JP3445794B2 - Scroll type fluid discharge device with high specific volume ratio and semi-compliant bias mechanism - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to fluid ejection devices. More particularly, the present invention relates to scroll-type fluid ejection devices that can achieve high intrinsic volume ratios without forcing other optimal design parameters to change. The present invention also relates to a "semi-compliant" mechanism for maintaining a desired working relationship between scroll members of a scroll fluid ejector.

2. Description of the Background Art Scroll-type fluid ejection devices are known. For example, U.S. Pat. No. 801,182 to Croix discloses a scroll-type fluid ejection device having two scroll members each having a circular end plate and a scroll or spiral scroll element. . These scroll elements have the same spiral shape and are angularly and radially offset to form a plurality of line contacts between interdigitated, spirally curved surfaces. There is. Thus, the interdigitated scroll elements seal and define at least one fluid pocket pair. By swirling one scroll element relative to the other, the line contact is moved along the spirally curved surface, resulting in a change in the volume of the fluid pocket. This volume increases with the direction of the relative orbital movement of the scroll elements,
Alternatively, as it decreases, the device can be used to compress or expand a fluid.

Referring to FIGS. 1a-1d, the general operation of a conventional scroll compressor is shown. 1a to 1d show the relative movement of interdigitated spiral scroll elements 1, 2 to compress a fluid. The spiral scroll elements 1, 2 are angularly radially offset and interdigitated with each other. FIG. 1a shows that the outer end of each scroll element is in contact with another scroll element, that is, suction is just completed,
The symmetric fluid pockets A1, A2 have just been formed.

Figures 1b to 1d respectively show the position of the scroll element at a particular drive shaft crank angle which is advanced from the angle shown in the previous figure. As the crank angle advances, the fluid pockets A1, A2 are moved radially in varying angles towards the center of the interfitting scroll elements, while at the same time each fluid pocket A1, A2.
The volume of A2 gradually decreases. As the crank angle transitions from the state shown in FIG. 1c to the state shown in FIG. 1d, the fluid pockets A1, A2 meet at the central portion A. The volume of the pockets, which are in communication with each other, is further reduced by further rotation of the drive shaft. During the relative swiveling movement of the scroll elements, the outer space, shown in FIGS. 1b and 1d, which is shown open, changes to a seal that encloses the volume of fluid to be compressed next. To form new fluid pockets.

FIG. 2 schematically shows a compression cycle that occurs in one of the fluid pockets A1 and A2 as the fluid pockets A1 and A2 approach the central portion A. FIG. 2 also shows the relationship between fluid pressure and volume in the fluid pocket.

The compression cycle begins when the fluid pocket is sealed (Fig. 1a). In Figure 1a, the aspiration phase has just been completed. In the aspiration phase, the fluid pressure in one fluid pocket is shown at point H in FIG.

Volume of the pocket at point H is the emissions V _H. As the scroll element rotates to a certain crank angle, the pocket volume continuously decreases and the fluid is continuously compressed. This state is indicated by a point L in FIG. Volume V _L of the pocket in the state L, as a final compression pocket volume is defined. As soon as point L is passed, the fluid pockets A1, A2 are in communication with each other and, at the same time, with the central volume A, which is filled with high-pressure fluid which is not discharged.

The ratio of the suction pocket volume V _{H to} the final compression pocket volume V _L is defined as the intrinsic volume ratio R _V. The ratio of the pressure P _H in the state H of the pressure P _L in the state L, as a pressure ratio, is defined.

Referring again to FIG. 2, as the crank angle passes state L, the fluid pockets in communication, i.e., the fluid in the central volume A, are in one of three processes:
Receive one.

1) Ideal compression The ideal compression process is the fluid pressure P _d1 in the central volume A.
Occurs when is equal to the final compression pressure P _L. In FIG. 2, the fluid is discharged without the pressure change indicated by the line LL. In this process, the natural volume ratio of the scroll members perfectly matches the operating conditions, so that high energy efficiency is achieved in the compression process.

2) Overcompression In this case, the fluid pressure P _L at point L in the final compression pocket is higher than the pressure P _d2 in the central volume A. After the crank angle passes point L, the fluid in the final compression pocket rapidly expands into the central volume and the pressure drops until it equals P _d2 at point M in FIG. . The shaded triangle LMO shows the energy loss due to overcompression.

3) Undercompression In this case, P _L is lower than the discharge pressure P _d3 . After the crank angle passes point L, the fluid in the central volume expands rapidly into the final compression pocket, and the fluid pressure in the final compression pocket is shown at point N in FIG. To P _d3 , it immediately rises. The fluid in the final compression pocket then drains at line LL. The shaded triangle LNT shows the energy loss due to under compression.

In order to achieve high energy efficiency, it is very important to design the intrinsic volume ratio as close to the ideal compression process as possible. In some cases, different inherent volume ratios are required to achieve the ideal compression process. For example, a heat pump requires a ratio of about 4, an air compressor requires a ratio of about 5, and a cryogenic refrigeration system requires a ratio of about 10 or much higher. However, many conventional scrolling devices cannot achieve such ratios. For example, in U.S. Pat. No. 3,884,599 the spiral element of the scroll member extends more than 2 turns but less than 3 turns. Therefore, this type of design has a specific volume ratio of only about 2.5.

