JPH05141367A - Scroll compressor - Google Patents

Abstract

PURPOSE:To prevent one-sided collision of a revolving bearing by independently balancing a centrifugal force, exerted on the revolving scroll of a scroll compressor, and a fluid force with each other. CONSTITUTION:Fixed scroll laps 3b and 3c are mounted on the two surfaces of the fixed scroll of a scroll compressor in a state that phases are displaced in a 180 deg. arc from each other and revolving scrolls are arranged vertically in two stages in a manner to combine the revolving scroll therewith. By displacing the phases of the fixed and revolving scrolls, arranged vertically in two stages, by 180 deg. from each other, a fluid force is balanced and one-sided collision of the revolving bearing is prevented from occurring, whereby the speed of the scroll compressor can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll fluid machine used as a compressor, and in particular, a scroll compressor in which a fixed scroll and a orbiting scroll are specially combined to prevent the orbiting scroll from being unbalanced against a bearing. Regarding

[0002]

2. Description of the Related Art In a scroll compressor, it is a technical problem to be solved to prevent centrifugal force generated in an orbiting scroll from acting on a bearing and causing one-sided contact on the bearing.
As a mechanism therefor, a crankshaft drive mechanism having a fixed eccentricity as described in JP-A-53-92915, and JP-A-
Swing ring mechanism as described in 50-32512 publication,
Also, a double bearing mechanism and the like as described in JP-A-59-79086 are known. Further, in Japanese Patent Laid-Open No. 59-15690, there is known one in which wraps are provided on both sides of an orbiting scroll flat plate and two or more scroll devices are provided, and the orbiting scroll is orbited through a special gear transmission mechanism. Has been.

[0003]

The mechanism described in JP-A-53-92915 is a mechanism in which a balance weight is added to the crankshaft so that the centrifugal force generated in the orbiting scroll does not act on the main bearing. However, it is not possible to prevent the centrifugal force from acting on the orbiting bearing of the orbiting scroll portion. Therefore, if an attempt is made to increase the speed of the scroll compressor, the centrifugal force acting on the orbiting bearing also becomes large, and it is difficult to completely prevent the bearing from being partially hit.

Further, in the mechanism disclosed in Japanese Patent Laid-Open No. 50-32512, a balance weight is engaged with a disk or the like integrated with the crankshaft via a key or a pin, and the balance weight is integrated with the crankshaft. By rotating, the centrifugal force in the opposite direction to the centrifugal force generated in the orbiting scroll acts, so that the centrifugal force of the orbiting scroll does not act on the main bearing and the orbiting bearing, and the speed can be increased. However, in this mechanism, the amount of eccentricity for causing the orbiting scroll to orbit is variable, so the movement of the orbiting scroll is restricted by the side surface of the scroll wrap. Therefore, the orbiting scroll moves freely, collides with the fixed scroll, and the wrap may be damaged. In addition, the inclination of the orbiting scroll due to the fluid pressure is not taken into consideration, and it is not possible to completely prevent one-sided bearing contact. ..

Further, in the mechanism described in Japanese Patent Laid-Open No. 59-79086, the orbiting scroll is externally fitted through a bearing to a boss portion into which the eccentric shaft of the crankshaft is fitted, and rotates integrally with the crankshaft. By providing a balance weight to obtain the centrifugal force which is opposite to the centrifugal force generated in the orbiting scroll and is almost equal to the centrifugal force, the centrifugal force is prevented from acting on both the main bearing and the orbiting bearing. It is a thing.
According to this mechanism, the centrifugal force does not act on the main bearing and the orbiting bearing, so that the speed can be increased and the eccentricity is fixed, so the wrap of the orbiting scroll and the wrap of the fixed scroll collide and are damaged. Things can be avoided. However, in this mechanism as well, no particular consideration is given to the inclination of the orbiting scroll due to the fluid pressure, and it is not possible to prevent the bearing from being partially biased.

On the other hand, in JP-A-59-15690, wraps are provided on both sides of an orbiting scroll flat plate to provide scroll devices in two stages, and a drive shaft provided with a drive gear is pivotally supported on a frame, Disclosed is a scroll fluid device in which a plurality of crank shafts provided with meshing driven gears are axially supported by a fixed scroll member and a crank pin portion is fed into a crank pin feed hole of an orbiting scroll flat plate. Since the device receives the crankshaft on the flat part of the orbiting scroll, the working point of the working fluid compression load and the supporting point can be made to coincide with each other, and the reliability of the bearing is improved. A special structure such as a drive shaft and a plurality of crankshafts provided with driven gears that mesh with the drive gears is required, and fluctuating loads on the gears, cranks, etc. are complicatedly applied.

