JP7154421B2 - scroll compressor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a mechanical capacity control technique for a scroll compressor.

Conventionally, there has been known a scroll compressor including a compression mechanism for compressing a fluid in a compression chamber formed by combining a fixed scroll and an orbiting scroll, and an electric motor connected to the compression mechanism via a rotating shaft. It is In this type of scroll compressor, in order to achieve high efficiency over a wide load range, a method is known in which the capacity of the scroll compressor is controlled by driving the electric motor with an inverter and controlling the rotation speed. However, if the number of rotations is too low at low load, the efficiency of the scroll compressor will decrease due to an increase in leakage of refrigerant from the compression chamber, and the performance will deteriorate. Therefore, it is difficult to maintain high efficiency at low speed and low load capability only by controlling the rotation speed by the inverter.

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

As a scroll compressor using mechanical capacity control, for example, in Patent Document 1, a fixed scroll is provided with a bypass port that allows communication between a compression chamber and a suction chamber, and the bypass port is opened and closed with a bypass valve to change the suction volume. It is made variable. The bypass valve opens and closes when the pressure acting on the bypass valve is switched between high pressure and low pressure by a pressure switching device provided outside the scroll compressor.

Japanese Patent Application No. 2016-217758

In Patent Document 1, it is necessary to adjust the pressure acting on the bypass valve from the outside of the scroll compressor in order to adjust the suction volume. In other words, additional piping or the like was required outside the scroll compressor, and a change in the surrounding structure was required.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems, and to provide a scroll compressor capable of adjusting the suction volume without changing the peripheral structure of the scroll compressor.

A scroll compressor according to the present invention has a fixed scroll having a fixed base plate and fixed spiral teeth formed on the fixed base plate, a swing base plate and a swing spiral tooth formed on the swing base plate, an orbiting scroll that combines an orbiting spiral tooth with a fixed spiral tooth of a fixed scroll to form a plurality of compression chambers for compressing a working gas from a low pressure to a high pressure; a drive shaft that drives the orbiting scroll; an autonomous movable tooth that is inserted into an insertion hole formed through the fixed scroll in the axial direction to form a part of the fixed spiral tooth and moves up and down autonomously inside the insertion hole; A magnet that draws the autonomous movable tooth to the opposite side of the oscillating scroll in the insertion hole and separates the tip surface of the autonomous movable tooth from the oscillating base plate, a fixed scroll, an oscillating scroll, a drive shaft, an autonomous movable tooth, and a magnet. The autonomous movable tooth has a closed container to accommodate, and the autonomous movable tooth has a magnitude relationship between the resultant force of the magnetic force by the magnet and the force acting on the autonomous movable tooth due to low pressure, and the force acting on the autonomous movable tooth due to high pressure. It moves up and down autonomously internally, and the tip surface of the autonomously movable tooth is flush with the tip surface of the fixed spiral tooth excluding the autonomously movable tooth. The inhalation volume is adjusted by switching.

According to the scroll compressor of the present invention, a part of the fixed scroll is composed of the autonomously movable teeth, and the autonomously movable teeth are moved up and down autonomously based on the magnetic force of the magnet and the pressure inside the sealed 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 not flush with the tip surface and is separated. Therefore, the suction volume can be adjusted without changing the peripheral structure of the scroll compressor.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional schematic diagram which shows the scroll compressor which concerns on embodiment. It is a cross-sectional schematic diagram of the compression mechanism part of the scroll compressor which concerns on embodiment. FIG. 5 is an operation explanatory diagram of the autonomous movable teeth in the fixed scroll of the scroll compressor according to the embodiment; It is a vertical cross-sectional schematic diagram which shows the state which removed the autonomous movable tooth from the fixed scroll of the scroll compressor which concerns on embodiment. It is a cross-sectional schematic diagram of the state which removed the autonomous movable tooth|gear from the fixed scroll of the scroll compressor which concerns on embodiment. It is a perspective view of the autonomous movable tooth of the scroll compressor which concerns on embodiment. FIG. 4 is a spiral motion diagram showing a compression stroke when the autonomously movable teeth are in a separated state in the scroll compressor according to the embodiment; It is explanatory drawing of the force which acts on the autonomous movable tooth|gear of the scroll compressor which concerns on embodiment.