U.S. Pat.No. 4,477,238 discloses a method for realizing a high pressure ratio in a scroll type fluid discharge device by providing a discharge valve, for example, a reed valve, at a discharge port while maintaining a specific volume ratio. is doing. Although this approach can reduce energy loss, the valve will be damaged and fragile, thus substantially increasing failure rate. It also increases the noise level due to valve vibration and shock motion.

Another approach to this problem is to increase the number of turns of the spiral scroll element. FIGS. 15 and 16 of US Pat. No. 801,182 disclose one example of this approach. The scroll element extends about 4 turns, and the specific volume ratio can be higher than 3. However, increasing the number of turns further increases the cost for mechanical finishing and requires higher mechanical accuracy. Also, increasing the number of turns is not practical at all due to emission requirements or space constraints.

The optimum number of turns of the scroll element is 2 or more and less than 3. In the case of an optimum number of turns, the suction area and the discharge area are always separated by at least one sealed pocket. This means that between the two areas,
Mass and heat flow is important in reducing unwanted leakage flow.

U.S. Pat. No. 3,989,422 discloses a method of making a spiral scroll element with a high intrinsic volume ratio and an optimal number of turns. According to this method, the first turn of the scroll element is designed in the usual way.
Reduces the volume of the final compression pocket, thereby
To increase the intrinsic volume ratio, the scroll element has its radius of curvature reduced sharply and dramatically by moving the center of the circle it creates to one side. This method has serious drawbacks. The center of the scroll element is
As it is moved to one side of the end plate, large forces and moments are generated due to the distance between the location of the compressive force and the center of the end plate increasing during the pivoting movement. In order to balance these forces and moments, '4
The '22 patent proposes a structure with multiple pairs of scroll elements in which forces and moments cancel each other out. However, this structure is complicated and requires a large number of scroll elements, which requires time for mechanical finishing, requires high mechanical accuracy, and increases material costs. Moreover, a structure with many complex scrolls requires a large space and is not realistic in location.

Currently, there are three approaches to maintain the operational relationship of the scroll member in the "axis" direction (measured linearly along the central axis of the scroll element). These approaches are
It can be called "constant gap", "axial compliant" or "semi-compliant".

The constant gap approach was used in earlier devices, as shown in US Pat. No. 801,182 to Croix. In this approach, the axial scroll member relationship does not change after assembly of the device. During normal operation,
The tip of either scroll member does not contact the base of the opposing scroll member. Between scroll members,
Precise mechanical finishing is required to maintain the proper gap and at the same time achieve high efficiency. Another more serious drawback of this approach is its inability to operate in unusual circumstances. There may be contaminants or incompressible fluids between the scroll members, or excessive heat,
If the scroll members come into contact with each other, the scroll members may be damaged due to seizure.

To overcome these shortcomings of the constant gap approach, various axial compliant methods have been developed. These methods can be divided into two categories: "tip seals" and "fully axial compliant."

The tip seal method is shown in FIG. 10 and an example thereof is disclosed in US Pat. No. 3,994,636 assigned to the McCraw method. A groove 501 is made in the center of the tip of the two scroll members 502, 503, as shown in FIG. A sealing element 504 is loosely fitted in the groove 501 and brought into contact with the base 505 of another scroll member by mechanical force and / or hydraulic pressure, so that the fluid flows across the spiral scroll members 502, 503. , Radial leakage is prevented. However, as shown by lines AA and BB in FIG. 10, the tip seal method inherently has a tangential leak path, which results in low compression efficiency. Another drawback of the tip seal method is that there is a frictional power loss and that the wear of the sealing elements gradually degrades the effectiveness of the seal.

In the fully axially compliant method, the scroll member maintains contact between the tip and the base by mechanical force or hydraulic pressure, which seals the fluid pocket regardless of the pressure in the scroll device. It U.S. Pat. No. 3,600,114 granted to Devolak et al.
The specification discloses a scroll device in which at least one of the scroll members receives a mechanical force or hydraulic pressure in the axial direction and holds the scroll members in a seal contact state. In the '114 patent, fluid at exhaust pressure is introduced to exert a biasing force on the back of the end plate of the scroll member. U.S. Patent No. 3,884,59 granted to Young's Law
No. 9 discloses a fully axial compliant method in which the orbiting scroll is axially subjected to a hydraulic forcing force at exhaust pressure. U.S. Pat. No. 4,357,132 to Kosokabe discloses a scroll device in which a fluid at an intermediate pressure is used to force a swirling scroll member against a fixed scroll member. U.S. Pat.No. 4,216,661 granted to Toujou,
A fully axial compliant method is disclosed in which fluid outside the device acts on the back of the orbiting scroll member to provide an axial bias. U.S. Pat. No. 4,611,975 issued to Blaine discloses a complete axial compressor in which an annular chamber formed at the interface of the scroll members is connected to a relatively low pressure source to "suck" the two scroll members together. The client method is disclosed. U.S. Pat. No. 4,496,296 to Ally discloses a fully axially compliant process in which two pressure chambers are formed in the back of a swiveling scroll member. These pressure chambers are connected to a compression pocket at intermediate pressure and a central volume at exhaust pressure. This method
It provides radial seal retention of the scroll member over a wide range of motion. U.S. Pat. Discloses a fully axially compliant method of forcing the

