JPH02149784A - Scroll type fluid device - Google Patents

Abstract

PURPOSE:To support a crankshaft on the inner circumferential face of a bearing without deflected contact, and form appropriate oil film so as to prevent breakage and the like of a bearing metal, by forming the inner circumferential face of a crank bearing into a taper face along inclination of the crankshaft. CONSTITUTION:The inner circumferential face of a main crank bearing 21 is formed to have a large diameter at the upper end and a small diameter at the lower end. Further, the inner circumferential faces of a stub bearing 16 and a subcrank bearing 22 are formed to have small diameters at the upper ends and large diameters at the lower end. Namely, the inner circumferential faces of respective bearings are formed along the inclination of a crankshaft 10. Meanwhile, clearances for forming oil film and clearances due to machining accuracy are generated between respective bearings 16, 21, 22 and a scroll shaft 12a and the crankshaft 10, and the crankshaft 10 inclines in the nearly same direction at drivingly rotation and is performed a few by the force of a revolving scroll 8 in the radial direction. Therefore, the inner circumferential faces of respective bearings are formed into taper faces corresponding to the inclination of the crankshaft 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a scroll-type fluid device used in a compressor of a refrigeration system, and particularly relates to a bearing structure.

(Prior Art) In general, scroll type fluid devices are
As disclosed in Japanese Patent No. 080, a fixed scroll and a revolving scroll are housed in a sealed casing with their respective wraps meshing with each other, while the revolving scroll is supported by a frame on the back side, and the revolving scroll is supported by a frame on the back side. There is one in which the crankshaft inserted into the shaft is eccentrically connected. Then, due to the rotation of the crankshaft, the revolving scroll revolves around the fixed scroll without rotating on its own axis, and the fluid is compressed and discharged between the two scrolls.

(Problems to be Solved by the Invention) In the scroll type fluid device described above, as shown in FIGS. 4 and 5, the crankshaft (a) is connected to the frame (b).
is supported via the upper main crank bearing (C) and lower sub-crank bearing (d), while the revolving scroll (e) is supported by the scroll shaft (f) or bearing hole (g) on the back side.
and a bearing hole (h) in the upper part of the crankshaft (a) or a stub shaft (i) are connected via a stub bearing (j).

There is a slight gap between each of the bearings (c), (d), (j) and the crankshaft (a), etc., and an oil film is formed in the gap. This gap causes the crankshaft (a) to be inclined as shown in FIGS. 4 and 5. In particular, in a scroll type fluid device, since the direction of load acting on the crankshaft (a) is always approximately the same direction, the crankshaft (a) is always inclined in approximately the same direction and is slightly bent by the load. It will be. Therefore, each of the above bearings (c), (d) (j)
However, the crankshaft (a) etc. are not evenly supported all over the top and bottom, and hit unevenly, resulting in oil film pressure distribution (F
l) reaches its maximum at the upper end of the main crank bearing (C) and at the lower end of the sub-crank bearing (d) and stub bearing (j), resulting in a problem in which the lubrication performance is significantly reduced.

Furthermore, there is a problem in that the minimum oil film thickness is reduced due to the inclination of the crankshaft (a), resulting in metal cracks and the like.

The present invention has been made in view of the above, and by forming the inner peripheral surface of the bearing into a tapered surface, the crankshaft, etc. can be supported without unevenly touching the inner peripheral surface of the bearing, and an appropriate oil film can be maintained. The purpose of this is to improve the lubrication performance.

(Means for Solving the Problem) In order to achieve the above object, the means taken by the invention according to claim (1) are as shown in FIGS. 1 and 2.
Wraps (13) are attached to the front of the mirror plates (11) and (12), respectively.
), (14) are installed in a fixed scroll (7)
and the revolving scroll (8) each lap (13),
(14) are arranged in parallel in mesh with each other, and the revolving scroll (8)
A crankshaft (10) connected to an electric motor (9) is connected to the rear surface of the mirror plate (14) eccentrically from the axis of the crankshaft (10), and the crankshaft (10) is connected to the rear surface of the revolving scroll (8). Mirror plate (14) Frame (1) provided on the back side
The revolving scroll (8) is fitted into and supported by the fixed scroll (7) by rotation of the crankshaft (10).
) is assumed to be a scroll-type fluid device that revolves around the Earth without rotating.

