JPH04203487A - Scroll type fluid machine - Google Patents

Abstract

PURPOSE:To reduce the reexpanded gas volume and enlarge the delivery port area of a machine by making the involute angle in a cross section perpendicular to scroll axis the nearer the end plate the smaller in the fixed side and the nearer the end plate the larger in the rotating side respectively. CONSTITUTION:Involute beginning angles E1-E3, B1-B3 of the central spiral body 1 of a fixed scroll are made smaller the more the body 1 nears the fixed scroll end plate 4. Similarly, involute beginning angles of the central spiral body of a rotating scroll are made larger the more the body nears the rotating scroll end plate the larger. Thereby a delivery port 5 in the fixed scroll side can be enlarged. And the tip portion of the spiral body of the rotating scroll is thinned. Thus the gap producing a small chamber between both spiral bodies can be eliminated to improve performance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in scroll-type fluid machines.

[Conventional technology]

For example, in a scroll-type fluid machine, a pair of spiral bodies are engaged with each other at different angles, and a relative circular motion (rotation interlocking only) is applied to them, so that a closed chamber formed between both spiral bodies is moved toward the center. This is a positive displacement compression device that gradually reduces the volume of the small chamber while moving the small chamber to compress the fluid in the small chamber, and discharges the pressure mfL body from the center.

An involute curve or the like is used for the curve of each spiral body, and the principle of such a scroll-type fluid machine has been known for a long time, and the principle is shown in Fig. 5 (A).
(B), (C).

(D) explains the principle of a scroll compressor. Two spiral bodies with the same shape.

2 are arranged so that they are relatively 180 degrees out of phase and interlock with each other, as shown in the same figure (trial), there are points a, b, where they touch, and points between the two spiral bodies 1 and 2. Closed small chambers 3a and 3b are formed between points al and b1. Here, one spiral body 2 is fixed as a fixed side spiral body, and the other spiral body 1 is set as a rotating side spiral body, with the center ○ of the fixed side spiral body 2 as the center and the center 0゛ of the rotating side spiral body l. When the spiral body l revolves with a radius of OO° while prohibiting its own rotation, the volumes of the closed chambers 3a and 3b gradually change.

That is, when the rotating side spiral body 1 revolves 90 degrees from the state shown in the figure (A), it becomes the state shown in the figure (B), and when it further revolves 180 degrees, it becomes the state shown in the figure (C), and then The state shown in FIG. 27D is reached, during which the volumes of the small chambers 3a and 3b gradually decrease, and in the state shown in FIG. From the state of (D) in the same figure, further 90
When the revolution angle reaches 360 degrees, the state shown in FIG.
Due to the revolution of the spiral body 1, this small chamber 3 is further expanded in the same figure (
B), the state shown in Figure (C) and its volume are reduced, and the volume becomes the minimum between Figure (C) and Figure (D).

Here, sole end plates are provided on the axial end faces of both spiral bodies 1.2, and a discharge boat 4 is provided approximately in the center of the seal end plate of one of the spiral bodies, so that the compressed fluid is discharged from here. During this period, the outer space that began to open in Figure (B) moves from Figure (C) and Figure (D) to Figure (A), taking in new fluid and forming closed chambers 3a and 3b. And then repeat this.

The actual scroll compressor based on the above working principle is
One spiral body integrally having a seal end plate with a discharge boat on one end face is fixed, and the other spiral body of the same shape that also has a seal end plate integrally on one end face is fixed. 180" out of phase with the one spiral body, and overlapped with the other spiral body by a distance of 1 [2ρ (= spiral pitch of the spiral body - 2 x plate thickness of the spiral body) so as to contact each other, and The other spiral body is prohibited from rotating and is allowed to revolve, and the other spiral body is rotated around the center of one spiral body (corresponding to the circle in Fig. 5) with a radius ρ using a crank mechanism having a crank radius ρ. Motion (in the same figure, 0 centered at 0
It is configured to make a revolution of ρ with a radius of ρ.

[Problems to be Solved by the Invention] However, this type of scroll compressor has the following problems.

