JPS58119901A - Bearing for scroll fluid machine - Google Patents

Abstract

PURPOSE:To prevent the abrasion and the burning of a bearing by employing proper ratio between the gap of two plain bearings and the distance between said bearings and producing the proper oil film pressure distribution on the bearing continuously. CONSTITUTION:A crank section for coupling a swing scroll 3 assembled with a fixed scroll and a shaft 9 is supported by a bearing 8 while a crank shaft 9 is supported by first and second plain bearings 11, 12. When the fluid pressure P1 functions through the scroll 3 and the bearing 8 onto the crank section, the crank shaft 9 will incline between the bearings 11, 12. Assuming the distance between the upper end of the bearing 11 and the lower end of the bearing 12 is L, while the gaps between the shaft 9 and the bearings 11, 12 are C1, C2, and employing the proper value of (C1+C2)/2L in the case of a fluid machine of the type shown on the drawing, the inclinations of the shaft section 9a and the crank section in the bearing 8 will be approximately same at the same time, thereby the oil film reactions F1-F3 sufficient for supporting the loads P1-P3 on the sliding faces of each bearing will be produced simultaneously and properly.

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 liquid pump, or the like.

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 with an involute or a curve close to an involute, and a fixed scroll that has a configuration in which a discharge boat is added to the orbit scroll, with the wraps facing each other inward. This is placed inside a housing having a suction boat, an Oldham ring 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 as not to apparently rotate, and the fluid in the closed space formed by both scrolls is pumped, or the pressure fluid is supplied from the discharge boat to expand the pressure fluid. It generates rotational power to the crankshaft. A scroll fluid machine of this type is disclosed, for example, in U.S. Pat. No. 3,884,599.

The crankshaft in this scroll fluid machine is usually arranged vertically, and the shaft portion is supported by two vertical bearings, upper and lower, and the crank portion is engaged with a horizontal bearing provided on the orbiting scroll. Therefore, the crankshaft is able to move a small amount in the radial direction within the gap that exists between the crankshaft and the opposing spec bearing.

On the other hand, in this scroll fluid machine, fluid pressure within a closed space formed by both scrolls acts in the radial direction of the crank portion of the crankshaft through the orbiting scroll. Therefore, the crankshaft tilts between the upper side bearing and the lower side bearing that support the shaft part.
It will be strongly pressed against each bearing in a one-sided state.

As a result, each bearing is unable to obtain an oil film reaction force that can cope with the load due to this fluid pressure, and each bearing may suffer wear or seizure.

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

The present invention is characterized in that a fixed scroll and an orbiting scroll are combined, a crank part connecting the orbiting scroll and a shaft is supported by a double bearing, and the shaft is provided in a frame and a crank part that is close to the orbiting scroll side. In a scroll fluid machine supported by a first sliding bearing and a second sliding bearing on the side far from the orbiting scroll, the bearing clearance between the first sliding bearing and the second sliding bearing and between these sliding bearings is By setting the ratio between the distance and the distance to an appropriate value, an appropriate oil film pressure distribution is always generated in the bearing, thereby preventing seizure or wear of 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.

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 an orbiting scroll. The fixed scroll 2 and the orbiting scroll 3 each have a disk-shaped end plate 4.5 and a spiral-shaped wrap 6.7 formed upright thereon, and these wraps 6.7 are turned inward and engaged. are combined. A Pesci bearing 8 is mounted on the lower surface of the orbiting scroll 3. A crank portion 9b that is eccentric with respect to the center of a shaft portion 9a of a crankshaft 9 engages with this flat bearing 8. The shaft portion 9a of the crankshaft 9 has an upper side bearing 11 and a lower side bearing 12 mounted on the frame 10.
Supported by The crankshaft 9 is rotated by an electric motor 13. Due to the rotation of the crankshaft 9, the orbiting scroll 3 performs an orbiting motion by the Oldham ring 14 and the Oldham key 15, but apparent rotation is prevented. Due to this movement, the suction pipe 16
The gas sucked in 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. Due to the compression action of the fluid confined by both scrolls 2゜3,
The loads acting on the shaft part 9 through the orbiting scroll 3, the double bearing 8 and the crank part 9b of the crankshaft 9 are stopped by the double bearings 11, 12. An eccentric oil supply path 19 is provided in the crankshaft 9, the eccentricity of which increases with respect to the center of the shaft portion 9 toward the top thereof. This eccentric oil supply path 19 sucks up oil at the bottom of the chamber 1 by the rotation of the crankshaft 9 and supplies it to each bearing 8, 11, 12 by the action of a centrifugal pump.

