JP7039320B2 - Scroll fluid machine - Google Patents

Description

The present invention relates to a scroll fluid machine.

Generally, there is known a scroll fluid machine that engages a fixed scroll member provided with a spiral wall body on an end plate and a swivel scroll member to perform a revolving swivel motion to compress or expand a fluid.

As such a scroll fluid machine, a so-called stepped scroll compressor as shown in Patent Document 1 is known. In this stepped scroll compressor, stepped portions are provided at positions along the spiral direction of the tooth tip surface and the tooth bottom surface of the spiral wall body of the fixed scroll and the swirl scroll, and the outer periphery of the wall body is provided with each step portion as a boundary. The height of the side is higher than the height of the inner circumference side. Since the stepped scroll compressor is compressed not only in the circumferential direction of the wall body but also in the height direction (three-dimensional compression), it is compared with a general scroll compressor (two-dimensional compression) that does not have a stepped portion. , The amount of push-out can be increased and the compressor capacity can be increased.

Japanese Unexamined Patent Publication No. 2015-55173

However, the stepped scroll compressor has a problem that the fluid leakage in the step portion is large. Further, there is a problem that stress is concentrated on the root portion of the step portion and the strength is lowered.

On the other hand, the inventors are considering providing a continuous inclined portion in place of the step portion provided on the wall body and the end plate.
However, no study has been made on how to set the tip clearance between the tooth tip of the wall body and the tooth bottom of the end plate when the inclined portion is provided to achieve the desired performance.

The present invention has been made in view of such circumstances, and it is possible to appropriately set the tip clearance at the tooth tip of the wall body having an inclined portion and the tooth bottom of the end plate to exhibit desired performance. It is intended to provide a capable scroll fluid machine.

In order to solve the above problems, the scroll fluid machine of the present invention employs the following means.
That is, the scroll fluid machine according to one aspect of the present invention is arranged so as to face the first end plate and the first scroll member provided with the spiral first wall body on the first end plate. With a second scroll member in which a spiral second wall is provided on the two end plates, and the second wall relatively revolves and turns so as to mesh with the first wall to form a compression chamber. In addition, at least one of the first wall body and the second wall body has a height of the wall body from the outer peripheral side to the inner peripheral side in the spiral direction of the first wall body or the second wall body. It has a continuously increasing first wall body inclined portion, and at least one of the first end plate and the second end plate has a tooth bottom surface facing the tooth tip of the first wall body inclined portion. It has a first end plate inclined portion that inclines according to the inclination of the inclined portion, and is between the tooth tip of the first wall body inclined portion and the tooth bottom of the first end plate inclined portion facing the tooth tip. The chip clearance at room temperature is constant in the spiral direction.

The inclined portion of the first wall body continuously increases from the outer peripheral side to the inner peripheral side in the spiral direction, and is used in a conventional wall body and a stepped scroll fluid machine having a stepped portion on the tooth bottom. In comparison, fluid leakage can be reduced.
"Continuously increasing" is not limited to the case of smooth connection, but small steps are inevitably connected in a staircase pattern in manufacturing, and the inclination is continuously increased as a whole. It also includes what you are doing.
In the compressed space formed by the inclined portion of the first wall body and the inclined portion of the first end plate, the distance between the facing surfaces of the end plates facing each other continuously increases, so that the compression of the fluid does not proceed significantly. Therefore, it is not necessary to reduce the tip clearance from the outer peripheral side to the inner peripheral side in the spiral direction in consideration of the heat of compression of the fluid. Therefore, by keeping the tip clearance between the inclined portion of the first wall body and the inclined portion of the first end plate at room temperature constant in the spiral direction, it is possible to obtain a desired tip clearance during operation, and fluid leakage is possible. Can be made smaller.

Further, in the scroll fluid machine according to one aspect of the present invention, at least one of the first wall body and the second wall body is the inner circumference from the outer peripheral side of the first wall body or the second wall body in the spiral direction. It has a second wall tilted portion in which the height of the wall body continuously decreases toward the side, and at least one of the first end plate and the second end plate is of the second wall slanted portion. The tooth bottom surface facing the tooth tip has a second end plate inclined portion that is inclined according to the inclination of the wall body inclined portion, and the tooth tip of the second wall body inclined portion and the second end plate facing the tooth tip. The tip clearance at room temperature between the inclined portion of the end plate and the tooth bottom is larger on the inner peripheral side than on the outer peripheral side in the spiral direction.

In the compressed space formed by the inclined portion of the second wall body and the inclined portion of the second end plate, the distance between the facing surfaces of the end plates facing each other is continuously reduced, so that the compression of the fluid proceeds. Therefore, in consideration of the heat of compression of the fluid, the tip clearance on the inner peripheral side is larger than that on the outer peripheral side in the spiral direction at room temperature. As a result, even if thermal expansion occurs during operation of the scroll fluid machine, the desired tip clearance can be set from the outer peripheral side to the inner peripheral side, and fluid leakage is minimized while avoiding interference between the tooth tip and the tooth bottom. can do.

