JP6758969B2 - Stepped scroll compressor and its design method - Google Patents

Description

The present invention relates to a stepped scroll compressor for preventing damage to the spiral wrap wall body and a method for designing the stepped scroll compressor.

In a scroll compressor that compresses refrigerant, air, etc., as disclosed in Patent Document 1 and the like, the tooth tip surface and tooth bottom surface of a spiral wrap wall body erected on the end plates of fixed scrolls and swivel scrolls. A so-called stepped scroll compressor is known in which stepped portions are provided at arbitrary positions along the spiral direction, and the lap height on the outer peripheral side of the stepped portion is made higher than the lap height on the inner peripheral side.
Such a stepped scroll compressor can compress the fluid to be compressed three-dimensionally in both the circumferential direction and the height direction of the spiral wrap wall body, so that the spiral wrap is compared with the non-stepped scroll compressor. The compression ratio can be increased without increasing the number of turns of the wall body.
Therefore, it is possible to increase the design volume ratio without increasing the outer diameter of the scroll compressor, and it is possible to reduce the size and weight of the scroll compressor.

According to Patent Document 1, in such a stepped scroll compressor, a thin portion is formed on the side surface of the spiral wrap wall body in the vicinity of the step portion formed on the bottom surface of the end plate of the fixed scroll and the swivel scroll. Are listed. By forming such a thin portion, the noise generated by the spiral wrap wall of the opposing scroll interfering with the burr that is likely to be generated when the stepped portion is processed and formed on the bottom surface of the end plate is eliminated. can do.

JP-A-2007-224775

Another problem with the stepped scroll compressor as described above is damage to the spiral lap wall in the outer peripheral section of the spiral wrap wall, that is, in the section where the lap height is high.
In the stepped scroll compressor, the lap height of the spiral lap wall body gradually decreases from the outer peripheral side to the inner peripheral side, but the height between the outermost peripheral side section and the innermost peripheral side section is high and low. The compression ratio can be increased by increasing the difference.
Therefore, in the most outer peripheral section, the wrap height of the spiral wrap wall body tends to be higher than the wrap height of the spiral wrap wall body in the non-stepped scroll compressor.
The higher the wrap height of the spiral wrap wall, the greater the bending stress applied to the base of the wrap when it comes into contact with the opposing spiral wrap wall, increasing the likelihood that the spiral wrap wall will be damaged. ..

In the stepped scroll compressor described in Patent Document 1, in order to prevent noise, a thin portion is formed on the side surface of the spiral wrap wall body in the vicinity of the step portion formed on the bottom surface of the scroll end plate. If the spiral wrap walls come into contact with each other on the outer peripheral side of the region where the thin portion is formed, there is a risk that the spiral wrap walls will be damaged.

The present invention has been made to solve such a problem, and prevents damage to the spiral wrap wall in a stepped scroll compressor, enhances durability and reliability, and minimizes compression leakage. It is an object of the present invention to provide a stepped scroll compressor capable of preventing a decrease in compression performance and a design method thereof.

In the stepped scroll compressor according to the first aspect of the present invention, the fixed scroll and the swirl scroll in which the spiral wrap wall bodies are erected on one side surface of each end plate bite each other of the spiral wrap wall bodies. By combining, a pair of compression chambers for compressing the fluid to be compressed are formed, and the height of the tooth bottom surface is the spiral wrap wall on the one side surface of the end plate of at least one of the fixed scroll and the swirl scroll. A tooth bottom step portion that rises from the outer peripheral side to the inner peripheral side in the spiral direction of the body is provided, and the spiral wrap wall body of the other scroll corresponding to the tooth bottom step portion has a tooth tip surface. A tooth tip step portion whose height decreases from the outer peripheral side to the inner peripheral side in the spiral direction is provided, and at least one of the fixed scroll and the swivel scroll is swirled more than the tooth bottom step portion. adjacent the bottom land of the direction outer peripheral side, and only the ventral surface of the spiral wrap wall in the region of overlap at least opposite the spiral wrap wall is retracted inward from its original side profile, the The spiral wrap wall body having the ventral surface of the spiral wrap wall body adjacent to the tooth bottom surface on the inner peripheral side in the spiral direction from the tooth bottom step portion as its original side profile and the ventral surface as its original side profile. Is 360 ° or more, excluding the non-involuted section .

In the method for designing a stepped scroll compressor according to a second aspect of the present invention, a fixed scroll in which a spiral wrap wall body is erected on one side surface of each end plate and a swirl scroll are formed on each other. A pair of compression chambers for compressing the fluid to be compressed are formed by engaging the bodies, and the height of the tooth bottom surface is swirled on the one side surface of the end plate of at least one of the fixed scroll and the swirl scroll. A tooth bottom step portion that rises from the outer peripheral side to the inner peripheral side in the spiral direction of the spiral wrap wall body is provided, and the spiral wrap wall body of the other scroll corresponding to the tooth bottom step portion has its teeth. A method for designing a stepped scroll compressor provided with a stepped tooth tip in which the height of the front surface decreases from the outer peripheral side to the inner peripheral side in the spiral direction, and for at least one of the fixed scroll and the swirl scroll. , Only the ventral surface of the spiral wrap wall body adjacent to the tooth bottom surface on the outer peripheral side in the spiral direction from the tooth bottom step portion and at least overlapping the spiral wrap wall body facing the original side surface thereof. The ventral surface of the spiral wrap wall, which is retracted inward from the profile and is adjacent to the tooth bottom on the inner peripheral side in the spiral direction from the stepped portion of the tooth bottom, is used as the original lateral profile, and the ventral surface is used as the original lateral profile. It said spiral wrap wall being, with the exception of the non-involute section is to shall and 360 ° or more.