Figures 2 and 3 show the oil supply structure for each bearing 8.11.12.
The diagram will be explained. In these figures, oil supply to the full bearing 8 of the orbiting scroll 3 is performed as follows.

That is, the centrifugal pumping action of the eccentric oil supply path 190 sucks up the oil at the bottom of the chamber l and guides it to the oil chamber 20 defined by the upper end of the crank portion 9b of the crankshaft 9, the veneer 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 lubricates the bottom bearing 8 of the orbiting scroll 3 and the crank portion 9b. The oil that lubricates the speci bearing 8 is transferred to the crank part 9 of the crankshaft 9.
An annular groove 2 provided at the connection part between b and the balance weight 22
3 and lubricates the thrust bearing 24 formed integrally with the lower part of the sliding bearing 8, and then is discharged into an intermediate chamber 25 defined by the seven frames 10 and the orbiting scroll 3.

To supply oil to the upper side bearing 11 that supports the shaft portion 9 of the crankshaft 9, the oil sucked up by the eccentric oil supply passage 19 is passed through the oil supply hole 2b which communicates with the eccentric oil supply passage 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 the entire bearing 11 is the shaft portion 9.
An annular groove 2 provided at the connection part between 1 and the balance weight 22
8 to the last bearing 29 integrally formed on the upper part of the Spep bearing 11, and after lubricating this, the intermediate chamber 2
It is discharged at 5. A portion of the oil lubricating the upper side bearing 11 is transferred from the lower end of the upper side bearing 11 to the shaft portion 9a,
The oil discharged into the oil drain chamber 30 defined by the frame 10, the flat bearing 11, and the flat bearing 12 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 transferred 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 path 19 is passed through the oil supply hole 33 which communicates with the eccentric oil supply path 19 and the shaft portion 9m. This is done by supplying oil to a groove 34 provided in the axial direction on the outer peripheral surface of the oil. The oil that has lubricated the full bearing 12 is discharged from the upper end of the full bearing 12 through the oil drain chamber 30 and the oil drain hole 31 into the chamber l, and is also discharged from the lower end of the full bearing 12 into the chamber 1. .

In this example, the axial oil supply grooves 21, 27.34 and the oil supply hole 26.33 described above are lines connecting the center S of the shaft portion 91 of the crankshaft 9 and the center C of the crank portion 9b, as shown in FIG. It is placed on X. That is, the oil supply groove 21 is provided at a position advanced by 90 degrees in the direction of rotation of the crankshaft 90 with respect to the fluid pressure P, the oil supply groove 27 is provided at a position shifted by 180 degrees with respect to the oil supply groove 21, and the oil supply groove 34 is provided at a position shifted by 180 degrees with respect to the oil supply groove 21. is provided at nine positions offset by 180 degrees with respect to the oil supply groove 27. The arrangement of these oil supply grooves 21°27.34 effectively generates a bearing oil film reaction force, and when viewed from the upper end of the crank part 9a, the eccentric oil supply passage 19 is located between the center 8 of the shaft part 9b and the crank part 9b. The oil supply hole 26 must be located on the 1lax line connecting the center 0.
．． This is based on the manufacturing viewpoint of No. 33. However, the oil supply grooves 21, 27, 34 and the oil supply holes 26, 33 do not necessarily need to be arranged on the above-mentioned line X for the following reason. That is, the total pressure P of the fluid in the plurality of sealed spaces formed by the scroll 2.3 acts on the crank portion 9b at a substantially right angle to the line X, as shown in FIG. It has been confirmed that the rotation moves in synchronization with the When this fluid pressure P is decomposed into component forces perpendicular to it, it can be divided into component force Px in the direction of line X and component force P1 perpendicular to line X, and these component forces P
The ratio of the sizes of x and P is about 8 as PX:P1=. Therefore, the fluid pressure P is a component force P1 perpendicular to the line
can be considered almost the same.