Further, in the scroll fluid machine according to one aspect of the present invention, the wall body flat portion having a constant height of the wall body is provided between the first wall body inclined portion and the second wall body inclined portion. Is provided, and between the first end plate inclined portion and the second end plate inclined portion, an end plate flat portion corresponding to the wall body flat portion is provided, and the tooth tip of the wall body flat portion is provided. The tip clearance at room temperature between the tooth bottom of the flat end plate facing the tooth tip is the inclined portion of the first wall and the inclined portion of the first end plate at the position where the flat wall portion is connected. The tip clearance is the same as the tip clearance between the second wall body inclined portion and the second end plate inclined portion at the position where the wall body flat portion is connected.

The tip clearance at the flat portion and the tip clearance at the inclined portion at the position connected to the flat portion are the same. As a result, the tip clearance is continuously formed and the fluid leakage can be minimized.

Since the tip clearance between the inclined portion of the first wall body and the inclined portion of the first end plate at room temperature is constant in the spiral direction, the desired tip clearance can be obtained during operation and the fluid leakage is minimized. be able to.

It is a schematic block diagram which showed the refrigerating cycle which uses the scroll compressor which concerns on one Embodiment of this invention. It is a partial vertical sectional view which showed the main part of the scroll compressor which concerns on one Embodiment of this invention. 2 is a vertical cross-sectional view of a fixed scroll of the scroll compressor of FIG. 2, and is a view taken along the line III-III of FIG. It is a top view of the fixed scroll of the scroll compressor of FIG. It is a top view which showed the wall body and the end plate of the fixed scroll of the scroll compressor of FIG. It is a side view which showed the wall body and the end plate of the fixed scroll of FIG. 4 expanded in the spiral direction. 2 is a vertical cross-sectional view of a swivel scroll of the scroll compressor of FIG. 2, and is a view taken along the line VII-VII of FIG. It is a top view which showed the swivel scroll of the scroll compressor of FIG. It is a top view which showed the wall body and the end plate of the fixed scroll of the scroll compressor of FIG. It is a side view showing the wall body and the end plate of the swivel scroll of FIG. 8 expanded in the spiral direction. The chip seal gap is shown, (a) is a side view showing a state where the chip seal gap is relatively small, and (b) is a side view showing a state where the chip seal gap is relatively large. It is a graph which showed the volume and pressure with respect to the turning angle of a scroll compressor. It is a graph which showed the tip clearance.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the refrigerating cycle 10 is composed of a scroll compressor (scroll fluid machine) 1 that compresses a refrigerant (fluid), a condenser 2 that dissipates the heat of the compressed refrigerant to the outside, and a condenser 2. A first expansion valve 3 provided on the high pressure side for reducing the pressure of the outflowing refrigerant, an economizer (gas-liquid separator) 4 for separating the reduced pressure refrigerant into a liquid refrigerant and a gas refrigerant, and a low pressure side for further reducing the pressure of the liquid refrigerant. It is provided with a second expansion valve 5 provided in the above, an evaporator 6 for absorbing heat in the decompressed refrigerant, an injection flow path 7 for guiding the gas refrigerant from the economizer 4 to the scroll compressor 1, and the like.

The scroll compressor 1 is a closed type compressor, and as shown in FIG. 2, a housing 11 having a closed space inside and a scroll compressor arranged in the housing 11 and compressing a refrigerant taken into the closed space are compressed. The main elements are a mechanism 12, a rotation shaft that transmits a rotational force to the scroll compression mechanism 12, and an electric motor that revolves and turns the scroll scroll 19 of the scroll compression mechanism 12 via the rotation shaft.

The bottom of the housing 11 is sealed by a lower cover, and the upper part of the lower cover is provided with a cylindrical intermediate cover 13 that is long in the vertical direction. A discharge cover 14 and an upper cover 15 are provided on the upper portion of the intermediate cover 13, and the housing 11 is sealed, and a compressed high-pressure gas is discharged between the discharge cover 14 and the upper cover 15. The chamber 16 is formed.

A scroll compression mechanism 12 is incorporated in the housing 11, and an electric motor including a stator and a rotor is installed below the scroll compression mechanism 12. The electric motor is incorporated by fixing the stator to the housing 11, and the rotating shaft is fixed to the rotor.

The scroll compression mechanism 12 is slidably supported by a fixed scroll (first scroll member) 18 fixedly installed with respect to the housing 11, and is engaged with the fixed scroll 18 to form a compression chamber 20. A scroll (second scroll member) 19 and the like are provided.

A suction port (not shown) for sucking the refrigerant is formed on the side surface of the housing 11 so as to communicate with the closed space, and the top side of the upper cover 15 communicates with the discharge chamber 16 and compresses. A discharge port 15a for discharging the generated refrigerant gas is formed.

The scroll compression mechanism 12 sucks the refrigerant gas sucked into the housing 11 through the suction pipe and the suction port into the compression chamber 20 from the suction port 21 on the outer peripheral side that is open to the inside of the housing 11 and compresses it. do. The compressed refrigerant gas is discharged into the discharge chamber 16 through the discharge port 22 provided in the center of the fixed scroll 18 and the discharge port 23 provided in the discharge cover 14, and further to the upper cover 15. It is provided and is sent out to the outside of the compressor via a discharge pipe 24 that communicates with the discharge chamber 16.