The fully axial compliant method has several drawbacks. For example, this method often uses gas pressure from the compression pocket and / or the exhaust chamber, which causes the gas pressure to fluctuate as the operating conditions change, ie, suction and exhaust pressures. However, these changes are not necessarily proportional to the separating forces acting on the scroll member tip and base. Therefore, as a design compromise, the bias force is:
When sufficient, at low suction pressure and low discharge pressure,
It is no longer sufficient to maintain stable operation. On the other hand, the same bias force becomes excessive for operating conditions at high suction pressure and high discharge pressure.

Another drawback of the fully axially compliant method is the non-negligible power loss due to friction between the contacting surfaces. For operating conditions at high suction and discharge pressures, excessive hydraulic forcing leads to large frictional power losses and severe wear, sometimes even chip and base seizures, which can even cause damage. .

Yet another drawback of the fully axial compliant method is
The contact between the chip and the base causes vibration and noise.

U.S. Pat. No. 4,958,993 to Fujio discloses a third approach for maintaining a gap between scroll members. This approach is called "semi-compliant" because the axial gap between the scroll members is enlarged by moving one of the scroll members from the other.

The '993 patent is not a non-orbiting scroll member,
It teaches that the orbiting scroll member should be made axially movable. By doing this, the orbiting scroll member is already movable and the non-orbiting scroll member is already stationary, so that even if this is done, the number of movable parts can be minimized. Moving parts cause unwanted vibrations and noise. Also, the orbiting scroll member is usually lighter than the non-orbiting scroll member, and therefore has less inertia, which results in faster response time of the orbiting scroll member.

The semi-compliant method taught by the '993 patent has several problems. For example, by making the orbiting scroll member movable in the axial direction, the potential for tilting it is significantly increased. As shown in FIG. 3 of this application, the orbiting scroll member receives a driving force Fd acting on the central portion of the drive pin boss 53 and a reaction force Fg acting on the central portion of the vane 51 from the compressed gas. These two forces are perpendicular to the axis S1-S1 and tilt the orbiting scroll member 50, creating a moment that causes it to wobble during orbit. The '993 patent teaches the range of motion (orbital and axial) of the orbiting scroll member which makes it extremely difficult to balance these forces and the moment acting on the scroll member and prevents the scroll member from tilting. There is. The tilting of the orbiting scroll member of the '993 patent results in the same unwanted noise vibration and leakage that the' 993 patent's design was intended to avoid.

The present invention provides a novel method for designing a scroll element of a scroll type fluid ejection device.
According to the invention, the design requirements for displacement, the high specific volume ratio and the optimum number of turns are all met. The present invention also provides an improved semi-compliant biasing method that eliminates the potential to tilt and significantly reduces the amount of unwanted noise, vibration and leakage.

SUMMARY OF THE INVENTION Accordingly, the object of the invention is typically caused by incompressible fluid, clogging of contaminants, or contact between the tip and the base caused by abnormal or excessive deformation of the scroll element. It is an object of the present invention to provide a scroll type fluid discharge device in which a scroll member which is not swiveled, ie, fixed, is configured to bend under abnormal load so as to protect the device. Further, during normal operation, an axial gap is maintained between the scroll member tip and the base to provide a hydrodynamic seal. Therefore, the present invention can eliminate the detrimental effects of frictional power loss, vibration, noise, and wear caused by frictional contact between the tip of the scroll member and the base.

The present invention also provides a novel method for designing a scroll-type fluid ejection device that provides a high inherent volume ratio, optimal number of turns and required ejection volume, without the drawbacks and limitations of the conventional designs described above. That is the purpose.

Another more specific object of the present invention is to achieve the desired specific volume ratio, emissions without producing significantly disproportionate forces or moments or dramatically complicating the scroll element. And to provide a novel structure for a scroll element of a scroll type fluid ejection device having a number of turns.

Yet another object of the present invention is to provide a novel structure for a scroll-type fluid ejection device in which the scroll elements have the same or different basic geometry.

To accomplish these and other objectives, the disclosed embodiments of the present invention provide a scroll-type fluid ejection device that includes a housing having a fluid inlet port and a fluid outlet port. The first scroll member has an end plate from which the first scroll element extends axially within the housing. The second scroll member also has an end plate from which the second scroll element extends axially. The second scroll member is movably arranged to make a non-rotating orbital motion with respect to the first scroll member.

The first and second scroll elements have angles
Radially offset and interdigitated to create a plurality of line contacts defining at least a pair of sealed fluid pockets. The drive means is operatively connected to the scroll member to cause relative rotation of the scroll member while allowing relative swirl movement to change the volume of the fluid pocket.

The disclosed embodiments of the present invention provide a novel method of designing the shape of the inner and outer surfaces of both scroll members so that the desired displacement, specific volume ratio and number of turns are achieved. The principle of this method is as follows.

