JPS5835201A - Bearing equipment for scroll fluid machine - Google Patents

Abstract

PURPOSE:To reduce loss of each bearing in such a way that the side pressure is set up to be almost equal in response to the bearing load which is worked on the bearings by fluid pressure between a rotary scroll and a stationary scroll. CONSTITUTION:A stationary scroll 2 and a rotary scroll 3 provide respectively discoid end plates 4, 5, and helical laps 6, 7 which are formed in erection to them, a plain bearing 8 is attached to the rotary scroll 3, and a crankshaft 9 is turned by a motor 13. Besides, the load which works on the shaft part 9a of the shaft 9 is sustained by plain bearings 11, 12 through compression of fluid which has been cooped in by the scrolls 2, 3. And the plain bearing 8, the upper plain bearing 11 and the lower plain bearing 12 of the rotary scroll part have the respective bearing diameters set up so that the side pressures of the bearings 8, 11, 12 will be almost equal by the fluid pressure between the rotary scroll 3 and the stationary scroll 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bearing device for a scroll fluid machine used in a compressor, an expander, a fluid pump, or the like.

A scroll fluid machine is a fixed scroll having a structure in which a discharge port is added to an orbiting scroll that has an end plate and a wrap that stands upright on the end plate and is formed with an involute or a curve close to an involute, and is engaged with each other with the wraps facing inward. This is then housed inside a housing having a suction boat, a blocking member for preventing rotation of the orbiting scroll is interposed between the orbiting scroll and the housing or the fixed scroll, and a crankshaft is engaged with the orbiting scroll. , the orbiting scroll is rotated by the crankshaft so that it does not apparently rotate on its own axis, and the fluid in the closed space formed by both scrolls is pumped, or the pressure fluid is supplied from the discharge port to expand the pressure fluid. This generates rotational power to the crankshaft.

The crankshaft in this scroll fluid machine is usually arranged vertically, and the crank portion of the crankshaft is attached to the first bearing provided on the orbiting scroll, and the shaft portion is attached to the second and third bearings provided on the frame. It is supported by a bearing. Since these bearing losses greatly affect the efficiency improvement of scroll fluid machines, it is required to reduce these bearing losses.

The present invention has been made based on the above-mentioned matters, and an object of the present invention is to reduce bearing loss and improve the efficiency of a scroll fluid machine.

In order to achieve the above object, the present invention provides a system in which the crank portion of a crankshaft is connected to a first bearing provided on an orbiting scroll, and the shaft portion of the crankshaft is connected to a second and third bearing provided in a frame. In a well-supported scroll fluid machine, the dark force of each bearing is set to the same level in response to the bearing load acting on each bearing due to the fluid pressure between the orbiting scroll and the fixed scroll, and the dark force of each bearing is set to the same level. This reduces losses.

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 flow sampling machine is used as a compressor.

1 to 3 show a scroll fluid machine equipped with an example of the oil supply device of the present invention. In FIG. 1, l is a chamber, 2 is a fixed scroll, and 3 is an orbiting scroll. The fixed scroll 2 and the orbiting scroll 3 each have disc-shaped end plates 4 and 5 and a spiral-shaped wrap 6.7 formed upright thereon, and these wraps 6.7 are turned inward. Let's meet. A bevel bearing 8 is mounted on the lower surface of the orbiting scroll 3. A crank portion 9b, which is eccentric with respect to the center of the shaft portion 9m of the crankshaft 9, is engaged with the flat bearing 8. A shaft portion 91 of the crankshaft 9 has an upper flat bearing 11 and a lower flat bearing 1 attached to the frame 10.
The crankshaft 9 is rotated by an electric motor 13.
Due to the rotation of the orbiting scroll 3, the Oldham ring 14
Although it makes a turning movement due to the Oldham key 15 and K, the apparent rotation is prevented. Due to this movement, the gas λ sucked from the suction tube 16 is compressed inside the orbiting scroll 3 and the fixed scroll 2, discharged into the chamber 1 from the discharge port 17, and discharged from the discharge pipe 18. The load acting on the shaft portion 9a through the orbiting scroll 3, the double bearing 8, and the crank portion 9b of the crankshaft 9 due to the compressive action of the fluid confined by both scrolls 2.3 is the double bearing 11.12. Accordingly, the uke is stopped. Inside the crankshaft 9, there are provided an eccentric oil supply passage 19' which is eccentric with respect to the center of the shaft portion 9a and an eccentric ρ oil passage 19 whose eccentricity increases with respect to the center of the shaft portion 9a as it goes toward the upper part. . The eccentric oil supply passages 19 and 19' suck up oil from the bottom of the chamber 1 during rotation of the crankshaft 9 and supply it to each bearing 8, 11, and 12 by means of a centrifugal pump.

