JP2021161942A - Scroll type compressor - Google Patents

Abstract

To provide a scroll type compressor capable of increasing a volume of a compression chamber, and capable of improving quietness.SOLUTION: In a scroll type compressor, a circumscribed partitioning point distance has a maximum value after having a minimum value while a revolving scroll makes a turn of 180° from a revolving start angle. Thereby, a part of a revolving side spiral wall at an outermost periphery protrudes toward an outer edge of a revolving side substrate, and therefore, a larger volume of a compression chamber can be secured on the revolving side substrate of a limited size. As a result, a rotation speed of the compressor can be reduced, and noise caused by vibration accompanied with rotation can be reduced.SELECTED DRAWING: Figure 10

Description

The present invention relates to a scroll type compressor that compresses a fluid in a compression chamber partitioned by a fixed scroll and a swirl scroll.

The scroll type compressor has a fixed scroll fixed in a housing and a swivel scroll that revolves with respect to the fixed scroll. The fixed scroll has a fixed side substrate and a fixed side spiral wall erected from the fixed side substrate, and the swivel scroll has a swirl side substrate and a swirl side swirl wall erected from the swivel side substrate. .. Then, the fixed-side spiral wall and the swirl-side spiral wall are meshed with each other, so that the compression chamber for compressing the refrigerant (fluid) by reducing the volume based on the revolution motion of the swirl scroll is partitioned.

Usually, in such a scroll type compressor, the fixed side spiral wall and the swirl side spiral wall are formed so that the entire outline is circular by using an involute curve based on a perfect circle with a predetermined radius. There is. In recent years, the scroll type compressor has been required to be quieter due to the circumstances such as mounting it on an electric vehicle. On the other hand, as in Patent Document 1, for example, the outline of the entire scroll and the shape of the spiral wall are circular. There is a technique to increase the volume of the scroll and the compression chamber in a limited space by flattening from. If the volume of the compression chamber is increased, the number of rotations of the spiral body can be reduced by that amount, so that the noise caused by the vibration accompanying the rotation can be reduced, and the effect of improving the quietness of the compressor can be obtained.

Japanese Unexamined Patent Publication No. 10-54380

The scroll described in Patent Document 1 has a shape close to a rectangle, and it is described that the entire compressor is miniaturized by this, but the shape of the substrate which is a part of the scroll is fully considered. No. Since the swirl wall swirls during fluid compression, the substrate integrated with the end of the swirl wall has a perfect circle or near contour for weight balance and productivity reasons. Therefore, the scroll described in Patent Document 1 has a shape in which a rectangular spiral wall extends from a perfect circular substrate. Therefore, there is a large gap between the contour of the substrate and the outer circumference of the spiral wall, and it cannot be said that the volume of the compression chamber is sufficiently large. Even in a normal scroll compressor having a circular spiral wall, the above problem exists because there is a gap between the contour of the substrate and the outer circumference of the spiral wall in the swirling scroll.

An object of the present invention is to provide a scroll type compressor capable of increasing the volume of a compression chamber and, by extension, improving quietness.

A scroll-type compressor for solving the above problems includes a rotating shaft, a fixed-side substrate, a fixed scroll having a fixed-side spiral wall erecting from the fixed-side substrate, and a swivel side facing the fixed-side substrate. The swirl scroll is provided with a substrate and a swirl scroll having a swirl side spiral wall that stands up from the swivel side substrate toward the fixed side substrate and meshes with the fixed side swirl wall, and the swivel scroll is generated by rotation of the rotation shaft. In a scroll type compressor that compresses fluid in a compression chamber partitioned by the fixed scroll and the swirl scroll by swirling, the swirl is formed on the outer periphery of the fixed side spiral wall when viewed from the axial direction of the rotation axis. The point where the inner circumferences of the side spiral walls are in contact with each other or close to each other to partition the compression chamber is defined as the circumscribing point, and the center of the basic circle of the involut curve drawn by the fixed side spiral wall and the base of the involut curve drawn by the swirl side spiral wall. The distance between the straight line passing through both the center of the circle and the extrinsic section point is defined as the extrinsic section point distance, and for the swirl angle of the swirl scroll, the swirl angle at which the compression chamber is formed and the compression of the fluid is started is started. As an angle, the distance between the extrinsic section points takes a maximum value after taking a minimum value during the period from the turning start angle to turning 180 °, and the maximum value is larger than the radius of the base circle. The gist is that the minimum value is smaller than the radius of the base circle.