Further, the discharge cover 14 is provided with an injection pipe 25 that introduces an intermediate pressure refrigerant from the outside into the compression chamber 20 of the scroll compression mechanism 12 so as to penetrate the upper cover 15. Refrigerant is supplied to the compression chamber 20 via the injection pipe 25 and the injection port 26.

The reed valve 27 is a thin plate-shaped member, which is provided at the outlet portion of the discharge port 22 and opens and closes the discharge port 22. The reed valve 27 regulates the flow of refrigerant in only one direction. By providing the reed valve 27, the refrigerant flows from the compression chamber 20 to the discharge chamber 16 side.

As shown in FIG. 2, the fixed scroll 18 has a substantially disk-shaped end plate (first end plate) 18a and a spiral wall body (first end plate) erected on one side surface of the end plate 18a. 1 wall body) 18b and is provided. As shown in FIG. 2, the swirl scroll 19 has a substantially disk-shaped end plate (second end plate) 19a and a spiral wall body (first) erected on one side surface of the end plate 19a. It is equipped with a two-walled body) 19b. The spiral shape of each wall body 18b, 19b is defined by using, for example, an involute curve or an Archimedes curve.

The fixed scroll 18 and the swivel scroll 19 are engaged with each other by separating the centers O1 and O2 by the swivel radius ρ and shifting the phases of the wall bodies 18b and 19b by 180 °, and the tooth tips of the wall bodies 18b and 19b of both scrolls 18 and 19. It is assembled so as to have a slight height clearance (tip clearance) between the tooth bottom and the tooth bottom at room temperature. As a result, between the scrolls 18 and 19, a plurality of pairs of compression chambers 20 formed by being surrounded by the end plates 18a and 19a and the wall bodies 18b and 19b are formed symmetrically with respect to the scroll center. The swivel scroll 19 revolves around the fixed scroll 18 by a rotation prevention mechanism such as an old dam ring (not shown).

As shown in FIG. 2, the distance L between the facing surfaces between the both end plates 18a and 19a facing each other is continuously decreased or increased from the outer peripheral side to the inner peripheral side of the spiral wall bodies 18b and 19b. , The inclination of the tooth tip in the wall bodies 18b and 19b and the inclination of the tooth bottom in the end plates 18a and 19a are set.

As shown in FIGS. 3, 5 and 6, the wall body 18b of the fixed scroll 18 has a wall body flat portion 18b1, a second wall body inclined portion 18b2, and a wall body flat portion from the outer peripheral side to the inner peripheral side. A portion 18b3, a first wall body inclined portion 18b4, a wall body flat portion 18b5, a second wall body inclined portion 18b6, and a wall body flat portion 18b7 are provided in this order. Further, as shown in FIGS. 3, 4, and 6, the tooth bottom surface of the fixed scroll 18 has an end plate flat portion 18a1, a second end plate inclined portion 18a2, and an end plate from the outer peripheral side to the inner peripheral side. The flat portion 18a3, the first end plate inclined portion 18a4, the end plate flat portion 18a5, the second end plate inclined portion 18a6, and the end plate flat portion 18a7 are provided in this order.

As shown in FIGS. 7, 9 and 10, the wall body 19b of the swivel scroll 19 has a wall body flat portion 19b1, a second wall body inclined portion 19b2, and a wall body flat portion from the outer peripheral side to the inner peripheral side. A portion 19b3, a first wall body inclined portion 19b4, a wall body flat portion 19b5, a second wall body inclined portion 19b6, and a wall body flat portion 19b7 are provided in this order. Further, as shown in FIGS. 7, 8 and 10, the tooth bottom surface of the swivel scroll 19 has an end plate flat portion 19a1, a second end plate inclined portion 19a2, and an end plate from the outer peripheral side to the inner peripheral side. The flat portion 19a3, the first end plate inclined portion 19a4, the end plate flat portion 19a5, the second end plate inclined portion 19a6, and the end plate flat portion 19a7 are provided in this order.

The heights of the wall flat portions 19b1, 19b3, 19b5, 19b7 provided on the wall body 19b of the swivel scroll 19 are constant from the outer peripheral side to the inner peripheral side, respectively. That is, the dimension in the axial direction passing through the center O2 (see FIG. 2) of the swivel scroll 19 is constant. Hereinafter, the height of the wall body and the tooth bottom means the dimension in the axial direction passing through the centers O1 and O2.

As shown in FIG. 10, flat wall portions 19b1 and 19b7 having a constant height are provided on the outermost peripheral side and the innermost peripheral side of the wall body 19b of the swivel scroll 19, respectively. .. As shown in FIG. 8, these flat wall portions 19b1 and 19b7 cover a region of 180 ° (for example, 180 ° or more and 360 ° or less, preferably 210 ° or less) around the center O2 (see FIG. 2) of the swivel scroll 19. It is provided.

