JP2006342775A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll compressor for improving compression efficiency by optimizing step difference mesh clearance in an operation state. <P>SOLUTION: This stepped-shaped scroll compressor has a step part mesh clearance preset value Hf generated between a connecting wall surface 12h of a fixed scroll 12 and a step part side surface with the connecting edge 13e of a turning scroll 13 and a step part mesh clearance preset value Ho generated between a connecting wall surface 13h of the turning scroll 13 and a step part side surface with the connecting edge 12e of the fixed scroll 12. The step part mesh clearance preset value (Hf in an illustrated example) of mutually approaching when the turning scroll 13 inclines by receiving gas pressure in operation, is set larger than the mutually approaching other (Ho in the illustrated example). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a scroll compressor applied to an air conditioner, a refrigeration apparatus, and the like.

In a scroll compressor, a fixed scroll and an orbiting scroll are arranged in combination with spiral walls, and the volume of the compression chamber formed between the walls is gradually increased by orbiting the orbiting scroll relative to the fixed scroll. The fluid in the compression chamber is compressed by decreasing. In such a scroll compressor, since the compression ratio can be increased and the compression capacity can be improved without increasing the size of the compressor itself, a scroll member having a stepped shape has been put into practical use. (For example, see Patent Document 1)
JP 2003-35285 A

Incidentally, in the stepped portion of the scroll member described above, a minute gap is formed between the fixed scroll side and the orbiting scroll side in order to permit the orbiting operation of the orbiting scroll. Therefore, when the volume of the compression chamber gradually decreases due to the progress of the compression process, the compressed gas leaks through the minute gap from the high pressure side to the low pressure side, so the minute gap formed in the stepped portion is This was a factor that reduced the compression efficiency of the scroll compressor.
As such a minute gap serving as a compressed gas leakage passage, there is a gap called a “step mesh gap” provided in a step portion of a scroll compressor adopting a stepped shape. This step mesh gap is a gap formed between the side surfaces of the step bottom side and the tooth tip side (between the connecting edge and the connecting wall surface) in the stepped step portion. The two step mesh gaps are set to have the same value when the operation is stopped.

However, when the orbiting scroll starts the compressing operation by operating the scroll compressor, one of the two step mesh gaps approaches and becomes smaller due to the inclination of the orbiting scroll, but the other is separated. Large gaps. From such a background, by optimizing the step mesh gap in the operating state of the scroll compressor, and reducing the amount of compressed gas leaking from the high pressure side to the low pressure side through the step mesh gap during operation, Efficiency improvement is required.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a scroll compressor that optimizes a step mesh gap in an operating state to improve compression efficiency.

In order to solve the above problems, the present invention employs the following means.
A scroll compressor according to the present invention has a fixed scroll having a spiral wall standing on one side of an end plate, and a spiral wall standing on one side of the end plate, A revolving scroll supported so as to be capable of revolving orbiting while preventing rotation and meshing with each other, and the end plate of at least one of the fixed scroll and the revolving scroll has a A step portion is formed so that the height is higher at the center side along the vortex of the wall body and lower at the outer end side, and the upper edge of the other wall body of the fixed scroll and the orbiting scroll is In the scroll compressor, which corresponds to the stepped portion of the end plate, is divided into a plurality of parts, and the height of the part is low on the center side of the vortex and high on the outer end side,
A first step mesh gap setting value (Hf) generated between the step side surfaces of the fixed scroll tooth bottom and the orbiting scroll tooth tip, and the orbiting scroll tooth bottom and the fixed scroll tooth tip And a second step mesh gap setting value (Ho) generated between the side surfaces of the step portions, and the step mesh gap setting values approaching each other when the orbiting scroll is inclined by receiving gas pressure during operation are separated from each other. It is characterized in that it is set larger than the other.