According to this, at the turning start angle where the compression chamber is partitioned and fluid compression is started, the portion of the swirl side spiral wall that forms the compression chamber but is on the outermost peripheral side protrudes outward in the radial direction. It becomes a shape. In the swivel scroll, the gap between the contour of the swirl-side substrate and the outer circumference of the swirl-side spiral wall is at a position where the above-mentioned portions of the swirl-side spiral wall are connected. Therefore, by projecting the above-mentioned portion of the swirl-side spiral wall outward in the radial direction, the distance between the contour of the swirl-side substrate and the swirl-side swirl wall can be reduced in the swivel scroll, and a larger volume of the compression chamber can be secured. can do.

A scroll-type compressor for solving the above problems includes a rotating shaft, a fixed-side substrate, a fixed scroll having a fixed-side spiral wall erecting from the fixed-side substrate, and a swivel side facing the fixed-side substrate. The swirl scroll includes a substrate and a swirl scroll having a swirl side swirl wall that stands up from the swivel side board toward the fixed side board and meshes with the fixed side swirl wall, and the swivel scroll is generated by rotation of the rotation shaft. In a scroll type compressor that compresses fluid in a compression chamber partitioned by the fixed scroll and the swirling scroll by swirling, the said is on the inner circumference of the fixed side spiral wall when viewed from the axial direction of the rotating shaft. The point where the outer periphery of the swirl-side spiral wall comes into contact with or is close to each other to partition the compression chamber is defined as an inscribed section point, and the center of the base circle of the involute curve drawn by the fixed-side swirl wall and the involute curve drawn by the swirl-side swirl wall. The distance between the straight line passing through both the center of the base circle and the involute section point is defined as the involute section point distance, and for the swirl angle of the swirl scroll, the swirl angle at which the compression chamber is formed and the compression of the fluid is started. Is the turning start angle, and the involute division point distance takes a maximum value after taking a minimum value while the turning scroll turns 180 ° from the turning start angle, and the maximum value is the base circle. It is a gist that the minimum value is larger than the radius of the base circle and smaller than the radius of the base circle.

According to this, at the turning start angle at which the compression chamber is partitioned and fluid compression is started, the portion of the fixed-side spiral wall that forms the compression chamber but is the outermost side protrudes outward in the radial direction. It becomes a shape. The outer edge of the swirl-side substrate is the outermost portion of the fixed-side spiral wall that forms the compression chamber and the outer peripheral end of the swirl-side spiral wall so that the compression chamber does not communicate with the outside at the swivel start angle. Both are usually designed so that the envelope is the outer edge. Further, the swivel side substrate is usually designed so that the outer edge is a perfect circle for reasons such as weight balance and productivity. Therefore, when the portion of the fixed-side spiral wall protrudes outward in the radial direction, the contour of the envelope circle approaches the swirl-side spiral wall. Therefore, in the swivel scroll, the distance between the contour of the swirl-side substrate and the swirl-side swirl wall can be reduced, and the volume of the compression chamber can be secured larger.

According to the present invention, the volume of the compression chamber can be increased, and thus the quietness can be improved.

The vertical sectional view which shows the scroll type compressor of an embodiment. The figure which shows the fixed side swirl wall and the swirl side swirl wall of embodiment at a turning angle 0 °. The figure which shows the fixed side swirl wall and the swirl side swirl wall of embodiment at a turning angle of 30 °. The figure which shows the fixed side spiral wall and the swirl side spiral wall of embodiment at a turning angle 60 °. The figure which shows the fixed side swirl wall and the swirl side swirl wall of embodiment at a turning angle 90 °. The figure which shows the fixed side spiral wall and the swirl side spiral wall of embodiment at a turning angle 120 °. The figure which shows the fixed side spiral wall and the swirl side spiral wall of embodiment at a turning angle 150 °. The figure which shows the fixed side spiral wall and the swirl side spiral wall of embodiment at a turning angle 180 °. An enlarged view showing the first end portion and the arc portion of the fixed side spiral wall and the swirl side spiral wall. A graph showing the relationship between the turning angle and the division point distance. The figure which shows the comparison of the fixed side swirl wall and the swirl side swirl wall of the prior art (a) and the embodiment (b). The figure which shows the comparison of the position of the swivel side substrate of the conventional and embodiment.