Similarly, the tooth bottoms of the end plates 19a of the swivel scroll 19 are provided with flat end plate portions 19a1 and 19a7 having a constant height. These flat end plate portions 19a1 and 19a7 are also provided around the center of the swivel scroll 19 over a region of 180 ° (for example, 180 ° or more and 360 ° or less, preferably 210 ° or less).

As shown in FIG. 4, the fixed scroll 18 is also provided with the wall flat portions 18b1, 18b7 and the end plate flat portions 18a1, 18a7, similarly to the swivel scroll 19. The flat wall portions 18b1, 18b7 and the flat end plate portions 18a1, 18a7 are also provided around the center of the fixed scroll 18 over a region of 180 ° (for example, 180 ° or more and 360 ° or less, preferably 210 ° or less).

As shown in FIG. 10, the height of the first wall body inclined portion 19b4 provided on the wall body 19b of the swivel scroll 19 continuously increases from the outer peripheral side to the inner peripheral side. As shown in FIG. 6, the tooth bottom surface on the end plate 18a of the fixed scroll 18 on which the tooth tips of the first wall body inclined portion 19b4 face each other is inclined according to the inclination of the first wall body inclined portion 19b4. 1 The end plate inclined portion 18a4 is provided. Similarly, as shown in FIG. 6, the first wall body inclined portion 18b4 provided on the wall body 18b of the fixed scroll 18 also continuously increases from the outer peripheral side to the inner peripheral side, and as shown in FIG. In addition, on the tooth bottom surface on the end plate 19a of the swivel scroll 19 facing the tooth tip of the first wall body inclined portion 18b4, the first end plate inclined portion inclined according to the inclination of the first wall body inclined portion 18b4. 19a4 is provided. The lengths of the first wall body inclined portions 18b4, 19b4 and the first end plate inclined portions 18a4, 19a4 in the spiral direction are set to be 20 ° or more, preferably 180 ° or more around the centers O1 and O2. ..

As a result, when the swivel scroll 19 revolves and swivels, the width of the compression chamber is reduced according to the spiral shape of the walls 18b and 19b, and the height of the compression chamber 20, that is, the facing surface between the end plates 18a and 19a. The distance increases. Therefore, depending on the position and shape of the first wall body inclined portion 18b4, 19b4 and the first end plate inclined portion 18a4, 19a4 in the spiral direction (for example, the inclination angle or the length in the spiral direction), the volume change of the compression chamber 20 is gradual or At least a part of the first region that is substantially constant is set. As the fluid sucked from the suction port 21 on the outer peripheral side goes toward the inner peripheral side, the pressure in the compression chamber 20 is maintained substantially constant in the first region.

The first region may be set by providing only one first wall body inclined portion 18b4, 19b4 or the first end plate inclined portion 18a4, 19a4 over the spiral direction, or a plurality of first walls. It may be set by arranging the body inclined portions 18b4, 19b4 or the first end plate inclined portions 18a4, 19a4 in series. When a plurality of first wall body inclined portions 18b4, 19b4 or first end plate inclined portions 18a4, 19a4 are arranged in series, the respective inclined angles may be different, or the wall body flat portion or the end plate flat portion may be located between them. It is realized by providing.

The end plate 18a of the fixed scroll 18 is provided with an injection port 26 that supplies a refrigerant having a pressure higher than the fluid pressure in the compression chamber 20 into the compression chamber 20. When the swivel scroll 19 revolves and swivels, the tooth tips of the wall body 19b of the swivel scroll 19 move onto the injection port 26 and both overlap, the communication between the compression chamber 20 and the injection port 26 is closed. On the contrary, when the tooth tip of the wall body 19b of the swivel scroll 19 moves from above the injection port 26 and the injection port 26 opens, the compression chamber 20 and the injection port 26 communicate with each other. The injection port 26 is provided in the first region where the volume change of the compression chamber 20 described above is gradual or substantially constant. Thereby, in a process in which the pressure change in the compression chamber 20 is gradual or substantially constant, the refrigerant can be supplied to the compression chamber 20 while maintaining the pressure difference with the refrigerant supplied from the injection port 26 at a predetermined value or more. In the first region, the injection step of the intermediate pressure refrigerant is performed.

The height of the second wall body inclined portions 19b2 and 19b6 provided on the wall body 19b of the swivel scroll 19 continuously decreases from the outer peripheral side to the inner peripheral side. The tooth bottom surface on the end plate 18a of the fixed scroll 18 with the tooth tips of the second wall body inclined portions 19b2, 19b6 facing each other has a second end plate inclined according to the inclination of the second wall body inclined portions 19b2, 19b6. Inclined portions 18a2 and 18a6 are provided. Similarly, the second wall body inclined portions 18b2, 18b6 provided on the wall body 18b of the fixed scroll 18 also continuously decrease from the outer peripheral side to the inner peripheral side, and the second wall body inclined portions 18b2, 18b6 The tooth bottom surface on the end plate 19a of the swivel scroll 19 facing the tooth tip is provided with the second end plate inclined portions 19a2, 19a6 which are inclined according to the inclination of the second wall body inclined portions 18b2, 18b6. ..

