JP3350024B2 - Scroll type fluid machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a scroll type fluid machine applicable as, for example, a scroll type compressor or a scroll type expansion machine.

[0002]

2. Description of the Related Art For example, the shape of the central portion of a scroll wrap of a scroll compressor has a great effect on the reliability and performance of a scroll. For example, in a scroll disclosed in Japanese Patent Application Laid-Open No. 59-58187, an example is shown in FIG.
The orbiting scroll moves around the fixed scroll (A),
(B), (C), and (D), when turning non-rotationally without rotation, the volume of the innermost package formed at the inner ends of both wraps becomes the final volume as shown in FIG. The so-called perfect meshing profile, which becomes zero in practice, is often adopted due to performance requirements. However, in this type of scroll profile, a maximum stress is generated at the center of the scroll wrap, and this point often leads to breakage. On the other hand, from the viewpoint of ensuring reliability, various means have been proposed for reducing the maximum generated stress and for increasing the fatigue strength of the material. As a means to reduce the maximum generated stress,
Moving the junction between the curve forming the central portion and the involute curve outside of the curve toward the larger involute opening angle, and turning the joint as disclosed in Japanese Patent Application Laid-Open No. 6-66273 and shown in FIG. It has been proposed that one of the scroll and the fixed scroll, which has a higher required strength, is made thicker and the other is made thinner. The real was or HirakiAkira 61-1718
No. 01 discloses a scroll having a trapezoidal wrap cross-section as shown in the cross-sectional view of the meshing portion of the spiral body in FIG. 8, but is practically used due to difficulty in actual processing. Not. As a means to increase the fatigue strength of the wood charge in addition, the actual fair 1-28315 Patent Publication No. 9
As shown in (1), it is also proposed to provide a rib at the base of the wrap, but in this type of structure, the rib at the base of the wrap does not function as a pressure partition, and it is impossible to form a so-called complete meshing profile. There are problems such as a decrease in compressor efficiency due to an increase in compression power.

[0003]

SUMMARY OF THE INVENTION The present invention has been proposed in view of such circumstances, and has a high strength at the center end of the scroll wrap, is easy to process, has a small power loss, and has a high efficiency. It is an object to provide a scroll-type fluid machine that can operate.

[0004]

To achieve the above object, according to an aspect of the scroll-type fluid machine of the first aspect of the invention, eccentric and fixed scroll are formed by erecting the spiral wrap on the end plate and the orbiting scroll from each other is allowed, and to limit the ventral closed space and the dorsal closed space by the respective spiral wrap at each end plates by having engaged by shifting the phase, blocking the rotation of said orbiting scroll the revolving scroll The fixed scroll and the orbit in a scroll-type fluid machine that compresses or expands gas taken into the abdominal closed space and the back closed space from a suction port by orbiting and then discharging from a discharge port. Involute each spiral wrap of the scroll
Of the involute curve.
Medium than involute starting point determined by volute extension angle
The vertical cross-sectional shape of each of the spiral wraps in the portion on the front end side of the central portion is formed in a step shape of at least two or more steps formed such that the wrap thickness becomes thinner toward the upper step away from the end plate due to a step. It is characterized by being.

[0005] A scroll type fluid machine according to a second aspect of the present invention is the scroll type fluid machine according to the first aspect,
Characterized in that a portion of the central portion the distal end side are connected by a small Do <br/> Kutomo two curves than involute starting point determined by the involute involute angle of the involute curve.

A scroll type fluid machine according to a third aspect of the present invention is the scroll type fluid machine according to the first or second aspect, wherein the scroll type fluid machine is configured such that the belly side closed space and the back side closed space are the most. When located in the outer part, gas is taken in from the suction port formed in the scroll type fluid machine, and as the ventral closed space and the back closed space move toward the center, the ventral sealed space is moved. And a compressor that discharges compressed gas from the discharge port formed in the scroll-type fluid machine by reducing the volume of the scroll-type fluid machine.

[0007]

FIG. 1 is a perspective view showing a central portion of a scroll wrap according to a first embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. FIG. 4 is an overall plan view showing the meshing state of the scroll of FIG.
FIG. 5 is a plan view showing the center tip portion of the scroll according to the second embodiment, and FIG. 5 is a sectional view taken along the line V-V of the wrap shown in FIG.

The spiral-shaped wraps of the fixed scroll and the orbiting scroll according to the present invention, that is, the inner ends of the scroll wraps 1 and 2, have the shapes shown in FIGS. As shown in FIG. That is, the vertical cross-sectional shape of the center end side of each spiral wrap of the fixed scroll 1 and the orbiting scroll 2 has at least two or more laps formed such that the lap thickness becomes thinner as the tier is separated from the end plate by the step. stair <br/> shape, and is formed, for example, FIG. 5 (a) are shown as two-step staircase.

