JPS60178988A - Scroll fluid device - Google Patents

Abstract

PURPOSE:To suppress up/down motion of shaft thus to prevent damage of bearing by forming an oil pressure chamber such that a circular inner wall higher than the lower end of bearing boss is arranged at the swivel scroll side of a balance weight secured to the shaft with correspondence to the outside of swivel scroll bearing boss. CONSTITUTION:An oil pressure chamber 34 is formed by an arched wall 33 continuous upwardly with the weight section 32 on the outercircumference of a balance weight 27 secured to the upper section of shaft 11. The upper end is made sufficiently higher than the lower end of a bearing boss 24 to enable storage of lubricant flowed through a gap of swivel bearing 18 under operation of compressor as well as stoppage. Consequently, even upon up/down motion of shaft due to some external force, the lubricant will function as a buffering member thus to protect the bearing boss from impact due to contact.

Description

[Detailed Description of the Invention] <Field of Application of the Invention> This invention relates to a closed scroll fluid device, and in particular, to a thrust bearing portion suitable for lubrication of a thrust bearing when suppressing axial movement of a shaft thereof. This invention relates to a scroll fluid device having a structure.

<Background of the Invention> Therefore, the conventional scroll compressor 1 for air conditioning is
To explain briefly in Fig. 4, a compressor section 3 is disposed in the upper part and an electric motor section 4 is disposed in the lower part in the airtight container 2. Scroll 5 and
It consists of an orbiting scroll 7 having a thinly wound protrusion on a flat plate integrally having a bearing boss 6, and the electric motor section 3 consists of a stator 9 having a stator winding 8 and a rotor 10 which is a rotor. Power is transmitted to the orbiting scroll 7 by the shaft 11 of the rotor 10 via the eccentric portion.

The rotation of the orbiting scroll 7 is prevented by the rotation mechanism 12 including an Oldham ring and an Oldham key (not shown in detail). After sealing the gas flowing in from the refrigerant gas inlet 12 into the closed space formed between the fixed scroll 5 and the orbiting scroll 7, the gas is moved to the center while being compressed by the space that is sealed and contracted. The closed container 2 is discharged from the discharge port 13 provided at the center of the fixed scroll 5 through a closed space that opens near the center.
The discharged compressed gas passes through the fixed scroll 5 and the discharge passage 16 provided on the outer periphery of the frame 14, flows around the electric motor section 4, and is discharged into the airtight container 2. The air is discharged from the compressor 1 through a pipe 17.

Loads due to gas compression act on the orbiting scroll 7 in the radial and thrust directions, and the radial load is applied to the orbiting scroll 7 from the orbiting bearing 18 as shown in FIG. - It is transmitted and acts on the bearings 20.21 provided above and below the bearing boss 19 of the frame 14, and is applied to the electric motor 4 as a load.

On the other hand, the thrust load acts as a force pushing down the orbiting scroll 7 toward the shaft 11 side, and the frame 14
By introducing the gas in the υ compression chamber through the back pressure hole 22 provided in the flat plate part of the orbiting scroll 7 into the back pressure chamber 27 formed by the orbiting scroll 7 and the orbiting scroll 7, the pressure inside the back pressure chamber 23 is reduced from the suction side to AaEK. t.

The structure is such that the orbiting scroll 7 is pressed against the fixed scroll side against the thrust load.

On the other hand, the shaft 11 is supported by bearings 20, 21 of a bearing boss 19 provided on the frame 14, as shown in FIG.
An eccentric part 25 is inserted into the holder, and a balance weight 27 is fixed to a fixed part 26 to reduce vibration.

Father, since the inside of the sealed container 2 is under high pressure, the oil supply to each bearing 18, 20, 21 is done using the differential pressure with the back pressure. For the swing bearing 18, the upper end of the shaft 11 and the groove 28 are connected to the gap 1 of the bearing 18 and the eccentric part 25V of the shaft 11.
Since it communicates with the back pressure chamber 23 through the longitudinal slit 29 provided in C, the difference between the high pressure side pressure in the closed container 2 and the pressure inside the back pressure chamber 23 causes the oil tank 30 under the container 2 to The lubricating oil ascends through the oil supply hole 31 of the shaft 11, is supplied to the cavity 28 at the upper end of the shaft 11, is led out into the orbiting bearing gap 18 and the slit 29, flows into the back pressure chamber 23, and then flows into the orbiting scroll. 4 and the back pressure introduction hole 12
The oil enters the compression chamber, is discharged into the closed container 2, is separated from the refrigerant gas, and returns to the oil tank 30 again.

However, in the conventional compressor I described above, when the lubricating oil is led out from the oil tank 30 to the upper cavity 28 of the shaft 11, the pressure decreases, and since the upper scroll part is the compression chamber, the pressure rises, and the lubricating oil As the refrigerant contained therein gasifies and enters the bearing 18, 20, 21, the passage resistance of the lubricating oil rapidly decreases, and the pressure inside the upper cavity 28 of the shaft 11 is suctioned by the back pressure, causing a significant This will result in a decline.