1) The curvature of the outer part of the first scroll element is designed in the same way as the conventional method so that the desired discharge amount is satisfied.

2) The curvature of the inner part of the first scroll element is also designed in the same way as the conventional method so that the desired specific volume ratio is satisfied.

3) The outer and inner parts of the first scroll element are smoothly connected with the middle part having a curvature selected to satisfy the desired number of turns.

4) The second scroll element is designed by differentiating the mathematical conjugate of the first scroll element. The second scroll element is angularly and radially offset and interdigitated with the first scroll element.

The present invention is disclosed by an air compressor having the same vane thickness and spiral mother circle on both the outer and inner portions of the scroll element. The outer part and the inner part of the scroll element are formed in a usual manner so as to satisfy a predetermined discharge amount and a specific volume ratio. Then they
Joined by an intermediate section, the intermediate section has zero and first derivatives that are equal to the derivatives of the outer and inner sections at the junction. The geometry of the middle section is chosen to achieve the optimum number of turns. Thus, a continuous spiral smooth wall is formed by the outer, middle and inner portions, respectively, to give the desired displacement, the desired specific volume ratio and the optimum number of turns.

In conventional scroll compressors, the scroll elements are made by spiral curves. For a pair of scroll elements, the spiral curves are geometrically identical and develop from the same mother circle. However, in the first embodiment of the invention, each scroll element comprises several parts of a spiral curve developed from different mother circles, yet the two scroll elements are They are identical in shape and substantially converge at the center of the end plate. In the second embodiment, the two scroll elements are geometrically different from each other. First
And the second embodiment is identified below as "same" and "not the same".

In another embodiment of the present invention, a scroll fluid ejection device comprises means for providing a mechanical force that forces two scroll members into an axial actuating relationship. At the same time, there is no potential to tilt the scroll member and a constant gap is maintained between the tip or tip of one scroll member and the base of the other scroll member.

In another embodiment of the present invention, a scroll fluid ejector comprises means for providing hydraulic pressure to force two scroll members into an axial working relationship.
At the same time, there is no potential to tilt the scroll member and a constant gap is maintained between the tip of one scroll member and the base of the other scroll member.

In another embodiment of the present invention, a scroll-type fluid ejection device includes an axially movable specific orbiting scroll member. The second scroll member revolves around an axis, but is fixed linearly along this axis. The first and second scroll members are interfitted to form a first
Of the scroll member is movably biased with respect to the second scroll member so as to flex axially under sufficient force.

In yet another embodiment of the present invention, the scroll-type fluid ejection device described above retains the first scroll member movably in a rearward direction along the axis perpendicular to the axis of the scroll element. It is equipped with a stabilization mechanism. At the same time, a constant gap is maintained between the tip or tip of one scroll member and the base of the other scroll member.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be better understood upon consideration of the following detailed description with reference to the accompanying drawings.

1a to 1d are schematic diagrams showing relative orbital movements of scroll elements in a conventional scroll compressor.

FIG. 2 is a compression-capacity graph showing a compression cycle including ideal compression, low compression, and overcompression.

FIG. 3 shows the forces and moments acting on the orbital scroll element.

FIG. 4 shows a cross-sectional view of a scroll type air compressor constructed according to the present invention.

FIG. 5 shows a top sectional view of a first embodiment of the invention in which the scroll elements are substantially identical.

Figures 6a and 6b show a top sectional view of a second embodiment of the invention in which the scroll elements are substantially non-identical.

FIG. 7 shows a conventional scroll element, from which the first and second embodiments of the invention have evolved.

FIG. 8 shows the interfitting scroll element of the first embodiment.

FIG. 9 shows the interfitting scroll element of the second embodiment.

FIG. 10 shows a typical structure of a general top seal.

11a and 11b show a sectional view and a plan view of a first embodiment of the axial semi-compliant mechanism of the present invention.

12a and 12b show a sectional view and a plan view of a second embodiment of the axial semi-compliant mechanism of the present invention.

13a and 13b show a sectional view and a plan view of a third embodiment of the axial semi-compliant mechanism of the present invention.

FIG. 14 shows a cross-sectional view and a front view of a scroll type air compressor having a semi-compliant structure in which gas acts on the rear portion of the first scroll member to generate an axial biasing force at the discharge pressure.

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 4 shows a scroll type air compressor designed according to the present invention. The compressor unit 10 has a main housing 20, a compressor shell 21 having a front plate 22, and a cup-shaped casing 23.
The front plate 22 is attached to the compressor shell 21 by a known means (for example, welding). The shell 21 and casing 23 are attached to the main housing 20 by conventional means (eg, welding or bolting). The main housing 20 holds a main journal bearing 30. The main shaft 40 is rotatably supported by the bearing 30, and when driven by an electric motor or an engine (not shown), rotates along its axis S1S1.
The sealing element 41 seals the shaft 40 and prevents the lubricating oil and air in the shell from leaking. The drive pin 42 extends from the rear end of the main shaft 40 and has a center axis S2−
S2 is offset from the main shaft axis S1-S1 by a distance equal to the orbiting radius R _or of the second scroll element. The orbiting radius is the radius of the orbiting circle laterally moved by the second scroll member when the second scroll member 50 orbits with respect to the first scroll member 60.