As a result, the width of the compression chamber 20 decreases according to the spiral shape of the wall bodies 18b and 19b during the revolution rotation motion of the swivel scroll 19, and the height of the compression chamber 20, that is, the opposition between the end plates 18a and 19a. The face-to-face distance is reduced. Therefore, it is compressed by the position and shape in the spiral direction (for example, the tilt angle and the length in the spiral direction) of the second wall body inclined portion 18b2, 18b6, 19b2, 19b6 and the second end plate inclined portion 18a2, 18a6, 19a2, 19a6. At least a part of each of the second region and the third region where the volume of the chamber 20 is reduced is set. The refrigerant sucked from the suction port 21 on the outer peripheral side is not only compressed by the reduction in the width of the compression chamber 20 according to the spiral shape of the wall bodies 18b and 19b as it goes toward the inner peripheral side, but also in the compression chamber 20. Further compression is achieved by reducing the height, that is, the distance between the facing surfaces between the end plates 18a and 19a. As a result, three-dimensional compression becomes possible and miniaturization can be realized.

The second region in which the volume of the compression chamber 20 is reduced is set before the first region in the moving direction of the compression chamber 20 accompanying the revolution swiveling motion of the swivel scroll 19, and the third region is set in the moving direction of the compression chamber 20. It is set after the first area. The second region is a region from the time when the wall bodies 18b and 19b mesh with each other on the outer peripheral side to form the compression chamber 20 and close the space until the first region starts. The third region is a region from the end of the first region to the end of the discharge of the compressed refrigerant from the discharge port 22.

By setting the second region in which the volume of the compression chamber 20 decreases in front of the first region, in the second region before the first region, the refrigerant in the compression chamber 20 is directed toward the inner peripheral side. The pressure rises. In the first region, the refrigerant whose pressure has increased tends toward the inner peripheral side, but the pressure in the compression chamber 20 is maintained substantially constant. Then, by setting the third region in which the volume of the compression chamber 20 decreases after the first region, the compression chamber 20 is set in the third region after the first region as the refrigerant moves toward the inner peripheral side. The pressure inside rises again. In the second region, a low-stage compression step is performed, and in the third region, a high-stage compression step is performed.

From the above, a two-stage compression refrigeration cycle is realized in which the refrigerant is introduced from the economizer 4 into the middle of the compression process of the scroll compression mechanism 12 via the injection flow path 7 and the injection port 26. Further, between the second region and the third region where the volume of the compression chamber 20 is reduced, a first region is provided in which the volume change of the compression chamber 20 is gradual or substantially constant, and only one scroll compression mechanism 12 is provided. In the single-stage scroll compressor 1, an intermediate pressure refrigerant can be introduced from the economizer 4 during the compression process of the scroll compression mechanism 12.

The first wall body inclined portion 18b4, 19b4, the first end plate inclined portion 18a4, 19a4, the second wall body inclined portion 18b2, 18b6, 19b2, 19b6 and the second end plate inclined portion 18a2, 18a6 in the present embodiment. , 19a2,19a6 are not limited to smoothly connected slopes, but small steps that inevitably occur during manufacturing by machining or laminated molding (AM) are connected in a staircase pattern. Including those that are continuously inclined when looking at the inclined part as a whole. However, it does not include a large step such as a so-called stepped scroll.

The first wall body inclined portion 18b4, 19b4, the first end plate inclined portion 18a4, 19a4, the second wall body inclined portion 18b2, 18b6, 19b2, 19b6 and the second end plate inclined portion 18a2, 18a6, 19a2, 19a6 A coating may be applied. Examples of the coating include manganese phosphate treatment and nickel phosphorus plating.

As shown in FIGS. 6 and 10, the tooth tip heights at the outer peripheral side end portions 18b8, 19b8 of the second wall body inclined portions 18b2, 19b2 arranged on the outer peripheral side of the first wall body inclined portions 18b4, 19b4 are , It is preferable that the height is the same as the tooth tip height at the inner peripheral side end portions 18b9, 19b9 of the first wall body inclined portions 18b4, 19b4. Thereby, the measurement can be performed at one end 18b8, 19b8 and the other end 18b9, 19b9 with the first wall inclined portion 18b4, 19b4 and the second wall inclined portion 18b2, 19b2 sandwiched between them. , The fixed scroll 18 or the swivel scroll 19 can be suitably measured.

As for the end plates 18a and 19a, as shown in FIGS. 6 and 10, the outer peripheral side end portions 18a8 of the second end plate inclined portions 18a2 and 19a2 arranged on the outer peripheral side of the first end plate inclined portions 18a4 and 19a4. , 19a8, the tooth bottom height may be the same as the tooth bottom height at the inner peripheral side end portions 18a9, 19a9 of the first end plate inclined portions 18a4, 19a4. As a result, the measurement is performed at one end 18a8, 19a8 and the other end 18a9, 19a9 with the first end plate inclined portion 18a4, 19a4 and the second end plate inclined portion 18a2, 19a2 sandwiched between them. The dimensions of the fixed scroll 18 or the swivel scroll 19 can be suitably measured.