As shown in FIG. 3, the fixed scroll 1 and the orbiting scroll 2 each having such an inner end shape have a fixed scroll upper wrap 11 and an orbiting scroll lower wrap 22, and a fixed scroll lower wrap 12 and an orbiting scroll. The upper wraps 21 are completely meshed with each other, and the orbiting scroll 2 orbits around the fixed scroll 1 in a non-rotating manner in the order shown in FIGS. At this time, the innermost compression chamber 3 shown in FIG.
The volume of 0 can be made zero as shown in FIG. FIG. 4 shows an example of a scroll profile in which the thickness of the fixed scroll upper wrap 11 and the lower scroll wrap 12 of FIG. Also in this profile, complete meshing is achieved, and it can be seen that the profile has a very high degree of design freedom. Further, the laps of the present embodiment are all two-stage changes, but as described above, the present invention is clearly established even if the laps are formed in three or more stages. Furthermore, although not shown, the orbiting scroll and the center portion profile of the fixed scroll constraints rather free of the same shape, the lower portion of the strength required scroll-side, one lower lap of the upper scrolling the other upper It can be thicker than the wrap. The basic spirit of the present invention is to reduce the tooth thickness of each spiral wrap, that is, the tip of each scroll wrap, in order to increase the strength of the central portion of the spiral body, and to considerably reduce the thickness of each spiral wrap, that is, the plate on the base side of the scroll wrap. The thickness is to be increased stepwise. As described above, the outer surface of each scroll wrap is a curved surface having no step in the axial direction, and the inner surface is formed in a step-like shape in which the thickness decreases stepwise from the base toward the tip due to the step. A wrap that is easy and has a strong inner end can be obtained. By the way, as shown in FIG. 5A, assuming that the bending moment is M, the sectional modulus is Z, and the bending stress is σ, the stress σ is symbolically represented by σ = M / Z. That is, when the plate thickness t is increased, Z increases and σ decreases. This can be applied to a completely meshing scroll. FIG. 5B shows a cross section of the central portion of the spiral body conventionally used.

According to this embodiment, since the root of each scroll wrap, that is, each spiral wrap, can be formed thick, the wrap rigidity at the center front end portion is high, and the stress generated at the same portion is suppressed low. It becomes possible. Further, since a complete engagement in the corresponding stepped portion by the fixed scroll and the orbiting scroll, the volume of the outermost enclosed compression chamber becomes zero, generation of power loss due to re-expansion can be prevented. In the above embodiment, since all the steps change stepwise due to the steps, it can be easily processed by a conventional processing machine, and each scroll wrap of high performance and high strength, that is, each spiral wrap is inexpensively manufactured. Can be provided.

[0011]

According to the present invention, the following effects can be obtained. (1) According to the scroll-type fluid machine of the first aspect of the present invention, the fixed scroll and the orbiting scroll, each of which has a spiral wrap standing on the end plate, are eccentric to each other, and are engaged with each other with their phases shifted. wherein the suction port by the aforementioned limitations and ventral closed space and the dorsal closed space by the respective spiral wrap at each end plates, thereby revolving the orbiting scroll to prevent rotation of the orbiting scroll by In a scroll-type fluid machine that compresses or expands gas taken in a ventral-side sealed space and the back-side sealed space and discharges the gas from a discharge port, the spiral wraps of the fixed scroll and the orbiting scroll are represented by an involute curve. Forming and involute
Start of involute determined by involute extension angle of curve
Each of the above vortex-shaped portions at the center tip side from the point
Is longitudinal section of the wrap and is formed in at least two stages or more stepped upper stage as the lap thickness is formed to be thinner away from the end plate by the step, the base in both the fixed scroll and the orbiting scroll As a result, the rigidity of each spiral wrap, that is, the scroll wrap, increases, and the stress generated at the center distal end of each spiral wrap decreases, and the strength of the central distal end of each spiral wrap increases. And the shape of each spiral wrap becomes thinner in the upper step away from the end plate due to the step, making it easy to process and providing a highly efficient scroll-type fluid machine with less power loss. it can. (2) According to the scroll-type fluid machine according to the second aspect of the invention, in the scroll-type fluid machine according to the first aspect,
Since the central portion leading end side portion than the involute starting point determined by the involute involute angle of the involute curve it is connected in small Do <br/> Kutomo two curves, increasing the thickness of the base in both the fixed scroll and the orbiting scroll As a result, the stiffness of each spiral wrap increases, the stress generated at the center distal end portion of each spiral wrap decreases, the strength of the central distal end portion of each spiral wrap increases, and each spiral wrap also increases. While the shape of the shape wrap is a shape formed using an involute curve,
Since the shape becomes thinner in the upper step away from the end plate due to the step, it is possible to obtain a high-efficiency scroll-type fluid machine that is easy to process and has little power loss. (3) According to the scroll-type fluid machine according to the third aspect of the present invention, in the scroll-type fluid machine according to the first or second aspect, the scroll-type fluid machine is configured such that: When is located at the outermost part, gas is taken in from the suction port formed in the scroll-type fluid machine, and as the ventral-side enclosed space and the back-side enclosed space move to the center side, the ventral side By reducing the volume of the closed space and the volume of the back side closed space, and configured as a compressor that discharges compressed gas from the discharge port formed in the scroll-type fluid machine, both the fixed scroll and the orbiting scroll The root can be made thicker, and as a result, the stiffness of each spiral wrap increases, the stress generated at the center end side of each spiral wrap decreases, and each spiral wrap decreases. The strength of the central part on the tip side of the wrap is high, and the shape of each vortex wrap is thinner as the upper step away from the end plate due to the step makes processing easier, and compressor efficiency is improved. A high-performance compressor with good quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing a central portion of a fixed scroll according to a first embodiment of the present invention.

