WO2021038614A1

WO2021038614A1 - Scroll compressor

Info

Publication number: WO2021038614A1
Application number: PCT/JP2019/032944
Authority: WO
Inventors: 秀明北川
Original assignee: 三菱電機株式会社
Priority date: 2019-08-23
Filing date: 2019-08-23
Publication date: 2021-03-04
Also published as: JP7154421B2; JPWO2021038614A1

Abstract

A scroll compressor includes: an autonomously-movable tooth that is inserted into an insertion hole penetrating through a fixed scroll and constitutes a part of fixed spiral teeth, the autonomously-movable tooth being configured to autonomously move up and down in the insertion hole; and a magnet that is provided on the fixed scroll and attracts the autonomously-movable tooth in the insertion hole toward a side away from a swing scroll so that an end face of the autonomously-movable tooth is moved away from a swing base plate. The autonomously-movable tooth autonomously moves up and down in the insertion hole according to a magnitude relation between: a force applied to the autonomously-movable tooth by a high pressure; and a combined force of a magnetic force of the magnet and a force applied to the autonomously-movable tooth by a low pressure. A suction volume is adjusted by switching between an abutting state in which the end face of the autonomously-movable tooth is flush with end surfaces of the fixed spiral teeth other than the autonomously-movable tooth and a spaced state in which the end face of the autonomously-movable tooth is not flush with the other end surfaces and is away from the swing base plate.

Description

Scroll compressor

The present invention relates to a mechanical capacity control technique in a scroll compressor.

Conventionally, a scroll compressor equipped with a compression mechanism unit that compresses a fluid in a compression chamber formed by combining a fixed scroll and a swing scroll and an electric motor connected to the compression mechanism unit via a rotation shaft has been known. Has been done. In this type of scroll compressor, in order to realize high efficiency over a wide load range, a method is known in which the electric motor is driven by an inverter and the capacity of the scroll compressor is controlled by controlling the rotation speed. However, if the rotation speed is too low when the load is low, the efficiency of the scroll compressor is lowered due to an increase in refrigerant leakage in the compression chamber, and the performance is lowered. Therefore, it is difficult to maintain high efficiency with a low load capacity at a low speed only by controlling the rotation speed with an inverter.

Therefore, a scroll compressor using mechanical capacity control that mechanically changes the exclusion volume (suction volume) has been proposed. In mechanical capacity control, the capacity is reduced by full-load operation, which is a normal operation of compressing the refrigerant, and by bypassing a part of the refrigerant in the compression chamber to the suction side without compressing and reducing the volume at the start of compression. By switching between the reduced partial load operation and the reduced partial load operation without reducing the rotation speed of the motor, the performance at low load is improved.

As a scroll compressor using mechanical capacity control, for example, in Patent Document 1, a bypass port capable of communicating a compression chamber and a suction chamber is provided in a fixed scroll, and the suction volume is increased by opening and closing the bypass port with a bypass valve. It is made variable. The bypass valve opens and closes by switching the pressure acting on the bypass valve to high pressure or low pressure by a pressure switching device provided outside the scroll compressor.

Japanese Patent Application No. 2016-217758

In Patent Document 1, when adjusting the suction volume, it is necessary to adjust the pressure acting on the bypass valve from the outside of the scroll compressor. That is, additional piping or the like was required outside the scroll compressor, and the surrounding structure had to be changed.

The present invention is for solving the above-mentioned problems, and an object of the present invention is to provide a scroll compressor capable of adjusting the suction volume without changing the peripheral structure of the scroll compressor.

The scroll compressor according to the present invention has a fixed base plate and a fixed scroll having fixed spiral teeth formed on the fixed base plate, and a rocking base plate and swinging spiral teeth formed on the rocking base plate. The oscillating spiral tooth is combined with the fixed vortex tooth of the fixed scroll to form a plurality of compression chambers that compress the working gas from low pressure to high pressure, and the driving shaft for driving the oscillating scroll and the driving shaft. An autonomous movable tooth that is inserted into an insertion hole formed through a fixed scroll in the axial direction to form a part of a fixed spiral tooth and moves up and down autonomously inside the insertion hole, and a fixed scroll. A magnet that pulls the autonomous movable tooth in the insertion hole to the opposite side of the swing scroll to separate the tip surface of the autonomous movable tooth from the swing base plate, and a fixed scroll, swing scroll, drive shaft, autonomous movable tooth, and magnet. It has a closed container to accommodate, and the autonomous movable tooth has an insertion hole depending on the magnitude relationship between the resultant force of the magnetic force of the magnet and the force acting on the autonomous movable tooth by low pressure and the force acting on the autonomous movable tooth by high pressure. It moves up and down autonomously inside, and the tip surface of the autonomous movable tooth is in a contact state where it is flush with the tip surface of the fixed spiral tooth excluding the autonomous movable tooth, and in a separated state where it is separated without being flush. The suction volume is adjusted by switching.

According to the scroll compressor of the present invention, a part of the fixed scroll is composed of autonomous movable teeth, and the autonomous movable teeth move up and down autonomously based on the magnetic force of the magnet and the pressure in the closed container. The tip surface is switched between a contact state in which the tip surface is flush with the tip surface of the fixed spiral tooth excluding the autonomous movable tooth and a separated state in which the tip surface is separated without being flush. Therefore, the suction volume can be adjusted without changing the peripheral structure of the scroll compressor.