Δ (11) In an actual machine, a slight gap occurs between the contact points at + b, + ax l b of both spiral bodies 1.2 shown in Fig. 5 (N), and these contact points aI
Since gas flows from the high pressure chamber to the low pressure chamber via r b, + at + bl (for example, if a gap occurs at the contact point, from chamber 3 to chamber 3b), the performance of the compressor decreases. do.

(2) Also, Japanese Patent Application No. 53-206088,
In the case of having a central shape in which the volume of the central small chamber is substantially zero as shown in No. 9-99085, re-expansion of the compressed gas is eliminated, but it is difficult to increase the area of the discharge boat.
Performance may deteriorate due to discharge pressure.

The present invention was developed in view of these circumstances, and since the gap between the two spiral bodies forming the small chamber is eliminated, the performance of the compressor is improved, the volume of compressed gas to be re-expanded is reduced, and the discharge boat is An object of the present invention is to provide a scroll-type fluid machine that can increase the area of the scroll and prevent performance deterioration due to discharge pressure loss.

[Means to solve the problem]

To this end, the present invention has a fixed scroll and an orbiting scroll in which the spiral bodies engage with each other, and the area of the small chamber in the center formed at the contact point of both the spiral bodies is substantially reduced as the spiral bodies rotate relative to each other. In a scroll-type fluid machine in which the rotation angle is zero, the involute extension angle of the central spiral body becomes smaller as it approaches the end plate of the fixed side scroll, and the involute extension angle of the central spiral body becomes smaller as it approaches the end plate. The axis-perpendicular cross-sectional shape of the spiral body is characterized in that the involute extension angle of the central spiral body increases as it approaches the end plates.

[Effect]

According to this configuration, by changing the cross-sectional shape of the central chamber in the height direction, that is, in the axial direction, it is possible to reduce the volume of the compressed gas to be re-expanded and to increase the discharge boat area. Improves machine performance.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the spiral body at the center of the fixed scroll;
Fig. 2 is a sectional view taken along the line A-A' in Fig. 1, Fig. 3 is an explanatory diagram showing the progress of the meshing of the scroll compressor with the fixed scroll shown in Fig. 1, and Fig. 4 is a sectional view taken along the line A-A' in Fig. Figure (E
) is a perspective view showing a state in which both spiral bodies are engaged with each other.

First, in Figures 1 and 2, the end plate 4 of the fixed scroll
The closer it gets to , the smaller the impoliate extension start angle E1-E3°B1-B3 of the central spiral body l. Similarly, in the spiral body 2 of the orbiting scroll (not shown), the impoliate extension start angle of the central spiral body increases as it approaches the orbiting scroll end plate.

As a result, the discharge boat 5 installed on the fixed scroll end plate can be made large, and the tip of the spiral body 2 of the orbiting scroll can be designed to be thin.

The cross-sectional shapes of both spiral bodies perpendicular to the axis can be expressed by the following formula. That is, in all the cross sections in the height direction of each spiral body, the ventral curve inside the point E, which will be described later, and the dorsal curve inside the point B, which will be described later, are given by, and b is the radius of the involute creation circle. , ρ is the turning radius, d is the point of contact between the dorsal curve and the ventral curve (the point with parameter 1 = 1c), and rl (t) smoothly connects with the involute at point E, and r at point tC.
, (t).Similarly, rt (t) is a function that satisfies the condition of smoothly connecting with the involute at point B and smoothly connecting with r, (t) at point tc. It is a function that satisfies

The shape given by these equations has a shape in which the central chamber area is substantially zero, and the extension start angle β of the involute curve connected to this central shape curve is expressed as β=f(h ) (f: any continuous function).

Next, FIG. 3 shows the change in the volume of the central chamber of the scroll compressor having a spiral body according to the present invention.
x, Ei indicate the medial involute extension start position, B+, B! , Bx indicates the starting position of the outer impoliate extension, and subscripts 1.2.3 indicate the cross sections of the spiral body corresponding to the height positions, , ht, and 'h3 in FIGS. 1 and 2.