When the crankshaft 10 is rotated by the electric motor 13 in the clockwise direction as shown by the arrow in FIG. is compressed internally and discharged from the discharge pipe 18. During such a compression stroke, the pressure P1 of the fluid in the closed space formed by both scrolls 2.3 is applied to the crankshaft through the orbiting scroll 3 and the bearing 8, as shown in FIGS. 3 and 4. It acts on the crank part 9b of No.9. Therefore, the crankshaft 9 is tilted between the upper side bearing 11 and the lower bearing 12, and even within the swing bearing 8, the crank portion 9b is tilted. If this inclination becomes thick, appropriate and sufficient oil film pressure and oil film reaction force based on the oil film pressure cannot be obtained within the bearing, and the lower part of the slewing bearing 8 and the upper and lower parts of the upper side bearing 11 cannot be obtained. If there is a large one-side contact at the bottom of the bearing,
There is a risk of seizure and wear. Therefore, it is necessary to suppress this inclination within a certain range. Now, upper sliding bearing 11
The distance between the upper end and the lower end of the lower bevel bearing 12 is L,
If the bearing diameter clearance between the upper side bevel bearing 11 and the lower side bevel bearing 12 is C1°Cs, then the bearing diameter clearance I
Considering that increasing Ct and Cm increases the inclination of the shaft, shortening the distance increases the inclination of the shaft, C, C, and L! , i.e. (C* + C
(Note)/2 Lt - By keeping it below a certain value, seizure and wear of the bearing can be prevented.

Next, the operation of the embodiment of the present invention described above will be explained.

Fluid pressure P acts on the crank portion 9b of the crankshaft 9 through the orbiting scroll 3 and the flat bearing 8. Therefore, the crankshaft 9 is mounted on the upper side bearing 1.
1 and the lower side bearing 12. As a result, a load P is applied to the sliding bearing 11, and a load Ps is applied to the sliding bearing 12. Each oil supply groove 21, 27.3 at this time
The relationship between the position of 4, the direction of load action, and the oil film pressure distribution generated in each bearing is shown in FIGS. 5 to 7, respectively.

In these figures, the fluid pressure P is expressed as its component force PR for convenience of explanation. As is clear from these figures, each oil supply groove 21, 27.34 has a load Pt e p,
It is always at a position 90 degrees clockwise with respect to the line of action of I ps, and each load PlePg @Pg Fi rotates in synchronization with the amount of 90 rotations of the crankshaft. At this time, if (Ct+Cm)/2L is set to an appropriate value, each bearing 8, 11.
The oil flowing into the 12 bearing clearances generates an oil film reaction force Ft e Fs e ·Fs sufficient to oppose each load PIe Pg * Ps K, as shown in FIGS. 5 to 7.

As mentioned above, the positional relationship between the line of action of the load P* and P snow ePs and the oil supply grooves 21, 27°34 is constant for each bearing, so the formation of oil film pressure generated in each bearing is almost the same. be. Therefore, the upper space bearing 11 shown in FIG.
The oil film pressure distribution formed between the shaft portion 9m and the shaft portion 9m will be explained in more detail.

The center 01 of the shaft portion 9m is a sliding bearing 8 due to the load.
is eccentric from the center B1. These centers ot I Bl
In mYl connecting the two, the minimum clearance position Zal of the bearing is formed on the side on which the load Pl acts, and the maximum clearance position Z12 is formed on the opposite side.

The oil introduced into the oil supply groove 27 with the supply oil pressure is drawn out into the bearing gap between the shaft part and the bevel bearing 11 due to the supply oil pressure and the rotation of the shaft part 9m, and the oil is drawn out into the bearing gap between the shaft part and the bevel bearing 11, and the oil is drawn out into the bearing gap between the shaft part and the bevel bearing 11, and the oil is drawn out by the oil supply oil pressure and the rotation of the shaft part 9m. It is forcibly pushed into the area of the bearing clearance, which has a narrower clearance in the direction, and a so-called wedge effect occurs.

Due to the effect of this wedge action, the oil film pressure rises from the maximum clearance position za and reaches its maximum before the minimum clearance position Zal, producing an oil film pressure F1 opposing the load P1. Thereafter, the oil film pressure decreases and becomes approximately an intermediate pressure at the minimum clearance position Zat. In the widening gap area from the minimum clearance position zz1 formed along the rotational direction of the shaft portion 9m, the oil film pressure decreases from the minimum clearance position 2-1 and becomes lower than the intermediate pressure. Thereafter, the oil film pressure reaches the minimum value and then recovers to the oil supply oil pressure at the oil supply groove 27. Since the gap between the oil supply groove 21 and the maximum clearance position Z- widens in the direction of rotation of the crank part 9b, the oil film pressure decreases and then gradually recovers, until the maximum clearance position K
At Za*, the pressure is approximately intermediate.