On the other hand, since the high pressure side pressure is applied to the lower part of the shaft 11, the differential pressure AP between the two is applied to the lower part of the shaft 11 and
If the upper radius D2 and Dl are Dl-D2-D, the cross-sectional area A
=(π/4)θ, and a thrust force Fθ−,4FA acts on the shaft 11.

The shaft 11 is lifted by the thrust force Ps as shown in FIG. 4, and its bent portion contacts and is pressed against the lower end of the bearing boss 24 of the orbiting scroll 4.

However, as mentioned above, the lubricating oil is insufficient, and the lubricating oil that has reached the lower end after passing through the bearing 18, 20, and 21 is blown away due to the centrifugal force caused by the rotation of the shaft 11. Therefore, there is a drawback that there is no residual lubrication, and there is also a drawback that there is a risk of damage to the end face due to a collision or the like.

<Object of the Invention> The object of the present invention is to solve the problem of lack of lubricating oil in the scroll compressor based on the above-mentioned conventional technology, and to solve the problem by constructing a balance weight part fixed to the shaft as an oil reservoir, and to create a core oil reservoir. The shaft has a function to improve the lubrication of the sliding parts and generates thrust force, suppressing the vertical movement of the shaft, thereby preventing accidents at the sliding parts and improving the reliability of the compressor. It is an object of the present invention to provide an excellent scroll fluid device that is useful in the field of fluid application in industry.

<Summary of the Invention> In order to solve the above-mentioned problems, the structure of the present invention, which is based on the above-mentioned object and has the gist of the above-mentioned claims, is to solve the above-mentioned problems. A hydraulic chamber is formed between the weight fixing part, and lubricating oil that is not affected by the back pressure chamber is stored in the hydraulic chamber, which functions as a buffer material to suppress vertical movement of the shaft and ensure smooth movement. Next, an embodiment of the present invention in which damage to the bearing does not occur will be described below based on the drawings from FIG. 5 onwards. The same reference numerals are used for the same parts as in FIGS. 1 to 4.

In the embodiment shown in FIGS. 5 to 10, the hydraulic chamber 34 is
By making the upper end of the bearing boss 24 sufficiently higher than the lower end of the bearing boss 24, the lubricating oil that has flowed in from the gap of the slewing bearing 18 can be stored not only when the compressor is stopped but also during operation. is made possible.

Once the lubricating oil has accumulated in the hydraulic chamber 34, the bearing boss 2
Since there is a certain amount of lubricating oil at the lower end of the bearing boss 24, even if the shaft 11 moves upward due to mechanical factors or the above-mentioned differential pressure, it will be buffered by the lubricating oil and no impact will be applied to the lower end of the bearing boss 24. The arcuate wall 33 does not come in contact with the bearing boss 2, and even if it is pressed, lubrication is performed well.
On the side closer to 4, oil pressure diffusion can occur due to the centrifugal force field. Therefore, this oil pressure acts as a force pushing down the shaft 11, and the thrust force applied to the shaft IIK decreases.

Furthermore, as shown in FIG. 8, if surface gas flows into the lower end of the bearing boss 24, it will leak into the radial oil groove 35.
Form 35.

In addition, as shown in Figure 7.9, a thrust plate 36 is provided inside the arcuate wall 33 of the balance weight 27 between the lower end of the bearing boss 24, the fixed portion 26 of the shaft 11, and the oil well chamber 34, By making the center of the outer circumference of the thrust plate eccentric and the center of the inner circular hole 37, it is made to rotate together with the shaft 11, and furthermore, a convex part on the outer circumference of the thrust plate 36 and a concave part in the balance weight part are provided to prevent rotation. It is also possible to design it so that

In the above configuration! When the E-compressor is operated, when lubricating oil containing gas flows out from the gap of the swing bearing 18 to the lower part of the bearing boss 24, some of the oil flows into the thrust plate 36, the shaft fixing part 26, and the oil well chamber 341 of the balance weight 27.
C flows in, and by the action of the centrifugal force of the balance weight 27, gas is pushed out into the back pressure chamber 23 through the gap between the lower end of the bearing boss 24 and the thrust plate 36, and the hydraulic chamber 34 is filled with oil. Therefore, a pressure (p/2) r2 w2 (p: density of oil, r: distance from the center of rotation, /, 1/2 rotational angular velocity) is generated in the oil well chamber 34, and the magnitude of this is Il /2) ω2 f f r3 d r
(It acts on the shaft 11 and the thrust plate 36 as a thrust force expressed by 1θ.

This thrust force suppresses the movement of the shaft 11 in the axial direction, and the oil in the hydraulic chamber 34 acts as a buffer, so that even if the shaft 11 is pushed upward, it will not come into contact with the shaft 11 in an impactful manner. do not have.