It is a vertical cross-sectional schematic diagram which shows the scroll compressor which concerns on embodiment. It is sectional drawing of the compression mechanism part of the scroll compressor which concerns on embodiment. It is operation explanatory figure of the autonomous movable tooth in the fixed scroll of the scroll compressor which concerns on embodiment. FIG. 5 is a schematic vertical cross-sectional view showing a state in which autonomous movable teeth are removed from the fixed scroll of the scroll compressor according to the embodiment. FIG. 5 is a schematic cross-sectional view showing a state in which autonomous movable teeth are removed from the fixed scroll of the scroll compressor according to the embodiment. It is a perspective view of the autonomous movable tooth of the scroll compressor which concerns on embodiment. It is a spiral operation diagram which shows the compression stroke when the autonomous movable tooth is separated in the scroll compressor which concerns on embodiment. It is explanatory drawing of the force acting on the autonomous movable tooth of the scroll compressor which concerns on embodiment.

Embodiment FIG. 1 is a schematic vertical cross-sectional view showing a scroll compressor according to the embodiment. Hereinafter, the configuration of the scroll compressor 100 will be described with reference to FIG. The scroll compressor 100 of FIG. 1 is a so-called vertical scroll compressor, which compresses and discharges a working gas such as a refrigerant. In FIG. 1, the Z direction indicates the axial direction.

The scroll compressor 100 includes a closed container 1, a compression mechanism unit 2 having a swing scroll 3 and a fixed scroll 4, an electric motor 16, a drive shaft 19, and an oil reservoir space 5.

The closed container 1 is formed in a cylindrical shape, for example, and has pressure resistance. A suction pipe 7 for taking the working gas into the closed container 1 is connected to the side surface of the closed container 1. A discharge pipe 11 for discharging compressed working gas from the closed container 1 to the outside is connected to the other side surface of the closed container 1. The arrow in the pipe indicates the direction in which the working gas flows. A check valve 9 and a spring 10 are arranged inside the suction pipe 7. The check valve 9 is urged by the spring 10 in the direction of closing the suction pipe 7, and prevents the backflow of the working gas.

The closed container 1 has a high pressure gas atmosphere 6 in the closed container 1. An oil reservoir space 5 for storing refrigerating machine oil (hereinafter referred to as oil) is formed at the bottom of the closed container 1. The oil reservoir space 5 is located in the high-pressure gas atmosphere 6, is below the subframe 37 that supports the lower end of the drive shaft 19, is below the auxiliary bearing 27 provided on the subframe 37, and is below the lower end of the drive shaft 19. It is a space below. The lower end surface of the drive shaft 19 is supported by a thrust bearing 28. The thrust bearing 28 is fixed to a holder 29 fixed to the subframe 37. The compression mechanism unit 2, the electric motor 16, and the drive shaft 19 are housed in the closed container 1.

In the closed container 1, a guide frame 30 is fixed to the closed container 1 at the upper part of the electric motor 16 and the lower part of the compression mechanism portion 2, and a subframe 37 holding the drive shaft 19 is fixed at the lower part of the electric motor 16. It is fixed at 1. The compliant frame 31 is housed on the inner peripheral side of the guide frame 30. An upper fitting cylindrical surface 30a is formed on the compression mechanism portion 2 side of the inner peripheral surface of the guide frame 30. The upper fitting cylindrical surface 30a is engaged with the upper fitting cylindrical surface 35a formed on the outer peripheral surface of the compliant frame 31. A gap is formed in a part of the circumferential direction between the upper fitting cylindrical surface 30a and the upper fitting cylindrical surface 35a to form the compliant frame upper space 32a.

On the other hand, a lower fitting cylindrical surface 30b is formed on the motor 16 side of the inner peripheral surface of the guide frame 30. The lower fitting cylindrical surface 30b is engaged with the lower fitting cylindrical surface 35b formed on the outer peripheral surface of the compliant frame 31. An upper annular seal member 36a and a lower annular seal member 36b are arranged at two locations on the outer peripheral surface of the compliant frame 31. The inner surface of the guide frame 30 and the outer surface of the compliant frame 31 are partitioned by an upper annular seal member 36a and a lower annular seal member 36b.

A compliant frame lower space 32b is provided between the upper annular seal member 36a and the lower annular seal member 36b. The upper annular seal member 36a and the lower annular seal member 36b are arranged at two locations on the outer peripheral surface of the compliant frame 31 in FIG. 1, but the positions of the seal members are not limited to the example of FIG. .. For example, the upper annular seal member 36a and the lower annular seal member 36b may be arranged at two locations on the inner peripheral surface of the guide frame 30.

The compliant frame 31 is formed with a gas introduction flow path 14 that communicates the thrust surface 33 that slides with the swing scroll 3 and the compliant frame lower space 32b. The gas introduction flow path 14 is provided so as to communicate with the bleeding hole 3e formed in the rocking base plate 3a described later of the rocking scroll 3. Further, a flow path 14a is formed between the guide frame 30 and the inner wall of the closed container 1. The flow path 14a is a flow path through which the high-pressure working gas flowing out from the discharge hole 4f formed in the fixed base plate 4a described later of the fixed scroll 4 passes.

An intermediate pressure space 38, which is an intermediate pressure space having a pressure lower than the discharge pressure and higher than the suction pressure, is formed between the outside of the boss portion 3c provided on the swing scroll 3 and the compliant frame 31. ing. Further, an intermediate pressure adjusting valve space 39d is formed in the compliant frame 31, and an intermediate pressure adjusting valve 39a for adjusting the pressure in the intermediate pressure space 38 and an intermediate pressure adjusting valve are formed in the intermediate pressure adjusting valve space 39d. A holding 39b and an intermediate pressure adjusting spring 39c are arranged. The intermediate pressure adjusting spring 39c is shortened from its natural length and is housed in the intermediate pressure adjusting valve space 39d. Further, the compliant frame 31 is formed with a through flow path 39e that communicates the intermediate pressure space 38 and the intermediate pressure adjusting valve space 39d.

