JPS6316562B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing device for a scroll fluid machine used in a compressor, an expander, a liquid pump, etc., and particularly to a sealing device for a bearing portion.

A scroll fluid machine consists of an orbiting scroll that has an end plate and a wrap that stands upright on the end plate and is formed by an involute or a curve close to an involute, and a fixed scroll that has a configuration in which a discharge port is added to the orbiting scroll, with the wraps facing inward. interlocking with each other and placing it inside a housing having a suction port, interposing an Oldham ring between the orbiting scroll and the housing or the fixed scroll to prevent rotation of the orbiting scroll,
A crankshaft is engaged with the orbiting scroll, the orbiting scroll is rotated by the crankshaft so as not to appear to rotate on its own axis, and a pump is applied to the fluid in the sealed space formed by both scrolls, or pressurized fluid is supplied from the discharge port. The compressed fluid is supplied and expanded to generate rotational power to the crankshaft. A scroll fluid machine of this type is disclosed, for example, in US Pat. No. 3,884,599.

The crankshaft in this scroll fluid machine is usually arranged vertically, and the shaft portion is supported by two upper and lower sliding bearings provided on the frame, and the crank portion is engaged with a sliding bearing provided on the orbiting scroll. . Some scroll fluid machines are provided with an intermediate chamber between the orbiting scroll and the frame and having a pressure intermediate between the discharge pressure and the suction pressure. In this case, the intermediate chamber pressure acts on one axial end of the upper sliding bearing provided in the frame, and the discharge pressure acts on the other end. Therefore, the discharged gas having the discharge pressure passes through this bearing, thereby preventing the bearing from generating an appropriate oil film pressure. As a result, the above-mentioned top sliding bearing was unable to obtain an oil film reaction force capable of responding to the load due to the fluid pressure, and wear or seizure occurred.

The present invention has been made based on the above-mentioned matters, and an object of the present invention is to provide a sealing device for a scroll fluid machine that can always generate an appropriate oil film pressure on a bearing and prevent wear and seizure of the bearing. do.

A feature of the present invention is that an annular groove is provided on the side opposite to the intermediate chamber of a sliding bearing provided in the frame to prevent discharge gas from flowing through the sliding bearing into the intermediate chamber. This system generates an oil film with a higher pressure than the bearing pressure, suppresses blow-by of discharged gas, and always generates an appropriate oil film pressure distribution in the bearing.

Embodiments of the present invention will be described below with reference to the drawings.

In the embodiments described below, a case will be described in which a scroll fluid machine is used as a compressor.

FIGS. 1 to 3 show a scroll fluid machine equipped with an example of the oil supply device of the present invention. In FIG. 1, 1 is a chamber, 2 is a fixed scroll, and 3 is a chamber.
is an orbiting scroll. The fixed scroll 2 and the orbiting scroll 3 each have disk-shaped end plates 4 and 5 and spiral wraps 6 and 7 formed upright thereon.
These laps 6 and 7 are engaged with each other facing inward. A sliding bearing 8 is mounted on the lower surface of the orbiting scroll 3. This slide bearing 8 has a shaft portion 9 of a crankshaft 9.
A crank portion 9b that is eccentric with respect to the center of a is engaged. A shaft portion 9a of the crankshaft 9 is supported by an upper sliding bearing 11 and a lower sliding bearing 12 mounted on a frame 10. The crankshaft 9 is rotated by an electric motor 13. Due to this rotation of the crankshaft 9, the orbiting scroll 3 is moved to the Oldham ring 14.
Although it makes a turning movement by the Oldham key 15 and the Oldham key 15, the apparent rotation is prevented. Due to this movement, the gas sucked in from the suction pipe 16 is compressed inside the orbiting scroll 3 and the fixed scroll 2, and is discharged from the discharge port 17 into the chamber 1 and discharged from the discharge pipe 18. Both scrolls 2,
Due to the compression action of the fluid confined by 3,
The load acting on the shaft portion 9a through the orbiting scroll 3, the slide bearing 8, and the crank portion 9b of the crankshaft 9 is received by the slide bearings 11 and 12. An eccentric oil supply passage 19 is provided in the crankshaft 9, and the eccentricity of the passage 19 increases with respect to the center of the shaft portion 9a toward the top thereof. The eccentric oil supply path 19 sucks up oil from the bottom of the chamber 1 by the action of a centrifugal pump as the crankshaft 9 rotates, and supplies the oil to each of the bearings 8, 11, and 12.