According to the stepped scroll compressor and the design method described above, the spiral wrap is adjacent to the section where the lap height of the spiral lap wall is the highest, that is, the tooth bottom surface on the outer peripheral side in the spiral direction from the step portion of the tooth bottom. Only the ventral surface of the shaped wrap wall retracts inward from the original lateral profile.
Therefore, in the section on the outermost peripheral side in the spiral direction where the lap height is the highest and the risk of damage is large, the spiral lap walls of the fixed scroll and the swirl scroll do not come into contact with each other, and the spiral lap walls of the spiral lap walls It is possible to prevent damage due to contact.

The amount of the ventral surface of the spiral wrap wall retracted inward is such that it does not adversely affect the compression of the fluid to be compressed, for example, about 100 μm or less. Therefore, while minimizing the compression leakage of the stepped scroll compressor and preventing the deterioration of the compression performance, the spiral wrap wall body is prevented from being damaged, and the durability and reliability of the stepped scroll compressor are improved. be able to.

In the method for designing the stepped scroll compressor according to the first aspect of the present invention and the stepped scroll compressor according to the second aspect of the present invention, the teeth excluding the non-involute section in the spiral wrap wall body. The spiral length of the section on the inner peripheral side in the spiral direction with respect to the stepped portion may be less than 360 °.
In other words, when the spiral length of the section on the inner peripheral side in the spiral direction from the stepped portion of the tooth tip is less than 360 °, the stepped scroll compressor according to the first aspect of the present invention and the first aspect of the present invention. It is preferable to apply the stepped scroll compressor design method according to the two aspects.

According to the above configuration, in the section on the inner peripheral side in the spiral direction from the stepped portion of the tooth bottom, the ventral surface and the back surface of the spiral wrap wall body do not recede inward and the original lateral profile is maintained. ..
Here, even if the spiral length of the section on the inner peripheral side in the spiral direction from the tooth tip step portion is less than 360 °, the spiral length when the section between the tooth tip step portion and the tooth bottom step portion is combined. The temperature exceeds 360 °.

Therefore, when the stepped scroll compressor is operated, the spiral lap walls come into contact with each other at two points in either the section on the inner peripheral side in the spiral direction or the section following the outer peripheral side in the spiral direction. Determines the turning trajectory of the turning scroll with respect to the fixed scroll.
Therefore, even if both the inner and outer surfaces of the spiral wrap wall are retracted inward in the section on the outer peripheral side in the spiral direction from the stepped portion of the tooth bottom, that is, in the section where the lap height of the spiral wrap wall is the highest, the recess is retracted. The swivel scroll does not move in the direction of the surface of the end plate by the amount, and damage due to contact between the spiral wrap walls can be prevented.

In the stepped scroll compressor according to the third aspect of the present invention, the fixed scroll and the swirl scroll in which the spiral wrap wall bodies are erected on one side surface of each end plate bite each other of the spiral wrap wall bodies. By combining, a pair of compression chambers for compressing the fluid to be compressed are formed, and the height of the tooth bottom surface is the spiral wrap wall on the one side surface of the end plate of at least one of the fixed scroll and the swirl scroll. A tooth bottom step portion that rises from the outer peripheral side to the inner peripheral side in the spiral direction of the body is provided, and the spiral wrap wall body of the other scroll corresponding to the tooth bottom step portion has a tooth tip surface. A tooth tip step portion whose height decreases from the outer peripheral side to the inner peripheral side in the spiral direction is provided, and at least one of the fixed scroll and the swivel scroll is swirled more than the tooth bottom step portion. The ventral surface and the back surface of the spiral wrap wall body adjacent to the tooth bottom surface on the outer peripheral side in the direction recede inward from the original side profile thereof, and the tooth bottom surface on the inner peripheral side in the spiral direction from the tooth bottom step portion. The spiral wrap wall body adjacent to the spiral wrap wall body having its original lateral profile and the ventral surface and back surface having its original side profile is 360, except for the non-involuted section. It is said to be above ° .

In the method for designing a stepped scroll compressor according to a fourth aspect of the present invention, a fixed scroll in which a spiral wrap wall body is erected on one side surface of each end plate and a swirl scroll are formed on each other. A pair of compression chambers for compressing the fluid to be compressed are formed by engaging the bodies, and the height of the tooth bottom surface is swirled on the one side surface of the end plate of at least one of the fixed scroll and the swirl scroll. A tooth bottom step portion that rises from the outer peripheral side to the inner peripheral side in the spiral direction of the spiral wrap wall body is provided, and the spiral wrap wall body of the other scroll corresponding to the tooth bottom step portion has its teeth. A method for designing a stepped scroll compressor provided with a stepped tooth tip in which the height of the front surface decreases from the outer peripheral side to the inner peripheral side in the spiral direction, and for at least one of the fixed scroll and the swirl scroll. , The ventral surface and the back surface of the spiral wrap wall body adjacent to the tooth bottom surface on the outer peripheral side in the spiral direction from the tooth bottom step portion are retracted inward from the original side profile thereof, and from the tooth bottom step portion. The spiral wrap wall body having the ventral surface and the back surface of the spiral wrap wall body adjacent to the tooth bottom surface on the inner peripheral side in the spiral direction as its original side profile, and the ventral surface and the back surface having the original side surface profile, except for the non-involute section is to shall and 360 ° or more.

