JPH0472997B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a scroll compressor, more specifically, it includes a fixed scroll and a revolving scroll, and a pressure chamber communicating with a discharge side is provided on the back side of the revolving scroll. , relates to a scroll compressor supporting the above-mentioned revolving scroll.

(Prior art) The scroll compressor configured as described above is
It is described in Japanese Patent No. 50-32512 and is already known. Briefly explaining this based on FIG. 6, a compression element 63 consisting of a fixed scroll 61 and a revolving scroll 62 is housed in a sealed casing 60 with a low internal pressure, while a part of the back surface of the revolving scroll 62 The working surface 62a
A pressure chamber 65 is defined between the working surface 62a and a receiver 64 provided at the lower end of the drive shaft 69, and compressed fluid (discharge pressure) is introduced into the pressure chamber 65 through a passage 66. By applying discharge pressure to the working surface 62a in the pressure chamber 65, the revolving scroll 62 is controlled by the internal pressure of the compression element 63 (both scrolls 6
1 and 62), so that the thrust surfaces of the scrolls 61 and 62 slide against the opposing thrust surfaces of the scrolls 61 and 62. It was constructed so that a load could be applied to it.

In addition, in FIG. 6, 67 is an O-ring, and 68 is a preload spring.

(Problem to be Solved by the Present Invention) By the way, if the compressor configured as described above is applied to a device in which the discharge pressure fluctuates greatly depending on the load, such as a compressor for a refrigeration system, the above-mentioned revolution will be affected due to this load fluctuation. The pressing force (supporting force) that presses the scroll 62 against the fixed scroll 61 fluctuates greatly. Therefore, for example, when the load is low and the discharge pressure is low, the working surface 62a is adjusted so that an appropriate thrust load can be obtained. If the area is set, when the discharge pressure becomes high due to high load, the thrust load becomes too large, and the sliding resistance between the thrust surfaces of the scrolls 61 and 62 increases, resulting in power loss. This resulted in problems such as excessive size, wear, and seizure.

Accordingly, the present invention adjusts the internal pressure of the pressure chamber using a pressure regulating valve whose back pressure is the intermediate pressure of the compression process in the compression element, so that the magnitude of the thrust load is controlled by changes in the discharge pressure. The purpose of this is to maintain a substantially constant level regardless of the current, thereby solving the conventional problems of power loss, seizure and wear on the thrust surface.

Furthermore, the pressure passage formed to guide intermediate pressure as back pressure to the pressure regulating valve is formed by using a packing and processing the packing, so that the passage has an extremely simple structure and is easy to manufacture. However, the diameter of the passage can be set arbitrarily, and in particular, the diameter can be made small to easily provide a throttling function.

(Means for Solving the Problem) Therefore, the present invention is provided with a compression element 4 having a fixed scroll and a revolving scroll, and a pressure is provided on the back side of the revolving scroll 3 and communicating with the discharge side of the compression element 4. In a scroll compressor in which chambers 12 are provided to support the revolving scroll 3, the pressure chambers 12 are provided between the pressure chambers 12 and the suction side of the compression element 4, and the pressure chambers 12 are connected to the suction side of the compression element 4. A pressure regulating valve 18 is provided in the communication path 17, and an intermediate pressure port 3 is provided in the fixed scroll 2 and opens into the compression chamber 25 in the middle of compression in the compression element 4.
2, the intermediate pressure port 32 and the back chamber 23 of the pressure regulating valve 18 are opened on one side of the fixed scroll 2, and these intermediate pressure ports 3
A lid plate is provided through a gasket on one side of the fixed scroll 2 where 2 and a back chamber 23 are opened, and an intermediate pressure passage communicating between the intermediate pressure port and the back chamber of the pressure regulating valve is provided in the gasket. It is characterized by the fact that it has been formed.

(Function) By doing as described above, the internal pressure of the pressure chamber is adjusted according to the intermediate pressure by the action of the pressure regulating valve, and for this reason, the magnitude of the thrust load between the scrolls is can be made independent of changes in discharge pressure, and can be stabilized at a substantially constant value even with changes in intermediate pressure. Furthermore, since the intermediate pressure passage is formed by a packing, the diameter of the passage can be adjusted to a desired size by appropriately setting the thickness of the packing and punching out a groove of an arbitrary width. It's easy to set up.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

The scroll compressor shown in FIG. 1 is used as a compressor for a refrigeration system, and a compression element 4 is formed by a fixed scroll 2 and a revolving scroll 3, and the compression device 4 and motor 5 are enclosed in a sealed casing. 1 and are arranged in the vertical direction.

Then, a crankshaft 6 fixed to the rotor 51 of the motor 5 is fitted onto the back surface of the revolving scroll 3 via a bearing metal 7, and the revolving scroll 3 is caused to revolve relative to the fixed scroll 2 by driving the motor 5. It's done like this.