Hereinafter, an embodiment in which the scroll type compressor is embodied will be described with reference to FIGS. 1 to 12.
As shown in FIG. 1, the scroll type compressor 10 includes a housing 11 in which a suction port 11a for sucking a fluid and a discharge port 11b for discharging a fluid are formed. The housing 11 has a substantially cylindrical shape as a whole. The housing 11 has a cylindrical first part 12 and a second part 13. The first part 12 and the second part 13 are assembled with their open ends abutting each other. The suction port 11a is provided at a position on the peripheral wall portion 12a of the first part 12, specifically, the peripheral wall portion 12a on the end wall 12b side of the first part 12. The discharge port 11b is provided on the end wall 13a of the second part 13.

The scroll type compressor 10 includes a rotating shaft 14, a compression unit 15 that compresses the suction fluid sucked from the suction port 11a and discharges it from the discharge port 11b, and an electric motor 16 that drives the compression unit 15. .. The rotating shaft 14, the compression unit 15, and the electric motor 16 are housed in the housing 11. The electric motor 16 is arranged in the housing 11 near the suction port 11a, and the compression unit 15 is arranged in the housing 11 near the discharge port 11b.

The rotating shaft 14 is housed in the housing 11 in a rotatable state. Specifically, a shaft support member 21 that pivotally supports the rotating shaft 14 is provided in the housing 11. The shaft support member 21 is fixed to the housing 11 at a position between the compression unit 15 and the electric motor 16, for example. The shaft support member 21 is formed with an insertion hole 23 in which the rotating shaft 14 can be inserted and the first bearing 22 is provided. Further, the shaft support member 21 and the end wall 12b of the first part 12 face each other, and a cylindrical boss 24 projects from the end wall 12b. A second bearing 25 is provided inside the boss 24. The rotating shaft 14 is rotatably supported by both bearings 22 and 25.

The compression unit 15 includes a fixed scroll 31 fixed to the housing 11 and a swivel scroll 32 that is swiveled with respect to the fixed scroll 31 by the rotation of the rotating shaft 14 and is capable of revolving.

The fixed scroll 31 has a disk-shaped fixed-side substrate 31a provided on the same axis as the rotating shaft 14, and a fixed-side spiral wall 31b rising from the fixed-side substrate 31a. Similarly, the swivel scroll 32 includes a swirl side substrate 32a which is disk-shaped and faces the fixed side substrate 31a, and a swirl side swirl wall 32b which stands up from the swivel side substrate 32a toward the fixed side substrate 31a. There is.

The fixed scroll 31 and the swivel scroll 32 mesh with each other. Specifically, the fixed-side swirl wall 31b and the swirl-side swirl wall 32b are in mesh with each other, and the tip surface of the fixed-side swirl wall 31b is in contact with the swirl-side substrate 32a and the tip surface of the swirl-side swirl wall 32b. Is in contact with the fixed side substrate 31a. A plurality of compression chambers 33 for compressing the fluid are partitioned by the fixed scroll 31 and the swivel scroll 32.

FIG. 2 shows the fixed scroll 31 and the swivel scroll 32 at the time when the fluid is first confined in the compression chamber 33 by the fixed scroll 31 and the swivel scroll 32. At this point, the first compression chamber 33a formed by the inner peripheral surface of the fixed-side spiral wall 31b and the outer peripheral surface of the swirl-side spiral wall 32b, and the outer peripheral side of the fixed-side spiral wall 31b and the inner circumference of the swirl-side spiral wall 32b. A second compression chamber 33b formed by the side is formed. That is, the plurality of compression chambers 33 include a first compression chamber 33a and a second compression chamber 33b. Further, the plurality of compression chambers 33 also include a compression chamber 33 partitioned inside the first compression chamber 33a and the second compression chamber 33b. Further, as shown in FIG. 5, as the swivel scroll 32 revolves, the first compression chamber 33a and the second compression chamber 33b are connected so that the central compression chamber 33c is formed in the central portion of the fixed scroll 31. It has become. Therefore, in the scroll type compressor 10, a plurality of compression chambers 33 are formed at the same time.

As shown in FIG. 1, the shaft support member 21 is formed with a suction passage 34 for sucking the suction fluid into the compression chamber 33. Further, the swivel scroll 32 is configured to revolve with the rotation of the rotation shaft 14. Specifically, a part of the rotating shaft 14 projects toward the compression portion 15 through the insertion hole 23 of the shaft support member 21. An eccentric shaft 35 is provided on the end face of the rotating shaft 14 on the side corresponding to the compression portion 15. The axis of the eccentric shaft 35 is eccentric with respect to the axis L of the rotating shaft 14. A bush 36 is provided on the eccentric shaft 35. The bush 36 and the swivel scroll 32 (specifically, the swivel side substrate 32a) are connected via a bearing 37.