The present invention solves the above-mentioned drawbacks of the prior art and balances the centrifugal force and the fluid pressure generated in the orbiting scroll so that the centrifugal force and the fluid pressure do not act on the main bearing and the orbiting bearing. Therefore, it is an object of the present invention to obtain a scroll fluid machine in which the main bearing and the slewing bearing do not have one-sided contact under any rotation speed and pressure conditions.

With such a structure, the scroll fluid machine of the present invention can have a long life and high speed. According to the present invention, the orbiting scroll is composed of two upper and lower stages, one of which is orbitally moved by a crankshaft having a fixed eccentric amount, and the other of the orbiting scrolls on the non-driving side is radially arranged with respect to the orbiting scroll on the driving side. It is also an object of the present invention to provide a scroll compressor that does not collide with the fixed scroll wrap and is not damaged by being rigidly fastened.

[0009]

In order to achieve this object, the present invention forms a closed space by combining a fixed scroll and an orbiting scroll, and rotates the orbiting scroll by a crankshaft having a fixed eccentric amount. In a scroll compressor that compresses a fluid by swirling in a blocked state, scroll wraps are formed on both sides of a base plate of a fixed scroll with their phases shifted from each other, and are combined with each fixed scroll wrap. Disclosed is a scroll compressor in which an orbiting scroll provided with an orbiting scroll wrap is configured in two stages.

It is a preferable mode that the phase shift is approximately 180 °, and further, the upper and lower two-stage orbiting scrolls are fastened rigidly in the radial direction and movably in the axial direction, and on the side of the driving machine. The object can be further achieved by configuring the same precession motion by the orbiting scroll.

[0011]

[Operation] In the scroll compressor configured as above, the centrifugal force can be canceled by the balance weight, and the phase of the scroll at the upper part of the scroll base plate and the phase of the lower scroll at the fluid pressure can be canceled. , And preferably by shifting by approximately 180 °, the fluid pressures acting on the upper and lower orbiting scrolls can be offset and balanced. As a result, the centrifugal force and the fluid force are individually balanced, so that the load applied to the orbiting scroll becomes negligible, and it is possible to prevent uneven contact between the main bearing and the orbiting bearing.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. FIG. 1 shows a vertical sectional view of a scroll compressor of the present invention. The pressure vessel 1 has a fixed frame 2 that can form a closed space, and a drive motor 12 is mounted on the lower end of the fixed frame 2. The rotary spindle 5 of the drive motor 12 extends upward in the drawing, and the spindle 5
Is rotatably supported on the fixed frame 2 by a main bearing 13 and a lower bearing 14. A tip end portion of the main shaft 5 is a crankshaft 6 which is eccentric by a predetermined amount, and a lower orbiting scroll 4 described later is mounted on the crankshaft 6 via an orbiting bearing 7.

On the other hand, a fixed scroll 3 is fixed to the fixed frame 2. The fixed scroll 3 is composed of a fixed scroll base plate 3a and fixed scroll wraps 3b and 3c formed on both surfaces thereof. In the illustrated embodiment, the scroll wraps 3b and 3c are wrap phases. Are formed 180 degrees apart. The lower orbiting scroll 4 and the upper orbiting scroll 10 are combined with the scroll wraps 3b and 3c, respectively.

The lower orbiting scroll 4 is fitted to a crankshaft 6 having a certain amount of eccentricity on a main shaft 5 via an orbiting bearing 7, and is connected to a fixed frame 2 via an Oldham ring 8. It is supported. Therefore, the lower orbiting scroll 4 is engaged with the crankshaft 6 while being prevented from rotating. The lower orbiting scroll 4 includes a lower orbiting scroll base plate 4a and a lower orbiting scroll wrap 4.
b, and is combined with one fixed scroll wrap 3c of the fixed scroll 3 described above to form the compression chamber 9.