According to the above-mentioned stepped scroll compressor and design method, the section where the lap height of the spiral lap wall body is high, that is, adjacent to the tooth bottom surface on the outer peripheral side in the spiral direction from the tooth bottom step portion, and The ventral and dorsal surfaces of the spiral wrap wall are retracted inward from their original lateral profile, at least to the extent that they overlap the opposing spiral wrap wall.
Therefore, in the section on the outer peripheral side in the spiral direction where the lap height is high, the spiral lap walls of the fixed scroll and the swirl scroll do not come into contact with each other, and damage due to contact between the spiral lap walls is prevented. can do.

The amount of retracting the ventral surface and the back surface of the spiral wrap wall body inward is such that it does not adversely affect the compression of the fluid to be compressed, for example, about 100 μm or less. Therefore, while minimizing the compression leakage of the stepped scroll compressor and preventing the deterioration of the compression performance, the spiral wrap wall body is prevented from being damaged, and the durability and reliability of the stepped scroll compressor are improved. be able to.

In the design method of the stepped scroll compressor according to the third aspect of the present invention and the stepped scroll compressor according to the fourth aspect of the present invention, the teeth excluding the non-involute section in the spiral wrap wall body. The spiral length of the section on the inner peripheral side in the spiral direction with respect to the stepped portion may be 360 ° or more.
In other words, when the spiral length of the section on the inner peripheral side in the spiral direction from the stepped portion of the tooth tip is 360 ° or more, the stepped scroll compressor according to the third aspect of the present invention and the first aspect of the present invention. It is preferable to apply the stepped scroll compressor design method according to the four aspects.

According to the above configuration, the spiral length in the section on the inner peripheral side in the spiral direction from the tooth tip step portion excluding the non-involute section is 360 ° or more, and in this section, the ventral surface and the back surface of the spiral wrap wall body. Is kept in its original lateral profile without retreating inward.
Therefore, when the stepped scroll compressor is operated, the spiral lap walls come into contact with each other at two points only in the section on the inner peripheral side in the spiral direction, whereby the turning trajectory of the turning scroll with respect to the fixed scroll is determined.
Therefore, even if the ventral surface and the back surface of the spiral wrap wall body are retracted inward in the section on the outer peripheral side in the spiral direction from the stepped portion of the tooth bottom, the swirl scroll moves in the surface direction of the end plate by the amount of the retracted portion. It is possible to prevent damage due to contact between the spiral wrap walls without causing damage.

The amount of retracting the ventral surface and the back surface of the spiral wrap wall body inward is such that it does not adversely affect the compression of the fluid to be compressed, for example, about 100 μm or less. Therefore, while minimizing the compression leakage of the stepped scroll compressor and preventing the deterioration of the compression performance, the spiral wrap wall body is prevented from being damaged, and the durability and reliability of the stepped scroll compressor are improved. be able to.

In the above-described configuration, the maximum value after withdrawal of the spiral wraps wall [delta], a turning radius of the orbiting scroll when the [rho, the retraction amount to be within a range of δ / ρ ≦ 0.01 It is preferable to set the maximum value δ of.

By determining the maximum value of the retreat amount in this way, it is possible to prevent damage to the spiral lap wall body and suppress performance deterioration due to compression leakage in stepped scroll compressors of various sizes.

In the above configuration, Shisaryou may be gradually reduced toward the inner circumferential side from the spiral direction outer peripheral side after the spiral wrap wall at the position of the tooth bottom step part. As a result, it is possible to prevent the generation of noise due to the interference of the spiral wrap wall of the opposing scroll with the burr that is likely to be generated when the tooth bottom step portion is machined and formed on the end plate.

In the above configuration, Shisaryou after the spiral wrap wall may be larger toward the front end side from the root side of the spiral wrap wall. By doing so, it is possible to prevent the spiral wrap walls from coming into contact with each other on the tip side without reducing the thickness dimension on the root side of the spiral wrap wall and impairing the strength, and the spiral wrap wall. You can prevent damage to your body.

As described above, according to the stepped scroll compressor and the design method thereof according to the present invention, it is possible to prevent damage to the spiral lap wall body in a section where the lap height is high, improve durability and reliability, and compress the compressor. Leakage can be minimized to prevent deterioration of compression performance.

It is a vertical sectional view of the step scroll compressor which concerns on embodiment of this invention. It is a vertical sectional view of the fixed scroll which concerns on 1st Embodiment of this invention. It is the bottom view of the fixed scroll by the arrow III-III of FIG. It is a conceptual perspective view of a fixed scroll. It is a conceptual perspective view of a swivel scroll. It is a developed view of the spiral wrap wall body in the fixed scroll and the swirl scroll which shows the 1st Embodiment of this invention. It is a vertical cross-sectional view which shows the mode of side receding of a spiral wrap wall body. It is a vertical cross-sectional view which shows the mode of side receding of a spiral wrap wall body. It is a vertical sectional view of the fixed scroll which concerns on 2nd Embodiment of this invention. It is a bottom view of the fixed scroll by the XX arrow view of FIG. It is a figure which combined the fixed scroll and the swivel scroll in the 2nd Embodiment. It is a developed view of the spiral wrap wall body in the fixed scroll and the swirl scroll which shows the 2nd Embodiment of this invention. It is a partial plan view near the tooth bottom step portion.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a vertical sectional view of a stepped scroll compressor according to an embodiment of the present invention. The stepped scroll compressor 1 is, for example, a closed electric scroll compressor for an HFC (hydrofluorocarbon) refrigerant, but the present invention is not limited to this type of scroll compressor.

The stepped scroll compressor 1 includes a tubular bottomed steel plate sealed housing 2 that is long in the vertical direction. A scroll compression mechanism 3 is installed in an upper portion of the closed housing 2, and an electric motor 4 is installed in a lower portion thereof.