Further, the scroll type compressor 10 is provided with a plurality of rotation regulation units 38 that regulate the rotation of the rotation scroll 32 while allowing the revolution movement of the rotation scroll 32. When the rotation shaft 14 rotates in a predetermined positive direction, the revolving motion of the swivel scroll 32 in the positive direction is performed. The swivel scroll 32 revolves in the positive direction around the axis of the fixed scroll 31 (that is, the axis L of the rotating shaft 14). As a result, the volume of the compression chamber 33 is reduced, so that the suction fluid sucked into the compression chamber 33 through the suction passage 34 is compressed. The compressed fluid is discharged from the discharge port 41 provided on the fixed-side substrate 31a, and then discharged from the discharge port 11b. The fixed-side substrate 31a is provided with a discharge valve 42 that covers the discharge port 41. The fluid compressed in the compression chamber 33 pushes away the discharge valve 42 and is discharged from the discharge port 41.

The electric motor 16 revolves the swivel scroll 32 by rotating the rotating shaft 14. The electric motor 16 includes a rotor 51 that rotates integrally with the rotating shaft 14, and a stator 52 that surrounds the rotor 51. The rotor 51 is connected to the rotating shaft 14. The rotor 51 is provided with a permanent magnet (not shown). The stator 52 is fixed to the inner peripheral surface of the housing 11 (specifically, the first part 12). The stator 52 has a stator core 53 that is radially opposed to the cylindrical rotor 51, and a coil 54 that is wound around the stator core 53.

The scroll type compressor 10 includes an inverter 55 which is a drive circuit for driving the electric motor 16. The inverter 55 is housed in a cylindrical cover member 56 attached to the housing 11, specifically the end wall 12b of the first part 12. The inverter 55 and the coil 54 are electrically connected.

2 to 8 show only the fixed-side swirl wall 31b of the fixed scroll 31 and the swirl-side swirl wall 32b of the swivel scroll 32. Each of the fixed-side swirl wall 31b and the swirl-side swirl wall 32b has a first end E located on the center side of the swirl and a second end S located on the outer peripheral side of the swirl, and has a first end. It extends spirally from the portion E toward the second end portion S.

In the fixed-side spiral wall 31b and the swirl-side spiral wall 32b, the first end portion E is formed by the arc C as shown by the alternate long and short dash line in FIG. Further, as shown by the solid line in FIG. 9, the outer peripheral surfaces of the fixed side spiral wall 31b and the swivel side spiral wall 32b are based on an involute curve until they are connected to one end of the arc C of the first end portion E from the second end portion S. Is formed. Further, the inner peripheral surfaces of the fixed-side spiral wall 31b and the swivel-side spiral wall 32b are formed from the second end portion S to immediately before the first end portion E based on the involute curve, and are formed along the two-dot chain line in FIG. As shown, an arc is formed from the end point F of the involute curve to the other end of the arc C of the first end E. The arc formed between the end point F of the involute curve and the arc C of the first end E is referred to as the arc portion R. The arc portion R is an arc connected to the tip (first end portion E) of the fixed side spiral wall 31b and the swirl side spiral wall 32b. On the inner peripheral surfaces of the fixed-side spiral wall 31b and the swirl-side spiral wall 32b, the involute curve and the arc portion R are switched by the end point F.

The involute curve is a plane curve formed by the locus drawn by the tip of the normal when one normal set on the base circle is moved so as to always be in contact with the base circle, and is also called an involute. The involute curve can be said to be a curve drawn by the tip of the thread when the thread wound around the base circle is unwound, and the locus is expressed by the involute angle and the unwinding line length. On the inner peripheral surfaces of the fixed-side spiral wall 31b and the swivel-side spiral wall 32b, the end point F immediately before the first end E corresponds to the start of winding of the involute curve, and the second end S corresponds to the end of winding of the involute curve. Corresponds to. Further, on the outer peripheral surfaces of the fixed-side spiral wall 31b and the swivel-side spiral wall 32b, one end of the arc C of the first end E corresponds to the start of winding of the involute curve, and the second end S corresponds to the end of winding of the involute curve. Applicable. In the present embodiment, the length of the involute is adjusted according to the extension angle so that the division point distance described later is characteristic.