An upper orbiting scroll 10 is provided so as to be combined with the upper fixed scroll wrap 3b, and the upper orbiting scroll 10 includes an upper orbiting scroll base plate 10a.
And the upper orbiting scroll wrap 10b, and the fixed scroll 3 is combined with the other fixed scroll wrap 3b which is formed in a phase different from that of the one scroll wrap 3c to form the compression chamber 9 in the same manner. Further, the upper orbiting scroll 10 is mounted rigidly in the radial direction and movably in the axial direction by a slide pin 11 attached to the lower orbiting scroll base plate 4a. Accordingly, the upper orbiting scroll 10 is the lower orbiting orbiting scroll 4
To perform the same precession exercise.

The pressure vessel 1 further has a fluid absorption port 15 which communicates with the outside of the machine, and the absorption port 15 is open to the compression chamber 9 formed by each scroll wrap described above. Also,
A discharge hole 16 is formed at the center of the fixed scroll base plate 3a, and a communication hole 17 having one end opened to the discharge hole 16 is provided extending radially inside the fixed scroll base plate 3a. The other end is open inside the pressure vessel 1. Reference numeral 18 is a discharge port communicating with the inside of the pressure vessel 1.

Further, the orbiting scroll base plates 4a and 10a are provided with communication holes 19a and 19b, and the compression chamber 9 is provided with an intermediate pressure formed between the back surface of the orbiting scrolls 4 and 10 and the fixed frame 2. It communicates with the chambers 20a and 20b. Also the spindle 2
Is provided with a balance weight 21 for generating a centrifugal force in the opposite direction to the centrifugal force due to the eccentricity of the crankshaft 6.

A lubricating oil reservoir is provided below the pressure vessel 1 and a lubricating oil 22 is contained therein. Further, the rotary main shaft 5 is provided with a through hole 30 over its entire length, and the lower end of the through hole 30 is connected to an oil supply port 24 formed in the oil supply pipe 23. Further, an oil supply hole 25 that communicates the through hole 30 with the surface of the bearing 14 is provided at the position where the lower bearing 14 is located. Next, the operation of the scroll compressor of the present invention will be described. The main shaft 5 is driven by a drive motor 12, and is supported and rotated by a main bearing 13 and a lower bearing 14. As the main shaft 5 rotates, the crankshaft 6 turns with a certain amount of eccentricity. As a result, the lower orbiting scroll 4 fitted to the crankshaft 6 via the orbiting bearing 7 makes an orbiting motion by the Oldham ring 8 without rotating. Further, the upper orbiting scroll 10 also orbits by the slide ring 11 attached to the lower orbiting scroll base plate 4 without rotating, like the lower orbiting scroll 4. Due to this turning motion, the volume of the upper and lower compression chambers 9 decreases toward the center.

The fluid flows in through the suction port 15 and is compressed by the orbiting scrolls. In the present invention, the compression chamber 9 is formed on both sides of the fixed scroll base plate 3a in a phase-shifted manner, and high-pressure fluid from both sides is discharged from the discharge hole 16a.
After merging in, the gas flows into the pressure vessel 1 through the communication hole 17 provided in the scroll base plate 3a and is discharged from the discharge port 18 to the outside of the device.

As described above, the orbiting scroll base plate 4
a, 10a are provided with pressure communication holes 19a, 19b,
Since the orbiting scrolls 4 and 10 communicate with the intermediate pressure chambers 20a and 20b on the back surface of the orbiting scrolls 4 and 10, the orbiting scrolls 4 and 10 are pressed against the fixed scroll 3 by the pressure formed in the intermediate pressure chambers. As a result, the pressure chamber is sealed and the thrust load of the slewing bearing 7 is reduced. Further, the centrifugal force due to the eccentricity of the crankshaft 6 is counterbalanced by the centrifugal force acting in the opposite direction by the balance weight 21 added to the main shaft 2.

On the other hand, the lubrication of the bearing is performed by the lubricating oil 22 stored in the lower portion of the pressure vessel 1 due to the differential pressure between the high pressure in the pressure vessel 1 and the intermediate pressure chambers 20a, 20b. That is, due to the pressure difference, the lubricating oil 22 is filled with the oil filling port 24 provided in the oil filling pipe 23.
The lower bearing 14 is guided through the through hole 30 of the rotary main shaft 5 through the inside.
Is supplied from the oil supply hole 25. Further, the slewing bearing 7
Similarly, the oil that is supplied by the outflow from the through hole 30 and that lubricates the orbiting bearing 7 also flows down to the main bearing 13 below the orbiting bearing to lubricate the main bearing 13.