In FIG. 3A, both spiral bodies are tangent to each other on an involute curve, and the seal line is perpendicular to the spiral body end plate. However, in the same figure (B), the seal line is higher,
From ht to ht is a curve, and from ht to ri is a line perpendicular to the end plate.

This is based on the engagement between the involute starting point B8 of the fixed scroll 1 and the inner involute starting point E2 of the rotating shaft t:I-ru at h=h, and h, ≦
The contact between the inner and outer profiles in the range h≦h is the contact between involute curves, but h! This is because, when ≦h≦h, profiles whose involute start β is shifted by the relationship β−f (h) come into contact with each other.

In the same figure (C), all the sole lines are curved lines, and the area of the central chamber at h is smaller than the area at hl.

This tendency becomes more and more remarkable in the same figure (D), and the compressed gas near h is forced to flow to hl, and it becomes easy to discharge from the discharge port.

Figure (E) shows the state just before the spiral body leaves in step 1.3, and the volume that has not yet been discharged at that time is extremely small compared to the conventional volume, as shown in Figure 4. Become.

According to such an orbiting scroll, the tip of the spiral body can be made thin, and when a light alloy is used to reduce the weight of the orbiting scroll, a structure advantageous in terms of strength can be obtained.

In addition, the contact seal line of the spiral body of the conventional scroll compressor was a straight line, but in the present invention, by changing the involute extension start angle in the height direction using an appropriate function, any contact seal line can be formed. can be formed in the central chamber,
By dispersing the force applied to the spiral body over a wide range, it is extremely advantageous in terms of strength even when wear or excessive pressure occurs.

In this embodiment, an example was shown in which the involute start angle β of the fixed scroll 1 is β=f(h), and β increases with the wrap height h, but of course, the relationship is opposite to this, that is, β decreases with h. or may be set in any relationship as described above.

(Effects of the Invention) In short, according to the present invention, the spiral body has a fixed scroll and an orbiting scroll that engage with each other, and the area of the small chamber in the center formed at the contact point of both the spiral bodies is In a scroll type fluid machine which is designed to become substantially zero as it rotates, in the fixed side scroll, the shape of the cross section perpendicular to the axis of the spiral body is such that the involute extension angle of the central spiral body becomes smaller as it approaches the end plate, In the above-mentioned orbiting side scroll, the cross-sectional shape of the spiral body perpendicular to the axis is such that the involute extension angle of the central spiral body increases as it approaches the end plate, so that the gap between the two spiral bodies that form the small chamber disappears, so that the compressor The present invention is industrially extremely useful because it provides a scroll-type fluid machine with improved performance, which can reduce the volume of re-expanded compressed gas and increase the area of the discharge port, thereby preventing performance deterioration due to discharge pressure loss. It is something.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a spiral body at the center of a fixed scroll according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A' in FIG. 1, and FIG. FIG. 4 is a perspective view showing the state of engagement of both spiral bodies in the state of FIG. 3(E). FIG. 5 is an explanatory diagram of the principle of a known scroll type compressor. 1... Fixed scroll spiral body, 2... Orbiting scroll spiral body, 4... Fixed scroll end plate, 5... Discharge port hl ~ h,... Fixed scroll lamp height, substitute. Person Patent Attorney Masa Tsukamoto Figure 1Et-El --R 4#Iin $+) 1-Hflk@
fm angle Bl -Bs ---f(i'l in g+/z-
)-4IPUFl is 7 angle'ht~hj---1T constant scroll ρu・v7@711 Fig. 2 Fig. 3

Claims (1)

[Claims] The spiral body has a fixed scroll and an orbiting scroll that engage with each other, and the area of the small chamber in the center formed at the contact point of both the spiral bodies becomes substantially zero as the spiral bodies rotate relative to each other. In a scroll-type fluid machine, in the fixed side scroll, the involute extension angle of the central spiral body becomes smaller as it approaches the end plate of the spiral body; A scroll-type fluid machine characterized by a shape in which the involute extension angle of the central spiral body increases as it approaches the end plates.