JPH023040B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scroll compressor, and more particularly to a tip seal thereof.

Before entering into the description of the present invention, the principle of a scroll compressor will be described.

The basic elements of a scroll compressor are shown in FIG. 1, in which 1 is a fixed scroll, 2 is an oscillating scroll, 3 is a discharge port, 4 is a compression chamber, O is a fixed point on the fixed scroll, O′ is a fixed point on the oscillating scroll. The fixed scroll 1 and the oscillating scroll 2 are composed of spirals having the same shape, and the shape thereof is as conventionally known.
It is a combination of involutes, circular arcs, etc.

Next, the operation will be explained. In Figure 1,
The fixed scroll 1 is stationary in space,
The oscillating scroll 2 is combined with the fixed scroll 1 as shown in the figure, and performs a rotational movement, that is, an oscillating movement, without changing its attitude with respect to space.
It moves like 0°, 90°, 180°, 270°. As the oscillating scroll 2 oscillates, the crescent-shaped compression chamber 4 formed between the fixed scroll 1 and the oscillating scroll 2 gradually reduces its volume, and the gas taken into the compression chamber 4 is compressed and discharged from the discharge port. It is discharged from 3. During this time, the distance from O to O' in FIG. 1 is kept constant, and if the interval between the spirals is expressed by p and the thickness is expressed by t, then OO'=p/2-t. p corresponds to the pitch of the spiral.

The outline of the device known as a scroll compressor is as above.

Figure 2 shows the relationship between the tip seal and the oscillating scroll, where 2 is the oscillating scroll, 5 is the oscillating scroll, and 5 is the oscillating scroll.
is a spiral body, 6 is a tip seal groove, and 7 is a tip seal. The tip seal 7 is adapted to fit into a tip seal groove 7 provided at the tip of the spiral body 5.

When the scroll compressor is operated according to the principle shown in FIG. 1, the pressure in the compression chamber 4 increases from the outer circumference toward the inner circumference. In this case, radial leakage occurs across the tip of the spiral body 5 of the oscillating scroll 2 from the high pressure side to the low pressure side. In such cases, compression efficiency is significantly reduced. In particular, chips
In the case of conventional techniques that do not provide seals, it is difficult to improve compression efficiency without relying on expensive means such as precision machining.

When using the tip seal 7 as shown in FIG. 2, during operation, the tip seal 7 is pressed by high pressure introduced into the tip seal groove to prevent leakage in the radial direction and seal the tip as shown in FIG. It functions as a. The back-up spring pushes up the tip seal 7, as at the time of startup.
Even when the high pressure rise is not sufficient, it performs sealing and performs an auxiliary action so that high pressure is applied to the back surface of the chip. Sealing force during operation is provided by both high pressure and spring force.

In the conventional example shown in FIG. 3, a back-up spring 8 is required on the back side of the tip seal 7, especially in order to ensure the sealing function, and the number of parts increases. It is also difficult to select the back up spring 8, and a space is required for the back up spring 8 in the tip seal groove, which has many disadvantages. Another drawback is that leakage occurs from high pressure to low pressure through the tip seal groove, and the secondary sealing effect is not sufficient.

This invention was made in order to eliminate the drawbacks of the conventional products as described above, and uses a tube-shaped elastic body as a tip seal, with the high-pressure end open and the low-pressure end sealed. The purpose is to introduce high pressure into the internal space, apply internal pressure, and expand the elastic body to seal the gap at the tip of the spiral body.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 4, 9 is a tube-shaped tip seal, 10 is a hollow part of the tube-shaped tip seal 9,
11 is a high-pressure side end, and 12 is a low-pressure side end. The high-pressure side end 11 is open, and the low-pressure side end 12 is sealed.