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

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

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

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

Inside the closed container 1, a guide frame 30 is fixed to the closed container 1 above the electric motor 16 and below the compression mechanism 2, and a sub-frame 37 for holding the drive shaft 19 is provided below the electric motor 16. Fixed to 1. A compliant frame 31 is housed inside the guide frame 30 . An upper fitting cylindrical surface 30a is formed on the inner peripheral surface of the guide frame 30 on the compression mechanism 2 side. The upper fitting cylindrical surface 30 a is engaged with an upper fitting cylindrical surface 35 a 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 a compliant frame upper space 32a.

On the other hand, a lower fitting cylindrical surface 30b is formed on the inner peripheral surface of the guide frame 30 on the electric motor 16 side. The lower fitting cylindrical surface 30 b is engaged with a lower fitting cylindrical surface 35 b formed on the outer peripheral surface of the compliant frame 31 . An upper annular seal member 36 a and a lower annular seal member 36 b 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. Although 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, the positions of the seal members are not limited to the example in FIG. . For example, the upper annular seal member 36 a and the lower annular seal member 36 b 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 passage 14 that communicates the thrust surface 33 that slides on the orbiting scroll 3 and the compliant frame lower space 32b. The gas introduction passage 14 is provided so as to communicate with an air bleed hole 3e formed in a later-described rocking bed plate 3a of the rocking scroll 3. As shown in FIG. Furthermore, between the guide frame 30 and the inner wall of the sealed container 1, a channel 14a is formed. The flow path 14a is a flow path through which a high-pressure working gas flowing out from a discharge hole 4f formed in a fixed base plate 4a (to be described later) of the fixed scroll 4 passes.

Between the outside of the boss portion 3c provided on the orbiting scroll 3 and the compliant frame 31, an intermediate pressure space 38, which is an intermediate pressure space lower than the discharge pressure and higher than the suction pressure, is formed. ing. An intermediate pressure regulating valve space 39d is formed in the compliant frame 31. In the intermediate pressure regulating valve space 39d, an intermediate pressure regulating valve 39a for adjusting the pressure of the intermediate pressure space 38 and an intermediate pressure regulating valve A presser 39b and an intermediate pressure adjusting spring 39c are arranged. The intermediate pressure adjusting spring 39c is contracted from its natural length and accommodated 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 regulating valve space 39d.

Also, the intermediate pressure regulating valve space 39d and the compliant frame upper space 32a are in communication. Furthermore, the compliant frame upper space 32a is formed so as to communicate with the inside of the Oldham ring 40 . Therefore, the intermediate pressure space 38 and the reciprocating sliding surface 41 of the Oldham ring 40 communicate with each other via the through passage 39e, the intermediate pressure regulating valve space 39d, and the compliant frame upper space 32a.

The compression mechanism section 2 compresses the working gas sucked into the sealed container 1 from the suction pipe 7 and has an orbiting scroll 3 and a fixed scroll 4 . The fixed scroll 4 is arranged above the orbiting scroll 3 . The fixed scroll 4 is made of 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 orbiting scroll 3 has an orbiting base plate 3a and an orbiting spiral tooth 3b formed on one surface of the orbiting base plate 3a. The fixed scroll 4 and the orbiting scroll 3 are arranged in the sealed container 1 in combination so that the fixed spiral teeth 4b and the orbiting spiral teeth 3b face each other. The fixed spiral teeth 4b and the oscillating spiral teeth 3b are combined in opposite phases, and a compression chamber 12 is formed between the fixed spiral teeth 4b of the fixed scroll 4 and the oscillating spiral teeth 3b of the oscillating scroll 3. ing.

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

A cylindrical boss portion 3c is formed on the surface of the oscillating base plate 3a of the oscillating scroll 3 that faces the surface on which the oscillating 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 rotation of the swing shaft portion 21 causes the swing scroll 3 to revolve.

A compliant frame 31 is positioned 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 be capable of revolving motion. Between the orbiting scroll 3 and the compliant frame 31 is provided an Oldham ring 40 which is pivotably supported by the compliant frame 31 in order to prevent the orbiting scroll 3 from rotating on its axis and to give it an orbiting motion. It is A pair of rocking-side Oldham ring grooves 15b are formed in a straight line on the outer peripheral portion of the rocking scroll 3 . The rocking-side Oldham ring groove 15b has a phase difference of about 90 degrees from the fixed-side Oldham ring groove 15a, and a pair of rocking-side keys 42b of the Oldham ring 40 are installed so as to be reciprocally slidable. .