Further, the intermediate pressure regulating valve space 39d and the compliant frame upper space 32a communicate with each other. Further, the compliant frame upper space 32a is formed so as to communicate with the inside of the old dam ring 40. Therefore, the intermediate pressure space 38 and the reciprocating sliding surface 41 of the old dam ring 40 communicate with each other via the through flow path 39e, the intermediate pressure adjusting valve space 39d, and the compliant frame upper space 32a.

The compression mechanism unit 2 compresses the working gas sucked into the closed container 1 from the suction pipe 7, and has a swing scroll 3 and a fixed scroll 4. The fixed scroll 4 is arranged above the swing scroll 3. The fixed scroll 4 is made of a metal such as cast iron, and is fixed to a guide frame 30 fixedly supported by the closed container 1 with bolts (not shown) or the like.

The fixed scroll 4 has a fixed base plate 4a and fixed spiral teeth 4b formed on one surface of the fixed base plate 4a. The rocking scroll 3 has a rocking base plate 3a and a rocking spiral tooth 3b formed on one surface of the rocking base plate 3a. The fixed scroll 4 and the swing scroll 3 are arranged in the closed container 1 by combining the fixed spiral teeth 4b and the swing spiral teeth 3b so as to face each other. The fixed spiral tooth 4b and the swinging spiral tooth 3b are combined in opposite phases, and a compression chamber 12 is formed between the fixed spiral tooth 4b of the fixed scroll 4 and the swinging spiral tooth 3b of the swing scroll 3. ing.

A pair of fixed side old dam ring grooves 15a are formed in a straight line on the outer peripheral portion of the fixed scroll 4. In the fixed side old dam ring groove 15a, two pairs of fixed side keys 42a of the old dam ring 40 are installed so as to be reciprocally slidable. A discharge hole 4f for discharging the high-pressure working gas compressed by the compression mechanism portion 2 is formed in the central portion of the fixed base plate 4a.

In the swing base plate 3a of the swing scroll 3, a tubular boss portion 3c is formed on the surface side facing the surface on which the swing spiral teeth 3b are formed. A swing bearing 26 is provided on the inner surface side of the boss portion 3c. The swing shaft portion 21 of the drive shaft 19 is inserted into the swing bearing 26, and the swing scroll 3 revolves due to the rotation of the swing shaft portion 21.

The compliant frame 31 is located below the oscillating base plate 3a of the oscillating scroll 3, and the oscillating scroll 3 is supported by the compliant frame 31 so as to revolve. An old dam ring 40 oscillatingly supported by the compliant frame 31 is provided between the oscillating scroll 3 and the compliant frame 31 in order to give an oscillating motion while preventing the oscillating scroll 3 from rotating. Has been done. A pair of swing-side oldham ring grooves 15b are formed in a straight line on the outer peripheral portion of the swing scroll 3. The swinging side old dam ring groove 15b has a phase difference of about 90 degrees from the fixed side old dam ring groove 15a, and two pairs of swinging side keys 42b of the old dam ring 40 are installed so as to be reciprocally slidable. ..

In the rocking base plate 3a of the rocking scroll 3, a thrust surface 3d slidable with the thrust surface 33 of the compliant frame 31 is formed on the outer peripheral portion of the surface on which the boss portion 3c is formed. A reciprocating sliding surface 41 is formed on the outer peripheral portion of the thrust surface 33 of the compliant frame 31, and the swinging side key 42b of the old dam ring 40 slides reciprocatingly. Here, the outer peripheral space of the base plate (hereinafter, the suction side space 8) outside the fixed spiral teeth 4b of the fixed scroll 4 and the swinging spiral teeth 3b of the swing scroll 3 is a low pressure space having an suction gas atmosphere which is the suction pressure. It has become.

The electric motor 16 rotationally drives the drive shaft 19, has an electric motor rotor 16a and an electric motor stator 16b, has a variable rotation speed, and generates a rotational force. The motor rotor 16a is fixed to the drive shaft 19 by shrink fitting or the like, and the motor stator 16b is fixed to the closed container 1 by shrink fitting or the like. A glass terminal (not shown) is connected to the motor stator 16b, and the glass terminal is connected to a lead wire (not shown) for obtaining electric power from the outside. Then, when the electric power is supplied to the electric motor stator 16b, the drive shaft 19 and the electric motor rotor 16a rotate with respect to the electric motor stator 16b. A balance weight 18a and a balance weight 18b are fixed to the motor rotor 16a and the drive shaft 19 in order to balance the entire rotating system in the scroll compressor 100.

The drive shaft 19 transmits the rotational force generated by the electric motor 16 to the compression mechanism unit 2. The drive shaft 19 has a spindle portion 20 joined to the motor rotor 16a, a swing shaft portion 21 provided above the spindle portion 20, and a sub-shaft portion 22 provided below the spindle portion 20. .. The central axis of the swing shaft portion 21 is eccentric from the central axis of the main shaft portion 20. The drive shaft 19 is a sub-shaft with a main bearing 25 provided on the inner peripheral surface of the compliant frame 31 supporting the main shaft portion 20 and a sub-bearing 27 provided in the sub-frame 37 fixedly supported by the closed container 1. Part 22 is supported. Further, the lower end surface of the drive shaft 19 is supported by its own weight by the thrust bearing 28. The main bearing 25 and the sub-bearing 27 have a cylindrical structure, and are composed of a bearing structure made of a slide bearing such as a copper-lead alloy, so that the main shaft portion 20 and the sub-shaft portion 22 of the drive shaft 19 can be rotated. It supports.

An oil supply passage 23, a supply passage 24a, and a supply passage 24b are formed inside the drive shaft 19. The oil supply passage 23 is formed so as to extend the inside of the drive shaft 19 in the axial direction from the lower end portion of the drive shaft 19 toward the upper end portion. The supply path 24a and the supply path 24b are formed so as to extend in the radial direction inside the drive shaft 19 and lead to the oil supply path 23. The supply path 24b is installed at a position where the opening thereof is covered with the main bearing 25. The oil is supplied to each sliding portion such as the main bearing 25 and the sub bearing 27 via the oil supply path 23, the supply path 24a and the supply path 24b.