Inside the closed housing 2, the upper side of the partition member 30 provided on the upper part of the scroll compression mechanism 3 is a discharge chamber 5 for discharging the high-pressure gas compressed by the scroll compression mechanism 3, and the discharge pipe 6 is connected to the discharge chamber 5. ing. Further, the lower side of the partition member 30 and the scroll compression mechanism 3 is a suction chamber 7 into which low-pressure suction gas is sucked, and a suction pipe 8 is connected to the suction chamber 7. On the suction chamber 7 side, an electric motor 4 composed of a stator 9 and a rotor 10 is installed in a sealed housing 2 by press fitting or the like, and a crank coupled to the rotor 10 of the electric motor 4. The shaft 11 extends in the vertical direction.

The lower end of the crankshaft 11 is supported by a lower bearing 12 provided in the sealed housing 2, and the upper end of the crankshaft 11 is rotatably supported by the journal bearing 15B of the upper bearing member 15. There is. The scroll compression mechanism 3 is fixed in the sealed housing 2 via the upper bearing member 15. The scroll compression mechanism 3 includes a fixed scroll 16 fixed on the upper bearing member 15 and a swivel scroll 20 supported on the upper bearing member 15 so as to revolve around the fixed scroll 16. ing.

As shown in FIGS. 2 to 4, the fixed scroll 16 has a fixed end plate 17 (end plate) fixed in the sealed housing 2 and a spiral fixed wrap wall body erected on one side surface thereof. 18 (spiral wrap wall body) is provided, and a discharge port 19 is provided at the center of the fixed end plate 17. Further, as shown in FIGS. 1 and 5, the swirl scroll 20 has a swirl end plate 21 (end plate) and a spiral swirl wrap wall 22 (spiral wrap wall) standing on one side surface thereof. ), And the swirl boss portion 23 is integrally provided on the back side of the swirl end plate 21.

In the swivel scroll 20, the back surface of the swivel end plate 21 is supported on the thrust bearing portion 15A of the upper bearing member 15, and the swivel boss portion 23 is installed with an eccentric amount ρ at the upper end of the crankshaft 11. The pin 11A is connected via a drive bush 25 and a swivel bearing 26 constituting a known driven crank mechanism, so that the pin 11A can be revolved and swiveled around the fixed scroll 16. The eccentric amount ρ of the crank pin 11A is, that is, the turning radius of the turning scroll 20 with respect to the fixed scroll 16.

The heights of the tooth bottom surfaces 17a and 21a of the fixed end plate 17 of the fixed scroll 16 and the swivel end plate 21 of the swivel scroll 20 are different from the outer peripheral side to the inner peripheral side in the spiral direction of the lap wall bodies 18 and 22. A tooth bottom step portion BS that is one step higher toward the side is provided. Corresponding to these tooth bottom step portions BS, the heights of the tooth tip surfaces 18a and 22a of the lap wall bodies 18 and 22 of the other scrolls 16 and 20 are directed from the outer peripheral side to the inner peripheral side in the spiral direction. A lower tooth tip step portion TS is provided.

In the fixed scroll 16 and the swivel scroll 20, the fixed lap wall body 18 and the swivel lap wall body 22 are 180 degrees out of phase and are meshed as known, so that a pair of compressions are performed between the fixed lap wall bodies 18 and 22. The chamber 24 is formed. The pair of compression chambers 24 are configured to perform a compression action by being moved from the outer peripheral position to the central portion while the volume is reduced by the revolving scroll 20.

The height of the crankshaft 11 in the axial direction of the compression chamber 24 is made higher on the outer peripheral side of the lap wall bodies 18 and 22 than the height on the inner peripheral side, so that the height of the lap wall bodies 18 and 22 is higher than the height on the inner peripheral side. It constitutes a scroll compression mechanism 3 capable of three-dimensional compression capable of compressing gas in both height directions. Tip seals 18b and 22b (see FIG. 5) for sealing between the tooth bottom surfaces 17a and 21a of the mating scroll are provided on the tooth tip surfaces 18a and 22a of the wrap wall bodies 18 and 22, respectively. , 22a are fitted in the grooves provided.

A rotation prevention means 27 including an old dam ring or the like for preventing the rotation of the rotation scroll 20 is incorporated between the back surface of the rotation end plate 21 of the rotation scroll 20 and the thrust bearing portion 15A of the upper bearing member 15. The fixed end plate 17 of the fixed scroll 16 is provided with a discharge cover 28 on the back side thereof, and a lead valve type discharge valve 29 for opening and closing the discharge port 19.

In the stepped scroll compressor 1 configured as described above, when the electric motor 4 is driven, low-pressure refrigerant gas (HFC refrigerant) is sucked into the sealed housing 2 via the suction pipe 8, and this refrigerant gas. Is sucked into the compression chamber 24 of the scroll compression mechanism 3 through the refrigerant flow path provided in the upper bearing member 15 and the like. The refrigerant gas sucked into the compression chamber 24 is a high-temperature high-pressure gas while the swivel scroll 20 is driven to revolve around the fixed scroll 16 and the compression chamber 24 is moved from the outer peripheral position to the center side while reducing the volume. Is compressed to. The compressed refrigerant gas opens the discharge valve 29, flows into the discharge chamber 5, and is supplied from the discharge pipe 6 to a heat exchanger such as a condenser via an external pipe.

[First Embodiment]
Next, the first embodiment of the present invention will be described.
FIG. 6 is a developed view of the lap walls 18 and 22 in the fixed scroll 16 and the swivel scroll 20 showing the first embodiment of the present invention. The angle values displayed in FIG. 6 match the positions of the same values on the fixed lap wall body 18 and the swivel lap wall body 22 shown in FIG. 3, respectively.
Each of the lap wall bodies 18 and 22 is referred to as a "ventral surface" on the inner peripheral side in the radial direction and a "back surface" on the outer peripheral side in the radial direction.