The first scroll member 60 has an end plate 61 from which a scroll element 62 extends. First scroll member
The 60 is attached to the main housing 20 by a method called "semi-compliant". When this mounting method is used, the first scroll member 60 has the axis S1−
S1 and the surface of the main housing 20 (spring
(According to 70) perpendicular to the spring bias. This ensures that a suitable gap 65 is maintained between the scroll element tip of one scroll member and the end plate base of the other scroll member.

These gaps should be wide enough to prevent the tips and bases of the scroll members from touching each other, taking into account production tolerances and thermal expansion of the scroll elements during normal operation. On the other hand, these gaps need to be small enough to be hydrodynamically sealed by the lubricating film during normal operation. When an abnormal condition occurs such as a contaminated liquid or an incompressible liquid existing between the scroll members, or when the scroll element undergoes abnormal thermal expansion, the first scroll element protects the spring 70 from damage. Axially (linearly along the central axis of the scroll element) against the biasing force of the. This mechanism is called "semi-compliant",
It will be explained in more detail later.

The first scroll member 60 includes a reinforcing sleeve 63 and a rib 64 in addition to the circular end plate 61 and the scroll element 62. The first scroll member 60 can be retracted in the axial direction. The scroll element 62 is attached to the front end face of the end plate 61, extends from the front end face thereof, and also has a reinforcing sleeve 63.
The rib 64 extends from the rear surface of the end plate 61.

The second scroll member 50 includes an annular end plate 51, a scroll element 52 mounted on the rear surface of the annular end plate 51 and extending therefrom, and a swivel bearing mounted on the rear surface of the annular end plate 51 and extending therefrom. It has a boss 53.

The scroll elements 52 and 62 are interdigitated and angled
It is offset by 180 degrees and is radially offset by the turning radius R _or . Thereby, at least one set of sealing fluid pockets is provided for the scroll elements 52, 62 and the end plate 5.
It is defined between 1 and 61. The second scroll member 50 is connected to the drive pin 42 (which penetrates the drive pin bearing 43) and the rotation preventing Oldham ring 80. Second scroll member 50
Is driven by the turning motion of the turning radius R _or by the rotation of the drive shaft 40, and compresses the fluid. The working fluid enters the compressor 10 through the suction port 91, is then compressed by the scroll member, and is discharged through the discharge hole 92, the passage 93, the chamber 94, and the discharge port 95. The exhaust gas is sealed from the chamber 96 by the bearing surface 54 and the sealing element 44 between the pin bearing 43 and the pin bearing boss 53. The exhaust gas acts on the bottom surface 45 of the boss 53 to reduce the axial thrust force from the compressed fluid in the operating compression pocket. The counterweights 97 and 98 cancel the centrifugal force acting on the second scroll member 50 due to the orbiting movement of the second scroll member 50.

The geometry of the scroll element will be described with reference to FIGS. 5, 6a and 6b.

In the first embodiment of the present invention, the scroll elements of the two scroll members have substantially the same structure. An example of such a scroll element is shown in FIG. The design parameters of the first embodiment are as follows: Discharge V _H = 13 ³ inches / rev / suction pocket; Specific volume ratio R _v = 5.6; Radius of basic mother circle (inside and outside of scroll element) the height h = 2.0 inches helical elements; circle the original involute surface) R _g = 0.14324 walls of the scroll element of the orbiting radius R _or = 0.2 inches first embodiment is designed as follows ing.

1) Design of a general spiral scroll element using the above-mentioned design parameters As a result of this design, the scroll element obtained is composed of almost complete four turns as shown in FIG. The condition of the specific volume ratio is satisfied. The initial and final helix angles of the outer wall of the scroll element are 224 ° and 1663 °, respectively. The center of the mother circle is 0 point. This scroll element is defined as the basic spiral element, and its mother circle is defined as the basic mother circle.

2) Arc surface EF from the basic spiral element shown in FIG.
Selection of ₁ E ₂ , IG ₁ I ₁ , E ₃ F ₂ E ₄ and I ₂ G ₂ I ₃ These arcs are selected to meet the desired emissions and volume ratios. In the first embodiment, the outer outer surface EF ₁ E
₂ extends to a helix angle of 540 °. The inner outer surface E ₃ F ₂ E ₄ is
It extends to a spiral angle of 179 °. The outer inner surface IG ₁ I ₁ and the inner inner surface I ₂ G ₂ I ₃ extend at helix angles of 360 ° and 359 °, respectively.
Since one complete turn of the outer part of the spiral element shown in FIG. 7 is selected for both scroll elements in the first embodiment, the emissions of the first embodiment are shown in FIG. Will be identical to the design shown. However, the outer surface selected for the interior of the scroll element is less than a complete turn. Therefore, the volume of the final seal compression pocket, ie the specific volume ratio in the first embodiment, differs somewhat from the basic design shown in FIG. This will be resolved later.

