform gap in the radial direction. In addition, the head 62 of the pin 60 corresponds to an example of the "fitting portion". In addition, the head portion 62 of the pin 60 and the recess 44 constitute the fixing portion 50.

In addition, to the gate rotor holder 4, a pressing member (not shown) that pushes the gate rotor 3 from the upper surface side to the lower surface side at the peripheral portion of the through hole 31 is installed. Further, by this pressing member, the movement of the gate rotor 3 on the gate rotor support 4 in the thickness direction is restricted. In addition, the movement of the gate rotor 3 on the gate rotor support 4 by the fixing portion 50 is also restricted in the circumferential direction, which will be described later.

Next, the dimensions of the head 62 and the recess 44 of the pin 60 will be described. The outer diameter ψ a of the head 62 of the pin 60 is smaller than the inner diameter ψ b of the recess 44 and satisfies the design of the diameter ratio ψ b / ψ a = 1.001. By making this design, the thermal expansion of the head 62 of the pin 60 in operation is allowed, and the state in which the outer circumferential surface of the head 62 of the expanded pin 60 is in contact with the inner circumferential surface of the recess 44 can be obtained. In addition, the height of the head 62 of the pin 60 is designed so that when the head 62 of the pin 60 thermally expands during operation, the front end surface 62a of the head 62 of the pin 60 does not contact the bottom surface 44a of the recess 44.

Also, as shown in FIG. 5, the outer diameter ψ a of the head 62 of the pin 60 is affected by It is formed to be larger than the inner diameter ψ c of the through hole 32. Suppose that when the outer diameter ψ a of the head 62 of the pin 60 is made the same as the inner diameter ψ c of the through-hole 32, it is necessary to make the inner diameter ψ b of the concave portion 44 larger than that of ψ c The amount by which the outer diameter ψ a of the head 62 is smaller than that in FIG. 5 is reduced. That is, in order to thermally expand the head portion 62 of the pin 60 during operation and come into contact with the concave portion 44, it is necessary to reduce the inner diameter ψ b of the concave portion 44. By making ψ a larger than ψ c, since the head 62 of the pin 60 is locked to the step difference between the recess 44 and the through hole 32 when the pin 60 is fitted to the gate rotor 3, it is easy to position the pin 60 and assemble Become easy

The tooth portion 30 and the tooth portion 43 of the assembled product of the gate rotor 3 and the gate rotor support 4 are engaged with the screw groove 2a of the screw rotor 2 of the iron material as described above. In order to avoid contact between the metals in the state where the teeth 30 and the teeth 43 mesh with the screw groove 2a, the outer diameter of the teeth 43 of the gate rotor support 4 is formed to be larger than the outer diameter of the teeth 30 of the gate rotor 3 small. Thereby, the front end portion of the tooth portion 30 of the gate rotor 3 made of resin is in contact with the screw groove 2a of the iron material, and metal contact can be avoided. Moreover, when the screw rotor 2 rotates, the gate rotor 3 contacting and meshing with the screw groove 2a receives the driving force generated by the rotation of the screw rotor 2, and the gate rotor support 4 installed in the gate rotor 3 rotates.

FIG. 6 is an enlarged cross-sectional view after expansion of the gate rotor and the fixed portion of the gate rotor support of the main portion of the single screw compressor according to the first embodiment of the present invention.

The head portion 62 of the pin 60 made of a resin material expands in the recess 44 by the amount of temperature rise (T2-T1) [° C] from the temperature T1 [° C] during stop to the temperature T2 [° C] during operation. Here, the temperature of the gate rotor support 4 made of iron material also rises more during operation than during stoppage, but the linear expansion of the resin material constituting the gate rotor The coefficient of expansion is about twice as large as the coefficient of linear expansion of the iron material constituting the rotor support 4 of the gate.

Therefore, during operation, the head 62 of the pin 60 expands and contacts the inner peripheral surface of the recess 44 as shown in FIG. 6. This contact pressure acts as the holding force of the gate rotor 3, and the tooth portion 30 of the gate rotor 3 can be fixed to the gate rotor support 4 during operation. This phenomenon occurs in the head portion 62 of all the pins 60 and the recess 44 of the gate rotor support 4. In this way, by fixing the tooth portion 30 of the gate rotor 3 to the gate rotor support 4 with the fixing portion 50, the axial and circumferential movement of the tooth portion 30 is restricted.

Next, the operation of the single screw compressor of the first embodiment will be described.

The motor 7 driving the single-screw compressor receives power from an inverter not shown and is started. When the motor 7 starts, the screw rotor 2 rotates as the rotary shaft 8 rotates, and the refrigerant is sucked into each compression chamber 10. In addition, as the screw rotor 2 rotates, the gate rotor 3 also rotates. After the refrigerant suction into the compression chamber 10 is completed, the volume of the compression chamber 10 is reduced, and the pressure of the refrigerant sucked into the compression chamber 10 gradually becomes higher. Then, the refrigerant whose pressure rises is discharged from the compression chamber 10 to the high-pressure space through a discharge port (not shown) provided in the casing. It was discharged out of the machine again. In addition, the timing of discharging the refrigerant in each compression chamber 10 from the discharge port (not shown) is adjusted by the internal volume ratio adjustable valve 12.