The ventral surfaces of the lap walls 18 and 22 have a non-involute section from the starting point SP to 0 °, a section A1 from 0 ° to 450 °, and a section A2 from 450 ° to 630 ° along the circumferential direction. , It can be divided into three sections with the section A3 from 630 ° to the end point EP before 900 °. The lap heights from the tooth bottom surfaces 17a and 21a to the tooth tip surfaces 18a and 22a in these three sections A1, A2 and A3 are H1, H2 and H3, respectively, and the magnitude relationship is H1 <H2 <H3. It has become.

The back of the wrap wall 18 and 22, along the circumferential direction, the start point SP or these non involute section, and Gu between B1, a section B2 from 270 ° to 450 °, in front of 720 ° from the 450 ° It can be divided into four sections, a section B3 up to the point P1 and a section B4 from the point P1 to the end point EP 900 ° before. The ventral surfaces of the opposing lap walls do not overlap the section B4. The lap heights from the tooth bottom surfaces 17a and 21a to the tooth tip surfaces 18a and 22a in these four sections B1, B2, B3 and B4 are H1, H2 and H3, respectively, and the magnitude relationship is H1 <H2 <. It is H3.

Swirl the fixed wrap wall 18 and the orbiting wrap wall 22, the tooth tip step portion TS effective spiral length of the spiral direction inner side of the section than, i.e. the section excluding the start point SP or these non involute section The length is 360 ° or more. That is, when the fixed wrap wall 18 and orbiting wrap wall 22 are combined, both of the lap wall 18,2 2 is adapted to overlap one round or more in the spiral direction.

In these lap wall bodies 18 and 22, each surface of the ventral side section A3 and the back surface side sections B2 and B3 adjacent to the tooth bottom surfaces 17a and 21a on the outer peripheral side in the spiral direction with respect to the tooth bottom step portion BS is covered. It recedes slightly inward from the original ventral and dorsal surface profiles to the extent that it does not adversely affect the compression of the compressible refrigerant. In other words, the thickness of the wrap walls 18 and 22 is thinner than before. In FIG. 3, the range in which the surface is retracted is indicated by the symbol XXX, and in FIG. 6, the range in which the surface is retracted is shaded.
The section B4 on the back side may also be retracted inward, but since the opposing spiral lap wall bodies 18 and 22 do not overlap with this surface (there is no concern of contact), the surface is not retracted. You may.
This retreat amount is set to be within the range of δ / ρ ≦ 0.01 when the maximum value is δ and the turning radius of the turning scroll 20 is ρ. As a specific numerical value, for example, it is preferably 100 μm or less, preferably about 10 to 20 μm. As a method of retracting the surface, it is conceivable to manufacture the surface in a retracted shape from the beginning, or to post-process the lap wall bodies 18 and 22 that have not been retracted. As a post-processing method, a mechanical method such as polishing or cutting, or a chemical method such as etching can be considered.

The fixed scroll 16 and the swivel scroll 20 are configured as described above. According to this, in the section where the lap heights of the lap wall bodies 18 and 22 are high, that is, in the sections A3 (ventral side) and B2 and B3 (back side) on the outer peripheral side in the spiral direction from the tooth bottom step portion BS. Since both sides of the lap wall bodies 18 and 22 are retracted inward from the original ventral surface profile, the fixed lap wall body 18 and the swirl are swiveled in the section on the outer peripheral side in the spiral direction where the lap heights H2 and H3 are high. It does not come into contact with the lap wall body 22. Therefore, it is possible to prevent damage due to contact between the lap wall bodies 18 and 22.

In the above configuration, there spiral length definitive between ward spiral direction inner side of the tooth tip step portion TS is 360 ° or more, both sides of the rear pressure surface of the wrap wall 18 and 22 and in this section is on the inside It is kept in its original lateral profile without retreating.
Therefore, during operation of the stepped scroll compressor 1, only rap wall 18 and 22 to each other Oite between wards the spiral direction inner side is in contact at two points, whereby the orbiting scroll 20 relative to the stationary scroll 16 The turning trajectory is fixed.
Therefore, even at between ward spiral direction outer peripheral side to retract the ventral surface and the back surface of the wrap wall 18, 22 on the inner side of the tooth bottom step part BS, by the amount obtained by the backward orbiting scroll 20 is the end plate It does not move in the plane direction of 21, and damage due to contact between the lap wall bodies 18 and 22 can be prevented.

The amount of retracting the ventral surface and the back surface of the lap wall bodies 18 and 22 inward is set to a degree that does not adversely affect the compression of the refrigerant, for example, about 100 μm or less, so that the compression leakage of the stepped scroll compressor 1 is minimized. It is possible to prevent damage to the lap wall bodies 18 and 22 and improve the durability and reliability of the stepped scroll compressor 1 while suppressing the deterioration of the compression performance to the limit. In the sections A1 and B1 on the inner peripheral side in the spiral direction where the compression pressure is highest, the ventral surface and the back surface of the lap wall bodies 18 and 22 do not recede, and no gap is generated between both lap wall bodies 18 and 22. Therefore, it is possible to prevent compression leakage of the refrigerant in this respect as well.

The maximum value of the receding amount of the ventral surface and the back surface of the lap wall bodies 18 and 22 is within the range of δ / ρ ≤ 0.01 when the maximum value is δ and the turning radius of the turning scroll 20 is ρ. δ is set. Therefore, in stepped scroll compressors of various sizes, it is possible to both prevent damage to the lap walls 18 and 22 and suppress performance deterioration due to compression leakage.