A tip seal is provided at the tooth tip of the wall body 18b of the fixed scroll 18. The tip seal is made of resin and comes into contact with the tooth bottom of the end plate 19a of the facing swivel scroll 19 to seal the fluid. The tip seal is housed in a tip seal groove 18d formed in the circumferential direction at the tooth tip of the wall body 18b. Similarly, a tip seal groove 19d is formed on the tooth tip of the wall body 19b of the swivel scroll 19, and a tip seal is provided in the tip seal groove 19d.

When both scrolls 18 and 19 perform a relative revolutionary turning motion, the positions of the tooth tip and the tooth bottom are relatively displaced by the turning diameter (turning radius ρ × 2). Due to this misalignment between the tooth tip and the tooth bottom, the tip clearance between the tooth tip and the tooth bottom changes in the inclined portion. For example, FIG. 11A shows that the tip clearance T is small, and FIG. 11B shows that the tip clearance T is large. Even if the tip clearance T changes due to the turning motion, the tip seal 28 is pressed from the back surface by the compressive fluid toward the tooth bottom side of the end plate 19a, so that the tip seal 28 can be subsequently sealed.

FIG. 13 shows the tip clearance, which is the distance between the tooth tips of the wall bodies 18b and 19b and the tooth bottoms of the end plates 18a and 19a facing the tooth tips. This tip clearance is at room temperature (eg, room temperature), that is, before operation. In the figure, the horizontal axis indicates the angle (that is, the distance in the spiral direction), and the vertical axis indicates the tip clearance. In the figure, the right side shows the outer peripheral side, and the left side shows the inner peripheral side.

As can be seen from the figure, the tip clearance T1 at the position corresponding to the wall flat portions 18b1 and 19b1 on the outermost peripheral side is set to be constant in the spiral direction and to be the smallest. This is because compression hardly progresses on the outermost peripheral side, and the distance between the end plates of the compression chamber 20 does not change.

The tip clearance T2 at the position corresponding to the second wall body inclined portion 18b2, 19b2 connected to the inner peripheral side of the wall body flat portion 18b1, 19b1 on the outermost outer peripheral side is from the outer peripheral side in the spiral direction toward the inner peripheral side. It is gradually increasing. This is because, in the second wall body inclined portions 18b2 and 19b2, the compression proceeds by reducing the distance between the end plates of the compression chamber 20 as the compression chamber 20 is compressed, and there is thermal expansion due to the heat of compression. The outer peripheral end of the tip clearance T2 is the same as the inner peripheral end of the tip clearance T1, and the tip clearance T1 and the tip clearance T2 are connected to each other. The increase width of the tip clearance T2 is set according to the length in the spiral direction, for example, on the order of 1/100 mm .

The tip clearance T3 at the position corresponding to the flat wall portions 18b3 and 19b3 connected to the inner peripheral side of the second wall body inclined portions 18b2 and 19b2 is constant in the spiral direction. This is because the distance between the end plates of the compression chamber 20 does not change. The outer peripheral end of the tip clearance T3 is the same as the inner peripheral end of the tip clearance T2, and the tip clearance T2 and the tip clearance T3 are connected to each other.

The tip clearance T4 at the position corresponding to the first wall body inclined portion 18b4, 19b4 connected to the inner peripheral side of the wall body flat portion 18b3, 19b3 is constant in the spiral direction. This is because the compression of the compression chamber 20 progresses in response to the turning, but the distance between the end plates of the compression chamber 20 increases, and the compression does not proceed significantly. The outer peripheral end of the tip clearance T4 is the same as the inner peripheral end of the tip clearance T3, and the tip clearance T3 and the tip clearance T4 are connected to each other.

The tip clearance T5 at a position corresponding to the flat wall portions 18b5 and 19b5 connected to the inner peripheral side of the first wall body inclined portions 18b4 and 19b4 is constant in the spiral direction. This is because the distance between the end plates of the compression chamber 20 does not change. The outer peripheral end of the tip clearance T5 is the same as the inner peripheral end of the tip clearance T4, and the tip clearance T4 and the tip clearance T5 are connected to each other.

The tip clearance T6 at the position corresponding to the second wall inclined portion 18b6, 19b6 connected to the inner peripheral side of the wall flat portion 18b5, 19b5 gradually increases from the outer peripheral side in the spiral direction toward the inner peripheral side. It has become. This is because, in the second wall inclined portions 18b6 and 19b6, the distance between the end plates of the compression chamber 20 decreases as the compression progresses, so that the compression proceeds and there is thermal expansion due to the heat of compression. The outer peripheral end of the tip clearance T6 is the same as the inner peripheral end of the tip clearance T5, and the tip clearance T5 and the tip clearance T6 are connected to each other. The increase width of the tip clearance T6 is set according to the length in the spiral direction, for example, on the order of 1/100 mm .

The tip clearance T7 at the position corresponding to the flat wall portions 18b7 and 19b7 connected to the inner peripheral side of the second wall body inclined portions 18b6 and 19b6 is constant in the spiral direction. This is because the distance between the end plates of the compression chamber 20 does not change. The outer peripheral end of the tip clearance T7 is the same as the inner peripheral end of the tip clearance T6, and the tip clearance T6 and the tip clearance T7 are connected to each other.
In this way, the tip clearance is set in a state of being connected like a polygonal line from the outer peripheral side to the inner peripheral side.