The oil supply structure for each bearing 8, 11, 12 will be explained with reference to FIG. In these figures, oil supply to the full bearing 8 of the orbiting scroll 3 is performed as follows. That is, the oil at the bottom of the chamber 1 is sucked up by the centrifugal pump action of the eccentric oil supply path 19 and is then transferred to the crank portion 9b of the crankshaft 9.
The upper end leads to an oil chamber 20 defined by the plain bearing 8 and the orbiting scroll 3. The oil led to the oil chamber 2o 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 is passed through the oil supply groove 21 provided in the axial direction on the outer circumferential surface of the crank portion 9b of the crankshaft 9, and is then passed through the oil supply groove 21 provided in the axial direction on the outer peripheral surface of the crank portion 9b of the crankshaft 9.
Lubricate the recess 2/recess 9b. The oil that lubricated the flat bearing 8 passed through an annular groove 23 provided at the connection between the crank part 9b of the crankshaft 9 and the balance weight 22, and then lubricated the thrust bearing 24 integrally formed at the bottom of the flat bearing 8. Thereafter, it is discharged into an intermediate chamber 25 defined by the 7-ray AIO and the orbiting scroll 3.

To supply oil to the upper side 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 communicating with the eccentric oil supply path 19 and the oil supply hole 26 that communicates with the eccentric oil supply path 19. This is done by supplying oil to the oil supply groove 27 provided in the axial direction on the outer circumferential surface. Lubricating this sub-bearing X1, the shaft part 9
An annular groove 2 provided at the connection part between a and the balance weight 22
8 flows into the thrust bearing 29 formed integrally with the upper part of the bevel bearing 11, and after lubricating this, the intermediate chamber 2
It is discharged at 5. Part of the oil that lubricates the upper flat bearing 11 is transferred from the lower end of the bearing 11 to the shaft portion 9a1.
After the oil is discharged into a drain chamber 30 defined by the frame 10, the side bearing 11, and the side bearing 12, the oil in the frame IO is discharged into the chamber 1 through a nine oil drain hole 31.

The oil discharged into the intermediate chamber 25 mentioned above is sent to the orbiting scroll 3.
It is discharged to the meshing portion of both scrolls 2.3 through the pores 32 provided in the scrolls 2.3. Therefore, the pressure in the intermediate chamber 25 is intermediate between the discharge pressure and the suction pressure. Therefore, oil supply to the upper side bearing 11 and the side bearing 8 of the orbiting scroll 3 is performed by the differential pressure between the discharge pressure and the intermediate pressure, and the centrifugal pump action of the eccentric oil supply path 19.

To supply oil to the lower side bearing 12 that supports the shaft portion 9a of the crankshaft 9, the oil sucked up by the eccentric oil supply passage 19/ is transferred to the oil supply hole 33 which communicates with the eccentric oil supply passage 19'.
This is carried out by supplying the oil to the oil supply groove 34 which is connected to this and is provided in the axial direction on the outer circumferential surface of the shaft portion 9a. The oil that has lubricated the flat bearing 12 is discharged from the upper end of the flat bearing 12 through the oil drain chamber 30 and the oil drain hole 31, and is discharged from the lower end of the flat bearing 12 into the chamber 1. be done.

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.

A sealing member 38 is provided between the upper sliding bearing 11 and the lower sliding bearing 12. This seal member 3
8 includes an annular groove 35 and a spiral groove 3 communicating with this annular groove 35.
6 is provided. The annular groove 35 communicates with the eccentric oil supply passage 19 by an oil supply passage 37 . The spiral groove 36 has one end communicating with the annular groove 35 as described above, and is spirally provided downward in the same direction as the rotational direction of the crankshaft 9.
The annular groove 35 and the spiral groove 36 are stopped so as not to open the other end.
It plays a role of blocking discharge gas from flowing into 5.

The above-mentioned sliding scroll bearing 8. The upper side bearing 11 and the lower side bearing 12 are connected to each other by the fluid pressure between the orbiting scroll 3 and the fixed scroll 2.
1.12 Each bearing 8. li
The surface pressure at t12 is set to be approximately the same. As one measure for this setting, in the embodiments shown in FIGS. 1 and 2, the bearing diameters of the bearings 8, 11, and 120 are changed so that the surface pressures of the bearings 8, 11, and 120 are approximately the same.

The principle for making the surface pressures of the bearings 8, 11 and 120 the same as described above will be explained with reference to FIG.

A load P generated by a positive pressure action between the fixed scroll 2 and the orbiting scroll 3 acts on the crank portion 9b through the orbiting bearing 8. Due to this load P, the shaft portion 9b is tilted within the upper and lower sliding bearings 11, 12, and a load F of 1% is applied to the upper sliding bearing U and a load F is applied to the lower sliding bearing 12. The point of application of the load is the midpoint of each bevel bearing 8°11.12, the distance between the points of application of load P and load F1 is tl, and the distance between the points of application of load F and load F is t. Then, the load r,,i;', is expressed by the following equation.