The thrust surface 33 of the compliant frame 31 and the thrust surface 3d which can slide are formed in the outer peripheral part of the surface in which the boss|hub part 3c is formed in the rocking base plate 3a of the rocking scroll 3. As shown in FIG. A reciprocating sliding surface 41 is formed on the outer periphery of the thrust surface 33 of the compliant frame 31, on which the rocking side key 42b of the Oldham ring 40 reciprocates. Here, the outer peripheral space of the base plate outside the fixed spiral tooth 4b of the fixed scroll 4 and the oscillating spiral tooth 3b of the oscillating scroll 3 (hereinafter referred to as the suction side space 8) is a low-pressure space of the suction gas atmosphere, which is the suction pressure. It has become.

The electric motor 16 rotates the drive shaft 19, has an electric motor rotor 16a and an electric motor stator 16b, and generates a rotational force with a variable rotational speed. 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 sealed 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. When electric power is supplied to the motor stator 16b, the drive shaft 19 and the motor rotor 16a rotate with respect to the motor stator 16b. In addition, balance weights 18a and 18b are fixed to the electric motor rotor 16a and the drive shaft 19 in order to balance the entire rotation system in the scroll compressor 100. As shown in FIG.

The drive shaft 19 transmits the rotational force generated by the electric motor 16 to the compression mechanism section 2 . The drive shaft 19 has a main shaft portion 20 joined to the electric motor rotor 16a, a swing shaft portion 21 provided above the main shaft portion 20, and a counter shaft portion 22 provided below the main shaft portion 20. . The pivot shaft portion 21 has its central axis eccentric from the central axis of the main shaft portion 20 . The drive shaft 19 has a main shaft portion 20 supported by a main bearing 25 provided on the inner peripheral surface of the compliant frame 31 and a sub-shaft portion 27 supported by a sub-frame 37 fixedly supported by the sealed container 1 . Part 22 is supported. Further, the lower end surface of the drive shaft 19 is supported by a thrust bearing 28 under its own weight. The main bearing 25 and the sub-bearing 27 have a cylindrical structure. supporting.

Inside the drive shaft 19, an oil supply passage 23 and supply passages 24a and 24b are formed. The oil supply passage 23 is formed so as to axially extend inside the drive shaft 19 from the lower end of the drive shaft 19 toward the upper end thereof. The supply passages 24 a and 24 b are formed extending radially inside the drive shaft 19 and communicate with the oil supply passage 23 . The supply path 24b is installed at a position where the opening is covered with the main bearing 25. As shown in FIG. Oil is supplied to each sliding portion such as the main bearing 25 and the sub-bearing 27 through the oil supply passage 23, the supply passage 24a and the supply passage 24b.

Next, the operation of scroll compressor 100 will be described. The low-pressure (suction pressure) working gas that has flowed into the suction pipe 7 overcomes the spring force of the spring 10 and pushes the check valve 9 down until it stops (not shown). After that, the working gas flows into the suction side space 8 inside the sealed container 1 .

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

As the orbiting scroll 3 oscillates, the outermost chamber decreases in volume while moving from the outer periphery toward the center, thereby increasing the pressure of the working gas from low to high. Then, the pressurized working gas is led to the high-pressure gas atmosphere 6 from the discharge hole 4f, passes through the flow path 14a, makes the inside of the sealed container 1 the high-pressure gas atmosphere 6, and discharge piping 11 provided on the side surface of the sealed container 1. is discharged to the outside.

The intermediate-pressure working gas that is being compressed in the compression mechanism 2 is led from the bleeding hole 3e of the rocking plate 3a to the compliant frame lower space 32b through the gas introduction passage 14. As shown in FIG. The intermediate pressure is pressure equal to or higher than the suction pressure and equal to or lower than the discharge pressure. The compliant frame lower space 32b is a space sealed by an upper annular seal member 36a and a lower annular seal member 36b. Therefore, the intermediate-pressure working gas introduced into the compliant frame lower space 32b floats the compliant frame 31 in the axial direction.

The intermediate pressure Pm1 in the intermediate pressure space 38 is composed of "predetermined pressure α determined by the elastic force of the intermediate pressure regulating spring 39c and the area exposed to the intermediate pressure of the intermediate pressure regulating valve 39a"; is the sum of the pressure Ps of , and becomes Ps+α. Further, the intermediate pressure Pm2 of the compliant frame lower space 32b is the product of "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 x β. becomes.