The tooth tips and corresponding ends of the connection portion between the wall body inclined portion 18b2, 18b4, 18b6, 19b2, 19b4, 19b6 and the wall body flat portion 18b1, 18b3, 18b5, 18b7, 19b1, 19b3, 19b5, 19b7. An R chamfered shape may be provided on the tooth bottom of the plate as an inclination-relaxing shape. This facilitates the processing by smoothly connecting the connection portion, suppresses the occurrence of burrs and sagging, and avoids excessive contact between the tooth tip and the tooth bottom.
The C chamfer shape may be used instead of the R chamfer shape used as the tilt relaxation shape. Alternatively, the shape may be such that the inclination is gradually changed and connected so as to alleviate the discontinuous inclination. Further, the tilt relaxation shape may be used for the tilt connection portion on either the wall body side or the end plate side.

The scroll compressor 1 described above operates as follows.
The swivel scroll 19 revolves around the fixed scroll 18 by a drive source such as an electric motor (not shown). As a result, the fluid is sucked from the outer peripheral side of the scrolls 18 and 19, and the refrigerant is taken into the compression chamber 20 surrounded by the wall bodies 18b and 19b and the end plates 18a and 19a.

First, the walls 18b and 19b are engaged with each other on the outer peripheral side to form a compression chamber and closed, and then in the second region, the refrigerant in the compression chamber 20 is compressed as it moves from the outer peripheral side to the inner peripheral side. , As shown in FIG. 12, the pressure in the compression chamber 20 rises. The compressed refrigerant moves to the first region, and in the first region, the refrigerant moves toward the inner peripheral side. Then, the intermediate pressure refrigerant is supplied from the economizer 4 to the compression chamber 20 via the injection pipe 25 and the injection port 26. In the first region, as shown in FIG. 12, the pressure change in the compression chamber 20 is gradual or substantially constant, and the fluid is compressed in the compression chamber while maintaining the pressure difference with the refrigerant supplied from the economizer 4 at a predetermined value or more. Can be supplied to 20.

After that, the refrigerant moves to the third region, and in the third region, the refrigerant is compressed toward the inner peripheral side, and as shown in FIG. 12, the pressure in the compression chamber 20 rises again. The compressed refrigerant is finally discharged from the discharge port 22 formed in the fixed scroll 18.

As described above, according to the scroll compressor 1 of the present embodiment, the following functions and effects are obtained.
In the compression chamber 20 formed by the first wall body inclined portions 18b4, 19b4 and the first end plate inclined portions 18a4, 19a4, the distance between the facing surfaces of the end plates facing each other continuously increases, so that the compression of the fluid is large. There is no progress. Therefore, it is not necessary to reduce the tip clearance T4 from the outer peripheral side to the inner peripheral side in the spiral direction in consideration of the heat of compression of the fluid. Therefore, by making the tip clearance T4 between the first wall body inclined portion 18b4, 19b4 and the first end plate inclined portion 18a4, 19a4 at room temperature constant in the spiral direction, it is possible to obtain a desired tip clearance during operation. , Fluid leakage can be reduced as much as possible.

In the compression chamber 20 formed by the second wall body inclined portion 18b2, 18b6, 19b2, 19b6 and the second end plate inclined portion 18a2, 18a6, 19a2, 19a6, the distance between the facing surfaces of the facing end plates is continuously reduced. Therefore, the compression of the fluid progresses. Therefore, in consideration of the heat of compression of the fluid, the tip clearances T2 and T6 on the inner peripheral side of the outer peripheral side in the spiral direction are increased at room temperature. As a result, even if the scroll compressor 1 is thermally expanded during operation, the desired tip clearance can be set from the outer peripheral side to the inner peripheral side, and fluid leakage is possible while avoiding interference between the tooth tip and the tooth bottom. It can be made smaller.

Tip clearances T1, T3, T5, T7 at positions corresponding to the flat wall portions 18b1, 18b3, 18b5, 18b7, 19b1, 19b3, 19b5, 19b7, and the flat wall portions 18b1, 18b3, 18b5, 18b7, 19b1, 19b3. , 19b5, 19b7, the tip clearances T2, T4, and T6 of the inclined portions 18b2, 18b4, 18b6, 19b2, 19b4, 19b6 at the positions connected to 19b5, 19b7 are the same. As a result, the tip clearance is continuously formed and the fluid leakage can be minimized.

In this embodiment, the first wall body inclined portion 18b4, 19b4, the first end plate inclined portion 18a4, 19a4, the second wall body inclined portion 18b2, 18b6, 19b2, 19b6 and the second end plate inclined portion 18a2, 18a6 , 19a2, 19a6 are provided on both scrolls 18, 19, but may be provided on either one.
Specifically, one wall body (for example, the wall body 19b of the swivel scroll 19) is provided with the first wall body inclined portion 19b4 and the second wall body inclined portion 19b2, 19b6, and the other end plate (for example, the fixed scroll 18) is provided. When the first end plate inclined portion 19a4 and the second end plate inclined portion 19a2, 19a6 are provided on the end plate 18a), the other wall body 18b and one end plate 19a are made flat.
Further, a shape combined with the conventional stepped shape, that is, the end plate 18a of the fixed scroll 18 is provided with the first end plate inclined portion 18a4 and the second end plate inclined portions 18a2, 18a6, while the end plate of the swivel scroll 19 is provided. It may be combined with a shape provided with a step portion in 19a.