Next, the operation of the scroll compressor 100 will be described. The check valve 9 overcomes the spring force of the spring 10 by the low-pressure (suction pressure) working gas that has flowed into the suction pipe 7, and is pushed down to the valve stop (not shown). After that, the working gas flows into the suction side space 8 in the closed container 1.

On the other hand, the drive shaft 19 rotates when electric power is supplied from the inverter device (not shown) to the electric motor 16. The swing shaft portion 21 rotates due to the rotation of the drive shaft 19, and the swing scroll 3 performs a swing motion (revolution motion). At this time, the working gas is sucked into the outermost chamber of the plurality of compression chambers 12 formed between the swing scroll 3 and the fixed scroll 4.

Then, the outermost chamber reduces the volume while moving from the outer peripheral portion toward the center along with the rocking motion of the rocking scroll 3, and boosts the working gas from low pressure to high pressure. Then, the boosted working gas is guided to the high-pressure gas atmosphere 6 from the discharge hole 4f, passes through the flow path 14a, makes the inside of the closed container 1 a high-pressure gas atmosphere 6, and the discharge pipe 11 provided on the side surface of the closed container 1. Is discharged to the outside.

The working gas of the intermediate pressure during compression by the compression mechanism unit 2 is guided from the bleeding hole 3e of the rocking base plate 3a to the compliant frame lower space 32b via the gas introduction flow path 14. The intermediate pressure is a pressure equal to or higher than the suction pressure and lower than the discharge pressure. The compliant frame lower space 32b is a space sealed by the upper annular seal member 36a and the lower annular seal member 36b. Therefore, the compliant frame 31 floats in the axial direction due to the intermediate pressure working gas introduced into the compliant frame lower space 32b.

The intermediate pressure Pm1 of the intermediate pressure space 38 is "a predetermined pressure α determined by the elastic force of the intermediate pressure adjusting spring 39c and the area exposed to the intermediate pressure of the intermediate pressure adjusting valve 39a" and "the suction side space 8". It is the sum of the pressure Ps and Ps + α. Further, the intermediate pressure Pm2 of the compliant frame lower space 32b is the product of "a predetermined magnification β determined by the position of the communicating compression chamber 12" and "pressure Ps of the suction side space 8", and is Ps × β. It becomes.

The intermediate pressure Pm1 and the intermediate pressure Pm2 act downward on the compliant frame 31, and the high pressure Pd due to the high pressure gas atmosphere 6 acts upward on the lower end surface 34 of the compliant frame. The upward load acting on the compliant frame 31 by the pressure Pd is larger than the downward load acting on the compliant frame 31 by the intermediate pressure Pm1 and the intermediate pressure Pm2. Therefore, the compliant frame 31 floats in the axial direction along the inner peripheral surface of the guide frame 30.

As a result, the swing scroll 3 also floats via the thrust surface 33, so that the gap between the tips of the spiral teeth of the fixed scroll 4 and the swing scroll 3 forming the compression chamber 12 and the base plate becomes small. As a result, the high-pressure working gas is less likely to leak from the compression chamber 12, and a highly efficient scroll compressor can be obtained.

On the other hand, if the pressure inside the compression chamber 12 becomes abnormally high during startup or liquid compression, the gas load in the axial direction acting on the swing scroll 3 becomes excessive. Then, the swing scroll 3 pushes down the compliant frame 31 via the thrust surface 33. That is, a relatively large gap is generated between the tips of the spiral teeth of the fixed scroll 4 and the swing scroll 3 and the base plate. With this gap, an abnormal increase in pressure in the compression chamber 12 can be suppressed, and a highly reliable scroll compressor without damage to the sliding portion can be obtained.

Next, the flow of oil will be described with reference to FIG. When the drive shaft 19 rotates with the rotation of the electric motor rotor 16a, the inside of the closed container 1 is filled with the gas compressed by the compression mechanism unit 2 to create a high-pressure gas atmosphere 6. Since the oil reservoir space 5 exposed to the high-pressure gas atmosphere 6 and the suction side space 8 of the compression mechanism unit 2 communicate with each other through the oil supply passage 23 of the drive shaft 19, the oil in the oil reservoir space 5 is affected by the differential pressure. It is sucked up. This oil is supplied from the oil supply path 23, the supply path 24a and the supply path 24b to the main bearing 25, the sub bearing 27 and the swing bearing 26, respectively. The oil supplied to the sub-bearing 27 lubricates the sub-bearing 27 and is then returned to the oil reservoir space 5 below the closed container 1.

The oil that has passed through the oil supply passage 23 and rises and is supplied to the main bearing 25 is guided to the intermediate pressure space 38 or the high pressure gas atmosphere 6 after lubricating the space between the main bearing 25 and the main shaft portion 20. After passing through the main bearing 25, the oil supplied to the boss portion 3c of the swing scroll 3 lubricates the swing bearing 26, is depressurized in the process, becomes an intermediate pressure, and is eventually guided to the intermediate pressure space 38. The oil guided to the intermediate pressure space 38 overcomes the spring force of the intermediate pressure adjusting spring 39c when passing through the through flow path 39e, pushes up the intermediate pressure adjusting valve 39a, and once discharges to the compliant frame upper space 32a. Will be done. After that, this oil is discharged inside the Oldam ring 40 and supplied to the suction side space 8.