Further, in the embodiment shown in FIG. 11, a minute gap is provided on the outer circumference of the bearing boss 24 to allow sliding, and a cylindrical sleeve 39 with a flange 33 is provided with the flange facing downward, so that the flat part of the orbiting scroll and the cylindrical sleeve 39 are provided with the flange facing downward. A coil spring 40 is interposed between the collar 38 and the boxwood 38 is pressed against the flat part of the fixing part 26 of the shaft 11 and the flat part of the balance weight 27.
The oil reservoir chamber 41 is shaped by separating the space between the lower end of the shaft 4 and the balance weight 27 of the shaft 11 from the back chamber 23.

Due to this configuration V, during operation, the back EE is lower than the upper pressure of the shaft 11, so the lubricating oil in the oil tank 30 is sucked up from the oil supply hole 31 of the shaft 11, and the lubricating oil is supplied to the swing bearing 18.

Therefore, lubricating oil always contains a bath of refrigerant, and as the force decreases and the width increases, the refrigerant that has entered the solution becomes gas and is released. Although the oil that has flowed out from the bearing 18 and entered the oil reservoir chamber 40 is in a state of gas-liquid interaction, it is pushed toward the outer circumference by the centrifugal force of the balance weight 27, and the gas gathers in the center. Gas escapes from the gas vent 38 to the back pressure village 23.

Therefore, since the oil stopper chamber 41 is filled with the lubricating oil V'i, pressure due to the centrifugal force of the balance weight 27 is generated.

This output is expressed as (p/2)ω2r2, where p is the density of lubricating oil, angular velocity of rotation is ω, and distance from the center of rotation is r. Therefore, the shaft 11- has (p/2>,
(1) 2fJ r3 d r a (The thrust force from the oil stopper 9 and the force of the coil spring 40 act, and the shirt 111
is pushed down.

The side pressure in the upper chamber 28 of the shaft 11 suddenly decreases, but even if the shaft 11 is suddenly pushed upward by mechanical force, the lubricating oil in the oil reservoir chamber 41 acts as a damper, and the impact is suppressed. Not only does it not come into contact with the lower end of the bearing boss 18, but even if it does come into contact with it, it is filled with lubricating oil, so it will be in a good lubrication state and the contact part will not be damaged.

Further, there is no adverse effect on other sliding parts due to the vertical movement of the shaft 11.

<Effects of the Invention> According to this invention, the lubrication of the thrust bearing in the scroll fluid device is improved, and the axial movement of the shaft can be reduced, and the impact force and excessive load on the thrust bearing can be reduced. Since the compressor does not act, damage to the bearing can be prevented and the reliability of the compressor can be improved, which is an excellent effect.

Further, not only is the lubrication of the lower part of the bearing boss improved, but also the vertical movement of the shaft is suppressed and smooth movement is achieved, which has the effect of eliminating damage to the bearing 18.

[Brief explanation of drawings]

Fig. 1-1 is a vertical sectional view of a conventional hermetic scroll compressor, Fig. 2 is a partially enlarged sectional view of the area around the conventional bearing, Fig. 3 is a sectional view taken along the line ■-■ in Fig. 2, and Fig. 4 is a sectional view of the shaft moved upward from FIG. 2, FIG. 5 and the following are detailed explanatory views of the present invention, FIG. Sectional view on the ■-Vl line in Figure 5, 7th
The figure is a partial enlarged sectional view of the bearing area in Figure 5, and Figure 8 is a partial enlarged sectional view of the area around the bearing in Figure 5.
■ll- in the figure is a thin line sectional view, Figure 9 is a plan view of the thrust plate, Figure 10 (1 Figure 7 is a partially enlarged sectional view,
FIG. 1 is a sectional view corresponding to FIG. 5 of another embodiment. 5...Fixed scroll 7...Group l scroll 1
8...Bearing 27...Balance weight 11...
・Shaft 25... Center part 1... Scroll fluid device 24... Bearing boss 33... Inner wall 34...
・Hydraulic chamber'-\ Ashi1 (2) Flash Z! A-Secret R ■F5 5th m 8 Tosutan 7th figure grass to dan 4

Claims (1)

[Claims] A fixed scroll having a thinly wound groove formed on a thick disk is disposed on the upper side, and an orbiting scroll having a corresponding thinly wound protrusion formed on a flat plate is arranged on the lower side, and the mutual thinly wound wall surface is arranged on the lower side. in a scroll fluid system in which a bearing forms a compression seal 9, a bearing is provided on the lower side of the thinly wound shape of the orbiting scroll, and an eccentric part of a drive shaft to which a balance weight is fixed is inserted into the bearing, A scroll fluid device characterized in that an oil well chamber is formed by providing an inner wall higher than a lower end of the bearing boss in correspondence with the outer side of the bearing boss on the orbiting scroll side of the balance weight fixed to the shaft.