3) Joining the inner and outer outer and inner surfaces of the scroll element The middle spiral arcuate surface extends at an involute angle of 360 ° from E2 to E3, and the radius of the mother circle is calculated as follows.

R _g1 = (E ₂ E ₃ ) / (2π) = 2 × R _g (1) where R _g and R _g1 are centered on 0 and 0 ₁ , respectively, as shown in FIG. It is the radius of the mother circle. Mother circle 0
And 0 ₁ have the same tangent at the locations of the end points E ₂ and E ₃ , respectively, on the outer surface. Similarly, in order to join the inner and outer inner surfaces of the spiral element of the first embodiment, the middle spiral arcuate surface extends at a 360 ° helix angle from I ₁ to I ₂ and has a radius of this mother circle. Is calculated as follows:

R _g2 = (I ₁ I ₂ ) / (2π) = 2 × R _g (2) where R _g and R _g2 are centered around 0 and 0 ₂ , respectively, as shown in FIG. Is the radius of the mother circle. The mother circles 0 and 0 ₂ are the end points I ₂ and I _{3 on the} outer surface, respectively.
Have the same tangent at the position. Due to the introduction of the middle part of the scroll element, the volume of the final seal compression pocket for the scroll element shown in FIG. 7 is slightly larger than the volume of the final seal compression pocket for the scroll element shown in FIG. To correct for this difference, the initial swirl angle inside the scroll element of the first embodiment can be increased and the outlet can be moved to increase the volume of the final seal compression pocket. it can. However, the difference in volume ratios is usually quite small, so no improvement is necessary.

4) Design of a scroll element that is a conjugate counterbalance to the scroll element shown in FIG. 5 It is not necessary to list this method in detail here as it is a well known operation to differentiate the conjugate of a curved surface. The term "balanced conjugation" refers to the required linear contact (and seal pocket) whenever the scroll elements are interfitted and relatively swiveled, no matter what the conjugate is differentiated. Is established and is used to indicate that the scroll elements are interdigitated. In the first embodiment, the conjugation is the same as the original scroll element.
Two "same" scroll elements are shown in FIG.

The second embodiment of the present invention is "not the same" here.
And is shown in FIGS. 6a and 6b. The general design specifications are the same as in the first embodiment. However, in the second embodiment, the second scroll element is
As shown, it has a wall of constant thickness. Compared to the first embodiment, the second scroll element is lighter and thus reduces centrifugal forces during the swiveling movement.

The scroll element shown in Fig. 6a consists of three spiral parts. Both the inner and outer parts
Figure 8 is a nearly complete one turn spiral wall directly taken from the general scroll element shown in Figure 7. More specifically, in FIG. 6a, the outer surface K ₂ L ₂ K ₃ of the inner portion extends from an initial helix angle of 224 ° to a final helix angle of 583 ° and has a radius of 0.1432.
It has a 4-inch mother circle. The outer surface KLK _{1 of the} outer part extends from an initial helix angle 1303 ° to a final helix angle 1663 ° and has a mother circle of the same radius. The outer surface of the intermediate portion, that is, the radius of the mother circle of the spiral surface K ₂ L ₁ K ₁ is as follows: R _g3 = (K1K2) / (2π) = 2 × R _g (3) This spiral surface K ₂ L ₁ K ₁ smoothly and continuously connects the inner and outer parts of the outer surface of the spiral wall. The inner surface of the scroll element shown in Figure 6a is parallel to its outer surface and has a wall thickness (t) of about 0.2 inches. Although the scroll elements shown in Figure 6b are balanced conjugates of the scroll elements shown in Figure 6a, they are not the same.

The outer surface of the second scroll element shown in FIG.
It is composed of three spiral curved portions of M ₂ , M ₂ P ₁ M ₃ , and M ₃ P ₂ M ₄ . The outer surface MPM ₂ and the inner surface M ₃ P ₄ M ₄ have a radius Rg = 0.14.
A spiral with a 324 inch mother circle. These surfaces extend from the initial helix angle 224 ° to the final helix angle 403 ° for the inner part and for the outer part,
It extends from an initial helix angle of 1123 ° to a final helix angle of 1663 °. The middle portion M ₂ P ₁ M ₃ is a spiral having a base circle radius represented by the following equation.

Rg ₄ = M ₂ M ₃ / (2 × π) = 2 × Rg (4) The inner surface of the scroll element shown in FIG. 6b also has NQN ₁ ,
It consists of three parts, N ₁ Q ₁ N ₂ and N ₂ Q ₂ N ₄ . The inner part and the outer part respectively extend from the initial helix angle 224 ° to the final helix angle 763 ° for the inner part and from the initial helix angle 1483 ° to the final helix angle 1663 ° for the outer part. extend. The middle part of the inner surface N ₁ Q ₁ N ₂ smoothly and continuously connects the inner part and the outer part, and has the same mother circle as the middle part of the outer surface.

