JP6339340B2 - Scroll type fluid machinery - Google Patents

Description

  The present invention relates to a scroll type fluid machine having a fixed scroll and a movable scroll that revolves around an axis of the fixed scroll.

  In Patent Document 1, the end portion of the spiral portion standing on the base end wall of the movable scroll is pulled inward from the periphery of the base end wall and separated, and the fixed scroll side has a sliding portion of the peripheral portion of the movable scroll. The sliding contact step to be contacted is provided in an annular shape, and the inner peripheral radius R2 of the sliding contact step is larger than the difference between the radius R1 of the base end wall of the movable scroll and the revolution radius r0, and the radius R1 and the revolution radius of the base end wall A scroll type that is set smaller than the sum of r0 and has a sliding relationship in which only a part of each other overlaps with the revolution of the movable scroll between the peripheral edge of the base wall of the movable scroll and the sliding contact step. A compressor is disclosed.

Japanese Utility Model Publication No. 6-43511

By the way, in the movable scroll, when the center of the bottom plate, the center of the base circle of the lap, and the center of the bearing portion provided on the bottom plate are all matched, the orbiting scroll has a high stability and high quietness. It becomes a scroll type fluid machine.
However, in the scroll type fluid machine configured as described above, the space in which the movable scroll orbits is increased in the radial direction, and in order to secure the space, the outer diameter of the housing that accommodates the movable scroll is increased. Will become larger.

On the other hand, the diameter of the movable scroll (bottom plate) can be reduced by offsetting the center of the base circle of the movable scroll wrap from the center of the bottom plate and the bearing portion, thereby reducing the outer diameter of the housing (scroll). The mold fluid machine can be downsized).
However, if the center of the base circle of the orbiting scroll is offset from the center of the bearing, the orbiting movement of the orbiting scroll becomes unstable and noise increases.

  Accordingly, an object of the present invention is to provide a scroll type fluid machine that can achieve both quietness and downsizing.

In order to achieve the above object, a scroll type fluid machine according to the present invention includes a center of a base circle of a scroll wrap of a movable scroll and a center of a bearing portion formed on a bottom plate on which the scroll wrap of the movable scroll is erected. The center of the bottom plate is offset with respect to the center of the base circle and the center of the bearing, and the center axis of the wrap housing that houses the scroll wrap and the center axis of the bottom plate housing that houses the bottom plate of the movable scroll And the inner diameter of the lap housing is made smaller than the inner diameter of the bottom plate housing.

According to the scroll type fluid machine according to the present invention, since the center of the base circle and the center of the bearing portion coincide with each other, the turning motion can be stabilized, while the center of the bottom plate and the center of the bearing portion are offset. Compared to the case where the center of the bottom plate and the center of the base circle coincide with each other, the diameter of the bottom plate can be reduced, and the center axis of the lap housing and the center axis of the bottom plate housing are offset, and Since the inner diameter is smaller than the inner diameter of the bottom plate housing, the outer diameter of the housing can be made as small as possible, and both quietness and downsizing can be achieved.

It is sectional drawing of the scroll compressor in embodiment of this invention. It is sectional drawing of the scroll compressor in embodiment of this invention. 1 is an external perspective view of a scroll compressor according to an embodiment of the present invention. It is a figure which shows the correlation with the center of a basic circle in the scroll compressor in embodiment of this invention, and the center of a baseplate. It is a figure for demonstrating the structure and dimensional relationship of the main housing in embodiment of this invention. It is a figure which shows the correlation with the deviation | shift amount of the center of gravity of a movable scroll wrap and the bearing center in embodiment of this invention, and the presence or absence of an offset. It is a figure which illustrates the symmetrical scroll and asymmetrical scroll in embodiment of this invention. It is a figure which shows the correlation with the phase angle of asymmetric scroll and the gravity center of a movable scroll lap in embodiment of this invention.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
1 to 3 are cross-sectional views showing a scroll compressor as an example of a scroll fluid machine according to the present invention.
The scroll compressor 1 shown in FIG. 1 is a compressor used for, for example, a vehicle air conditioner. The scroll compressor 1 includes a fixed scroll 4 in which a fixed scroll wrap 2 is erected on a fixed bottom plate 3, and a fixed scroll wrap 2. The movable scroll wrap 5 to be joined is provided with a movable scroll 7 erected on the movable side bottom plate 6.

The movable scroll 7 is revolved around the axis of the fixed scroll 4 in a state where the rotation of the movable scroll 7 is prevented from rotating, thereby moving the fluid pocket formed between the scroll wraps 2 and 5 toward the center. The volume is reduced and the compression operation is performed.
Both scroll wraps 2 and 5 are formed by, for example, circular involute curves.
The fixed scroll 4 is connected and fixed to the main housing 8 by fastening bolts (not shown).