Further, some oil is supplied to the reciprocating sliding surface 41 after being supplied from the intermediate pressure space 38 to the thrust surface 3d, and flows into the suction side space 8. The oil that has flowed into the suction side space 8 is sucked into the compression mechanism 2 together with the low-pressure working gas. The sucked oil enables normal operation by sealing and lubricating the gaps between the fixed scroll 4 and the swing scroll 3 constituting the compression mechanism unit 2.

Next, the configuration of the characteristic portion of the present embodiment will be described. The present embodiment is characterized in a structure in which the suction volume is adjusted and the capacity is controlled without changing the peripheral structure of the scroll compressor. Further, in the present embodiment, the suction volume is adjusted without reducing the rotation speed of the electric motor 16 to switch between full load operation and partial load operation. Hereinafter, the capacity control technique of the present embodiment will be described.

FIG. 2 is a schematic cross-sectional view of the compression mechanism portion of the scroll compressor according to the embodiment. FIG. 3 is an explanatory diagram of the operation of the autonomous movable tooth in the fixed scroll of the scroll compressor according to the embodiment. FIG. 3A shows the position of the autonomous movable tooth during full load operation, and FIG. 3B shows the position of the autonomous movable tooth during partial load operation. FIG. 4 is a schematic vertical cross-sectional view showing a state in which the autonomous movable teeth are removed from the fixed scroll of the scroll compressor according to the embodiment. FIG. 5 is a schematic cross-sectional view showing a state in which the autonomous movable teeth are removed from the fixed scroll of the scroll compressor according to the embodiment. FIG. 6 is a perspective view of the autonomous movable teeth of the scroll compressor according to the embodiment.

The fixed scroll 4 of the present embodiment has an insertion hole 46 formed so as to penetrate in the axial direction as shown in FIGS. 3 and 4, and the autonomous movable tooth 50 can be moved in the axial direction in the insertion hole 46. It has been inserted. The autonomous movable tooth 50 operates autonomously by the force relationship acting on the autonomous movable tooth 50, and switches between full load operation and partial load operation. Specifically, the autonomous movable tooth 50 moves downward, that is, toward the swing scroll 3 side as shown in FIG. 3A when the load is high, whereby the scroll compressor 100 performs the high load operation. When the load is low, the autonomous movable tooth 50 moves upward, that is, in a direction away from the swing scroll 3, whereby the scroll compressor 100 performs a partial load operation. The specific configuration and operation of the autonomous movable tooth 50 will be described in detail again.

The insertion hole 46 has a stepped communication hole 44 formed in the fixed base plate 4a and a tooth hole 45 formed in the fixed spiral tooth 4b as shown in FIGS. 4 and 5. The stepped communication hole 44 and the tooth hole 45 communicate with each other in the axial direction. The stepped communication hole 44 has a columnar upper hole 44a and a columnar lower hole 44b having a diameter smaller than that of the upper hole 44a. The tooth hole 45 is formed by cutting out the fixed spiral tooth 4b from the base end portion to the tip end portion facing the rocking base plate 3a.

As shown in FIG. 6, the autonomous movable tooth 50 mainly has a pressure receiving portion 51 having a columnar shape and a partial spiral tooth 53 integrally formed with the pressure receiving portion 51. The pressure receiving portion 51 has a diameter larger than the outer shape of the partial spiral tooth 53 when viewed in a plane, and is inserted into the upper hole 44a of the insertion hole 46. The partial spiral tooth 53 is inserted into the lower hole 44b and the tooth hole 45 of the insertion hole 46. By inserting the partial spiral tooth 53 into the tooth hole 45 in this way, at least one portion of the fixed spiral tooth 4b is composed of the partial spiral tooth 53.

The upper opening of the upper hole 44a is closed with a magnet 13. The magnet 13 is held by the fixed base plate 4a by a magnetic force acting between the magnet 13 and the fixed scroll 4 made of iron. The magnet 13 is provided to attract the autonomous movable tooth 50 and move the autonomous movable tooth 50 in a direction away from the swing scroll 3. At the boundary between the upper hole 44a and the lower hole 44b, a step 44c for positioning the autonomous movable tooth 50 on the lower side in the axial direction is formed.

The fixed base plate 4a of the fixed scroll 4 is further formed with a high-pressure gas introduction flow path 43 extending radially inward from the outer peripheral surface of the fixed base plate 4a. The radial inner end of the high pressure gas introduction flow path 43 communicates with the upper hole 44a of the stepped communication hole 44. The high-pressure gas introduction flow path 43 communicates with the high-pressure gas atmosphere 6, and introduces the high-pressure gas of the high-pressure gas atmosphere 6 into the upper hole 44a. By introducing the high pressure gas into the upper hole 44a, a downward pressing force acts on the pressure receiving portion 51 of the autonomous movable tooth 50.

As shown in FIG. 6, the pressure receiving portion 51 of the autonomous movable tooth 50 has a curved surface 51a on the upper surface, and has a surface shape that is easily affected by the force of high pressure gas. Further, the pressure receiving portion 51 of the autonomous movable tooth 50 is provided with a seal groove 52, and a seal member (not shown) such as an O-ring is mounted on the seal groove 52 to form the pressure receiving portion 51 and the upper hole 44a. Is tightly sealed. As a result, the high-pressure gas introduced into the upper hole 44a from the high-pressure gas introduction flow path 43 is prevented from flowing into the compression mechanism portion 2.

Further, in the autonomous movable tooth 50, both end surfaces of the partial spiral tooth 53 in the circumferential direction are tapered surfaces 53a, and the tapered surfaces along the inclined surface 45a (see FIG. 5) of the tooth hole 45 formed in the fixed spiral tooth 4b. It has become. Each tapered surface 53a of the partial spiral tooth 53 is composed of an inclined surface whose distance from each other decreases from the inner side in the radial direction to the outer side in the radial direction.