Next, the axial oil film pressure distribution generated between the upper flat bearing 11 and the shaft portion 9a will be explained. Since the shaft 7) portion 9a of the crankshaft 9 is tilted within the upper and lower side bearings 11 and 12, the bearing clearance tzb at the upper end of the load side of the upper side bearing 11 is small as shown in Fig. 4. , on the other hand, the clearance at the lower end is larger by 1ZcFi. Therefore, the oil film pressure becomes intermediate pressure at the upper end of the flat bearing 11,
The oil film pressure initially increases rapidly as it goes downward, reaches a maximum value, and then gradually decreases until it reaches approximately the supply oil pressure at the lower end of the slide bearing 11.

As mentioned above, if (Ct + C snow) / 2 L is set to an appropriate value, the upper side bearing 11 and the lower side bearing 1
The inclination of the shaft portion 9a in the bearing 8 and the inclination of the crank portion 9b in the swing bearing 8 are simultaneously set to approximately the same appropriate values, and a load is applied to the sliding surface of each bearing 8, 11° 12. Oil film reaction force F1 sufficient to support P direct ~ Ps
~F, simultaneously and properly. Also, loads P1 to P
The oil film reaction force Fs that opposes the moment that tends to tilt the crankshaft caused by , and the reaction moment caused by Fs is large, and the inclination of the shaft can be reduced. As a result, the crankshaft 9 and each bearing 8°11.
12 is prevented, and wear and seizure of each bearing 8, 11 and 12 can be prevented at the same time. And the value of (CI 10s)/2L that can prevent seizure and wear is 6
It has been confirmed that the size is less than ×10″6.

Figures 8 and 9 show cases where the bearing diameter clearance between the upper side bearing 11 and the lower side bearing 12 is large (Ct+
Cs)/2 It shows the oil film pressure distribution generated within the bearing when L increases. In this case, since the inclination between the upper side flat bearing 11 and the shaft portion 9 in Fig. 8 is large, the clearance Zc at the lower end of the upper side flat bearing 11 is larger than that in Fig. 4, and the oil film pressure increases. The rate of decrease in oil film pressure after reaching the maximum value is large, and for this reason the maximum value is also smaller than in the embodiment shown in FIG. Therefore, as shown in FIG. 9, the maximum value of the oil film pressure in the circumferential direction is also small, and the oil film pressure generated within the bearing is reduced overall. As a result, sufficient oil film reaction force to support the loads P1 to P3 cannot be obtained on the sliding surface of each bearing 8° 11.12, and the reaction moment due to the oil film reaction force Fm * PI does not act sufficiently. , each shaft bearing s, 11.12 and the crankshaft part 9 come into partial contact, and each bearing 8, 1
1.12 There is a risk of wear and seizure.

FIG. 10 shows an embodiment in which an example of the bearing device of the present invention is applied to another type of scroll fluid machine. In this figure, 35 is a fixed scroll, and 36 is an orbiting scroll. A Pesci bearing 38 is mounted inside the upper side of the large diameter portion 37m of the crankshaft 37. This side bearing 38 is eccentric with respect to the center of the large diameter portion 37a, and a rotating shaft 36a formed integrally with the orbiting scroll 36 is engaged with the side bearing 38. The large diameter portion 37m of the crankshaft 37 is supported by an upper side bearing 40 and a lower side bearing 41 mounted on the frame 39. Due to the compression action of the fluid confined by both scrolls 35 and 36, the orbiting scroll 36 and the orbiting shaft 36
A1 side bearing.

The load acting on the crankshaft 37 through 38 is received by the pesci bearings 40, 41. An eccentric oil supply path 42' is provided in the crankshaft 37, and the eccentricity of the oil supply path 42' increases with respect to the center of the crankshaft 37 toward the top thereof.