A stub bearing (16) is provided between the end plate (14) of the revolving scroll (8) and the crankshaft (10), and a stub bearing (16) is provided between the crankshaft (10) and the frame (10).
5), a main crank bearing (21) is provided on the revolving scroll (8) side, and a sub-crank bearing (22) is provided on the electric motor (9) side. Furthermore, each bearing (
16).

(21), (22) inner peripheral surface (16b), (2
1b) and (22b) are formed in tapered surfaces along the inclination of the crankshaft (10).

Moreover, the means taken by the invention according to claim (2) is each of the above-mentioned bearings (16) in the invention according to claim (1).

(21), (22) inner peripheral surface (16b), (2
1b) and (22b) are the inner peripheral surfaces (16b) and (21b
), (22b) are formed with the same diameter throughout, the crankshaft (10) is inclined due to the gap created when
It is formed into a tapered surface corresponding to the inclination of
The measures taken by the invention according to 3) are the above-mentioned bearings (16),
(21), (22) inner peripheral surfaces (16b), (2
1b) and (22b) are formed in a tapered surface corresponding to the inclination of the crankshaft (10), which includes, in addition to the above-mentioned gap, an inclination due to the deflection of the crankshaft (1o) caused by the action of the load. .

(Function) With the above configuration, in the present invention, when the electric motor (9) is driven to rotate the crankshaft (10), the crankshaft (10) is rotated.
) A revolving scroll (8) installed eccentrically from the axis of
revolves around the fixed scroll (7) without rotating, and the wrap (13) of both scrolls (7) and (8)
), (14) A fluid flows in between, and the fluid is compressed or expanded.

During the revolution of the revolving scroll (8), the crankshaft (10) receives a radial force from the revolving scroll (8) in substantially the same direction, and is inclined in substantially the same direction. In response to the inclination of the crankshaft (10), both crank bearings (
21).

(22) and the inner circumferential surfaces (21b), (22b) of the stub bearing (16) that supports the revolving scroll (8),
Since (16b) is formed in a tapered surface, each of the bearings (16), (21), and (22) receives force throughout the axial direction. In particular, in the invention according to claim (3), each bearing (16), (21
), (22) will surely be along the crankshaft (10), etc.

(Effect of the invention) Therefore, according to the scroll type fluid device of the present invention, the inner peripheral surface (1) of each bearing (16), (21), (22)
6b), (21b), and (22b) on the crankshaft (10)
Because the tapered surface is formed along the slope of each bearing (
16), (21), and (22) can support the crankshaft (10) etc. in the entire axial direction without unevenly touching each other, so that an appropriate oil film is reliably formed. Bearing load capacity can be improved, and bearing performance reliability can be improved.

Furthermore, since the minimum oil film thickness can be reliably maintained, metal cracking, etc. can be reliably prevented, and bearings (16
), (21), and (22) can be extended in life.

(Example) Embodiments of the present invention will be described below based on the drawings.

As shown in FIG. 1, (1) is a scroll-type fluid device, which is used in a compressor in a refrigeration system to compress refrigerant gas (fluid) to high pressure and discharge it.

The scroll type fluid device (1) has a closed casing (2
) A scroll mechanism (3) and a drive mechanism (4) are housed in the casing (2), and a suction pipe (5) is connected to the side of the casing (2), and a discharge pipe (6) is connected to the upper part of the casing (2). It is set up.

The scroll mechanism (3) consists of a fixed scroll (7) and a revolving scroll (8), and the drive mechanism (
4) is composed of an electric motor (9) and a crankshaft (10).

The fixed scroll (7) and the revolving scroll (8) each have a wrap (13) on the front surface of the end plate (11), (12).
(14) are arranged in a spiral shape, and both scrolls (7
), (8) is the mirror plate (11).