Further, the fixed scroll 2 in the compression element 4 is provided with a suction port 21 and a discharge port 22, and the suction pipe 8 is connected to the suction port 21, while the discharge port 22 is opened into the casing 1. In this way, low-pressure gas is sucked into the compression element 4 through the suction pipe 8 by the revolution of the revolving scroll 3, compressed, and the compressed fluid is once discharged into the casing 1 from the discharge port 22,
Furthermore, an external discharge pipe 9 connected to the casing 1
It is configured such that it is discharged outside the machine via the.

In the fluid machine configured as described above, a frame 10 that supports the compression element 4 and the motor 5 is press-fitted into the casing 1 and fixed therebetween, and the frame 10 is press-fitted into the casing 1 and fixed. 1
A recessed portion 11 is formed on the compression element 4 side at 0,
Moreover, this recessed portion 11 is closed by the compression element 4 to form a pressure chamber 12 on the back side of the revolving scroll 2.

In FIG. 1, 13 is a bearing provided in the frame 10, 14 is a bearing metal installed in the bearing 13, 15 is a bearing provided between the frame 10 and the crankshaft 6, and 6a is the crank. A balance waist 16 provided on the shaft 6 is an Oldham joint that prevents the revolution scroll 3 from rotating.

Furthermore, a communication passage 17 is formed by using a member of the fixed scroll 2 to communicate the pressure chamber 12 with the suction side of the compression element 4, and this connection passage 1
A pressure regulating valve 18 is interposed at 7.

That is, the communication passage 17 has one end communicating with the pressure chamber 12 and the other end communicating with the suction port 21, and has a valve chamber 19 in which the pressure regulating valve 18 is interposed in the intermediate part thereof. The pressure regulating valve 18 is housed in the valve chamber 19.

Further, this pressure regulating valve 18 is internally installed so that it can be driven by the valve chamber 19, and the pressure chamber 1 of the communication passage 17
Valve body 20 that opens and closes the 2 side and the suction port 21 side
and a pressing body 24 made of a coil spring, which is installed in the back chamber 23 of the valve body 20 and presses the valve body 20 in the closing direction of the communication passage 17,
Back chamber 23 of the valve body 20 in the valve chamber 19
is open on the back side of the fixed scroll 2. In addition, as shown enlarged in Figures 2 and 3,
The fixed scroll 2 is formed with an intermediate pressure port 32 that opens into the compression chamber 25 which is at an intermediate pressure during compression in the compression element 4. Like the back chamber 23, this intermediate pressure port 32 is also connected to the fixed scroll. It has an opening on the back of 2.

A cover plate 34 is provided on the back surface of the fixed scroll 2 through a packing 33 at a portion corresponding to the opening portion where the intermediate pressure port 32 and the back chamber 23 open, and An intermediate pressure passage 26 is formed that communicates the port 32 with the back chamber 23 of the pressure regulating valve 18. Specifically, the intermediate pressure passage 26 is provided with a packing 33 of an appropriate thickness, and the packing 33 is
First, a groove of a predetermined width is punched out so that the passage 26 has a desired passage diameter, and this packing 33 is interposed between the outer surface of the scroll 2 and the cover plate 34. In addition, 35, 36
is a tightening bolt.

Further, the intermediate pressure passage 26 provided in the packing 33 introduces intermediate pressure to the back chamber 23, and
In order to absorb the pulsations associated with the compression cycle at the intermediate pressure, the diameter of the passage is made sufficiently small to function as a throttling mechanism.

As described above, since the intermediate pressure passage 26 is formed using the packing 33,
By arbitrarily setting the thickness of the packing 33 and the width of the groove formed in the packing 33, the diameter of the passage 26 can be arbitrarily and easily changed. In particular, if the diameter of this passage is to be reduced, this can be achieved by reducing the thickness of the packing 33 and narrowing the groove width. This is much easier than setting up a

In this embodiment, no special means for communicating the pressure chamber 12 with the discharge side is provided, but the pressure chamber 12 is connected to the bearing metal 14 in the bearing portion 13 of the frame 10 and the crankshaft 6. Inside the casing 1 (discharge side) through the gap between
It communicates with

Furthermore, the frame 10 may be provided with a separate passage that communicates the pressure chamber 12 with the inside of the casing 1.

Further, in this embodiment, one end of the communication passage 17 is communicated with the suction port 21 of the compression element 4, but when the space inside the casing 1 on the back side of the fixed scroll 2 is used as a suction chamber, this It may also open into the suction chamber.

The operation of the scroll type fluid machine constructed as above will be explained.

When the compression element 4 is actuated by the drive of the motor 5, compressed fluid is discharged from the discharge port 22 into the casing 1, and the inside of the casing 1 becomes high pressure. The compressed fluid in the casing 1 flows into the pressure chamber 12 through the gap between the bearing metal 14 and the crankshaft 6, etc.