  According to the scroll compressor of the present invention, the first step mesh gap setting value (Hf) generated between the stepped side surfaces of the fixed scroll tooth bottom and the orbiting scroll tooth tip, and the orbiting scroll tooth bottom fixed. One of the set dimensions of the second step mesh clearance set value (Ho) generated between the step side surfaces of the scroll teeth and the scroll scroll tip, and the orbiting scrolls are close to each other by being inclined by receiving gas pressure during operation. Since the setting value of the step mesh gap is set to be larger than the other one that is separated from each other, if the orbiting scroll is inclined due to the gas pressure during operation, the approaching step mesh gap and the separation step mesh Since the gap can be set to a substantially minimum optimum value, the amount of leakage from the step mesh gap can be reduced.

2. The scroll compressor according to claim 1, wherein the first and second stepped mesh gap setting values (Hf, Ho) are larger at the end of meshing than the stepped mesh gap amount (hs) formed at the start of meshing. Reduce the amount of gap (he) in the step mesh formed (hs
> He) is preferably set so that the step mesh gap amount (h) gradually decreases from the start of meshing to the end of meshing. As a result, the step mesh mesh gap amount ( Since h) is reduced, the amount of leakage from the step mesh gap in the compression process can be reduced.

  3. The scroll compressor according to claim 1, wherein a cross-sectional shape of a tooth bottom and a tooth tip meshed at the stepped portion is an asymmetric shape in which a radius of curvature is changed so that a contact area is increased from the start of meshing to the end of meshing. Preferably, the contact area is increased and the sealing performance is increased in a state where the differential pressure is large, so that the amount of leakage from the step mesh gap in the compression process can be reduced.

According to the above-described present invention, the step mesh gap formed between the side surfaces of the tooth bottom side and the tooth tip side in the stepped step portion is optimized in the operating state, and the gap step mesh is compressed in the compression process during operation. Since the amount of compressed gas leaking from the gap can be reduced, a remarkable effect of improving the compression efficiency of the scroll compressor can be obtained.
Furthermore, sealing performance is achieved by setting the step mesh gap smaller in the latter half of the compression process where the differential pressure is larger, and by adopting an asymmetric cross-sectional shape that increases the contact area between the connecting wall surface and the connecting edge in the latter half of the compression process where the differential pressure is larger. Thus, the compression efficiency of the scroll compressor having a stepped portion having a stepped shape can be further improved.

Hereinafter, an embodiment of a scroll compressor according to the present invention will be described with reference to the drawings.
FIG. 3 is a cross-sectional view showing a configuration example of the scroll compressor. In the figure, reference numeral 1 denotes a sealed housing, 2 denotes a discharge cover that separates the inside of the housing 1 into a high pressure chamber HR and a low pressure chamber LR, and 5 denotes a frame. , 6 is a suction pipe, 7 is a discharge pipe, 8 is a motor, 9 is a rotating shaft, and 10 is a rotation prevention mechanism. Reference numeral 12 is a fixed scroll, and 13 is a turning scroll that meshes with the fixed scroll 12.

As shown in FIG. 4A, the fixed scroll 12 has a configuration in which a spiral wall body 12b is erected on one side surface of the end plate 12a. As shown in FIG. 4B, the orbiting scroll 13 has a configuration in which a spiral wall body 13b is erected on one side surface of the end plate 13a, like the fixed scroll 12, and the wall body 13b is The wall body 12b on the fixed scroll 12 side has substantially the same shape. The orbiting scroll 13 is assembled with the wall bodies 12b and 13b meshed with each other in a state of being eccentric with respect to the fixed scroll 12 by the revolution orbiting radius and shifted in phase by 180 degrees.
In this case, the orbiting scroll 13 performs a revolving orbiting motion with respect to the fixed scroll 12 by the action of the eccentric pin 9 a provided at the upper end of the rotating shaft 9 driven by the motor 8 and the orbiting rotation mechanism 10. It has become. On the other hand, the fixed scroll 12 is fixed to the housing 1, and a compressed fluid discharge port 11 is provided at the center of the back surface of the end plate 12a.