A discharge hole 11 is provided in the central portion in the radial direction of the fixed scroll 4, and compressed fluid discharged through the discharge hole 11 is discharged from a discharge chamber 12 formed in the main housing 8 through a discharge port 13. It is sent to an external circuit.
A fluid to be compressed is sucked into the suction chamber 14 from the suction port 10 provided in parallel with the discharge port 13 on the outer periphery of the main housing 8, and is subjected to a compression operation by the fixed scroll 4 and the movable scroll 7.

The movable scroll 7 is turned by a main shaft 16 having a crank portion 15.
The main shaft 16 is inserted through the front housing 17 and is rotationally driven by a driving force transmitted from, for example, a vehicle engine (not shown) as an external drive source.
An eccentric pin 21 protruding from the large-diameter portion 20 of the crank portion 15 is fitted into the eccentric rotating roller 22 so as to be relatively rotatable, and the eccentric rotating roller 22 is connected to the back surface of the movable scroll 7 via a bearing 23. Arranged on the side.

The movable side bottom plate 6 of the movable scroll 7 is formed with a bottomed cylindrical bearing 6a to which the bearing 23 is fitted.
Then, the movable scroll 7 is turned via the eccentric rotating roller 22 by the rotation of the crank portion 15 of the main shaft 16.
Further, the scroll compressor 1 includes a balance weight 24 and a ball coupling 25 for preventing rotation of the movable scroll 7.

In the movable scroll 7 of the scroll compressor 1, the center of the base circle of the movable scroll wrap 5 coincides with the center of the bearing 6 a (bearing 23) of the movable side bottom plate 6. The center of the disk-shaped movable side bottom plate 6 is shifted from the center (and the center of the bearing portion 6a).
That is, the center of the movable side bottom plate 6 is decentered in the direction from the center of the base circle of the movable scroll wrap 5 toward the end portion 5b (outer peripheral side end, winding end end) of the movable scroll wrap 5.

  As described above, when the center of the base circle of the movable scroll wrap 5 and the center of the movable side bottom plate 6 coincide with each other by offsetting the center of the base circle of the movable scroll wrap 5 and the center of the movable side bottom plate 6. In comparison, the diameter of the movable side bottom plate 6 can be reduced.

FIG. 4 is a diagram for explaining the difference in the diameter of the bottom plate depending on the presence or absence of an offset.
When the base circle center K1 of the movable scroll wrap 5 and the center K2 of the movable side bottom plate 6 are matched (when there is no offset), a sealed space is formed inside the end portion 5b of the movable scroll wrap 5 at the start of compression. Thus, when the diameter of the movable side bottom plate 6 is set, the distance from the center of the movable side bottom plate 6 to the outermost movable scroll wrap 5 on the side facing the terminal portion 5b across the basic circle center K1 is the terminal portion 5b. Since it is shorter than that, the peripheral edge portion of the movable side bottom plate 6 becomes a waste portion. Here, if the distance from the base circle center K1 to the end portion 5b of the movable scroll wrap 5 is a, the radius of the movable side bottom plate 6 is a.

  On the other hand, when the center K2 of the movable side bottom plate 6 is decentered in the direction from the basic circle center K1 toward the end portion 5b of the movable scroll wrap 5 (with offset), the center K2 of the movable side bottom plate 6 is movable scroll. The radius of the movable bottom plate 6 can be reduced by the amount closer to the end portion 5b of the wrap 5. In other words, the radius of the movable side bottom plate 6 is shorter than the distance a by an offset, and the movable side bottom plate 6 is reduced in the direction of the end portion 5b of the movable scroll wrap 5 so that the thin portion is reduced. .

Incidentally, the upper limit of the offset amount of the center K2 of the movable side bottom plate 6 from the basic circle center K1 is half of the turning radius R0.
Similarly, by decentering the center J2 of the fixed-side bottom plate 3 from the basic circle center J1 of the fixed scroll wrap 2 toward the terminal end of the fixed scroll wrap 2, the end portion of the fixed scroll wrap 2 and the basic circle center are aligned. It is possible to reduce the diameter of the fixed-side bottom plate 3 by reducing the portion of the meat that is sandwiched and opposed.

Furthermore, as shown in FIG. 5, the main housing 8 includes a wrap housing 81 that houses the fixed scroll wrap 2 and the movable scroll wrap 5, and a bottom plate housing 82 that houses the movable side bottom plate 6. The shaft and the center axis of the bottom plate housing 82 are offset in the offset direction of the base circle center K1, and the outer diameter D1 (inner diameter d1) of the lap housing 81 is made smaller than the outer diameter D2 (inner diameter d2) of the bottom plate housing 82. It is.
In other words, by offsetting the central axis of the lap housing 81 and the central axis of the bottom plate housing 82, the lap housing 81 is formed with a minimum inner diameter sufficient to accommodate the fixed scroll wrap 2, and the bottom plate housing 82 can be formed to a minimum inner diameter sufficient to accommodate the movable bottom plate 6.