At this time, if the pressure in the pressure chamber 12 is equal to or less than the sum of the intermediate pressure and the pressure set by the pressing body 24, the pressure regulating valve 18 closes;
The communication passage 17 is closed, and therefore the pressure in the pressure chamber 12 gradually increases.

On the other hand, when the pressure in the pressure chamber 12 becomes higher than the sum of the intermediate pressure and the pressure set by the pressing body 24, the pressure regulating valve 18 opens the communication passage 17, and the pressure chamber 12 moves to the suction side. As a result, the pressure in the pressure chamber 12 decreases.

In this way, the pressure in the pressure chamber 12 can always be maintained at a pressure higher than the intermediate pressure by the pressure set by the pressing body 24.

As described above, since the internal pressure of the pressure chamber 12 can be adjusted independently of the discharge pressure and in accordance with the intermediate pressure, the magnitude of the thrust load can be stabilized at a substantially constant level regardless of load fluctuations.

Moreover, since the diameter of the intermediate pressure passage 26 is made narrower so that it functions as a throttling mechanism, the pressure in the back chamber 23 can be stabilized despite pulsations caused by the compression cycle of the intermediate pressure. Therefore, the pressure in the pressure chamber 12 does not pulsate, and as a result, the scrolls 2 and 3
The thrust load acting between the two can also be made more stable.

In addition to the embodiments described above, as shown in FIGS. 4 and 5, the intermediate pressure passage 2 is provided on the outer surface of the fixed scroll 2.
6 and is closed by the gasket 33 and the lid plate 34, the recess 40 functions as an accumulator to more effectively reduce the pulsation pressure in the back chamber 23 caused by the compression cycle. It may also be attenuated.

In this embodiment, the sliding surface of each bearing is supplied with oil by communicating within the crankshaft 6 at its lower end with an oil reservoir 38 formed at the bottom of the casing 1, and branching off at its upper end to supply oil to each bearing side. An oil supply passage 37 is formed that opens to the oil supply passage 37, and the oil supply passage 37 is formed so as to utilize the pump action generated in the passage 37 by the rotation of the crankshaft 6 and the differential pressure between the pressure chamber and the casing. In this example, as described above, the internal pressure of the pressure chamber 12 is raised by guiding the pressure inside the casing 1 in which the oil sump 38 is located, so that the pressure in the pressure chamber 12 increases when the oil sump 38 is located. 3
Therefore, the pressure on the outlet side of the oil supply passage 37, which is defined by the internal pressure of the pressure chamber 12, remains within the oil reservoir 38 even during startup. As a result, sufficient lubricating oil can be reliably supplied to the sliding surfaces of each bearing through the oil supply passage 37 even during this startup.

(Effects of the Invention) As described above, in the present invention, the pressure in the pressure chamber 12 is controlled using the pressure regulating valve 18 which uses the intermediate pressure as the back pressure.
The magnitude of the thrust load between scrolls 2 and 3 can be stabilized at an appropriate value almost independently of changes in discharge pressure and also against changes in suction pressure. It can solve the problems of wear, seizure and power loss, and
Since the intermediate pressure passage 26 is formed using the packing 33, it is easy to manufacture horizontally, and the diameter of the passage can be arbitrarily set, and in particular, the diameter can be easily made small. It is.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, Fig. 2 is a schematic front enlarged cross-sectional view of an intermediate pressure passage portion, Fig. 3 is a schematic enlarged cross-sectional view of the same side, and Fig. 4 is an intermediate view of another embodiment. FIG. 5 is a schematic front sectional view of the pressure passage portion, FIG. 5 is a schematic side sectional view of the same embodiment, and FIG. 6 is an explanatory view of the conventional example. 2...Fixed scroll, 3...Revolving scroll, 12...Pressure chamber, 17...Communication path, 18...
Pressure adjustment valve, 23...back chamber, 25...compression chamber,
32...Intermediate pressure port, 33...Packing.

Claims (1)

[Claims] 1 A compression element 4 having a fixed scroll 2 and a revolving scroll 3 is provided, and a pressure chamber 12 communicating with the discharge side of the compression element 4 is provided on the back side of the revolving scroll 3 to support the revolving scroll 3. In the scroll compressor, between the pressure chamber 12 and the suction side of the compression element 4,
A communication passage 17 is provided to communicate these pressure chambers 12 with the suction side of the compression element 4.
, a pressure regulating valve 18 is provided, and an intermediate pressure port 32 is formed in the fixed scroll 2 to open into the compression chamber 25 during compression in the compression element 4. The rear chamber 23 of the fixed scroll 2 is opened on one side of the fixed scroll 2, and a lid plate 34 is provided via a packing 33 on one side of the fixed scroll 2 where the intermediate pressure port 32 and the rear chamber 23 are opened. A scroll compressor characterized in that a packing 33 is formed with an intermediate pressure passage 26 that communicates the intermediate pressure port 32 with the back chamber 23 of the pressure regulating valve 18.