The receding of the ventral surface and the back surface of the lap wall bodies 18 and 22 does not necessarily have to be performed evenly over the entire height direction of the ventral surface and the back surface, and the wrap wall bodies 18 and 22 are directed from the root side to the tip side. The amount of retreat may be increased. For example, as shown in FIG. 7, the vertical cross-sectional shape of the lap wall bodies 18 and 22 is tapered from the root side to the tip side, and as shown in FIG. 8, the vertical cross section of the wrap wall bodies 18 and 22 is formed. It is conceivable that the surface shape gradually becomes thinner from the root side to the tip side.

By doing so, it is possible to prevent the lap wall bodies 18 and 22 from coming into contact with each other on the tip side without reducing the thickness dimension on the root side of the wrap wall bodies 18 and 22 and impairing the strength. It is possible to prevent damage to the bodies 18 and 22. If the fixed lap wall body 18 and the swivel lap wall body 22 that face each other have the same tapered cross-sectional shape or a stepped cross-sectional shape, the cross-sectional shapes of both lap wall bodies 18 and 22 are equal and opposite to each other. Therefore, it is possible to prevent the leakage of the refrigerant by minimizing the meshing interval between the lap walls 18 and 22.

[Second Embodiment]
Next, the second embodiment of the present invention will be described.
FIG. 9 is an enlarged vertical sectional view of the fixed scroll 16 according to the second embodiment of the present invention, and FIG. 10 is a bottom view of the fixed scroll 16. Further, FIG. 11 is a diagram in which a fixed scroll and a swivel scroll are combined. Further, FIG. 12 is a developed view of the lap wall bodies 18 and 22 in the fixed scroll and the swivel scroll showing the second embodiment of the present invention. The fixed scroll 16 and the swivel scroll 20 shown here differ only in the number of turns (angle values) of the lap wall bodies 18 and 22 from those of the first embodiment, and the heights of the lap wall bodies 18 and 22 and each part are different. The basic structure is similar. Therefore, the same reference numerals are given to the parts having the same configuration, and the description thereof will be omitted.

The ventral surfaces of the lap walls 18 and 22 have a non-involuted section from the starting point SP to 0 °, a section A1 from 0 ° to the tooth tip step portion TS (point P1), and a tooth tip step along the circumferential direction. It can be divided into three sections, a section A2 from the portion TS (P1) to the tooth bottom step portion BS (point P2) and a section A3 from the tooth bottom step portion BS (P2) to the end point EP. The lap heights from the tooth bottom surfaces 17a and 21a to the tooth tip surfaces 18a and 22a in these three sections A1, A2 and A3 are H1, H2 and H3, respectively, and the magnitude relationship is H1 <H2 <H3. It has become.

The back surfaces of the lap wall bodies 18 and 22 have a non-involuted section from the starting point SP to 0 °, a section B1 from 0 ° to the tooth bottom step portion BS, and a tooth tip from the bottom step portion BS along the circumferential direction. It can be divided into three sections, a section B2 up to the step portion TS (point P1) and a section B3 from the tooth tip step portion TS (P1) to the end point EP. The lap heights from the tooth bottom surfaces 17a and 21a to the tooth tip surfaces 18a and 22a in these three sections B1, B2 and B3 are also H1, H2 and H3, respectively, and the magnitude relationship is H1 <H2 <H3. ing.

The fixed wrap wall 18 and the swirl wrap wall 22 exclude the effective spiral length of the section on the inner peripheral side in the spiral direction from the tooth tip step portion TS, that is, the non-involute section from the start point SP to 0 °. The spiral length of the section B1 from 0 ° to the tooth tip step portion TS is set to be less than 360 °. That is, when the fixed lap wall body 18 and the swivel lap wall body 22 are combined, the circumference in which the sections A1 and B1 + B2 on the inner peripheral side of the lap wall bodies 18 and 22 overlap is less than one lap, and the whole The number of turns of is also reduced, and the turning radius ρ of the turning scroll is set to be larger by that amount.

In this way, when the spiral length of the sections A1, B1 + B2 on the inner peripheral side of the tooth tip step portion TS in the spiral direction is less than 360 °, the tooth bottom 17a on the outer peripheral side in the spiral direction than the tooth bottom step portion BS, Only the ventral surfaces of the spiral wrap walls 18 and 22 adjacent to 21a are retracted slightly inward from the original side profile to the extent that they do not adversely affect the compression of the refrigerant. That is, the surface of the lap wall bodies 18 and 22 is retracted with respect to the section A3 on the ventral surface side. In FIG. 10, the range in which the surface is retracted is indicated by the symbol XXX, and in FIG. 12, the range in which the surface is retracted is shaded. The setting conditions and the like for the retreat amount are the same as those in the first embodiment.

In this way, in the section where the lap heights of the lap walls 18 and 22 are the highest, that is, in the section A3 on the outer peripheral side in the spiral direction with respect to the tooth bottom step portion BS, the ventral surfaces of the lap walls 18 and 22 are formed. Since the lap height H3 is the highest and the risk of damage is highest in the sections A3 and B3 on the outermost side in the spiral direction because the lap height H3 is retracted inward from the original side profile, the lap walls 18 and 22 come into contact with each other. It is possible to prevent damage due to contact between the lap wall bodies 18 and 22.

In the above configuration, the side surfaces of the spiral wrap walls (18, 22) retract inward in the sections A1 + A2 on the inner peripheral side in the spiral direction from the tooth bottom step portion BS on the ventral surface side and in all sections B1 + B2 + B3 on the back surface side. It is said that the original side profile is maintained.