(12) are arranged vertically in parallel with their front surfaces facing each other, and both wraps (13) and (14) are engaged with each other. The fixed scroll (7) has a flange (11a) connected to the outer peripheral edge of the end plate (11), and is fixed to the casing (2) by the flange (11a). ) It is divided into an upper high pressure chamber (2a) and a lower low pressure chamber (2b). Further, a scroll shaft (12a) is provided protruding from the central portion of the back surface of the end plate (12) of the revolving scroll (8). On the other hand, the crankshaft (10) has a boss (10c) connected to the upper end of the crank main shaft (10a) and having a concave scroll bearing hole (10b), and is connected to the flange (11a) of the fixed scroll (7). It is fitted and supported by a fixed support frame (15). Furthermore, the above crankshaft (
10a) is connected to a motive force (9) at 7, and the scroll bearing hole (10b) is provided so that its bearing center (01) is eccentric from the axis (02) of the crank main shaft (10a). The scroll shaft (12a) of the above-mentioned revolving scroll (8) is inserted into the hole (10b) using the stub bearing (16).
It is mated through. The orbiting scroll (8) revolves around the fixed scroll (7) due to the eccentricity of the scroll bearing hole (10b), and the center (0+) of the scroll bearing hole (10b) (the center of the scroll shaft (12a)) is the movable fulcrum of the revolving scroll (8), and the axis (02) of the crank main shaft (10a) is the center of revolution.

The fixed scroll (7) and the revolving scroll (8) have both wraps (13) and (upper 4) in multi-point contact on the sides (17)
each wrap (13),
(14) whose end face is the other scroll end plate (12);
Closed chamber (18) in contact with (1,1) and between contact (17)
is formed.

In addition, the flange (11a) of the fixed scroll (7)
and the wrap (13) is an inlet (19) that opens on the bottom surface.
), while a discharge port (20) is bored in the approximate center of the end plate (11), and low-pressure refrigerant gas is supplied from the suction port (19) to the sealed chamber (18), High pressure refrigerant gas is discharged from the sealed chamber (18) into the high pressure chamber (2a) via the discharge port (20).

The support frame (15) also has a revolving scroll (
The end plate (12) of 8) is composed of a substantially donut-shaped disk portion (15a) extending toward the back side, and a substantially cylindrical cylindrical portion (15b) extending downward from the lower inner end of the zero disk portion (15a). ing. The disk portion (15a) is fixed to the flange (11a) of the fixed scroll (7) at its upper outer periphery, and a communication hole (15c) through which the refrigerant gas passes extends vertically across the suction port (19). and a stepped portion (15) on which the end plate (12) of the revolving scroll (8) is located.
d) is formed on the top. An electric motor (9) is attached to the lower part of the cylindrical part (15b), and a large diameter hole (15) into which the boss (10c) of the crankshaft (10) is fitted.
e) and a small diameter hole (
15r) is drilled, the main crank bearing (21) is installed in the large diameter hole (15e), the sub crank bearing (22) is installed in the lower part of the small diameter hole (15f), and the crankshaft (10) is fitted. is supported.

Further, a thrust bearing (31) is interposed between the end plate (12) of the revolving scroll (8) and the stepped portion (15d) of the support frame (15), and the revolving scroll (8)
) thrust force is stopped by the receiver. Although not shown, the revolving scroll (8) is provided with a rotation prevention mechanism, and is configured to only revolve relative to the fixed scroll (7).

On the other hand, the disk portion (15) in the support frame (15)
The inner peripheral side of a) is configured as a balancer chamber (32),
A main balancer (33) located within the balancer chamber (32)
is provided protrudingly on the upper end of the boss (, 10c) of the crankshaft (10), and is provided on the rotor (9a) of the electric motor (9).
) is provided with a sub-balancer (34) at the lower part of the balancer (33).

(34) maintains the inertial balance of the revolving scroll (8).

Next, the bearing structure of the crankshaft (10), etc., which is a feature of the present invention, will be explained.