Then, when the single screw compressor receives the stop command, when there is no power input from the inverter not shown, the rotation speed of the screw rotor 2 gradually decelerates. During deceleration, the compression action continues until the forward rotation of the screw stops.

Then, when the screw rotor 2 is stopped, the refrigerant from the high-pressure space to the low-pressure space 20 flows due to the differential pressure between the high-pressure space and the low-pressure space 20. The refrigerant in the high-pressure space gradually flows into the low-pressure space 20 through the compression chamber 10. Take this flow The screw rotor 2 system reverses.

In the reverse rotation of the screw rotor 2, the force from the bottom to the top acts on the teeth 30 of the gate rotor 3. However, as described above, during operation, since the tooth portion 30 can be fixed to the gate rotor support 4 by the fixing portion 50, the tooth portion 30 can be prevented from being bent and deformed during reverse rotation.

As shown in the above description, according to the first embodiment, the fixing portion 50 includes the pin 60 fixed to the gate rotor 3 thermally expands during operation, and the head portion 62 and the concave portion of the gate rotor support 4 The inner peripheral surface of 44 contacts, and the tooth part 30 is fixed to the gate rotor support 4. Therefore, it is possible to prevent the tooth portion 30 of the gate rotor 3 from bending in the upper direction when reversing. Therefore, excessive stress does not occur at the root of the tooth portion 30, and fatigue damage of the gate rotor 3 can be prevented.

In addition, by making the outer diameter ψ a of the head 62 of the pin 60 larger than the inner diameter ψ c of the through hole 32, the following effects can be obtained. That is, as described above, compared with the case where the outer diameter ψ a of the head 62 is made equal to the inner diameter ψ c of the through hole 32, the pin 60 can be more easily positioned on the gate rotor 3, and assembly can be improved . In addition, as the outer diameter ψ a of the head 62 becomes larger, the contact pressure during operation can be increased, so that the gate rotor 3 and the gate rotor support 4 can be firmly fixed.

In addition, since the central axis of the head 62 of the pin 60 coincides with the central axis of the recess 44, the entire inner peripheral surface of the recess 44 can be thermally expanded to contact the inner peripheral surface of the recess 44 due to thermal expansion of the head 62. The contact pressure becomes uniform.

In addition, in the first embodiment, the configuration in which the pin 60 has the shaft portion 61 and the head portion 62 having a larger diameter than the shaft portion 61 is exemplified, but it is not necessarily limited to this configuration. For example, a pin with the same diameter from one end to the other end may be used, and the diameter of the portion inserted into the through hole 32 may be larger than the portion inserted into the recess 44 Greater sales.

In addition, in the conventional configuration in which the fixing portion 50 is not provided, and when the tooth portion 30 of the gate rotor 3 is deformed to be bent upward, the tooth portion 30 comes into contact with a portion called the tongue surface in the housing 1 and gradually wears out. In addition, when this abrasion progresses, the tongue gap between the upper surface of the gate rotor 3 and the tongue surface expands, which causes internal leakage of the refrigerant and causes insufficient refrigeration performance. However, in the first embodiment, since the fixing portion 50 is provided to prevent bending of the tooth portion 30, the wear of the tooth portion 30 in the thickness direction can be reduced, and insufficient freezing performance during operation can be prevented.

Second Embodiment

The second embodiment is different from the first embodiment in the structure of the fixing portion 50. In the following, only the differences from the first embodiment will be described for the second embodiment.

FIG. 7 is a view showing the gate rotor of the single screw compressor according to the first embodiment of the present invention. FIG. 7 (a) is a plan view, and FIG. 7 (b) is an A-A sectional view of FIG. 7 (a). Fig. 8 is an enlarged cross-sectional view before expansion of the gate rotor and the fixed portion of the gate rotor support of the main portion of the single screw compressor according to the second embodiment of the present invention.

In the first embodiment, the pin 60 is fixed to the gate rotor 3, but the second embodiment has a structure in which the gate rotor 3 and the pin 60 are integrated with resin of the same material. This structure can also be said to be a structure in which the lower surface of the gate rotor 3 protrudes toward the gate rotor support 4 side. In addition, the protrusion 33 corresponds to an example of the "fitting portion".

FIG. 9 is an enlarged cross-sectional view after expansion of the gate rotor and the fixed portion of the gate rotor support of the main portion of the single screw compressor according to the second embodiment of the present invention.