Here, if the tapered surface 53a of the partial spiral tooth 53 is in the opposite direction, that is, the tapered surface in which the distance between the partial spiral teeth 53 increases from the inner side in the radial direction to the outer side in the radial direction, the following problems occur. In the compression mechanism portion 2, the pressure increases from the outer side in the radial direction toward the central portion, so that a gas load outward in the radial direction acts on the autonomous movable tooth 50. Therefore, if the tapered surface 53a of the partial spiral tooth 53 is inclined so that the distance between the partial spiral teeth 53 increases from the inside in the radial direction to the outside in the radial direction, the partial spiral tooth 53 is pressed outward in the radial direction by this gas load. , There is a possibility of forming a gap with the tooth hole 45. If a gap is formed between the partial spiral tooth 53 and the tooth hole 45, the compression efficiency is lowered, which is not preferable.

From this, the tapered surface 53a of the partial spiral tooth 53 is composed of a tapered surface whose distance from each other decreases from the inner side in the radial direction to the outer side in the radial direction. As a result, even if a gas load that presses outward in the radial direction acts on the partial spiral tooth 53, the partial spiral tooth 53 is supported by the inclined surface 45a of the tooth hole 45, and is between the partial spiral tooth 53 and the tooth hole 45. It is possible to avoid the formation of gaps. As a result, it is possible to prevent a gap from being formed between the partial spiral tooth 53 and the inclined surface 45a of the tooth hole 45 while maintaining the airtightness between the partial spiral tooth 53 and the tooth hole 45.

Next, the position of the autonomous movable tooth 50 will be described with reference to FIG.
In the autonomous movable tooth 50, as shown in FIG. 3A, the pressure receiving portion 51 is in contact with the step 44c, and as shown in FIG. 3B, the pressure receiving portion 51 is separated from the step 44c of the pressure receiving portion 51. It moves up and down in the stepped communication hole 44 at a position where the upper surface abuts on the magnet 13. As shown in FIG. 3A, when the pressure receiving portion 51 is in contact with the step 44c, the tip surface 53b of the partial spiral tooth 53 follows the tip surface 4ba of the fixed spiral tooth 4b excluding the partial spiral tooth 53. It is flush with the virtual surface 60. Hereinafter, the state in which the tip surface 53b of the partial spiral tooth 53 is flush with the virtual surface 60 is referred to as a “contact state”.

In the autonomous movable tooth 50, when the pressure receiving portion 51 is at a position away from the step 44c as shown in FIG. 3B, the tip surface 53b of the partial spiral tooth 53 is in a state of being separated from the virtual surface 60. Hereinafter, the state in which the tip surface 53b of the partial spiral tooth 53 is separated from the virtual surface 60 is referred to as a “separation state”. In the separated state, a gap 61 is formed between the tip surface 53b of the autonomous movable tooth 50 and the virtual surface 60.

FIG. 7 is a spiral operation diagram showing a compression stroke when the autonomous movable teeth are in a separated state in the scroll compressor according to the embodiment. It should be noted that the illustration of the autonomous movable tooth is omitted in FIG. 7. In FIG. 7, (a) shows the time when the suction is completed when the outermost chamber is formed, and the rotation phase of the drive shaft 19 in this state is set to 0 °. (B), (c), and (d) show the states of the fixed spiral tooth 4b and the swinging spiral tooth 3b when the rotation phase is advanced by 90 ° from 0 °.

When the autonomous movable teeth 50 are in contact with each other, the outermost chamber 70, which has completed sucking the working gas, moves toward the center along with the swinging motion of the swinging scroll 3 and reduces the volume of the working gas inside. Compress. Therefore, the suction volume when the autonomous movable tooth 50 is in contact is the volume V1 of the outermost chamber 70 indicated by dots in FIG. 7A.

On the other hand, when the autonomous movable teeth 50 are in a separated state, as shown in FIG. 7A, two compression chambers constituting the outermost chamber 70, that is, outer compression chambers 12a adjacent to each other in the radial direction with the autonomous movable teeth 50 as a boundary. And the inner compression chamber 12b communicate with each other through the gap 61. The outer compression chamber 12a is formed between the outer surface of the fixed spiral tooth 4b and the inner surface of the swinging spiral tooth 3b. The inner compression chamber 12b is formed between the inner surface of the fixed spiral tooth 4b and the outer surface of the swinging spiral tooth 3b. When the outer compression chamber 12a and the inner compression chamber 12b communicate with each other through the gap 61, the outermost chamber 70 is shown in FIGS. 7 (a) → (b) → (c) as the rocking scroll 3 swings. As shown, the volume is reduced while moving toward the center, but the compression operation is not performed.

Then, as shown in FIG. 7C, the outer compression chamber 12a and the inner compression chamber 12b are not communicated with each other, so that the compression operation is started in the outer compression chamber 12a. Continuing to reduce the volume while the outer compression chamber 12a moves toward the center as shown in FIGS. 7 (c) to 7 (d), the compression of the working gas is continued, and when the outer compression chamber 12a becomes the innermost chamber, the maximum The working gas in the inner chamber is discharged from the discharge hole 4f.

As described above, when the autonomous movable teeth 50 are in the separated state, the compression is started from the state shown in FIG. 7C, so that the volume V2 of the outer compression chamber 12a shown by the cross hatching becomes the suction volume. The inner compression chamber 12b, which is not communicated with the outer compression chamber 12a in FIG. 7C, communicates with the outside of the inner compression chamber 12b through the gap 61 in the rotation phase of FIG. 7D, so that it is compressed. It does not function as a room.

In this way, when the autonomous movable tooth 50 is in the separated state, the suction volume is reduced from V1 to V2 as compared with the case where the autonomous movable tooth 50 is in the contact state. Therefore, the operation with a low load can be performed without reducing the rotation speed of the electric motor 16. That is, since it is not necessary to reduce the rotation speed of the electric motor 16 when the load is low, leakage of working gas can be prevented.