The oil supply structure for each bearing 8, 11, 12 will be explained with reference to FIG. In these figures, oil supply to the sliding bearing 8 of the orbiting scroll 3 is performed as follows. That is, oil at the bottom of the chamber 1 is sucked up by the centrifugal pump action of the eccentric oil supply path 19 and guided to the oil chamber 20 defined by the upper end of the crank portion 9b of the crankshaft 9, the sliding bearing 8, and the orbiting scroll 3. . The oil led to the oil chamber 20 passes through an oil supply groove 21 provided in the axial direction on the outer peripheral surface of the crank portion 9b of the crankshaft 9, and lubricates the sliding bearing 8 of the orbiting scroll 3 and the crank portion 9b. The oil that has lubricated the slide bearing 8 passes through an annular groove 23 provided at the connection between the crank portion 9b of the crankshaft 9 and the balance weight 22, and lubricates the thrust bearing 24 integrally formed at the bottom of the slide bearing 8. The liquid is discharged into an intermediate chamber 25 defined by the frame 10 and the orbiting scroll 3.

To supply oil to the upper plain bearing 11 that supports the shaft portion 9a of the crankshaft 9, the oil sucked up by the eccentric oil supply path 19 is passed through the oil supply hole 26 which communicates with the eccentric oil supply path 19, and the shaft portion 9a. This is done by supplying oil to a groove 27 provided in the axial direction on the outer peripheral surface of the oil. The oil that lubricates this sliding bearing 11 flows through an annular groove 2 provided at the connection between the shaft portion 9a and the balance weight 22.
8 and flows into the thrust bearing 29 formed integrally with the upper part of the slide bearing 11, and after lubricating this, is discharged into the intermediate chamber 25. A portion of the oil lubricating the upper sliding bearing 11 is discharged from the lower end of the sliding bearing 11 into the oil drain chamber 30 defined by the shaft portion 9a, the frame 10, the sliding bearings 11, and 12. The oil is discharged into the chamber 1 through the oil drain hole 31 provided in the frame 10.

The oil discharged into the intermediate chamber 25 mentioned above is discharged to the meshing portion of both scrolls 2 and 3 through the pores 32 provided in the orbiting scroll 3. Therefore, the pressure in the intermediate chamber 25 is intermediate between the discharge pressure and the suction pressure. Therefore, the upper plain bearing 11
The oil supply to the sliding bearing 8 of the orbiting scroll 3 is carried out by the differential pressure between the discharge pressure and the intermediate pressure, and by the eccentric oil supply path 1.
This is done by the centrifugal pump action of 9.

To supply oil to the lower plain bearing 12 that supports the shaft portion 9a of the crankshaft 9, the oil sucked up by the eccentric oil supply passage 19 is passed through the oil supply hole 33 which communicates with the eccentric oil supply passage 19 and the oil supply hole 33 that communicates with the eccentric oil supply passage 19. This is done by supplying the oil to the oil supply groove 34 provided in the axial direction on the outer circumferential surface of 9a. The oil that lubricates this sliding bearing 12 is
The oil is discharged into the chamber 1 from the upper end through the oil drain chamber 30 and the oil drain hole 31, and is also discharged into the chamber 1 from the lower end of the slide bearing 12.

The aforementioned axial oil supply grooves 21, 27, 34 and oil supply holes 26, 33 are provided at positions shifted from the load direction of the fluid pressure acting in the radial direction of the crankshaft 9.

An annular groove 35 and a spiral groove 36 communicating with the annular groove 35 are provided on the side of the upper sliding bearing 11 opposite to the intermediate chamber 25 . The annular groove 35 is the oil supply path 3
7 leads to the eccentric oil supply channel 19 . The spiral groove 36 has one end communicating with the annular groove 35 as described above, spirally extending downward in the same direction as the rotational direction of the crankshaft 9, and the other end thereof is fixed so as not to open. The annular groove 35 and the spiral groove 36 allow the discharged gas having the discharge pressure in the chamber 1 to pass through the sliding bearing 11 and reach the intermediate chamber 25.
It plays the role of blocking the discharge gas from flowing into the tank.