  That is, in the configuration in which the center of the base circle of the movable scroll wrap 5 and the center of the movable side bottom plate 6 are offset, when the central axis of the lap housing 81 and the central axis of the bottom plate housing 82 are aligned, the outer diameter of the lap housing 81 D1 (inner diameter d1) or outer diameter D2 (inner diameter d2) of the bottom plate housing 82 needs to be increased excessively, but the center axis of the lap housing 81 and the center axis of the bottom plate housing 82 correspond to the offset of the center of the base circle. By offsetting them, the diameters of the lap housing 81 and the bottom plate housing 82 can be made as small as possible.

In this embodiment, the bottom plate housing 82 integrally forms the mounting flange portion 84 in which the through-hole 83 for the mounting bolt is opened, but it is obvious that the structure is not limited to such a structure. The outer periphery of the bottom plate housing 82 can be formed into a substantially uniform shape with an outer diameter D2.
Moreover, in this embodiment, when the terminal part 5b of the movable scroll wrap 5 is located in the outermost side with the turning motion of the movable scroll wrap 5 on the inner peripheral surface surrounding the movable scroll wrap 5 of the lap housing 81, it is movable. A concave portion 8a that constitutes a moving space of the end portion 5b of the scroll wrap 5 is formed, and a convex portion (protruding portion) 8b that protrudes outward at a portion corresponding to the concave portion 8a is formed on the outer periphery of the lap housing 81. It is formed. That is, in order to make the thickness of the concave portion 8a the same as the others, the concave portion 8a is protruded outward.
As described above, if a part of the hollow portion of the lap housing 81 is enlarged by the recessed portion 8a and the convex portion 8b, the movable scroll wrap 5 performs the turning motion while reducing the outer diameter of the lap housing 81 as much as possible. A space volume can be secured.

Further, since the center of the base circle of the movable scroll wrap 5 coincides with the center of the bearing portion 6a (bearing 23) of the movable bottom plate 6, the turning motion of the movable scroll 7 is stabilized and noise can be reduced.
That is, if the deviation between the center of gravity of the movable scroll 7 and the center of the bearing portion 6a (bearing 23) of the movable side bottom plate 6 is large, a rotating moment is generated in the movable scroll 7 and the turning motion of the movable scroll 7 becomes unstable. .

Here, the center of the base circle of the movable scroll wrap 5 and the center of the bearing portion 6a (bearing 23) of the movable side bottom plate 6 are made to coincide with each other, and the center of the movable side bottom plate 6 is offset with respect to these (see FIG. 6 (B)), the center of the base circle of the movable scroll wrap 5, the center of the bearing portion 6a (bearing 23) of the movable side bottom plate 6, and the center of the movable side bottom plate 6 are all matched (FIG. 6). Compared to (see (A)), the center of gravity of the movable scroll 7 can be brought closer to the center of the bearing portion 6a (bearing 23) of the movable side bottom plate 6, and the rotational moment can be reduced and the orbiting motion of the movable scroll 7 can be further increased. Can be stabilized.
As described above, the center of the base circle of the movable scroll wrap 5 and the center of the bearing portion 6a (bearing 23) of the movable side bottom plate 6 coincide with each other, while the center of the base circle K1 of the movable scroll wrap 5 (and the bearing portion 6a). The center and the center K2 of the movable side bottom plate 6 are offset, so that both quietness and downsizing can be achieved at a high level.

By the way, as the scroll wrap, as shown in FIG. 7A, a symmetrical scroll in which the winding angle of the movable scroll wrap 5 and the winding angle of the fixed scroll wrap 2 are substantially the same can be used. As shown in B), an asymmetric scroll having a difference between the winding angle of the movable scroll wrap 5 and the winding angle of the fixed scroll wrap 2 can be used.
In the asymmetric scroll wrap shown in FIG. 7B, the winding start position 5a of the movable scroll wrap 5 and the winding start position 2a of the fixed scroll wrap 2 are symmetrically different by 180 degrees, while the winding end position ( The end portion 5b) and the winding end position 2b of the fixed scroll wrap 2 have substantially the same phase, and the fixed scroll wrap 2 is wound 180 degrees more.