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

As a result, the orbiting scroll 3 also floats via the thrust surface 33, so that the clearance between the tips of the spiral teeth of the fixed scroll 4 and the orbiting scroll 3 forming the compression chamber 12 and the base plate becomes smaller. 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 start-up or liquid compression, the axial gas load acting on the orbiting scroll 3 becomes excessive. Then, the orbiting scroll 3 pushes down the compliant frame 31 via the thrust surface 33 . That is, a relatively large gap is generated between the tip of each spiral tooth of the fixed scroll 4 and the orbiting scroll 3 and the base plate. Due to this gap, an abnormal pressure rise in the compression chamber 12 can be suppressed, and a highly reliable scroll compressor with no 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 motor rotor 16 a , the inside of the sealed container 1 is filled with the gas compressed by the compression mechanism 2 and becomes a high-pressure gas atmosphere 6 . The oil reservoir space 5 exposed to the high-pressure gas atmosphere 6 and the suction side space 8 of the compression mechanism 2 communicate with each other through the oil supply passage 23 of the drive shaft 19. be sucked up. This oil is supplied to the main bearing 25, the sub-bearing 27 and the rocking bearing 26 from the oil supply passage 23, the supply passage 24a and the supply passage 24b, 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 sealed container 1 .

The oil that has passed through the oil supply passage 23 , rises, and has been supplied to the main bearing 25 lubricates the space between it and the main shaft portion 20 , and then is guided to the intermediate pressure space 38 or the high-pressure gas atmosphere 6 . After passing through the main bearing 25 , the oil supplied to the boss portion 3 c of the orbiting scroll 3 lubricates the orbiting bearing 26 . The oil guided to the intermediate pressure space 38 overcomes the spring force of the intermediate pressure regulating spring 39c when passing through the through passage 39e, pushes up the intermediate pressure regulating valve 39a, and is temporarily discharged into the compliant frame upper space 32a. be done. After that, this oil is discharged inside the Oldham ring 40 and supplied to the suction side space 8 .

A part of the oil is supplied to the reciprocating sliding surface 41 after being supplied to the thrust surface 3 d from the intermediate pressure space 38 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 portion 2 together with the low-pressure working gas. The sucked oil seals and lubricates the gaps between the fixed scroll 4 and the orbiting scroll 3 that constitute the compression mechanism 2, thereby enabling normal operation.

Next, the configuration of the characteristic portion of this embodiment will be described. The present embodiment is characterized by a structure in which capacity control is performed by adjusting the suction volume without changing the surrounding structure of the scroll compressor. Further, in the present embodiment, the suction volume is adjusted without lowering the rotational speed of the electric motor 16 to switch between full-load operation and partial-load operation. A capacity control technique according to the present embodiment will be described below.

FIG. 2 is a schematic cross-sectional view of a compression mechanism portion of the scroll compressor according to the embodiment. FIG. 3 is an explanatory diagram of the operation of the autonomous movable teeth in the fixed scroll of the scroll compressor according to the embodiment. FIG. 3(a) shows the positions of the autonomous movable teeth during full-load operation, and FIG. 3(b) shows the positions of the autonomous movable teeth 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 cross-sectional schematic diagram of 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.

As shown in FIGS. 3 and 4, the fixed scroll 4 of this embodiment has an insertion hole 46 formed through it in the axial direction. inserted. The autonomous movable tooth 50 operates autonomously according to the force relationship acting on the autonomous movable tooth 50, and switches between full load operation and partial load operation. Specifically, when the load is high, the autonomously movable tooth 50 moves downward, that is, toward the orbiting scroll 3, as shown in FIG. When the load is low, the autonomous movable tooth 50 moves upward, that is, in a direction away from the orbiting scroll 3, as shown in FIG. The specific configuration and operation of the autonomous movable tooth 50 will be described in detail again.

As shown in FIGS. 4 and 5, 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. 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 smaller diameter than the upper hole 44a. The tooth hole 45 is formed by notching the fixed spiral tooth 4b from the base end to the tip facing the rocking base plate 3a.