  The end plate 12a of the fixed scroll 12 has a stepped portion 42 formed on one side where the wall body 12b is erected so as to be higher at the center side along the vortex direction of the wall body 12b and lower at the outer end side. I have. Similarly to the end plate 12a of the fixed scroll 12, the end plate 13a on the side of the orbiting scroll 13 is on one side where the wall body 13b is erected and is higher on the center side along the vortex direction of the wall body 13b and on the outer end side. The step part 43 formed so that it may become low is provided. The step portions 42 and 43 advance by π (rad) from the outer end (suction side) to the inner end (discharge side) of the wall bodies 12b and 13b, for example, with reference to the spiral centers of the wall body 12b and the wall body 13b. It is provided in the position.

The bottom surface of the end plate 12a is divided into two parts, a shallow bottom surface 12f provided from the center and a deep bottom surface 12g provided from the outer terminal, by forming the step portion 42. It has been. Between adjacent bottom surfaces 12f and 12g, a stepped portion 42 is formed, and there is a connecting wall surface 12h that connects the bottom surfaces 12f and 12g and stands vertically.
Similarly to the above-described end plate 12a, the bottom surface of the end plate 13a is formed with the stepped portion 43, so that the bottom bottom surface 13f provided at the center and the bottom bottom provided at the outer end are formed. It is divided into two parts of 13g. A stepped portion 43 is formed between the adjacent bottom surfaces 13f and 13g, and there is a connecting wall surface 13h that connects the bottom surfaces 13f and 13g and stands vertically.

The wall 12b on the fixed scroll 12 side corresponds to the stepped portion 43 of the orbiting scroll 13, the upper edge of the spiral is divided into two parts, and is low at the center of the vortex and high at the outer end side. It has a stepped shape. Similarly to the wall 12b, the wall 13b on the side of the orbiting scroll 13 corresponds to the stepped portion 42 of the fixed scroll 12, the upper edge of the spiral is divided into two parts, and the outer end is low at the center of the vortex. High stepped shape on the side.
Specifically, the upper edge of the wall body 12b is divided into two parts, a lower upper edge 12c provided near the center and a higher upper edge 12d provided near the outer end, and adjacent upper parts. Between the edges 12c and 12d, there is a connecting edge 12e that connects the two and is perpendicular to the turning surface. Similarly to the wall body 12b described above, the upper edge of the wall body 13b is divided into two parts: a lower upper edge 13c provided near the center and a higher upper edge 13d provided near the outer end. Between the adjacent upper edges 13c and 13d, there is a connecting edge 13e that connects the two and is perpendicular to the turning surface.

When the wall 12b is viewed from the direction of the orbiting scroll 13, the connecting edge 12e has a semicircular shape that is smoothly continuous with both the inner and outer side surfaces of the wall 12b and has a diameter equal to the wall thickness of the wall 12b. Similarly to the connecting edge 12e, it also has a semicircular shape that is smoothly continuous with both the inner and outer side surfaces of the wall 13b and has a diameter equal to the wall thickness of the wall 13b.
The connecting wall surface 12h has an arc that matches the envelope drawn by the connecting edge 13e as the orbiting scroll turns when the end plate 12a is viewed from the turning axis direction, and the connecting wall surface 13h is the same as the connecting wall surface 12h. A circular arc that coincides with the envelope drawn by the connecting edge 12e is formed.

The wall body 12b of the fixed scroll 12 is provided with chip seals 14a and 14b divided into two near the connection edge 12e on the upper edges 12c and 12d. Similarly, the wall body 13b of the orbiting scroll 13 is provided with tip seals 15a and 15b divided into two near the connection edge 13e on the upper edges 13c and 13d. These tip seals leak gas fluid compressed by sealing the tip seal gap formed between the upper edge (tooth tip) and the bottom surface (tooth bottom) between the orbiting scroll 12 and the fixed scroll 13. Is to minimize.
That is, when the orbiting scroll 13 is assembled to the fixed scroll 12, the tip seal 15b provided on the lower upper edge 13c contacts the shallow bottom surface 12f, and the tip seal 15a provided on the upper upper edge 13d is the bottom bottom. It will contact 12g. At the same time, the tip seal 14a provided on the lower upper edge 12c contacts the shallow bottom surface 13f, and the tip seal 14b provided on the upper upper edge 12d contacts the deep bottom surface 13g. As a result, the compression chamber C is formed between the scrolls 12 and 13 by being divided into end plates 12a and 13a and wall bodies 12b and 13b facing each other. In FIG. 4, the fixed scroll 12 is illustrated upside down in order to show the stepped shape of the fixed scroll 12.