FIG. 9 shows two non-identical scroll elements that fit together during operation. Due to the middle section, the volumes of the suction pocket and the final seal compression pocket are slightly different from the specifications. This can be easily adjusted by slightly changing the helix angles of the outer and / or inner parts of the inner and outer surfaces of the scroll element. Since the two scroll elements are not the same, the volumes of the pair of compression pockets A1 and A2 are slightly different, as shown in FIG. 9, but this difference does not affect most applications. A similar situation occurs for the final compression pocket and the intrinsic volume ratio. To compensate for these differences, the initial helix angle of the inner portion of the scroll element can be adjusted. Usually, the deviation of the specific volume ratio from the basic specifications is extremely small and does not need to be adjusted.

Three embodiments of a semi-compliant mechanism constructed in accordance with the present invention will be described with reference to FIGS.

In the case of the first embodiment, as shown in FIGS. 11a and 11b, the outer peripheral surface 160 of the end plate 61 of the first scroll member 60 is
Has three flat edges 161 spaced at equal intervals. The three positioning blocks 162 form a stabilizing mechanism to prevent the first scroll member from "tilting". The block 162 is attached to the main housing 20 with a bolt 163. The block 162 is a flat edge 161 of the end plate 61.
Tight contact, thereby maintaining the scroll member 60 perpendicular to the axis S1-S1 and the block 162
The scroll member 60 can be retracted in the axial direction by being guided by.

The term "axial" is used herein to describe a linear movement along an axis, not a rotational movement about the axis. The first scroll member 60 is biased toward the second scroll member 50 by the spring 70 until it is stopped by the surface 24 of the main housing 20. This ensures a suitable gap 165 between the tip of one scroll member and the base of the other scroll member.

The second scroll member 50 is also stabilized to prevent tilting. The stabilizing mechanism for the second scroll member 50 is a housing 20 that acts as a thrust bearing on one side of the end plate.
And the high gas pressure in the space between the scroll members 50 and 60.

The gap 165 should be large enough to ensure non-contact between the chip and the base during normal operation. On the other hand, the gap 165 allows the leakage of the working fluid through the gap to be very small compared to the drained fluid, or is formed between the tip of the scroll member and the base during normal operation. It must be small enough so that it can be totally sealed by the lubricating oil film. For example, a cast iron scroll compressor having an axial height of 2 inches would have a 0.0030 inch gap 165 under cold conditions based on the disclosed design.
Need. In particular, if the separating force acting on the front surface of the first scroll member 60 exceeds the biasing force of the spring due to an abnormal operating condition, the first scroll member 60 will be blocked by the limiting lip 164 of the positioning block 162. Retract axially until stopped.

12a and 12b show a second embodiment of the invention. The first scroll member 60 is stabilized by three stabilizing pins 261 and attached to the main housing 20. These stabilizing pins 261 prevent rotation or “tilt” of the first scroll member 60. The first scroll member 60 is biased by the spring 70 until it is stopped by the surface 24 of the main housing 20. This ensures that there is an appropriate gap 265 between the tip of one scroll member and the base of the other scroll member.
Is secured. When the separating force acting on the front surface of the first scroll member 60 exceeds the biasing force of the spring, the first scroll member 60 retracts axially until it is stopped by the limiting lip 264 of the positioning block 262. .
Block 262 is the main housing with bolts 263
Mounted on 20.

Figures 13a and 13b show a third embodiment of the invention. Three elastic positioning plates 361 are attached to the stabilizing block 362 by bolts 363. The block 362 is attached to the main housing 20 with bolts 366. The positioning plate 361 has a groove 367.
These grooves 367 firmly hold the ribs 64 of the first scroll member 60, thereby stabilizing the first scroll member 60 and rotating the first scroll member 60, and
Although it is prevented from inclining in a plane perpendicular to the axis S1-S1, the positioning plate 361 has elasticity, so that the first scroll member 60 can be retracted in the axial direction. The stabilizing block 362 firmly holds the first scroll member 60 at the position of the edge 367 and prevents the first scroll member 60 from "tilting". The first scroll member 60 is biased towards the second scroll member 50 by the spring 70 until it is stopped by the surface 24 of the main housing 20. This ensures an appropriate gap 365 between the tip of one scroll member and the base of the other scroll member. When the separating force acting on the front surface of the first scroll member 60 exceeds the biasing force of the spring,
The first scroll member 60 retracts axially until it is stopped by the limiting lip 364 of the stabilizing block 362.

FIG. 14 shows a cross-sectional view of the fourth embodiment of the present invention. The basic operation principle of this embodiment is the same as the operation principle of the device shown in FIG. However, in this embodiment, the exhaust gas is used to create the axial biasing force. Therefore, FIG. 14 shows improved versions of the compressor shown in FIG. 4, and these improved parts will be described below.