As shown in FIG. 6 , the autonomously movable tooth 50 has a pressure receiving portion 51 whose shape is mainly cylindrical, and a partial spiral tooth 53 integrally formed with the pressure receiving portion 51 . The pressure receiving portion 51 is formed to have a diameter larger than the outer shape of the partial spiral tooth 53 in a plan view, and is inserted into the upper hole 44 a of the insertion hole 46 . Partial spiral tooth 53 is inserted into lower hole 44 b of insertion hole 46 and tooth hole 45 . 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 configured with the partial spiral tooth 53. As shown in FIG.

The upper opening of the upper hole 44a is blocked by the magnet 13. As shown in FIG. The magnet 13 is held on the fixed base plate 4a by a magnetic force acting between it 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 away from the orbiting scroll 3 . A step 44c is formed at the boundary between the upper hole 44a and the lower hole 44b for positioning the axially lower side of the autonomous movable tooth 50. As shown in FIG.

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

The pressure receiving portion 51 of the autonomous movable tooth 50 has a curved upper surface 51a as shown in FIG. In addition, a seal groove 52 is provided in the pressure receiving portion 51 of the autonomous movable tooth 50, and a sealing member (not shown) such as an O-ring is mounted in the seal groove 52 to separate the pressure receiving portion 51 and the upper hole 44a. and are tightly sealed. This prevents the high-pressure gas introduced from the high-pressure gas introduction channel 43 into the upper hole 44 a from flowing into the compression mechanism section 2 .

In the autonomous movable tooth 50, both circumferential end surfaces of the partial spiral tooth 53 are tapered surfaces 53a, which are 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 formed of an inclined surface whose distance from each other narrows from the radially inner side to the radially outer side.

Here, if the tapered surfaces 53a of the partial spiral teeth 53 are tapered in opposite directions, that is, if the tapered surfaces increase in distance from the radially inner side toward the radially outer side, the following problems arise. In the compression mechanism portion 2 , the pressure increases from the radially outer side toward the central portion, so a radially outward gas load acts on the autonomous movable teeth 50 . Therefore, if the tapered surfaces 53a of the partial spiral teeth 53 are inclined so that the distance between them increases from the radially inner side toward the radially outer side, the partial spiral teeth 53 are pressed radially outward by the gas load. , and the tooth hole 45 may form a gap. 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.

Therefore, the tapered surfaces 53a of the partial spiral teeth 53 are tapered surfaces whose mutual distance decreases from the radially inner side to the radially outer side. As a result, even if a gas load that presses radially outward 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 there is a gap between the partial spiral tooth 53 and the tooth hole 45. It is possible to avoid gaps. As a result, while maintaining airtightness between the partial spiral tooth 53 and the tooth hole 45 , it is possible to prevent a gap from being generated between the partial spiral tooth 53 and the inclined surface 45 a of the tooth hole 45 .

Next, the position of the autonomous movable tooth 50 will be described with reference to FIG.
The autonomously movable tooth 50 has a position where the pressure receiving portion 51 is in contact with the step 44c as shown in FIG. It moves up and down within the stepped communication hole 44 to the position where the upper surface is in contact with 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 except for the partial spiral tooth 53. It becomes flush with the virtual plane 60 . Hereinafter, the state in which the tip surface 53b of the partial spiral tooth 53 is flush with the virtual surface 60 will be referred to as the "contact state".

In the autonomously movable tooth 50, the tip surface 53b of the partial spiral tooth 53 is separated from the virtual surface 60 when the pressure receiving portion 51 is positioned away from the step 44c as shown in FIG. 3(b). Hereinafter, the state in which the tip surface 53b of the partial spiral tooth 53 is separated from the virtual surface 60 will be referred to as the "separated 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. As shown in FIG.

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

When the autonomously movable teeth 50 are in the contact state, the outermost chamber 70, which has completely taken in the working gas, moves toward the center along with the orbiting motion of the orbiting scroll 3 and reduces its volume, thereby releasing the working gas inside. compression. 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. 7(a).

On the other hand, when the autonomous movable teeth 50 are in the separated state, two compression chambers constituting the outermost chamber 70, that is, the outer compression chambers 12a adjacent to each other in the radial direction with the autonomous movable teeth 50 as a boundary, as shown in FIG. and the inner compression chamber 12b communicate with each other through a 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 oscillating 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 oscillating spiral tooth 3b. When the outer compression chamber 12a and the inner compression chamber 12b are communicated with each other through the gap 61, the outermost chamber 70 moves in the order of (a)→(b)→(c) in FIG. As shown, the volume is reduced while moving toward the center, but no compression action is performed.