Immediately before the first end portion E, an arc portion R is formed on the inner peripheral surfaces of the fixed side spiral wall 31b and the swivel side spiral wall 32b. As a result, as shown in FIG. 2, when one first end E of the fixed-side spiral wall 31b and the swirl-side spiral wall 32b comes into contact with the inner peripheral surface of the other spiral wall, the fluid in the central compression chamber 33c Leakage is suppressed.

As shown in FIG. 2, the center of the base circle (not shown) of the involute curve drawn by the fixed-side spiral wall 31b is referred to as the fixed-side base circle center P1, and the base circle of the involute curve drawn by the swirl-side spiral wall 32b (FIG. 2). The center of (not shown) is referred to as the center of the foundation circle on the turning side P2. The straight line passing through both the fixed-side foundation circle center P1 and the turning-side foundation circle center P2 is referred to as a radial direction line M. The radial direction line M is a straight line extending in the radial direction of the base circle.

As shown in FIGS. 2 to 8, there are a plurality of partition points T in which the fixed side spiral wall 31b and the swirl side spiral wall 32b are in contact with each other. The number of partition points T varies depending on the number of turns of the spiral walls 31b and 32b.

The partition points T are the circumscribed partition point T1 in which the inner peripheral surface of the swirl side spiral wall 32b is circumscribed on the outer peripheral surface of the fixed side spiral wall 31b when viewed from the axial direction of the rotating shaft 14, and the inside of the fixed side spiral wall 31b. There is an inscribed partition point T2 on the peripheral surface where the outer peripheral surface of the swirl side spiral wall 32b is inscribed. That is, the circumscribed partition point T1 is a point where the inner circumference of the swirl-side spiral wall 32b comes into contact with the outer circumference of the fixed-side spiral wall 31b when viewed from the axial direction of the rotating shaft 14, and partitions the compression chamber 33. The point T2 is a point where the outer circumference of the swirl side spiral wall 32b comes into contact with the inner circumference of the fixed side swirl wall 31b when viewed from the axial direction of the rotating shaft 14, and the compression chamber 33 is partitioned. Further, as the partition points T, the central side partition point T3 (not shown) in which the first end E of the fixed side spiral wall 31b abuts on the inner peripheral surface of the swirl side spiral wall 32b, and the swirl side spiral wall 32b. There is a central section point T4 (not shown) where the first end E abuts on the inner peripheral surface of the fixed side spiral wall 31b. With the revolving motion of the swivel scroll 32, the circumscribed section point T1 moves toward the first end E along the outer peripheral surface of the fixed side spiral wall 31b, and the volume of the second compression chamber 33b decreases. Finally, the circumscribed division point T1 is switched to the central division point T3. Further, as the revolving motion of the swivel scroll 32, the inscribed division point T2 moves toward the first end portion E along the inner peripheral surface of the fixed side spiral wall 31b, and the volume of the first compression chamber 33a is increased. Is decreasing, and finally the inscribed division point T2 is switched to the central division point T4. The central partition point T3 and the central partition point T4 form a central compression chamber 33c (not shown) communicating with the discharge port 41 at the central portion of the fixed scroll 31.

FIG. 2 shows a fixed-side spiral wall 31b and a swirl-side spiral wall 32b having about two turns. As shown in FIG. 2, one inscribed partition point T2 formed near the second end S of the fixed side swirl wall 31b follows the fixed side swirl wall 31b to the first end of the fixed side swirl wall 31b. When moving to part E, it will move about two turns. When one circumscribed partition point T1 formed near the second end S of the swirl wall 32b follows the swirl wall 32b to the first end E of the swirl wall 32b, 2 Move about a spiral. The positions of the circumscribed section points T1 and the inscribed section points T2 that move along the spiral walls 31b and 32b correspond to the turning angle of the turning scroll 32. The maximum value of the turning angle is the turning end angle. It should be noted that the swirl at the time when one partition point T1 and the inscribed partition point T2 are formed near each of the second end portions S, that is, when the compression of the fluid confined in the compression chamber 33 is started. The angle is called the turning start angle.

Then, as shown in FIG. 4, when the turning angle reaches the turning end angle, the circumscribed section point T1 and the inscribed section point T2 become the first end E of the fixed side spiral wall 31b and the swirl side spiral wall 32b. To reach. Specifically, the circumscribed compartment point T1 and the inscribed compartment point T2 coincide. The time when the partition point T reaches the first end portion E is the time when the volume of the central compression chamber 33c becomes zero and the compression of the fluid in the central compression chamber 33c is completed.