Next, the autonomous up-and-down movement of the autonomous movable tooth 50 according to the force acting on the autonomous movable tooth 50 will be described.

FIG. 8 is an explanatory diagram of a force acting on the autonomous movable teeth of the scroll compressor according to the embodiment.
After the scroll compressor 100 is started, the pressure in the closed container 1 gradually increases, and the pressure in the high pressure gas atmosphere 6 also increases. Since the high-pressure gas introduction flow path 43 communicates with the high-pressure gas atmosphere 6, the pressure of the high-pressure gas introduction flow path 43 is the same pressure Pd as the high-pressure gas atmosphere 6. Considering the force applied to the autonomous movable tooth 50, the gas force Fd due to the pressure Pd is applied downward in the axial direction to the curved surface 51a of the pressure receiving portion 51. Further, an axially upward force Fm is applied to the autonomous movable tooth 50 by the magnetic force of the magnet 13. Further, in the autonomous movable tooth 50, an axially upward force Fs due to the suction pressure Ps is applied to the tip surface 53b of the partial spiral tooth 53. Due to these force relationships, the autonomous movable tooth 50 moves up and down autonomously to switch between full load operation and partial load operation.

(Full load operation)
When the load is high, that is, when the high-pressure working gas flows into the upper hole 44a through the high-pressure gas introduction flow path 43 and the force relationship acting on the autonomous movable tooth 50 is Fd> Fm + Fs, the autonomous movable tooth 50 is axially oriented. Pressed downwards. That is, the autonomous movable tooth 50 is pressed against the swing scroll 3 side and is in a contact state, and full load operation is performed in which the suction volume is V1.

(Partial load operation)
When the load is low, that is, when the force relationship acting on the autonomous movable tooth 50 is Fd ≦ Fm + Fs, the autonomous movable tooth 50 is attracted to the magnet 13 and becomes separated. Therefore, the outermost chamber 70 becomes an invalid space that does not function as a compression chamber, and a partial load operation in which the suction volume becomes V2 is performed.

As described above, the scroll compressor 100 of the present embodiment includes a fixed scroll 4 having a fixed base plate 4a and fixed spiral teeth 4b formed on the fixed base plate 4a, a swing base plate 3a, and a rocking base. It has a swinging spiral tooth 3b formed on the plate 3a. The scroll compressor 100 includes a swing scroll 3 in which the swing spiral teeth 3b are combined with the fixed spiral teeth 4b of the fixed scroll 4 to form a plurality of compression chambers 12 for compressing the working gas from low pressure to high pressure. The drive shaft 19 for driving the scroll 3 and the insertion hole 46 formed through the fixed scroll 4 in the axial direction of the drive shaft 19 are inserted to form a part of the fixed spiral tooth 4b, and the inside of the insertion hole 46 is formed. The autonomous movable tooth 50 that moves up and down autonomously and the fixed scroll 4 are provided, and the autonomous movable tooth 50 is pulled to the opposite side of the swing scroll 3 in the insertion hole 46 to pull the tip surface 43b of the autonomous movable tooth 50. It has a magnet 13 that is separated from the swing base plate 3a, and a closed container 1 that houses a fixed scroll 4, a swing scroll 3, a drive shaft 19, an autonomous movable tooth 50, and a magnet 13. The autonomous movable tooth 50 is autonomous inside the insertion hole 46 due to the magnitude relationship between the combined force of the magnetic force of the magnet 13 and the force acting on the autonomous movable tooth 50 by the low pressure and the force acting on the autonomous movable tooth 50 by the high pressure. The tip surface 53b of the autonomous movable tooth 50 moves up and down so that it is flush with the tip surface 4ba of the fixed spiral tooth 4b excluding the autonomous movable tooth 50, and the separated state is separated without being flush with each other. Adjust the suction volume by switching to.

In this way, a part of the fixed spiral teeth 4b of the fixed scroll 4 is composed of autonomous movable teeth 50 that move up and down autonomously inside the insertion hole 46, and the magnetic force of the magnet 13 and the pressure in the closed container 1 are combined. Based on the autonomous vertical movement of the autonomous movable tooth 50, the tip surface 53b of the autonomous movable tooth 50 is flush with the tip surface 4ba of the fixed spiral tooth 4b excluding the autonomous movable tooth 50. It is configured to switch to a separated state without being separated. As a result, the suction volume can be adjusted according to the position of the autonomous movable tooth 50 without changing the peripheral structure of the scroll compressor 100.

In the scroll compressor 100 of the present embodiment, when the force acting on the autonomous movable tooth 50 due to high pressure is larger than the resultant force, the autonomous movable tooth 50 is pressed toward the swing scroll 3 side, and among the plurality of compression chambers 12, Two compression chambers 12 adjacent to each other in the radial direction of the drive shaft 19 are partitioned by the autonomous movable tooth 50 as a boundary. Further, when the force acting on the autonomous movable tooth 50 due to the high pressure is equal to or less than the resultant force, the autonomous movable tooth 50 is pressed in a direction away from the swing scroll 3 to communicate the two compression chambers 12.

In this way, when the force acting on the autonomous movable tooth 50 due to the high pressure is larger than the resultant force, the two compression chambers 12 adjacent to each other in the radial direction of the drive shaft 19 are partitioned by the autonomous movable tooth 50 as a boundary, so that when the load is high. Full load operation can be performed. Further, when the force acting on the autonomous movable tooth 50 due to the high pressure is equal to or less than the resultant force, the two compression chambers 12 adjacent to each other in the radial direction of the drive shaft 19 with the autonomous movable tooth 50 as a boundary do not communicate with each other to perform the compression operation. Partial load operation can be performed when the load is low.