FIG. 2 is an overall plan view of FIG.

FIG. 3 is an explanatory diagram showing a change in a meshing state between the fixed scroll of FIG. 2 and a corresponding orbiting scroll.

FIG. 4 is an overall plan view showing a fixed scroll according to a second embodiment of the present invention.

5A is a cross-sectional view taken along the line VV of the wrap of FIG. 4, and FIG. 5B is a cross-sectional view of a conventional wrap.

FIG. 6 is an explanatory view of the operation principle showing the non-rotating turning procedure of the orbiting scroll of the scroll type compressor described in JP-A-59-58187.

FIG. 7 is an explanatory view of the operation principle showing the non-rotating turning procedure of the orbiting scroll of the scroll compressor described in Japanese Patent Application Laid-Open No. 6-66273.

FIG. 8 is a view showing a cross section of a scroll and a spiral body described in Japanese Utility Model Laid-Open No. 61-171801.

FIG. 9 is a perspective view showing a scroll disclosed in Japanese Utility Model Publication No. 1-28315.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed scroll 2 Orbiting scroll 11 Fixed scroll upper wrap 12 Fixed scroll lower wrap 21 Orbiting scroll upper wrap 22 Orbiting scroll lower wrap 30 Compression chamber 31 Discharge port

Continued on the front page (72) Inventor Tetsuzo Ukai 3-1-1 Asahicho, Nishibiwajima-cho, Nishi-Kasugai-gun, Aichi Prefecture Mitsubishi Heavy Industries, Ltd. Aircon Works (56) References JP-A-9-68177 (JP, A) JP-A-5-215084 (JP, A) JP-A-59-58187 (JP, A) JP-A-1-257778 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F04C 18/02 311 F01C 1/02

Claims (3)

(57) [Claims] 1. A swirling wrap formed on an end plate, and a fixed scroll and an orbiting scroll are eccentric to each other, and are engaged with each other with their phases shifted. to limit the ventral closed space and the dorsal closed space by wrap, said orbiting scroll to said ventral closed space and said dorsal closed space from the suction port by revolved by preventing rotation of the orbiting scroll In a scroll-type fluid machine that compresses or expands a taken-in gas and discharges the discharged gas from a discharge port, the spiral-shaped wraps of the fixed scroll and the orbiting scroll are formed as involute curves, and
Involute determined by the involute opening angle of the volute curve
Each of the above at the center tip side from the lute start point
Longitudinal section of the spiral wrap, characterized in that it is formed in at least two stages or more stepped upper stage as the lap thickness is formed to be thinner away from the end plate by the step, scroll Fluid machinery. 2. A scroll type fluid machine according to claim 1, the central tip-side portion than the involute starting point determined by the involute involute angle of the involute curve are connected by two curves even without least A scroll type fluid machine characterized by the above-mentioned. 3. The scroll-type fluid machine according to claim 1, wherein the scroll-type fluid machine is configured such that when the belly-side closed space and the back-side closed space are located at the outermost portions, Gas is taken in from the suction port formed in the type fluid machine, and the volume of the ventral closed space and the volume of the back closed space as the ventral closed space and the back closed space move toward the center. A scroll-type fluid machine characterized in that the compressor is configured as a compressor that discharges compressed gas from the discharge port formed in the scroll-type fluid machine.