  FIG. 5 shows a state in which the fixed scroll 12 and the orbiting scroll 13 are combined to form the compression chamber C and compression is started. In this compression start state, the outer end of the wall body 12b contacts the outer surface of the wall body 13b, and the outer end of the wall body 13b contacts the outer surface of the wall body 12b, and the end plates 12a and 13a and the wall body 12b. , 13b is filled with a fluid to be compressed, and two compression chambers C having a maximum volume are formed at positions facing each other across the center of the scroll compression mechanism. At this time, the connecting edge 12e and the connecting wall surface 13h, and the connecting edge 13e and the connecting wall surface 12h are in sliding contact with each other, but are separated immediately by the turning operation of the orbiting scroll 12.

Further, in a state where the fixed scroll 12 and the orbiting scroll 13 are combined, the stepped mesh gap setting values Ho and Hf (see FIG. 1) at the two stepped portions 42 and 43 are as follows in a no-load operation stop state. It is set like this. Note that the stepped mesh gap is formed between the connecting edges 12e and 13e that are the side surfaces of the tooth tip side stepped portions and the connecting wall surfaces 12h and 13h that are the side surfaces of the tooth bottom side stepped portions. It is a gap formed in
That is, in the stepped portion 42, the first stepped mesh generated between the stepped side surfaces of the connecting wall surface (tooth bottom side stepped wall surface) 12 h of the fixed scroll 12 and the connecting edge (tooth top side stepped wall surface) of the orbiting scroll 13. A clearance set value (hereinafter referred to as “fixed side set value”) Hf, and a connecting wall (tooth bottom side step wall surface) 13h of the orbiting scroll 13 and a connecting edge (tooth tip side step portion) of the fixed scroll 12 at the step 43. When the second step mesh clearance set value (hereinafter referred to as “turning side set value”) Ho generated between the step side surface with the wall surface 12e is compared, the turning scroll 13 receives the gas pressure during operation. The fixed side set value Hf that is closer to each other by tilting is set to be larger than the turning side set value Ho that is separated from each other (Hf> Ho).

When the operation of the scroll compressor described above is started, as shown in FIG. 2, the orbiting scroll 13 is slightly tilted in the right direction (clockwise direction) in response to the gas pressure. Therefore, the fixed-side set value Hf and the orbiting-side set value Ho set in the stopped state shown in FIG. 1 are respectively set to the fixed-side step mesh gap Hf ′ and the orbiting-side step by the orbiting scroll 13 being inclined. The mesh gap changes to Ho ′.
One fixed-side stepped mesh gap Hf ′ has a fixed side set value Hf set in a stopped state because the connecting edge 13e approaches the connecting wall surface 12h due to the inclination of the orbiting scroll 13.
Narrower. On the other hand, the orbiting stepped mesh gap Ho ′ has a fixed side set value Ho set in a stopped state because the connecting edge 12e is separated from the connecting wall surface 13h by the inclination of the orbiting scroll 13.
Become wider.

  For this reason, the step mesh gap in the driving state in which the orbiting scroll 13 is inclined is smaller than the stationary step mesh gap Hf ′ on the step portion 42 side when stopped, and the orbiting step mesh after separation on the step portion 43 side. Since the clearance Ho ′ is also smaller than in the prior art, the swivel side and the fixed side can be optimized to reduce the overall opening area. Therefore, in the compression process of the scroll compressor, the amount of gas leaking from the high pressure side to the low pressure side through the opening area of the step mesh gap is reduced, so that the compression efficiency of the scroll compressor adopting the stepped shape is improved. Can do.