As shown in FIG. 2, the distance between the circumscribed division point T1 and the radial direction line M is defined as the circumscribed division point distance K1. Specifically, the circumscribed division point distance K1 is the length of a perpendicular line drawn from the circumscribed division point T1 with respect to the radial direction line M. Further, the distance between the inscribed division point T2 and the radial direction line M is defined as the inscribed division point distance K2. Specifically, the inscribed division point distance K2 is the length of a perpendicular line drawn from the inscribed division point T2 with respect to the radial direction line M. The lengths of the circumscribed division point T1 and the inscribed division point T2 vary according to the change in the turning angle. The circumscribed division point distance K1 switches to the distance K3 (not shown) between the central division point T3 and the radial direction line M near the turning end angle. The inscribed division point distance K2 switches to the distance K4 (not shown) between the central division point T4 and the radial direction line M near the turning end angle. These distances are collectively referred to as the division point distance K.

The graph of FIG. 10 shows the relationship between the turning angle and the division point distance K. The partition point distance K suddenly increases (suddenly changes) before the completion of compression of the fluid by the central compression chamber 33c. This is because the position of the section point T moves from the involute curve to the arc portion R.

In the following description, the turning angle at the position where the contact between the first end portion E and the arc portion R is started is defined as the tip contact start angle. The tip contact start angle is such that the first end E of the swirl side spiral wall 32b contacts the arc portion R drawn on the inner peripheral surface of the fixed side swirl wall 31b before the compression in the central compression chamber 33c is completed. Is the turning angle to start. As shown in FIG. 4, the tip contact start angle is also the position where the position of the section point T is switched from the involute curve to the arc portion R at the end point F on the inner peripheral surfaces of the fixed side spiral wall 31b and the swivel side spiral wall 32b. be. Then, the division point distance K rapidly increases due to the movement of the division point T along the arc portion R after the division point T has passed the tip contact start angle, then decreases sharply, and becomes zero when the compression is completed.

Here, the division point distance K from the turning start angle to the turning end angle will be described.
As shown in the graph of FIG. 10, both the circumscribed division point distance K1 and the inscribed division point distance K2 have a constant period and width amplitude from the turning start angle (0 °) to a predetermined turning angle exceeding 180 °. It is constantly changing as shown. The amplitude period (turning angle) and width (division point distance) at the circumscribed division point distance K1 and the inscribed division point distance K2 are the same, but they are deviated by half a period (half wavelength) from each other, and one of them becomes maximum. The turning angle and the turning angle at which the other is the minimum are the same. The circumscribed division point distance K1 and the inscribed division point distance K2 take constant values from different turning angles to the tip contact start angle. The division point distance Ka, which is a constant value, corresponds to the radius of the involute base circle. The maximum values of the circumscribed division point distance K1 and the inscribed division point distance K2 are larger than the radius of the involut base circle, that is, the division point distance Ka, and the minimum values of the circumscribed division point distance K1 and the inscribed division point distance K2 are It is smaller than the radius of the circumscribed circle, that is, the division point distance Ka.

In FIG. 10, at the turning start angle (0 °), the circumscribed division point distance K1 is minimized, while the inscribed division point distance K2 is maximized, and at the turning angle 180 °, the circumscribed division point distance K1 is maximized. The inscribed division point distance K2 is minimized. That is, the circumscribed division point distance K1 takes a maximum value after taking a minimum value during the period from the turning start angle to turning 180 °. Further, the amplitude periods at the circumscribed division point distance K1 and the inscribed division point distance K2 are 120 °, which are the same. Therefore, the circumscribed division point distance K1 increases from the minimum to the maximum as shown in FIGS. 2 to 4, and then decreases from the maximum to the minimum as shown in FIGS. 4 to 6. Further, as shown in FIGS. 6 to 8, the turning angle reaches 180 ° when it increases from the minimum to the maximum again. Further, the inscribed division point distance K2 decreases from the maximum to the minimum as shown in FIGS. 2 to 4, and then increases from the minimum to the maximum as shown in FIGS. 4 to 6. Further, as shown in FIGS. 6 to 8, the turning angle reaches 180 ° when the value decreases from the maximum to the minimum again. That is, the inscribed division point distance K2 takes a maximum value after taking a minimum value during the period from the turning start angle to turning 180 °.