Usually, the distance between the points of application zt=tt is 1. >1. Therefore, the relationship between the magnitudes of these loads is F t > P >
It becomes K like Ft. Therefore, in one embodiment of the present invention shown in FIGS. 1 and 2, each bearing 8. ．． In order to make the surface pressures of bearings 8, 11, and 12 the same, the bearing diameters of each bearing 8, 11, and 12 are changed.

Due to this configuration, each bearing is 8°11.12
Since the surface pressure with respect to the bearing load at is approximately the same, no large load acts on at least one bearing. In addition, in the burnt embodiment, the lower flat bearing 12
Since the diameter of the bearing can be made smaller than that of other bearings, the circumferential speed of the shaft portion 9b is reduced), and bearing loss is reduced. Furthermore, since the inner diameter of the sealing member 38, which is composed of the annular groove 35 and the spiral groove 36 communicating with the annular groove 35, can be made small in the same manner as the lower shear bearing 12, the sliding loss in this portion is reduced. Furthermore, since the diameter of the lower side bearing 12 is made smaller, the diameter of the lower part of the frame 1o can be made smaller. Therefore, the counterbore 3 at the top of the rotor 13a of the electric motor
9 can be made smaller, and the efficiency of the electric motor can be improved.

In addition, in the above embodiment, the bearing diameter of each bearing 8° 11.12 was changed in order to make the bearing surface pressure of each bearing 8, 11.12 approximately the same, but as shown in FIG. It is also possible to change the bearing width of each bearing 8, 11° 12 while keeping the diameter of the shaft portion 9a of the crankshaft 9 the same. Furthermore, the bearing width of the full bearing 8 of the orbiting scroll 3 portion is shortened, and each bearing 8, 11.1 generated at this time is
It is also possible to make the surface pressure of each bearing 8, 11, 12 approximately the same depending on the bearing load of 2.

In the embodiment shown in FIG. 4 described above, the bearing width of the swing bearing 8 and the lower sliding bearing 1'2 is set to
Since these sliding areas are made smaller than that of , the friction loss becomes smaller. Therefore, efficiency can be improved.

As detailed above, according to the present invention, the surface pressure of each bearing supporting the crankshaft can be set to approximately the same level, so bearing loss can be reduced and the efficiency of the scroll fluid machine can be improved. It is something.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a scroll fluid machine equipped with an embodiment of the bearing device of the present invention, and FIG. 2 is a longitudinal cross-sectional view showing an enlarged crankshaft portion equipped with an embodiment of the bearing device of the present invention. The third tooth is a diagram showing the relationship between the position and load of each bearing in an embodiment of the bearing device of the present invention shown in FIG.
FIG. 4 is a longitudinal sectional view showing another embodiment of the bearing device of the present invention. 1...Chamber, 2...Fixed scroll, 3...
Orbiting scroll, 8...Sliding bearing, 9...Crankshaft, 9a...Shaft portion of crankshaft 9, 9b...Crank portion of crankshaft, 10.
...Frame, 11.12...Slide bearing, 19...
・Eccentric oil supply path, 25... intermediate chamber, 21.27.34.
...Oil supply groove. Fig. 1 Fig. 2 %, 5 [U 嶌 4 Oral procedural amendment (voluntary)
Invention 0 Name Invention 0 Title - Bearing device & correction person for fluid machinery + 51Q + Material J (Meeting 11 +) Standing
Table 6 - Snake January
Representative Shigeru Katsura Person & Target of correction Drawing

Claims (1)

[Claims] 1. Scroll fluid in which the crank portion of the crankshaft is supported by a first bearing provided on the orbiting scroll, and the shaft portion of the crankshaft is supported by second and third bearings provided in the frame. A bearing device for a scroll fluid machine, characterized in that the surface pressure of each bearing is set to the same level in response to the bearing load acting on each bearing due to fluid pressure between an orbiting scroll and a fixed scroll. . 2. The scroll fluid machine according to claim 1, wherein the bearing diameter of each bearing is changed in accordance with the applied bearing load as a means for setting the surface pressure of each bearing to the same level. bearing device. 3. The scroll fluid machine according to claim 1, wherein the bearing width of each bearing is changed in accordance with the bearing load acting as a means for setting the surface pressure of each bearing to the same level. bearing device. 4. The means for setting the surface pressure of each bearing to the same level is to shorten the bearing width of the first bearing and to set the bearing width of the second and third bearings based on the bearing loads of the second and third bearings that change accordingly. 2
2. The bearing device for a scroll fluid machine according to claim 1, wherein dimensions of the third bearing and the third bearing are changed.