Next, the operation of an example of the sealing device of the present invention described above will be explained.

Due to the rotation of the crankshaft 9, the annular groove 35
Oil from the upper sliding bearing 11 and oil from the eccentric oil supply passage 19 flow into the oil supply passage 19 through the oil supply passage 37 . The oil guided into the annular groove 35 is forcibly fed into the lower part of the helical groove 36 through the helical groove 36 by the rotation of the crankshaft 9. At this time, the pressure within the intermediate chamber 25 acts on the intermediate chamber 25 side of the upper sliding bearing 11, and the oil drain hole 31 is passed through the chamber 25 through the lower end of the upper sliding shaft 11 opposite to the intermediate chamber 25.
The discharge pressure of the discharge gas inside is acting. Therefore, the upper sliding bearing 11 has a discharge pressure and an intermediate chamber 25.
Due to the pressure difference between the pressure of
Trying to blow through towards. However, on the side of the upper sliding bearing 11 opposite to the intermediate chamber 25, an oil film having a pressure higher than the discharge pressure is generated at its end due to the aforementioned spiral groove 36, so this oil film passes through the upper sliding bearing 11 and This prevents the discharge gas from flowing through the chamber 25. Therefore, an appropriate oil film pressure is generated in the top sliding bearing 11, and the bearing 1
It is possible to prevent seizure and wear of item 1.

In the above embodiment, the annular groove 35 and the spiral groove 36 are provided in the upper sliding bearing 11, but they may also be provided in the outer peripheral surface of the shaft portion 9a of the crankshaft 9. It is also possible to arrange the annular groove 35 and the helical groove 36 in reverse order, that is, to provide the helical groove 36 from the annular groove 35 toward the crank portion.

As described in detail above, according to the present invention, the relationship between the discharge pressure and the intermediate chamber pressure makes it possible to prevent the flow of the discharged gas from passing through the bearing section that supports the crankshaft. Pressure generation can be maintained appropriately. the result,
This can prevent seizure and wear of the bearing.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a scroll fluid machine equipped with an example of the sealing device of the present invention, and FIG. 2 is a vertical cross-sectional view showing an enlarged crankshaft portion equipped with an example of the sealing device of the present invention. DESCRIPTION OF SYMBOLS 1... Chamber, 2... Fixed scroll, 3... Orbiting scroll, 9... Crankshaft, 9a... Shaft part of crankshaft 9, 10... Frame,
11, 12...Sliding bearing, 19...Eccentric oil supply path, 2
5... Intermediate chamber, 35... Annular groove, 36... Spiral groove, 37
...Refueling route.

Claims (1)

[Claims] 1. A fixed scroll and an orbiting scroll are combined, a crank portion of a crankshaft is connected to the orbiting scroll, the shaft portion of the crankshaft is supported by a bearing provided in a frame, and the orbiting scroll and the frame are connected to each other. In a scroll fluid machine having an intermediate chamber having an intermediate pressure between a discharge pressure and a suction pressure, an annular groove is provided on a side opposite to the intermediate chamber of the bearing to prevent discharge gas from flowing through the bearing and into the intermediate chamber. A sealing device for a scroll fluid machine, characterized in that: 2. The sealing device for a scroll fluid machine according to claim 1, wherein a spiral groove communicating with the front annular groove is provided on the side of the bearing opposite to the intermediate chamber. 3. The sealing device for a scroll fluid machine according to claim 2, wherein the annular groove communicates with an oil supply passage provided in a shaft portion of a crankshaft. 4. The sealing device for a scroll fluid machine according to claim 2 or 3, wherein the spiral groove is provided toward the end of the shaft portion of the crankshaft in the same direction as the rotational direction of the shaft. 5. The sealing device for a scroll fluid machine according to claim 4, wherein the end of the spiral groove on the side opposite to the annular groove is not open.