Then, as shown in FIG. 7(c), the outer compression chamber 12a and the inner compression chamber 12b are disconnected, and the compression operation is started in the outer compression chamber 12a. As the outer compression chamber 12a continues to move toward the center as shown in FIG. The working gas in the inner chamber is discharged from the discharge hole 4f.

Thus, when the autonomous movable tooth 50 is in the spaced state, compression starts from the state shown in FIG. 7(c), so the volume V2 of the outer compression chamber 12a indicated by cross hatching becomes the suction volume. The inner compression chamber 12b, which is not in communication with the outer compression chamber 12a in FIG. 7(c), communicates with the outside of the inner compression chamber 12b through the gap 61 in the rotational phase of FIG. 7(d). It doesn't work as a room.

Thus, when the autonomous movable tooth 50 is in the separated state, the suction volume is reduced from V1 to V2 compared to when the autonomous movable tooth 50 is in the contact state. Therefore, it is possible to operate with a low load without lowering the rotational speed of the electric motor 16 . In other words, since it is not necessary to reduce the rotational speed of the electric motor 16 when the load is low, leakage of the working gas can be prevented.

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

(full load operation)
When the load is high, that is, when high-pressure working gas flows into the upper hole 44a through the high-pressure gas introduction passage 43 and the force relationship acting on the autonomously movable tooth 50 becomes Fd>Fm+Fs, the autonomously movable tooth 50 moves in the axial direction. pressed downwards. In other words, the autonomously movable tooth 50 is pressed toward the orbiting scroll 3 and comes into contact, and full-load operation is performed in which the suction volume becomes V1.

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

As described above, the scroll compressor 100 of the present embodiment includes the fixed scroll 4 having the fixed base plate 4a and the fixed spiral teeth 4b formed on the fixed base plate 4a, the swing base plate 3a and the swing base. It has an oscillating spiral tooth 3b formed on the plate 3a. The scroll compressor 100 includes an oscillating scroll 3 in which the oscillating 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 a working gas from low pressure to high pressure, and an oscillating A driving shaft 19 for driving the scroll 3 is inserted into an insertion hole 46 formed through the fixed scroll 4 in the axial direction of the driving shaft 19 to form a part of the fixed spiral tooth 4b, and an inner portion of the insertion hole 46. and the autonomous movable tooth 50 which is provided in the fixed scroll 4 and is drawn to the opposite side of the orbiting scroll 3 in the insertion hole 46 to move the tip surface 43b of the autonomous movable tooth 50. It has a magnet 13 spaced apart from the oscillating base plate 3 a , and a sealed container 1 housing the fixed scroll 4 , the oscillating scroll 3 , the drive shaft 19 , the autonomous movable teeth 50 and the magnet 13 . The autonomous movable tooth 50 is autonomously moved inside the insertion hole 46 by the magnitude relationship between the resultant force of the magnetic force by the magnet 13 and the force acting on the autonomous movable tooth 50 due to the low pressure, and the force acting on the autonomous movable tooth 50 due to high pressure. and 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, and the separated state is separated without becoming flush. The inhalation volume is adjusted by switching to .

In this way, a part of the fixed spiral tooth 4b of the fixed scroll 4 is composed of the autonomous movable tooth 50 that moves up and down autonomously inside the insertion hole 46, and the magnetic force of the magnet 13 and the pressure inside the sealed container 1 are A contact state in which the tip surface 53b of the autonomous movable tooth 50 becomes flush with the tip surface 4ba of the fixed spiral tooth 4b excluding the autonomous movable tooth 50 due to the autonomous vertical movement of the autonomous movable tooth 50 based on It is configured to be switched to a separated state in which the two are separated without being separated from each other. Thereby, 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 autonomously movable teeth 50 due to the high pressure is greater than the resultant force, the autonomously movable teeth 50 are pressed toward the orbiting scroll 3, 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 . Further, when the force acting on the autonomously movable tooth 50 due to the high pressure is equal to or less than the resultant force, the autonomously movable tooth 50 is pushed away from the orbiting scroll 3, and the two compression chambers 12 are communicated with each other.

In this way, when the force acting on the autonomous movable tooth 50 due to the high pressure is greater than the resultant force, the two compression chambers 12 adjacent in the radial direction of the drive shaft 19 with the autonomous movable tooth 50 as a boundary are separated. Full load operation is possible. 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 in the radial direction of the drive shaft 19 with the autonomous movable tooth 50 as a boundary are communicated with each other so that no compression operation is performed. Part load operation can be performed at low load.