The tubular tip seal 9 shown in front view in Figure 4A and in side view in Figure 4B is shown in Figure 4C.
It is bent into a spiral shape as shown in FIG. This condition is shown in cross-section in FIG. Fifth
In the figure, 1 is a fixed scroll, 2 is an oscillating scroll, 6 is a tip seal groove, 9 is a tube-shaped tip seal, and 10 is a hollow portion. The tube-shaped tip fitted into the tip seal groove 6
As described above, the seal 9 has an open end 11 on the high pressure side and a sealed end 12 on the low pressure side.

When compression operation is performed based on the principle shown in FIG. 1, the pressure in the compressor 4 shown in FIG. 1 increases as it enters from the outside to the inside.
The discharge pressure is reached at the center, and the compressed fluid is discharged from the discharge port 3.

As shown in Figure 5, the tube-shaped tip
The seal 9 is fitted into the tip seal groove, and the end exposed to the high pressure part, the high pressure side end 11, is open as shown in FIG. High pressure gas flows in. At this time, if the pressure on the outer periphery of the tube-shaped tip seal 9 is lower than the pressure in the hollow part 10, the pressure in the hollow part 10 causes the tube-shaped tip seal 9 to move as shown in FIG. trying to expand. In FIG. 6, if the tube-shaped tip seal 9 expands within the tip-seal groove 6 at the tip of the spiral body 5, for example, if a tube-shaped tip seal is provided in the swinging scroll 2 as shown in the figure, As a result of the expansion, it comes into contact with the bottom surface of the fixed scroll 1 and seals leakage in the radial direction from the high pressure side to the low pressure side.

Further, in the above embodiment, the cross-sectional shape of the tube-shaped tip seal 9 was circular;
As shown in the figure, it may have a rectangular cross section so that it can fit tightly into the groove, or other cross-sectional shapes may be used depending on the purpose. Furthermore, it goes without saying that the shape of the hollow portion 10 is not limited to a circular shape, but may be any other shape.

In FIGS. 6 and 7, ``A'' is a chamber on the high pressure side, and ``B'' is a chamber on the low pressure side.

Furthermore, it is possible to perform a secondary sealing action against gas leaking from the high pressure side to the low pressure side passing through the tip seal groove. Further, it goes without saying that there is no need for a spring or the like to assist the sealing action as in the conventional example, and reliability and cost are improved.

As described above, according to the present invention, the chip seal is provided with a hollow part, shaped like a tube, the high pressure side is open and the low pressure side is sealed, high pressure is introduced into the hollow part, and the internal pressure acting on the hollow part is Accordingly, the tip seal is expanded, and the expanded tip seal seals the radial leakage at the tip of the volute, thereby improving the efficiency of the compressor.

[Brief explanation of drawings]

Fig. 1 is a diagram of the operating principle of a scroll compressor, Fig. 2 is a diagram of a tip seal fitted into an oscillating scroll, Fig. 3 is a conventional example of a tip seal, and Fig. 4 is a diagram of a tube-shaped tip of the present invention. 5 is a sectional view of the tube-shaped tip seal shown in FIG. 4, and FIG. 6 is a cross-sectional view of the tube-shaped tip seal shown in FIG.
FIG. 7 is an explanatory view of the operation of the tube-shaped tip seal shown in the figure, and is a tube-shaped tip seal having a rectangular cross section which is another embodiment of the present invention. In the figure, 1 is a fixed scroll, 2 is an oscillating scroll, 3 is a discharge port, 4 is a compression chamber, 5 is a spiral body, 6 is a tip seal groove, 7 is a tip seal, 8 is a back up spring, 9 1 is a tube-shaped tip seal, 10 is a hollow portion, 11 is a high-pressure side end, 12 is a low-pressure side end, and 13 is a rectangular cross-section tube-shaped tip seal. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A chip that is configured in the shape of a tube with a hollow part, and when the high-pressure end side is opened, high pressure is introduced into the hollow part and expands, sealing the axial clearance that causes radial leakage in the scroll compressor. A scroll compressor characterized by being equipped with a seal.