In a general scroll compressor formed by meshing spiral walls that draw an ordinary involute curve, the curvature of the spiral walls increases uniformly as the involute angle increases, so the circumscribed division point distance K1 And the inscribed division point distance K2 is constant regardless of the turning angle. On the other hand, in the present embodiment, since the change in curvature of the spiral wall is not uniform, the circumscribed division point distance K1 and the inscribed division point distance K2 change depending on the turning angle. As the extension angle of the fixed-side spiral wall 31b and the swirl-side spiral wall 32b increases, the curvatures of the fixed-side spiral wall 31b and the swirl-side spiral wall 32b are changed so as to be large as a whole while the portions having a large curvature and the portions having a small curvature are alternately continuous. The fixed scroll 31 and the swivel scroll 32 partition the compression chamber while the portions having a large curvature are in contact with each other at a certain swivel angle and the portions having a small curvature are in contact with each other at a certain swivel angle. Here, the portion having a large curvature is a portion where the division point distance K increases as the turning angle increases, and the portion having a small curvature is a portion where the division point distance K decreases as the turning angle increases. .. From FIG. 10, in the swirl side spiral wall 32b of the present embodiment, the curvature of the portion circumscribing the fixed side swirl wall 31b is relatively large at the swirl angles 0 ° to 60 ° and 120 ° to 180 °, and the swirl angle is 60 ° to 60 °. At 120 °, the curvature of the portion circumscribing the fixed side spiral wall 31b is relatively small. Further, in the fixed side spiral wall 31b, the curvature of the portion inscribed by the swirl side spiral wall 32b is relatively small at the swivel angle 0 ° to 60 ° and 120 ° to 180 °, and the swirl side swirl at the swivel angle 60 ° to 120 °. The curvature of the portion inscribed by the wall 32b is relatively large.

As shown in FIG. 11, the swivel side substrate 32a has a shape that covers the entire first compression chamber 33a at the swivel start angle and the second end portion S of the swirl side spiral wall 32b so that the compression chamber does not communicate with the outside. Required. Further, from the viewpoints of reducing the manufacturing cost, stabilizing the weight balance, increasing the area for providing the plurality of rotation control portions, and the like, the swivel side substrate 32a is required to have a perfect circle or a shape close to it. As a result, as shown in FIG. 11, the outer edge 32c of the swirl-side substrate 32a becomes a perfect circle that envelops the entire first compression chamber 33a and the second end portion S of the swirl-side swirl wall 32b. Here, FIG. 11A shows a fixed scroll 31 and a swivel scroll 32 formed by meshing spiral walls that draw a normal involute curve. Further, FIG. 11B shows the fixed scroll 31 and the swivel scroll 32 of the present embodiment. The swivel side substrate 32a shown in FIGS. 11 (a) and 11 (b) has the same shape and the same area. In FIG. 11B, the swirl side spiral wall 32b has a shape protruding toward the outer edge 32c with respect to a portion circumscribing the fixed side swirl wall 31b at a swivel angle of 0 ° to 60 ° and 120 ° to 180 °. There is. As a result, the swirl-side swirl wall 32b of the present embodiment is closer to the outer edge 32c than the swirl-side swirl wall 32b in a normal scroll, and a larger volume of the compression chamber 33b is secured on the same swirl-side substrate 32a. can do.

FIG. 12 shows a diagram comparing the outer edge 32c (dashed line) in a normal scroll with the outer edge 32c (broken line) in the present embodiment. Both outer edges 32c coincide with the center of the base circle of the swirl side spiral wall 32b. The fixed-side spiral wall 31b of the present embodiment has a shape in which the swirl-side spiral wall 32b inscribes at a swivel angle of 60 ° to 120 ° and protrudes outward from the normal fixed-side swirl wall 31b. There is. The outer edge 32c has a perfect circular shape that encloses the entire first compression chamber 33a and the second end S of the swirl side spiral wall 32b, but its position is on the fixed side of the position (dashed line) in a normal scroll. The position (broken line) is shifted in the local protrusion direction of the spiral wall 31b. As a result, the outer edge 32c of the present embodiment is closer to the swirl side spiral wall 32b than the outer edge 32c in the normal scroll, and the volume of the compression chamber 33 can be secured larger on the same swirl side substrate 32a. can.

According to the above embodiment, the following effects can be obtained.
(1) In the scroll type compressor 10, the circumscribed division point distance K1 is configured to take a maximum value after taking a minimum value during the period from the turning start angle to turning 180 ° in the turning scroll 32. As a result, a part of the swirl side spiral wall 32b on the outermost circumference has a shape protruding toward the outer edge 32c, and a larger volume of the compression chamber 33b is secured on the swivel side substrate 32a having a limited size. be able to. As a result, the rotation speed of the compressor 10 can be reduced, and the noise caused by the vibration accompanying the rotation can also be reduced.