Above stub bearing (16), main crank bearing (21)
As shown in FIG. 2, the sub-crank bearing (22) is formed into a substantially cylindrical shape, and each outer peripheral surface (16a),
(21a) and (22a) are formed to have the same diameter throughout the axial direction (vertical direction), and the stub bearings (16
) is the scroll bearing hole (10b) of the crankshaft (10)
The main crank bearing (21) is attached to the support frame (15).
), and the sub-crank bearing (22) is fitted into the small diameter hole (15f) of the support frame (15), respectively.

On the other hand, the inner peripheral surfaces (16b), (21b), and (22b) of each of the above-mentioned bearings (16), (21), and (22) are formed into tapered surfaces, and the inner peripheral surfaces of the main crank bearing (21) are tapered. The surface (2l b) is formed so that the diameter is large at the upper end and becomes smaller toward the lower end. Also, the inner circumferential surface (16b) of the stub bearing (16) and sub-crank bearing (22).

(22b) is formed to have a small diameter at the upper end (and a larger diameter toward the lower end).
(21), (22) inner peripheral surfaces (16b), (21b
), (22b) are formed along the inclination of the crankshaft (10), that is, the crankshaft (10)
receives radial force from the revolving scroll (8) from approximately the same direction, while each bearing (16), (21)
(22) and the scroll shaft (12a) and the crankshaft (10), there will be a gap for forming an oil film and a gap due to machining accuracy, and the crankshaft (10) will be They are tilted in substantially the same direction and are also slightly bent by the radial force of the revolving scroll (8). Therefore, this crankshaft (10)
Corresponding to the inclination of each bearing inner peripheral surface (16b), (21b)
, (22b) are formed on tapered surfaces.

Specifically, each bearing inner peripheral surface (16b), (21b).

The slope rate of (22b) is as follows. First, when dealing with the inclination of the crankshaft (10) due to the shaft clearance, it is set to (CI 10Cz)/(2·L)-2 to 5X10'. Here, (L) is from the upper end of the main crank bearing (21) to the sub crank bearing (22).
), (C1) is the length to the bottom of the main crank bearing (
The gap with the crankshaft (10) when the entire inner circumferential surface (21b) of 21) is formed with the same diameter, (C2) is the gap between the entire inner circumferential surface (2l b) of the sub-crank bearing (22) with the same diameter This is the gap with the crankshaft (10) when formed.

Moreover, as mentioned above, each bearing inner circumferential surface (16b).

(21b) and (22b) are formed with the same diameter, and when dealing with the inclination of the crankshaft (10) due to the gap and the inclination due to the bending of the crankshaft (10), (CI 10C2)/ ( 2.L)-3 to 8X10-'.

In addition, (51) in Fig. 1 is a lubricating oil reservoir,
Although not shown, lubricating oil is supplied from the oil supply path formed on the crankshaft (10) to each oil pan (16).

(21) and (22). Also, (5
2) is a gas passage formed in the cylindrical part (15b) of the support frame (15) through which the refrigerant gas passes;
2).

Next, the operation of this scroll type fluid device (1) will be explained.

First, refrigerant gas flows into the case (2) from the suction pipe (5), passes outside the electric motor (9) in the low pressure chamber (2b), and passes through the communication hole (15e) of the support frame (15). The closed chamber (
18).

On the other hand, the revolving scroll (8) revolves around the fixed scroll (7) due to the rotation of the crankshaft (10), and
It rotates without rotating due to a rotation prevention mechanism (not shown). The revolution of this revolving scroll (8) causes the closed room (
18) is sequentially formed between the wraps (13) and (14) and contracts, compressing the refrigerant gas and discharging it from the discharge port (20).

During this compression operation, the crankshaft (10) is subjected to a radial force from the revolving scroll (8) via the scroll shaft (12a), and this radial force is applied to the scroll type fluid device (1). , they always act in approximately the same direction. The radial force causes the crankshaft (10) to tilt in substantially the same direction and to be slightly bent. In other words, the crankshaft (10) has both crank bearings (21).

(22), each bearing inner circumferential surface (16b) is inclined due to the gap and deflection generated between the bearings (16b) and (22).

(21b) and (22b) are formed into tapered surfaces corresponding to this inclination, so that the crankshaft (10) and scroll shaft (12a) are connected to each bearing (21).