The sliding bearing 38 is supplied with oil through an oil chamber 43 that communicates with the eccentric oil supply path 42 and an axial oiling groove 44 that communicates with this and is provided on the inner peripheral surface of the sliding bearing to the upper sliding bearing 40. The oil supply hole 45 that communicates with the eccentric oil supply passage 42 and the large diameter portion of the crankshaft 370 that communicates with this and the large diameter portion of the crankshaft 370;
Through the axial oil supply groove 46 provided on the outer peripheral surface of 7,
The lower sliding bearing 41 is supplied with oil through an oil supply hole 47 that communicates with the eccentric oil supply path 42 and an axial oil supply #1148 that communicates with this and is provided on the outer peripheral surface of the shaft portion 37b of the crankshaft 37. The oil that lubricates the flat bearing 38 and the oil that lubricates the upper flat bearing 4o pass through the annular groove 5o provided at the connection between the large diameter portion 37a of the crankshaft and the balance weight 49 to the upper part of the flat bearing 4o. The integrally molded thrust bearing 51 is lubricated and discharged into an intermediate chamber 52 defined by the frame 39 and the orbiting scroll 36. A part of the oil that lubricated the double bearing 4o was discharged from the lower end of the double bearing 40 into an oil drain chamber 53 defined by the shaft portion 37b, the seventh frame 39, the double bearing 4o, and the double bearing 41. After l, frame 3
The oil is discharged into the chamber through the oil drain hole 54 provided at 9.

The shaft that lubricated the lower bearing 41 is this bearing 4.
The upper end of the bearing 41 is discharged into the chamber through the oil drain chamber 53, and the lower end of the bearing 41 is discharged into the chamber.

The oil discharged into the dead intermediate chamber 52 as described above is transferred to the orbiting scroll 3.
Both scrolls 35.3
It is discharged to the meshing part 6. Therefore, the pressure in the intermediate chamber 52 is intermediate between the discharge pressure and the suction pressure. Therefore, oil supply to the upper side bearing 40 and the side bearing 38 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 42. Lower side bearing 4
1 is supplied with oil by the centrifugal pump action of the eccentric oil supply path 42.

The aforementioned axial oil supply grooves 44, 46, and 48 are located on the line X connecting the center S of the crankshaft 37 and the center O of the veneer bearing 38, and are centered on the veneer bearing 38 with respect to the middle center of the crankshaft 37. is placed at an eccentric position. When K is set in this way, the positional relationship between the load acting direction and each oil supply groove is the same as in the above-described embodiments Figs. At advanced positions, the relationship between each oil supply groove position and oil film pressure distribution will be the same.

In this embodiment, the pivot shaft 36a is engaged with the flat bearing 38 located inside the large diameter portion 37a of the crankshaft 37, so the load P1 due to fluid pressure acts on the upper flat bearing 40. .

Therefore, the crankshaft 37 is forced to one side as shown in FIG. If the bearing diameter clearance between the upper flat bearing 40 and the large diameter portion 371 of the crankshaft 370 is CI, and the clearance between the lower flat bearing 41 and the shaft part 37b of the crankshaft 37 is Cs, then The diameter of the 9-bearing 40 is larger than that of the upper bearing 41. In such a case, the clearance CI usually becomes larger than the clearance Cm. Due to the difference between this clearance CI and the clearance, the crankshaft 37 tilts between the upper and lower side bearings 40 and 41. When this inclination increases, the upper ends of the upper and lower side bearings 40 and 41 tilt. The large diameter part 37m of the crankshaft 37 and the shaft part 37b have a large one-sided contact, and at the same time the two-sided bearing 38
The lower end of the rotary shaft has a large contact area with the pivot, and there is a risk of seizure and wear.

The magnitude of the inclination of the crankshaft 37 is defined as the distance between the upper ends of the upper bearing 41 and the lower bearing 41. In this embodiment, (CI C snow)/2L.
It is represented by t. If this value is set to 6×10''4 or less as in the above-mentioned embodiment, the bearings 38, 4
0.41 seizure and wear can be prevented at the same time.

In the embodiments shown in FIGS. 1θ to 12, the diameter of the shaft portion 37b of the crankshaft 37 is smaller than that of the large diameter portion 37a, but the same can be considered even if the shaft portion 37b has the same diameter. That is, the bearing diameter clearances CI and C3 cannot be made the same due to machining. Clearance CI is clearance C
If the clearance CI is larger than s, it is the same as the embodiment shown in Figs. 10 to 12, but if the clearance CI is smaller than the clearance C3, the slope is reversed.
One-sided contact occurs at the upper ends of the upper and lower side bearings 40, 41 and at the upper end of the side bearing 38. In such a case, the distance between the upper ends of the upper and lower Speshi bearings 40.41 should be set as Ls.
Then, the magnitude of the inclination of the crankshaft 37 is (C
s Ct)/2Lm. This value is 6×l
O → It is necessary to set it below.