In the present embodiment, the section on the inner peripheral side in the spiral direction from the tooth tip step portion TS, that is, the section A1 on the ventral surface side and the section B1 + B2 on the back surface side both have a spiral length of less than 360 °, but are on the ventral surface side. In, the spiral length exceeds 360 ° when the section A2 between the tooth tip step portion TS and the tooth bottom step portion BS (point P2) is combined. On the back side, the spiral length exceeds 360 ° when the section from the point P1 to the section corresponding to the point P2 in the section B3 is combined (see also FIG. 11).

Therefore, when the stepped scroll compressor 1 is operated, as shown in FIG. 11, the section (shaded range) from 0 ° to the point P2 in each of the lap wall bodies 18 and 22 exceeds 360 ° with each other. At any position in both sections, the lap wall bodies 18 and 22 come into contact with each other at two points T1 and T2, whereby the turning trajectory of the turning scroll 20 with respect to the fixed scroll 16 is determined.

Therefore, even if the ventral surface of the lap wall bodies 18 and 22 is retracted inward in the section A3 on the outer peripheral side in the spiral direction with respect to the tooth bottom step portion BS, that is, in the section where the lap height H3 of the lap wall bodies 18 and 22 is the highest. The swivel scroll 20 does not move in the surface direction of the end plate 21 by the amount of the retracted portion, and damage due to contact between the lap wall bodies 18 and 22 can be prevented.

According to this configuration and the design method, of the entire circumferences of the lap wall bodies 18 and 22, only the ventral side is retracted in the outermost section A3 where the lap height is the highest, and the other sections A1 and A2 and the back side. In sections B1, B2, and B3, neither the ventral side nor the back side is retracted. Therefore, it is possible to suppress compression leakage of the refrigerant as compared with the configuration of the first embodiment, and it is possible to prevent a decrease in compression efficiency particularly in a stepped scroll compressor having a small number of turns of the lap wall bodies 18 and 22. it can.

By the way, as shown in FIG. 13, at the position of the tooth bottom step portion BS, the amount of retreat of the ventral surfaces of the lap wall bodies 18 and 22 may be gradually reduced from the outer peripheral side in the spiral direction to the inner peripheral side. This prevents the generation of noise due to the lap walls 18 and 22 of the scrolls 16 and 20 facing each other interfering with the burrs that are likely to be generated when the tooth bottom step portion BS is machined and formed on the end plates 17 and 21. be able to.

As described above, according to the stepped scroll compressor and the design method thereof according to the present invention, it is possible to prevent damage to the spiral lap wall body in a section where the lap height is high, and to improve durability and reliability. , It is possible to minimize the compression leakage and prevent the deterioration of the compression performance.

It should be noted that the present invention is not limited to the configuration of the above-described embodiment, and changes and improvements can be made as appropriate, and the embodiments to which the changes and improvements have been made are also included in the scope of rights of the present invention. And.
For example, the internal configuration of the stepped scroll compressor 1, the posture arrangement such as vertical type and horizontal type, the application, the type of the fluid to be compressed, and the detailed shape of the fixed scroll 16 and the swivel scroll 20 are not necessarily described above. It does not have to be in line with the embodiment.

Further, in the present embodiment, the tooth bottom step portions BS are provided on the tooth bottoms 17a and 21a of both the fixed scroll 16 and the swivel scroll 20, and the tooth tip step portions TS are provided on both the tooth tip surfaces 18a and 22a. Although the model has been described, the present invention can be applied to a model in which only the tooth bottom step portion BS is provided on one scroll and only the tooth tip step portion TS is provided on the other scroll.

In the present embodiment, both the fixed lap wall 18 of the fixed scroll 16 and the swivel lap wall 22 of the swivel scroll 20 have their ventral surfaces and back surfaces retracted, but one of the scrolls It is also conceivable to retract only the lap wall. In this case, contact with the opposing wraps is prevented only on either the ventral or back surface of the wrap wall.

1 Scroll compressor 16 Fixed scroll 17 Fixed end plate (end plate)
17a, 21a Tooth bottom 18 Fixed wrap wall (spiral wrap)
18a, 22a Tooth tip surface 20 Swivel scroll 21 Swivel end plate (end plate)
22 Swirling wrap wall (spiral wrap wall)
24 Compression chamber BS Tooth bottom step TS Tooth tip step ρ Swing radius of swivel scroll

Claims (11)