(22) and (16), it is supported substantially evenly throughout the entire axial direction. As shown in Fig. 2, the oil film pressure distribution (F) is different for each bearing (16), (21), (
22), and a proper distribution state is formed to support the crankshaft (10) and the scroll shaft (12a).

Figure 3 shows the engagement relationship between the crankshaft (10) and the revolving scroll (8) reversed;
A stub shaft (10g) is formed protruding from the upper end of the
There is a bearing hole (
12b) is formed. A stub bearing (16) is fitted into the bearing hole (12b), and the stub shaft (
10s) is fitted and inserted, and the inner peripheral surface (16b) of the stub bearing (16) is connected to the crankshaft (10) as detailed in the previous embodiment.
It is formed into a tapered surface along the slope. Other configurations and operations are the same as in the previous embodiment.

Therefore, each of the above bearings (16), (21), (22)
The inner circumferential surfaces (16b), (21b), (22b) of the bearings (16), (21) are tapered along the inclination of the crankshaft (10).

(22) can support the crankshaft (10) etc. in the entire axial direction without uneven contact, so an appropriate oil film is reliably formed and the bearing load capacity can be improved. It is possible to improve the reliability of bearing performance.

Furthermore, since the minimum oil film thickness can be reliably maintained, metal cracking, etc. can be reliably prevented, and the bearing (16)
, (21), (22) can be extended in life.

Although the scroll type fluid device (1) of each embodiment is applied to a compressor of a refrigeration system, it may be applied to a blower or an expander in addition to the compressor of other devices.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, in which FIG. 1 is a longitudinal sectional view of a scroll type fluid device, and FIG. 2 is an enlarged view of essential parts showing a state in which a crankshaft is supported. FIG. 3 is an enlarged view of essential parts showing another state of engagement between the crankshaft and the revolving scroll. FIGS. 4 and 5 are enlarged views of main parts showing the support state of a conventional crankshaft. (1)...Scroll type fluid device, (2)...Casing, (7)...Fixed scroll, (8)...Revolving scroll, (10)...Crankshaft, (11)
. (12)... End plate, (13), (14)... Wrap, (16)... Stub bearing, (18)... Sealed chamber, (21)... Main crank bearing, (22 )・・
・Sub crank bearing, (16b), (21b),
(22b)...Inner peripheral surface. Fig.

Claims (3)

[Claims] (1) Wrap (
13) and (14) are installed upright.
) and the orbiting scroll (8) each lap (13)
, (14) are arranged in parallel in mesh with each other, and the revolving scroll (8
) A crankshaft (10) connected to an electric motor (9) is connected eccentrically from the axis of the crankshaft (10), and the crankshaft (10) is connected to the revolving scroll (8). The frame provided on the back side of the mirror plate (14) (
15) and is supported by the crankshaft (10).
Due to the rotation of the revolving scroll (8), the fixed scroll (
7) In a scroll-type fluid device that revolves around the axis without rotating, a stub bearing (16) is provided between the end plate (14) of the orbiting scroll (8) and the crankshaft (10). At the same time, a main crank bearing (
21) is the sub-crank bearing (22) on the electric motor (9) side.
are provided respectively, while the inner circumferential surface (16) of each of the bearings (16), (21), and (22)
b), (21b), and (22b) are the crankshafts (10
1. A scroll-type fluid device characterized by being formed on a tapered surface along an inclination of ). (2) The inner circumferential surface (16b), (21b), (22b) of each bearing (16), (21), (22) is
6b), (21b), and (22b) all having the same diameter, the crankshaft (10) is formed with a tapered surface that corresponds to the inclination of the crankshaft (10) that is inclined due to the gap created when the crankshaft (10) is formed with the same diameter throughout. Scroll type fluid device according to claim (1). (3) The inner circumferential surface (16b), (21b), (22b) of each bearing (16), (21), (22) is
6b), (21b), and (22b) with the same diameter throughout, and the deflection of the crankshaft (10) caused by the action of the load. The scroll-type fluid device according to claim 1, wherein the scroll-type fluid device is formed with a corresponding tapered surface.