(2) In the scroll type compressor 10, the inscribed division point distance K2 takes a maximum value after taking a minimum value during the period from the turning start angle to turning 180 ° in the turning scroll 32. As a result, a part of the fixed-side spiral wall 31b on the outermost circumference has a shape protruding outward, and the outer edge 32c approaches the swirl-side spiral wall 32b. Therefore, a larger volume of the compression chamber 33b can be secured on the swivel side substrate 32a having a limited size. As a result, the rotation speed of the compressor 10 can be reduced, and the noise caused by the vibration accompanying the rotation can also be reduced.

The above embodiment may be changed as follows.
○ In the embodiment, the division point distance K is defined as the distance between the point where the fixed-side spiral wall 31b and the swirl-side spiral wall 32b come into contact with each other to partition the compression chamber 33 and the radial direction line M, but the distance is not limited to this. If there is no fluid leakage through the gap, the point where the fixed-side spiral wall 31b and the swirl-side spiral wall 32b are close to each other to partition the compression chamber 33 is defined as a partition point, and the distance between this partition point and the radial direction line M is defined as a partition point. The point distance K may be set.

P1 ... Fixed side foundation circle center, P2 ... Turning side foundation circle center, K1 ... External division point distance, K2 ... Internal division point distance, M ... Radial direction line as a straight line, T1 ... External division point, T2 ... Internal division Section point, 10 ... Scroll type compressor, 14 ... Rotating shaft, 31 ... Fixed scroll, 31a ... Fixed side substrate, 31b ... Fixed side spiral wall, 32 ... Swivel scroll, 32a ... Swivel side substrate, 32b ... Swivel side swirl wall , 33 ... Compression chamber.

Claims (2)

Rotation axis and
A fixed-side substrate and a fixed scroll having a fixed-side spiral wall erecting from the fixed-side substrate,
A swirl-side substrate facing the fixed-side substrate and a swirl-scroll having a swirl-side swirl wall that stands up from the swivel-side substrate toward the fixed-side substrate and meshes with the fixed-side swirl wall.
In a scroll type compressor that compresses a fluid in a compression chamber partitioned by the fixed scroll and the swivel scroll by swiveling the swivel scroll due to the rotation of the rotating shaft.
A point at which the inner circumference of the swirl-side spiral wall comes into contact with or is close to the outer circumference of the fixed-side swirl wall when viewed from the axial direction of the rotation axis and partitions the compression chamber is defined as an circumscribed section point.
The distance between the extrinsic section point and the straight line passing through both the center of the base circle of the involute curve drawn by the fixed-side spiral wall and the center of the base circle of the involute curve drawn by the swirl-side spiral wall is defined as the circumscribing point distance.
Regarding the turning angle of the turning scroll, the turning angle at which the compression chamber is formed and the compression of the fluid is started is defined as the turning start angle.
During the period from the turning start angle until the turning scroll turns 180 °, the circumscribed division point distance takes a maximum value after taking a minimum value.
A scroll type compressor characterized in that the maximum value is larger than the radius of the base circle and the minimum value is smaller than the radius of the base circle. Rotation axis and
A fixed-side substrate and a fixed scroll having a fixed-side spiral wall erecting from the fixed-side substrate,
A swirl-side substrate facing the fixed-side substrate and a swirl-scroll having a swirl-side swirl wall that stands up from the swivel-side substrate toward the fixed-side substrate and meshes with the fixed-side swirl wall.
In a scroll type compressor that compresses a fluid in a compression chamber partitioned by the fixed scroll and the swivel scroll by swiveling the swivel scroll due to the rotation of the rotating shaft.
The point at which the outer circumference of the swirl-side spiral wall comes into contact with or is close to the inner circumference of the fixed-side swirl wall when viewed from the axial direction of the rotation axis and partitions the compression chamber is defined as an inscribed partition point.
The distance between the straight line passing through both the center of the base circle of the involute curve drawn by the fixed-side spiral wall and the center of the base circle of the involute curve drawn by the swirl-side spiral wall and the inscribed division point is the inscribed division point distance. year,
Regarding the turning angle of the turning scroll, the turning angle at which the compression chamber is formed and the compression of the fluid is started is defined as the turning start angle.
During the period from the turning start angle until the turning scroll turns 180 °, the inscribed division point distance takes a maximum value after taking a minimum value.
A scroll type compressor characterized in that the maximum value is larger than the radius of the base circle and the minimum value is smaller than the radius of the base circle.

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