As shown in FIG. 14, the air passes through the suction port 491, enters the compressor 10, and then the scroll member 50.
And 60, and is discharged through the discharge hole 493 and the discharge port 495. The exhaust gas is sealed within the exhaust chamber 496 by using the O-ring 497 and by closing the tolerance between the sleeve 63 and the lid 498. The sleeve 63 and lid 498 also provide an additional stabilizing mechanism for the scroll members 50 and 60. The outlet 495 is welded to a lid 498 which is bolted to the casing 23. The exhaust gas exerts a biasing force on the inner surface 499 of the sleeve 63. A portion of this inner surface 499 is selected so that the biasing force slightly exceeds the separating force acting on the front face of the first scroll member 60 during normal operation. Therefore, the first scroll member 60 is biased toward the second scroll member 50 and stopped by the surface 24 of the main housing 20 to provide a suitable gap 465 between the tip and base of the two scroll members 50 and 60. Secure. The stabilizing pin 466 prevents the first scroll member 60 from rotating in a plane perpendicular to the axis S _i -S _i and also prevents it from “tilting”. When an abnormal operating condition such as that described above occurs, the first scroll member 60 resists the bias force until it is stopped by the lip 464.
Retreat in the axial direction.

Although the embodiment described above is a preferred embodiment of the present invention, those skilled in the art can recognize changes in the structure, arrangement, configuration and the like without departing from the original scope of the present invention. Let's do it. The invention is defined by the appended claims, and any literal and equivalent apparatus and / or method that can be construed within the definition of the claims is encompassed by the invention.

Continuation of the front page (56) Reference JP-A-51-104609 (JP, A) JP-A-59-90789 (JP, A) JP-A-4-121482 (JP, A) JP-A-63-80088 (JP , A) JP-A-3-237283 (JP, A) US Pat. No. 3874827 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01C 1/02 F04C 18/02

Claims (11)

(57) [Claims] 1. A first scroll member having a first scroll element having a first inner side surface and a first outer side surface, and a second scroll member having a second scroll element having a second inner side surface and a second outer side surface. In the line contact portion between the first inner side surface and the second outer side surface, and the line contact portion between the first outer side surface and the second inner side surface, Positioned to meet each other, the line contact portion includes the first scroll element and the second scroll element.
The scroll elements move along the first inner surface, the second outer surface, the first outer surface and the second inner surface when the scroll elements are moved relative to each other; The first inner surface further includes an action surface on the first scroll element and the second scroll element, which is formed by a region crossed by the line contact portion when the two scroll elements are moved relative to each other. And the working surface of the second outer surface forms a portion of a first fluid pocket, and the second inner surface and the working surface of the first outer surface form a portion of a second fluid pocket. Each of the working surfaces has two or more curved portions, and each of the curved portions has a generation circle having a radius and a center, and the bending portion is substantially the same as the center of the generation circle of the bending portion. Focusing towards the same center point, Each of the working surfaces has a first portion having one of said two or more curved portions, said first portion converging towards a central point, said one generation circle of said two or more curved portions. The radius of is selected such that the first portion provides an initial number of turns, provided that the first portion is continuous to the center point, and each of the working surfaces has one of the two or more curved portions. And a radius of the other generation circle of the two or more bends, wherein the first scroll element has an actual number of turns that is at least about one less than the initial number of turns. A scroll-type ejection device, characterized in that it is selected to have. 2. The apparatus according to claim 1, further comprising a biasing mechanism for creating a gap between the first scroll member and the second scroll member in the axial direction. 3. A first scroll member of the urging mechanism,
3. The device of claim 2, which allows yielding away from the second scroll member under a separating force generated by an abnormal operating condition. 4. A first stabilizing mechanism for preventing the first scroll member from tilting, and a second stabilizing mechanism for preventing the second scroll member from tilting. The apparatus according to Item 1. 5. A first scroll member having a first scroll element having a first inner side surface and a first outer side surface, and a second scroll member having a second scroll element having a second inner side surface and a second outer side surface. In the line contact portion between the first inner side surface and the second outer side surface, and the line contact portion between the first outer side surface and the second inner side surface, Positioned to meet each other, the line contact portion includes the first scroll element and the second scroll element.
The scroll elements move along the first inner surface, the second outer surface, the first outer surface and the second inner surface when the scroll elements are moved relative to each other; The first inner surface further includes an action surface on the first scroll element and the second scroll element, which is formed by a region crossed by the line contact portion when the two scroll elements are moved relative to each other. And the working surface of the second outer surface forms a portion of a first fluid pocket, and the second inner surface and the working surface of the first outer surface form a portion of a second fluid pocket. Each of the working surfaces has two or more curved portions, and each of the curved portions has a generation circle having a radius and a center, and the bending portion is substantially the same as the center of the generation circle of the bending portion. Focusing towards the same center point, One of the bends on each of the working surfaces is such that the first portion provides an initial number of turns, provided that one of the bends on each of the working surfaces is continued to the center point. Focusing towards the center point, another of the bends on each of the working surfaces is such that the first scroll element has an actual number of turns that is at least about one less than the initial number of turns. A scroll-type ejector having a generation circle having a selected radius. 6. The device of claim 5, having a built-in volume ratio of greater than 2.5. 7. The device of claim 5, wherein the other one of the bends has a predetermined curvature selected to meet a desired evacuation volume of the device. 8. A third of each of the working surfaces has a predetermined curvature selected to meet a desired evacuation volume of the device.
6. The device of claim 5, having a curved portion. 9. The apparatus of claim 8 wherein the desired built-in volume ratio is greater than 2.5. 10. The device of claim 5, wherein the actual number of turns is less than four. 11. The device of claim 5, wherein the bend is an involute helix.