Further, in the step portions 42 and 43 of the scroll compressor described above, the fixed side set value Hf and the orbiting side set value Ho are formed at the start of engagement of the fixed scroll 12 and the orbiting scroll 13 as shown in FIG. The step mesh gap amount he formed at the end of meshing is set smaller (hs> he) than the step mesh mesh gap amount hs. Is set to
In this case, the cross-sectional shapes of the connecting wall surfaces (tooth bottoms) 12h and 13h and the connecting edges (tooth tips) 12e and 13e engaged with the stepped portions 42 and 43 are both substantially semicircular.

In FIG. 6, compression starts from the meshing start state shown in (a), and the connecting edge 13 e of the orbiting scroll 13 moves in the order of (b) to (d) as the compression process proceeds, and compression is completed in (e). To do. In such a compression process, the compression chamber C is divided into the high pressure side PH and the low pressure side PL by the wall body 13 b of the orbiting scroll 13.
However, at the initial stage of compression when the differential pressure between the high-pressure side PH and the low-pressure side PL is small, the amount of compressed gas leakage is not so large even if the stepped mesh gap amount h is relatively large. Then, as the compression process proceeds and the differential pressure between the high pressure side PH and the low pressure side PL increases, the amount of leakage increases if the step mesh amount h is constant, but the step mesh gap amount h gradually increases. Since it is set to be small, the amount of compressed gas leakage is also limited and can be reduced. As a result, the amount of compressed gas leakage as a whole of the compression process can be reduced, so that the compression efficiency of the scroll compressor adopting the stepped shape can be improved.

FIG. 7 shows a modified example of FIG. 6 described above. The connecting wall surfaces (tooth bottoms) 12h ′ and 13h ′ and the connecting edges (tooth tips) 12e ′ and 13e meshed with the step portions 42 ′ and 43 ′. The cross-sectional shape of ′ is an asymmetrical shape in which the radius of curvature is changed so that the contact area increases from the start of engagement to the end of engagement.
In FIG. 7, the compression starts from the meshing start state shown in FIG. 7A, and the connecting edge 13 e ′ of the orbiting scroll 13 moves in the order of (b) to (d) as the compression process proceeds, and the compression is performed in (e). Complete. In such a compression process, the compression chamber C is divided into the high pressure side PH and the low pressure side PL by the wall body 13 b of the orbiting scroll 13.

In this modification, since the radius of curvature is asymmetrical, the contact area between the connection wall surface and the connection edge can be increased in a state where the differential pressure between the high pressure side PH and the low pressure side LH is large, and the sealing performance can be increased.
More specifically, even in the state where meshing is started, even if the contact area is reduced by reducing the contact area, the amount of leakage is not large because the differential pressure is small. However, the connecting wall surfaces (tooth bases) 12h ′ and 13h ′ and the connecting edges (tooth tips) 12e ′ and 13e ′ change from line contact to surface contact as the pressure increases and the differential pressure increases, and the contact area increases. Since the cross-sectional shape of the asymmetric curvature radius gradually increases, sufficient sealing performance can be obtained with a large contact area in the latter half of the compression process with a large differential pressure. For this reason, since the amount of leakage from the step mesh gap can be reduced even in the latter half of the compression process with a large differential pressure, the compression efficiency of the scroll compressor adopting the stepped shape can be improved.

As described above, according to the scroll compressor of the present invention, the step mesh gap formed between the side surfaces of the tooth bottom side and the tooth tip side in the stepped steps 42 and 43 is optimal. As a result, it is possible to reduce the amount of compressed gas leaking from the gap step mesh gap during the compression process during operation. Therefore, the remarkable effect that the compression efficiency of the scroll compressor having a stepped stepped portion is improved is obtained.
Further, since the step mesh gap is set to be smaller in the latter half of the compression process where the differential pressure is large, a remarkable effect of improving the compression efficiency of the scroll compressor having the stepped stepped portion can be obtained. In addition, an asymmetric cross-sectional shape that increases the contact area between the connecting wall surface and the connecting edge in a state where the differential pressure is large is adopted, and the sealing performance is increased in the latter half of the compression process. The remarkable effect that the compression efficiency of the scroll compressor which has this is improved is acquired.
In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the summary of this invention, it can change suitably.