A fixed scroll and a swirl scroll having a spiral wrap wall body erected on one side surface of each end plate form a pair of compression chambers that compress the compressed fluid by engaging the spiral wrap wall bodies with each other. And
On the one side surface of the end plate of at least one of the fixed scroll and the swivel scroll, the height of the tooth bottom surface increases from the outer peripheral side in the spiral direction to the inner peripheral side of the spiral wrap wall body. There is a step,
The spiral wrap wall body of the other scroll corresponding to the tooth bottom step portion is provided with a tooth tip step portion in which the height of the tooth tip surface decreases from the outer peripheral side in the spiral direction to the inner peripheral side. It is a stepped scroll compressor
At least one of the fixed scroll and the swirl scroll is the spiral wrap in a range adjacent to the tooth bottom surface on the outer peripheral side in the spiral direction with respect to the tooth bottom step portion and at least overlapping with the spiral wrap wall body facing the tooth bottom. Only the ventral surface of the wall body recedes inward from its original lateral profile , and the ventral surface of the spiral wrap wall body adjacent to the tooth bottom surface on the inner peripheral side in the spiral direction from the tooth bottom step portion is originally It is said to be a side profile of
The spiral wrap wall body whose ventral surface is the original lateral profile is a stepped scroll compressor whose temperature is 360 ° or more, excluding the non-involute section . A fixed scroll and a swirl scroll having a spiral wrap wall body erected on one side surface of each end plate form a pair of compression chambers that compress the compressed fluid by engaging the spiral wrap wall bodies with each other. And
On the one side surface of the end plate of at least one of the fixed scroll and the swivel scroll, the height of the tooth bottom surface increases from the outer peripheral side in the spiral direction to the inner peripheral side of the spiral wrap wall body. There is a step,
The spiral wrap wall body of the other scroll corresponding to the tooth bottom step portion is provided with a tooth tip step portion in which the height of the tooth tip surface decreases from the outer peripheral side in the spiral direction to the inner peripheral side. It is a stepped scroll compressor
In at least one of the fixed scroll and the swivel scroll, the ventral surface and the back surface of the spiral wrap wall body adjacent to the tooth bottom surface on the outer peripheral side in the spiral direction from the tooth bottom step portion are inside the original side profile. The ventral surface and the back surface of the spiral wrap wall body adjacent to the tooth bottom surface on the inner peripheral side in the spiral direction with respect to the tooth bottom step portion are defined as the original lateral profile.
The spiral wrap wall body whose ventral surface and back surface have the original lateral profile is a stepped scroll compressor whose temperature is 360 ° or more, excluding the non-involute section . The stepped scroll compressor according to claim 1, wherein in the spiral wrap wall body, the spiral length of the section on the inner peripheral side in the spiral direction with respect to the tooth tip step portion excluding the non-involute section is less than 360 °. .. The stepped scroll compressor according to claim 2, wherein in the spiral wrap wall body, the spiral length of the section on the inner peripheral side in the spiral direction with respect to the tooth tip step portion excluding the non-involute section is 360 ° or more. .. The maximum value after withdrawal of the spiral wraps wall [delta], wherein the turning radius of the orbiting scroll when the [rho, the maximum value of δ / ρ ≦ 0.01 the retraction amount to be within a range of [delta] The stepped scroll compressor according to any one of claims 1 to 4, wherein is set. Stepped scroll compressor according to any one of the tooth bottom withdrawal amount after the spiral wrap wall at the position of the stepped portion from claim 2 gradually decreases toward the inner circumferential side from the spiral direction outer peripheral side 4 Machine. Shisaryou after the spiral wrap wall is stepped scroll compressor according to any one of claims 1 to 4 which is greater toward the distal end side from the root side of the spiral wrap wall. A fixed scroll and a swirl scroll having a spiral wrap wall body erected on one side surface of each end plate form a pair of compression chambers that compress the compressed fluid by engaging the spiral wrap wall bodies with each other. And
On the one side surface of the end plate of at least one of the fixed scroll and the swivel scroll, the height of the tooth bottom surface increases from the outer peripheral side in the spiral direction to the inner peripheral side of the spiral wrap wall body. There is a step,
The spiral wrap wall body of the other scroll corresponding to the tooth bottom step portion is provided with a tooth tip step portion in which the height of the tooth tip surface decreases from the outer peripheral side in the spiral direction to the inner peripheral side. It is a design method of a stepped scroll compressor.
The spiral wrap for at least one of the fixed scroll and the swirl scroll in a range adjacent to the tooth bottom surface on the outer peripheral side in the spiral direction from the tooth bottom step portion and at least overlapping with the spiral wrap wall body facing the tooth bottom. Only the ventral surface of the wall body is retracted inward from its original lateral profile , and the ventral surface of the spiral wrap wall body adjacent to the tooth bottom surface on the inner peripheral side in the spiral direction from the tooth bottom step portion is the original surface. As a side profile,
It said spiral wrap wall of the ventral surface is the original side profile, with the exception of the non-involute section, the design method of to that stepped scroll compressor with more than 360 °. A fixed scroll and a swirl scroll having a spiral wrap wall body erected on one side surface of each end plate form a pair of compression chambers that compress the compressed fluid by engaging the spiral wrap wall bodies with each other. And
On the one side surface of the end plate of at least one of the fixed scroll and the swivel scroll, the height of the tooth bottom surface increases from the outer peripheral side in the spiral direction to the inner peripheral side of the spiral wrap wall body. There is a step,
The spiral wrap wall body of the other scroll corresponding to the tooth bottom step portion is provided with a tooth tip step portion in which the height of the tooth tip surface decreases from the outer peripheral side in the spiral direction to the inner peripheral side. It is a design method of a stepped scroll compressor.
For at least one of the fixed scroll and the swirl scroll, the ventral surface and the back surface of the spiral wrap wall body adjacent to the tooth bottom surface on the outer peripheral side in the spiral direction from the tooth bottom step portion are inside the original side profile. The ventral surface and the back surface of the spiral wrap wall body adjacent to the tooth bottom surface on the inner peripheral side in the spiral direction from the tooth bottom step portion are used as the original lateral profile thereof.
It said spiral wrap wall ventral surface and the back is the original side profile, with the exception of the non-involute section, the design method of to that stepped scroll compressor with more than 360 °. The stepped scroll compressor according to claim 8, wherein in the spiral wrap wall body, the spiral length of the section on the inner peripheral side in the spiral direction with respect to the tooth tip step portion excluding the non-involute section is less than 360 °. Design method. The stepped scroll compressor according to claim 9, wherein in the spiral wrap wall body, the spiral length of the section on the inner peripheral side in the spiral direction with respect to the tooth tip step portion excluding the non-involute section is 360 ° or more. Design method.

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