During the operation of the protrusion 33, the protrusion 33 thermally expands and contacts the inner peripheral surface of the recess 44 of the gate rotor holder 4, and the contact pressure is generated as in the first embodiment. This contact pressure acts as a holding force for fixing the tooth portion 30 of the gate rotor 3 to the gate rotor support 4. Therefore, it is possible to prevent the tooth portion 30 of the gate rotor 3 from bending and deforming in the direction from the lower surface to the upper surface during the reverse rotation.

According to the second embodiment, the same effect as the first embodiment can be obtained, and the assembly of the gate rotor 3 and the pin 60 is not required, and the assembly process can be simplified and the cost can be reduced.

Third embodiment

The third embodiment relates to a refrigeration cycle apparatus including the single screw compressor of the first embodiment or the second embodiment.

Fig. 10 is a diagram showing a refrigerant circuit of a refrigeration cycle apparatus according to a third embodiment of the present invention.

The refrigeration cycle device 70 includes the single screw compressor 71 of the first embodiment or the second embodiment, a condenser 72, a pressure reduction device 73, and an evaporator 74. The pressure reduction device 73 is composed of an expansion valve, a capillary tube, or the like. In the refrigeration cycle device 70 configured in this manner, the gas refrigerant discharged from the single screw compressor 71 flows into the condenser 72, exchanges heat with the air passing through the condenser 72, and becomes a high-pressure liquid refrigerant and flows out. The high-pressure liquid refrigerant flowing out of the condenser 72 is reduced in pressure by the pressure reducing device 73 to become a low-pressure gas-liquid two-phase refrigerant, and flows into the evaporator 74. The low-pressure gas-liquid two-phase refrigerant flowing into the evaporator 74 exchanges heat with the air passing through the evaporator 74 to become a low-pressure gas refrigerant, which is then sucked into the single screw compressor 71.

The refrigeration cycle device 70 constructed in this way includes the single screw compressor 71 of the first embodiment or the second embodiment, which can suppress the single screw pressure. The failure of the compressor 71 can be used as a highly reliable refrigeration cycle device. In addition, the constituent elements shown in FIG. 10 represent the basic constituent elements of the refrigeration cycle apparatus, and the refrigeration loop apparatus of the present invention may further include a constituent element such as a trap.

In addition, the refrigeration cycle device 70 configured as described above can be applied to air conditioners, refrigerator freezers, and the like.

In addition, in the first to third embodiments, as the single screw compressor, a single-screw compressor with a single-stage screw rotor and a double gate rotor system is exemplified, but the present invention is not limited to this system. A two-stage single screw compressor including two screw rotors in the direction of the rotating shaft can also be used. Furthermore, a single-screw compressor of a single-gate rotor type in which a gate rotor meshes with a screw rotor to form a compression chamber can also be used. Applying the present invention to these single screw compressors can also obtain the same effects as the present invention.

Claims (8)

A single-screw compressor includes a screw rotor formed with a plurality of screw grooves on an outer peripheral surface; a disc-shaped gate rotor having a plurality of tooth portions meshing with the plurality of screw grooves on an outer peripheral portion; and a gate rotor The support has a contact surface that contacts the plurality of teeth of the gate rotor; with the rotation of the screw rotor, the gate rotor and the gate rotor support rotate to compress the refrigerant, the single screw compressor system includes A fixing portion that fixes the tooth portion of the gate rotor and the gate rotor support; the fixing portion includes: a fitting portion provided at the tooth portion of the gate rotor; and a recessed portion formed at the gate rotor support The contact surface, and the fitting part is inserted; the linear expansion coefficient of the fitting part is greater than the linear expansion coefficient of the gate rotor support, by thermal expansion of the fitting part according to the temperature rise during operation, The fitting portion comes into contact with and fits with the concave portion. For example, in the single screw compressor of claim 1, the fixing portion is provided for each tooth portion of the gate rotor. A single screw compressor as claimed in item 1 or 2 of the patent application, which includes a pin fitted with a through hole formed in the tooth portion of the gate rotor; a part of the pin extends from the gate rotor to the gate rotor support The side protrudes to form the fitting portion. A single-screw compressor as claimed in item 3 of the patent application, in which the pin forming the fitting portion is formed in a cylindrical shape and has an outer diameter larger than the inner diameter of the through hole. As in the single screw compressor of claim 1 or 2, the fitting portion is formed integrally with the gate rotor and is a protrusion protruding from the tooth portion to the gate rotor support. For example, in the single screw compressor of claim 1 or 2, the central axis of the fitting portion is consistent with the central axis of the recessed portion. A single screw compressor as claimed in item 1 or 2 of the patent application, wherein the fitting portion is formed in a cylindrical shape, and the diameter ratio of the outer diameter ψ a of the fitting portion to the inner diameter ψ b of the recessed portion ψ b / ψ a satisfies 1.001. A refrigeration cycle device includes a single screw compressor, a condenser, a pressure reduction device, and an evaporator as described in any of items 1 to 7 of the patent application.