By adopting the asymmetric scroll, the volume of the compressor can be increased by increasing the number of turns of the fixed scroll wrap 2.
In the example shown in FIG. 7B, the relative phase (hereinafter referred to as the phase angle) between the movable scroll wrap 5 and the fixed scroll wrap 2 in the asymmetric scroll is 180 deg. The shift between the center of gravity of the scroll 7 and the center of the bearing portion 6a (bearing 23) of the movable side bottom plate 6 can be further reduced, and the stability of the orbiting motion of the movable scroll 7 can be improved.

FIG. 8 shows an example of the change in the center of gravity of the movable scroll 7 and the change in the deviation between the center of gravity and the center of the bearing 23 with respect to the change in the phase angle.
Note that the change in the position of the center of gravity of the movable scroll 7 with respect to the change in the phase angle is described separately in the X-axis direction and the Y-axis direction shown in FIG. Also, the characteristics shown in FIG. 8 may change as the scroll parameters change.

As shown in FIG. 8, by changing the phase angle of the asymmetric scroll, the center of gravity of the movable scroll 7 changes, and the amount of deviation between the center of gravity and the center of the bearing 23 changes with the change of the center of gravity. To do.
Therefore, by selecting the phase angle of the asymmetric scroll, the displacement amount between the center of gravity and the center of the bearing 23 can be reduced while increasing the volume, and the stability of the orbiting motion of the movable scroll 7 can be improved.

In the example shown in FIG. 8, when the phase angle is around 70 deg, the amount of deviation between the center of gravity and the center of the bearing 23 is minimized, and the stability of the orbiting motion of the movable scroll 7 is the highest.
Here, considering that the phase angle at which the deviation between the center of gravity position and the center of the bearing 23 is minimized may vary depending on the scroll parameters, and there is a demand to increase the volume by asymmetric scrolling, It is preferable to select a phase angle within a range of 50 deg to 140 deg as a phase angle that can achieve a sufficient balance of the center of gravity while increasing the volume.

Although the contents of the present invention have been specifically described with reference to the preferred embodiments, it is obvious that those skilled in the art can take various modifications based on the basic technical idea and teachings of the present invention. It is.
For example, the center of the movable scroll wrap is coincident with the center of the bearing (bearing) of the movable side bottom plate, and the center of the movable side bottom plate with respect to the center of the movable scroll wrap (and the center of the bearing). The scroll type fluid machine formed by shifting can be a scroll type expander in addition to the scroll type compressor 1 described above.

Further, the configuration is not limited to the configuration in which the discharge port 13 and the suction port 10 are provided side by side on the outer periphery of the main housing 8. For example, the suction port 10 may be provided along the axial direction of the main shaft 16.
In addition to the involute curve, the lap curve may be an Archimedes curve, an algebraic spiral curve, or a combination of two or more of these.

DESCRIPTION OF SYMBOLS 1 ... Scroll type compressor, 2 ... Fixed scroll wrap, 3 ... Fixed side bottom plate, 4 ... Fixed scroll, 5 ... Movable scroll wrap, 6 ... Movable side bottom plate, 6a ... Bearing part, 7 ... Movable scroll, 8 ... Main housing , 23 ... Bearing, 81 ... Lap housing, 82 ... Bottom plate housing

Claims (7)

A scroll type fluid machine having a fixed scroll and a movable scroll that revolves around an axis of the fixed scroll,
The center of the base circle of the scroll wrap of the movable scroll is aligned with the center of the bearing portion formed on the bottom plate on which the scroll wrap of the movable scroll is erected, with respect to the center of the base circle and the center of the bearing portion Offsetting the center of the bottom plate,
A scroll type in which a central axis of a wrap housing that accommodates a scroll wrap and a central axis of a bottom plate housing that accommodates a bottom plate of the movable scroll are offset, and an inner diameter of the lap housing is smaller than an inner diameter of the bottom plate housing Fluid machinery.   2. The scroll fluid machine according to claim 1, wherein a part of an outer periphery of the wrap housing has a protruding portion protruding outward in a radial direction in a radial direction corresponding to a terminal end portion of a scroll wrap of the movable scroll.   The scroll type fluid machine according to claim 1, wherein a concave portion constituting a moving space of a terminal end portion of the scroll wrap of the movable scroll is formed on an inner peripheral surface of the wrap housing.   The scroll type fluid machine according to claim 3, wherein an outer peripheral surface of the lap housing corresponding to the recessed portion forms a protruding portion that protrudes outward in a radial direction.   The scroll type fluid machine according to any one of claims 1 to 4, wherein the scroll type fluid machine is an asymmetric scroll having a phase angle of 50 deg to 140 deg.   The scroll type fluid machine according to any one of claims 1 to 4, wherein the scroll type fluid machine is an asymmetric scroll having a phase angle of approximately 70 degrees.   The scroll type fluid machine according to any one of claims 1 to 6, which is a compressor for compressing a fluid.