In the present embodiment, the flat wall portions 18b1, 18b7, 19b1, 19b7 and the flat end plate portions 18a1, 18a7, 19a1, 19a7 are provided, but the flat portions on the inner peripheral side and / or the outer peripheral side are omitted. The second wall body inclined portion 18b2, 19b2 may be provided so as to extend over the entire wall body 18b, 19b.

Although described as a scroll compressor in the present embodiment, the present invention can also be applied to a scroll expander used as an expander.

1: Scroll compressor (scroll fluid machine)
2: Condensator 3: First expansion valve 4: Economizer (gas-liquid separator)
5: Second expansion valve 6: Evaporator 7: Injection flow path 10: Refrigeration cycle 11: Housing 12: Scroll compression mechanism 13: Intermediate cover 14: Discharge cover 15: Top cover 15a: Discharge port 16: Discharge chamber 18: Fixed Scroll (first scroll member)
18a: End plate (first end plate)
18a1: End plate flat portion 18a2: Second end plate inclined portion 18a3: End plate flat portion 18a4: First end plate inclined portion 18a5: End plate flat portion 18a6: Second end plate inclined portion 18a7: End plate flat portion 18a8: Outer peripheral side end 18a9: Inner peripheral side end 18b: Wall body (first wall body)
18b1: Wall body flat portion 18b2: Second wall body inclined portion 18b3: Wall body flat portion 18b4: First wall body inclined portion 18b5: Wall body flat portion 18b6: Second wall body inclined portion 18b7: Wall body flat portion 18b8: Outer peripheral side end 18b9: Inner peripheral side end 18d: Tip seal groove 19: Swirling scroll (second scroll member)
19a: End plate (second end plate)
19a1: End plate flat portion 19a2: Second end plate inclined portion 19a3: End plate flat portion 19a4: First end plate inclined portion 19a5: End plate flat portion 19a6: Second end plate inclined portion 19a7: End plate flat portion 19a8: Outer peripheral side end 19a9: Inner peripheral side end 19b: Wall body (second wall body)
19b1: Wall body flat portion 19b2: Second wall body inclined portion 19b3: Wall body flat portion 19b4: First wall body inclined portion 19b5: Wall body flat portion 19b6: Second wall body inclined portion 19b7: Wall body flat portion 19b8: Outer peripheral side end 19b9: Inner peripheral side end 20: Compression chamber 21: Suction port 22: Discharge port 23: Discharge port 24: Discharge pipe 25: Injection pipe 26: Injection port 27: Lead valve 28: Chip seal

Claims (3)

A first scroll member provided with a spiral first wall on the first end plate, and
A spiral second wall is provided on the second end plate arranged so as to face the first end plate, and the second wall meshes with the first wall to form a compression chamber. The second scroll member that relatively revolves and turns,
Equipped with
At least one of the first wall body and the second wall body has a continuous height of the wall body from the outer peripheral side to the inner peripheral side in the spiral direction of the first wall body or the second wall body. It has an increasing first wall slope and
At least one of the first end plate and the second end plate is a first end plate inclined portion in which the tooth bottom surface facing the tooth tip of the first wall inclined portion is inclined according to the inclination of the wall inclined portion. Have,
A scroll fluid machine in which the tip clearance at room temperature between the tooth tip of the first wall body inclined portion and the tooth bottom of the first end plate inclined portion facing the tooth tip is constant in the spiral direction. At least one of the first wall body and the second wall body has a continuous height of the wall body from the outer peripheral side to the inner peripheral side in the spiral direction of the first wall body or the second wall body. Has a reduced second wall slope,
At least one of the first end plate and the second end plate is a second end plate inclined portion in which the tooth bottom surface facing the tooth tip of the second wall inclined portion is inclined according to the inclination of the wall inclined portion. Have,
The tip clearance at room temperature between the tooth tip of the second wall body inclined portion and the tooth bottom of the second end plate inclined portion facing the tooth tip is closer to the inner peripheral side than the outer peripheral side in the spiral direction. The scroll fluid machine according to claim 1, wherein the size is increased. A flat wall portion having a constant height of the wall body is provided between the inclined portion of the first wall body and the inclined portion of the second wall body.
An end plate flat portion corresponding to the wall body flat portion is provided between the first end plate inclined portion and the second end plate inclined portion.
The tip clearance at room temperature between the tooth tip of the wall flat portion and the tooth bottom of the end plate flat portion facing the tooth tip is the inclination of the first wall body at the position where the wall flat portion is connected. Chip clearance between the portion and the first end plate inclined portion, and chip clearance between the second wall body inclined portion and the second end plate inclined portion at a position where the wall body flat portion is connected. The scroll fluid machine according to claim 2, which is the same as the above.

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