In scroll compressor 100 of the present embodiment, autonomous movable tooth 50 has cylindrical pressure receiving portion 51 and partial spiral tooth 53, and partial spiral tooth 53 forms part of fixed spiral tooth 4b. A high-pressure gas introduction passage 43 extending radially inward from the outer peripheral surface and communicating with the insertion hole 46 is formed in the fixed base plate 4a. 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 manner, high pressure can be applied to the pressure receiving portion 51 of the autonomous movable tooth 50 by the high-pressure gas introduction passage 43 , and the autonomous movable tooth 50 can be operated by the pressure inside the closed container 1 .

Reference Signs List 1 sealed container 2 compression mechanism 3 oscillating scroll 3a oscillating bedplate 3b oscillating spiral tooth 3c boss portion 3d thrust surface 3e bleeding hole 4 fixed scroll 4a fixed bedplate 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 magnet 14 gas introduction channel 14a channel 15a fixed-side Oldham ring groove 15b rocking-side Oldham ring groove 16 electric motor 16a electric motor rotor 16b electric motor stator 18a balance weight 18b balance weight, 19 drive shaft, 20 main shaft portion, 21 swing shaft portion, 22 sub-shaft portion, 23 oil supply passage, 24a supply passage, 24b supply passage, 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 sealing member 36b Lower annular sealing member 37 Subframe 38 Intermediate pressure space 39a Intermediate pressure regulating valve 39c Intermediate pressure regulating spring 39d intermediate pressure regulating valve space 39e through passage 40 Oldham ring 41 reciprocating sliding surface 42a fixed side key 42b rocking side key 43 high pressure gas introduction passage 44 stepped communication hole 44a upper portion 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 imaginary plane, 61 gap, 70 outermost chamber, 100 scroll compressor.

Claims (4)

a fixed scroll having a fixed base plate and a fixed spiral tooth formed on the fixed base plate;
It has an oscillating bed plate and oscillating spiral teeth formed on the oscillating bed plate, and the oscillating spiral teeth are combined with the fixed spiral teeth of the fixed scroll to compress working gas from low pressure to high pressure. an orbiting scroll forming a plurality of compression chambers;
a drive shaft that drives the orbiting scroll;
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 that moves up and down autonomously within the insertion hole; ,
a magnet provided on the fixed scroll for drawing the autonomously movable tooth to the opposite side of the oscillating scroll in the insertion hole to separate the tip surface of the autonomously movable tooth from the oscillating base plate;
a closed container containing the fixed scroll, the orbiting scroll, the drive shaft, the autonomously movable teeth, and the magnet;
The autonomous movable tooth is positioned inside the 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 due to the low pressure, and the force acting on the autonomous movable tooth due to the high pressure. A contact state in which the tip surface of the autonomously movable tooth is flush with the tip surface of the fixed spiral tooth excluding the autonomously movable tooth, and a separated state in which the tip surface is separated from the stationary spiral tooth except for the autonomously movable tooth. A scroll compressor that adjusts the suction volume by switching to When the force acting on the autonomously movable tooth due to the high pressure is larger than the resultant force, the autonomously movable tooth is pressed toward the oscillating scroll, and the plurality of compression chambers are driven with the autonomously movable tooth as a boundary. partitioning two compression chambers adjacent to each other in the radial direction of the shaft;
2. The scroll compressor according to claim 1, wherein when the force acting on said autonomously movable tooth due to said high pressure is equal to or less than said resultant force, said autonomously movable tooth is pressed in a direction away from said orbiting scroll to allow communication between said two compression chambers. . The autonomous movable tooth has a cylindrical pressure-receiving portion and a partial spiral tooth, the partial spiral tooth forming a part of the fixed spiral tooth,
A high-pressure gas introduction passage extending radially inward from an outer peripheral surface and communicating with the insertion hole is formed in the fixed base plate. 3. The scroll compressor according to claim 1, wherein the high pressure is applied to the pressure-receiving portion of the autonomous movable tooth by being guided into the insertion hole. The partial spiral tooth of the autonomously movable tooth has a tapered surface in which the distance between both end surfaces in the circumferential direction narrows from the radially inner side to the radially outer side, and the insertion hole is inclined along the tapered surface. 4. The scroll compressor of claim 3, having a face.

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