In the scroll compressor 100 of the present embodiment, the autonomous movable tooth 50 has a columnar pressure receiving portion 51 and a partial spiral tooth 53, and the partial spiral tooth 53 forms a part of the fixed spiral tooth 4b. The fixed base plate 4a is formed with a high-pressure gas introduction flow path 43 extending radially inward from the outer peripheral surface and communicating with the insertion hole 46, and the high-pressure gas introduction flow path 43 allows high-pressure operation in the closed container 1. The gas is guided to the insertion hole 46, and a high pressure acts on the pressure receiving portion 51 of the autonomous movable tooth 50.

In this way, a high pressure can be applied to the pressure receiving portion 51 of the autonomous movable tooth 50 by the high pressure gas introduction flow path 43, and the autonomous movable tooth 50 can be operated by the pressure in the closed container 1.

1 closed container, 2 compression mechanism, 3 rocking scroll, 3a rocking base plate, 3b rocking spiral tooth, 3c boss part, 3d thrust surface, 3e air extraction hole, 4 fixed scroll, 4a fixed base plate, 4b fixed spiral Teeth, 4ba tip surface, 4f discharge hole, 5 oil reservoir space, 6 high-pressure gas atmosphere, 7 suction pipe, 8 suction side space, 9 check valve, 10 spring, 11 discharge pipe, 12 compression chamber, 12a outer compression chamber, 12b inner compression chamber, 13 magnets, 14 gas introduction flow path, 14a flow path, 15a fixed side old dam ring groove, 15b rocking side old dam ring groove, 16 electric motor, 16a electric motor rotor, 16b electric motor stator, 18a balance weight, 18b balance weight, 19 drive shaft, 20 spindle, 21 swing shaft, 22 sub-shaft, 23 refueling path, 24a supply path, 24b supply path, 25 main bearing, 26 swing bearing, 27 sub-bearing, 28 thrust Bearing, 29 holder, 30 guide frame, 30a upper fitting cylindrical surface, 30b lower fitting cylindrical surface, 31 compliant frame, 32a compliant frame upper space, 32b compliant frame lower space, 33 thrust surface, 34 compliant frame Lower end surface, 35a upper fitting cylindrical surface, 35b lower fitting cylindrical surface, 36a upper annular seal member, 36b lower annular seal member, 37 subframe, 38 intermediate pressure space, 39a intermediate pressure adjusting valve, 39c intermediate pressure adjustment Spring, 39d intermediate pressure control valve space, 39e through flow path, 40 old dam ring, 41 reciprocating sliding surface, 42a fixed side key, 42b rocking side key, 43 high pressure gas introduction flow path, 44 stepped communication hole, 44a upper part Hole, 44b lower hole, 44c step, 45 tooth hole, 45a inclined surface, 46 insertion hole, 50 autonomous movable tooth, 51 pressure receiving part, 51a curved surface, 52 seal groove, 53 partial spiral tooth, 53a tapered surface, 53b tip surface , 60 virtual surface, 61 gap, 70 outermost room, 100 scroll compressor.

Claims

A fixed base plate and a fixed scroll having fixed spiral teeth formed on the fixed base plate,
It has a rocking base plate and swinging spiral teeth formed on the rocking base plate, and the swinging spiral teeth are combined with the fixed spiral teeth of the fixed scroll to compress the working gas from low pressure to high pressure. Swirling scrolls that form multiple compression chambers,
The drive shaft that drives the swing scroll and
An autonomous movable tooth that is inserted into an insertion hole formed through the fixed scroll in the axial direction of the drive shaft to form a part of the fixed spiral tooth and autonomously moves up and down inside the insertion hole. ,
A magnet provided on the fixed scroll that attracts the autonomous movable tooth to the side opposite to the swing scroll in the insertion hole to separate the tip surface of the autonomous movable tooth from the swing base plate.
It has the fixed scroll, the swing scroll, the drive shaft, the autonomous movable tooth, and a closed container for accommodating the magnet.
The autonomous movable tooth has a magnitude relationship between the magnetic force of the magnet and the force acting on the autonomous movable tooth due to the low pressure and the force acting on the autonomous movable tooth due to the high pressure in the inside of the insertion hole. A contact state in which the tip surface of the autonomous movable tooth moves up and down autonomously and is flush with the tip surface of the fixed spiral tooth excluding the autonomous movable tooth, and a separated state in which the tip surface is separated without being flush with each other. A scroll compressor that adjusts the suction volume by switching to.
When the force acting on the autonomous movable tooth due to the high pressure is larger than the resultant force, the autonomous movable tooth is pressed toward the swing scroll side, and the driving is performed with the autonomous movable tooth as a boundary among the plurality of compression chambers. Dividing two compression chambers adjacent to each other in the radial direction of the shaft,
The scroll compressor according to claim 1, wherein when the force acting on the autonomous movable tooth due to the high pressure is equal to or less than the resultant force, the autonomous movable tooth is pressed in a direction away from the swing scroll to communicate the two compression chambers. ..
The autonomous movable tooth has a columnar pressure receiving portion and a partial spiral tooth, and the partial spiral tooth forms a part of the fixed spiral tooth.
The fixed base plate is formed with a high-pressure gas introduction flow path extending radially inward from the outer peripheral surface and communicating with the insertion hole, and the high-pressure gas introduction flow path causes the high-pressure working gas in the closed container. The scroll compressor according to claim 1 or 2, wherein the high pressure acts on the pressure receiving portion of the autonomous movable tooth, which is guided to the insertion hole.
The partial spiral tooth of the autonomously movable tooth has a tapered surface in which both end surfaces in the circumferential direction are narrowed from each other as the distance between them decreases from the inner side in the radial direction to the outer side in the radial direction, and the insertion hole is inclined along the tapered surface. The scroll compressor according to claim 3, which has a surface.