As an embodiment of the scroll compressor according to the present invention, (a) is a plan view showing the meshing state of the fixed scroll and the orbiting scroll when stopped, and (b) is an enlarged view showing the vicinity of the stepped portion 42 of (a). FIG. 4C is an enlarged view showing the vicinity of the stepped portion 43 of FIG. As an embodiment of the scroll compressor according to the present invention, (a) is a plan view showing a meshed state of a fixed scroll and a turning scroll during operation, and (b) is an enlarged view showing the vicinity of a stepped portion 42 of (a). FIG. 4C is an enlarged view showing the vicinity of the stepped portion 43 of FIG. It is a fragmentary sectional view showing the example of composition of the scroll compressor concerning the present invention. (A) is a perspective view which shows a structural example with a fixed scroll turned upside down, (b) is a perspective view which shows the structural example of a turning scroll about the scroll compressor which concerns on this invention. It is sectional drawing which shows the state which forms a compression chamber combining a fixed scroll and a turning scroll, and starts compression. It is the elements on larger scale which show compression operation in steps from the state of the meshing start shown to (a) to the state of the compression end shown to (e) about the step part which concerns on this invention. It is the elements on larger scale which show compression operation in steps from the state of the meshing start shown in (a) to the state of compression end shown in (e) about the modification of the stepped part concerning the present invention. .

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 2 Discharge cover 11 Discharge port 12 Fixed scroll 12a, 13a End plate 12b, 13b Wall body 12c, 12d, 13c, 13d Upper edge (tooth tip)
12e, 13e Connecting edge (tooth tip)
12f, 12g, 13f, 13g Bottom (tooth base)
12h, 13h Connecting wall (bottom)
13 Orbiting scroll 42, 43 Stepped portion C Compression chamber Hf, Ho Stepped mesh gap set value h, hs, he Stepped mesh gap amount

Claims (3)

A fixed scroll having a spiral wall standing on one side of the end plate and a spiral wall standing on one side of the end plate, and rotating by rotating the wall members together And at least one end plate of the fixed scroll and the orbiting scroll has a height along the vortex of the wall body. A step portion formed so as to be higher at the center side and lower at the outer end side, and an upper edge of one of the fixed scroll and the orbiting scroll corresponds to the step portion of the end plate. In a scroll compressor that is divided into a plurality of parts and has a stepped shape in which the height of the part is low on the center side of the vortex and high on the outer end side,
A first step mesh gap setting value (Hf) generated between the step side surfaces of the fixed scroll tooth bottom and the orbiting scroll tooth tip, and the orbiting scroll tooth bottom and the fixed scroll tooth tip And a second step mesh gap setting value (Ho) generated between the side surfaces of the step portions, and the step mesh gap setting values approaching each other when the orbiting scroll is inclined by receiving gas pressure during operation are separated from each other. A scroll compressor characterized in that it is set larger than the other. The scroll compressor according to claim 1, wherein
The first and second step mesh gap set values (Hf, Ho) are the step mesh gap amount (hs) formed at the start of meshing.
The step mesh gap amount (he) formed at the end of meshing is set to be smaller (hs> he) than the mesh) so that the step mesh gap amount (h) gradually decreases from the start of meshing to the end of meshing. A scroll compressor characterized by setting. The scroll compressor according to claim 1 or 2,
A scroll compressor characterized in that a cross-sectional shape of a tooth bottom and a tooth tip meshed at the stepped portion is an asymmetrical shape having a curvature radius changed so that a contact area is increased from the start of meshing to the end of meshing.

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