By the way, FIG. 2 is a diagram for explaining the operating principle of a normal scroll compressor, and schematically shows the positional relationship between the fixed scroll x and the orbiting scroll y at a specific rotation angle. The load applied to the orbiting scroll y at each position is illustrated in FIG.
That is, the centrifugal force Fpr is applied in the eccentric direction of the crankshaft O. On the other hand, the fluid pressure acts as P in the direction opposite to the eccentric direction of the crankshaft O and Fpt in the tangential direction, and as a result, the load indicated by F in FIG. 3 is applied to the orbiting scroll y. In other words, in the conventional one-stage scroll compressor, since the load due to the fluid pressure F is applied to the orbiting scroll y as shown in FIG. 4, the orbiting scroll has a moment with respect to the crankshaft. A load will be added. As a result, the orbiting scroll y is tilted with respect to the crankshaft O, and the bearings of the orbiting scroll y are unevenly contacted.

As described above, in the conventional scroll compressor, many means have been proposed for balancing the centrifugal load applied to the orbiting scroll, but no particular consideration has been given to the load due to the fluid force. ..
On the other hand, in the scroll compressor of the present invention, the scroll wrap 3 is provided on both sides of the base plate 3b of the fixed scroll 3.
b and 3c are formed 180 degrees out of phase with each other, and the orbiting scrolls 4 and 10 provided with the orbiting scroll wraps 4b and 10b so as to be combined with the fixed scroll wraps are configured in two stages. As can be easily understood from the state diagram of each scroll wrap shown in Fig. 4, the fluid pressures acting on the orbiting scrolls of the upper and lower compression chambers 9 and 9 act so as to cancel each other, and therefore, the fluid pressures The load due to is balanced.

On the other hand, the centrifugal force due to the eccentricity of the crankshaft can be balanced by the balance weight 21 independently of the fluid pressure described above. Can prevent one-sided contact without applying a moment load.
Therefore, the bearing will not be burned out even under high speed and low speed and high pressure conditions.

[0025]

As described above, in the present invention, the fixed scroll wraps are provided in the upper and lower two stages, and the phases of the upper and lower scroll wraps are preferably shifted by 180 ° to balance the load due to the fluid pressure, while The centrifugal force due to the eccentricity of the shaft can be independently balanced by the balance weight, so that no moment load is applied to the slewing bearing. Therefore, one-sided contact does not occur in the slewing bearing, and the speed can be increased.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating an operation principle of a scroll compressor.

FIG. 3 is an explanatory diagram of a load applied to the orbiting scroll.

FIG. 4 is a partial cross-sectional view of a conventional orbiting scroll.

FIG. 5 is a diagram for explaining the operation principle of the orbiting scroll of the present invention.

[Explanation of symbols]

1 pressure vessel 2 frame 3 fixed scroll 3b fixed scroll base plate 3c fixed scroll wrap 4 lower orbiting scroll 4b lower orbiting scroll base plate 4c lower orbiting scroll wrap 5 main shaft 6 crankshaft 7 orbiting bearing 9 compression chamber 10 upper orbiting scroll 10a upper orbiting Scroll base plate 10b Upper orbiting scroll wrap 11 Slide pin

Claims (3)

[Claims] 1. A scroll for compressing a fluid by combining a fixed scroll and an orbiting scroll to form a closed space, and the orbiting scroll orbits in a state in which its rotation is prevented by a crankshaft having a fixed eccentric amount. In the compressor, the scroll wrap is formed on both sides of the base plate of the fixed scroll with their phases shifted from each other, and the orbiting scroll is provided with two orbiting scroll wraps so as to be combined with each fixed scroll wrap. Characteristic scroll compressor. 2. The scroll compressor according to claim 1, wherein the scroll wraps formed on both surfaces of the base plate of the fixed scroll are formed with a phase shift of approximately 180 °. 3. The upper and lower two-stage orbiting scrolls are rigidly fastened in the radial direction and movably in the axial direction, and are made to perform the same precession movement by the orbiting scrolls on the driving machine side. The scroll compressor according to claim 1 or 2, which is characterized.