The case described above is a case where the inclination of the crankshaft within the bearing becomes large. However, as the bearing diameter clearance decreases, the slope decreases, but if the clearance is too small, the amount of heat generated within the bearing will increase, the bearing temperature will rise, and the viscosity of the oil will decrease, so the crankshaft and bearing If the oil film thickness is too small, metal-to-metal contact may occur, and there is a risk of bearing seizure and wear. Therefore, the bearing clearance, that is, the size of the shaft inclination C! +Cs)/2L
.

(Cs-Cs)/2Lx, (Cs-Ct)/2Ls
must be greater than a certain value. And this value is 2×
It is confirmed that the temperature is lO°4.

As detailed above, according to the present invention, it is possible to prevent the bearings of the scroll fluid machine from hitting one side, thereby preventing seizure and wear of the bearings, and improving the life and reliability of the scroll fluid machine. can be done.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a scroll fluid machine equipped with an embodiment of the oil supply device of the present invention, and FIG. 2 is a longitudinal cross-section showing an enlarged crankshaft portion equipped with an embodiment of the oil supply device of the present invention. 3 is a plan view of the crankshaft showing the relationship between the oil supply groove and the direction of load application in the device of the present invention, and FIG.
The figure is a crankshaft of the scroll fluid machine shown in Figure 2. Figures 5 to 7 are plan views showing the relationship between the direction of load action on each bearing and the bearing oil film pressure distribution, and Figure 5 is the same as Figure 4. FIG. 6 is an explanatory diagram showing the relationship between the W-heavy action direction and the bearing oil film pressure distribution in FIG. 4, and FIG. 9 is a view along the rX-ff line in FIG. 8. FIG. 10 is a plan view showing the relationship between the direction of load action and the bearing oil film pressure distribution. FIG. 11 is a plan view of the crankshaft portion shown in FIG. 1θ, and FIG. 12 is the crankshaft of the scroll fluid machine shown in FIG. FIG. 3 is an explanatory diagram showing the relationship between the direction of load action and the bearing oil film pressure distribution in the state. 1...Chamber, 2...Fixed scroll, 3...
Orbiting scroll, 4.5... End plate, 6.7... Wrap, end... Sugeshi bearing, 9... Crankshaft, 9
Shaft part of m...ri 5 linkage 7 to 9, 9b...
Crank part of crankshaft, 11.12...Subbe bearing, 19...Eccentric oil supply path, 21.27.34...
・Oil supply groove. Agent Patent Attorney Toshiyuki Usuda 16 Figure ■Figure 7 Figure B Figure '¥3 '7 Figure B+ No. 11 Figure J72

Claims (1)

[Claims] 1. A combination of a fixed scroll and an orbiting scroll, a crank unit connecting the orbiting scroll and a shaft is supported by a sub-bearing, and the shaft is provided in a frame and close to the orbiting scroll side. In a nine-scroll fluid machine supported by a first all-round bearing and a second all-round bearing distal to the orbiting scroll, a first bearing diameter clearance between the first all-round bearing and the shaft and a second all-round bearing are provided. The second bearing diameter clearance with respect to the shaft in the flat bearing and the distance between the first and second flat bearings are set to a vIt relationship that prevents uneven contact with the bearing due to shaft tilting. A bearing device for a scroll fluid machine characterized by: 2. In a crank unit that combines a shaft body provided eccentrically at the end of the shaft and a sliding bearing provided in the boss portion of the orbiting scroll, the first bearing diameter clearance C1;
The second bearing diameter clearance C, and the distance @L between the orbiting scroll side end of the first side bearing and the anti-orbiting scroll side end of the second side bearing are set to the following relationship. A bearing device for a scroll fluid machine according to claim 1, characterized in that: 3. The crank part is a combination of a shaft body provided eccentrically on the boss part of the orbiting scroll and a bevel bearing provided at the end of the shaft, in which the first bearing diameter clearance is the second bearing diameter clearance.
When the diameter of the bearing is larger than C1, the distance between these clearances Ol eCl and the orbiting scroll side ends of the first and 1s2 clear bearings is set to the following relationship. A bearing device for a scroll fluid machine according to claim 1. 4. In a crank unit that combines a shaft body provided eccentrically to the boss portion of an orbiting scroll and a beveled bearing provided at the end of the shaft, the first bearing diameter clearance C! Claim 1, characterized in that when the second bearing diameter clearance is 0 and the width is also small, these clearances chCl and the first and second clearance bearings are set in an anti-swivel relationship. A bearing device for a scroll fluid machine according to .1.