JPS593191A - Scroll compressor - Google Patents

Abstract

PURPOSE:To improve reliability of scroll type compressor bearing by providing exhaust oil basin on outer side of main bearing housing and to store the exhaust oil remaining after differential pressure feeding as the bearing section coolant. CONSTITUTION:Chamber 1 is maintained at exhaust pressure and intermediate pressure chamber is maintained at intermediate pressure. Lubricant 9 lubricates main bearing 13 etc. and discharged into intermediate pressure chamber 8 when the oil port in shaft 4 is lifted due to the differential pressure between the exhaust pressure and the intermediate pressure. The exhaust oil temperature is lower than the feed oil temperature due to evaporaton of coolant in the lubricant. A recess serving as an oil basin for exhaust oil is provided on outer side of main bearing 13 housing of frame 5 and upper side of main bearing 13 housing are cooled by said exhaust oil.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improving the reliability of bearings for scroll compressors used in air conditioners, refrigerators, and the like.

A conventional scroll compressor will be explained with reference to FIG.

Inside the closed container 1, a compressor section 2 is housed in an upper part and an electric motor part 3 is arranged in a lower part.

The compressor section includes an orbiting scroll 6 which has a thinly wound wrap 6b standing upright on a flat plate part 6a and performs an orbiting motion, and a thinly wound wrap 7b which stands upright on a flat plate part 7a and is fixed to the frame 5. It is formed by interlocking fixed scrolls 7. The lower end of the crankshaft 4, which is integral with the rotating shaft of the electric motor 3, is immersed in an oil reservoir 9 formed at the bottom of the closed container 1. On the other hand, an oil hole 4a that opens at an eccentric position is provided. The orbiting scroll 6 is provided with a communication hole 10 at a position where the pressure is approximately intermediate between the suction pressure and the discharge pressure, and is provided with an intermediate pressure chamber 8 where the pressure is intermediate. The upper end of the crankshaft 4 is fitted into a boss portion 6C projecting downward from the orbiting scroll 6. The rotation of the crankshaft 4 causes the embossed portion 6C to rotate within the intermediate crown 8 of the frame 5, causing the orbiting scroll 6 to perform an orbiting motion, and the mutual contact points of the orbiting wrapper b and the fixed wrapper 7b to move, causing the suction pipe to move. 11 is compressed inward from the thinly wound outer chamber, and is discharged into the sealed container 1 from the discharge port IC provided at the center of the fixed scroll 7, and is discharged into the airtight container 1 through the passage 7d provided on the outer periphery of the fixed scroll. , a portion passes through the outer circumferential passage 5a of the motor 3, and a portion passes through the space between the frame 5 and the electric motor 3, and is sent out of the machine via the discharge pipe 12. Both wrap portions 6b, 7b and flat plate portions 5a, 7a of the orbiting scroll 6 and fixed scroll 7
The volume of the sealed chamber formed by this decreases and the pressure increases as you move from the outside to the center. As described above, the intermediate pressure chamber 8 formed by the orbiting scroll 6 and the frame 5 is maintained at a pressure between the suction pressure and the discharge pressure by the communication hole 10. Therefore, the orbiting scroll 6 is pressed against the fixed scroll 7 by the differential pressure between this intermediate pressure and the pressure inside the compression section, and the tips of the lap portions sb and 7b and the flat plate portion -
'a, 5a to maintain close contact of the seal portion in the gap. Furthermore, since the discharge pressure inside the closed container 1 is higher than that in the intermediate pressure chamber 8, the pressure difference causes the refrigerating machine oil to be pushed up the oil hole 4a in the crankshaft and supplied to the sliding parts. On the other hand, in this scroll compressor, the fluid pressure in the closed space formed by both scrolls acts in the radial direction of the crank part of the crankshaft 4 through the orbiting scroll 6. Therefore, the crankshaft 4 is attached to the main bearing on the upper side of the frame. 13 and a lower bearing 14 on the lower side.

However, the hermetic scroll compressor having the above structure has the following problems. The closed container is in a high-temperature discharge gas atmosphere, and the scroll compressor and electric motor that constitute the discharge gas passage are exposed to high temperatures and maintained at approximately the same level as the discharge gas temperature. Under such high temperatures, the bearing temperature becomes high, which reduces the viscosity of the lubricating oil and reduces the reliability of the sliding parts. Furthermore, as mentioned above, in a scroll compressor with a structure in which the crankshaft is supported in an inclined state between the main bearing and the lower bearing, the upper end of the main bearing supports a large gas load, and the bearing temperature increases. The present invention has been made in view of the above problems, and this invention has been made in view of the above-mentioned problems. The bearings of scroll compressors with intermediate pressure chambers are reliable, and when the pressure is reduced in this state, the refrigerant in the pond evaporates, absorbing latent heat and lowering the temperature of the oil. On the other hand, when refueling is performed using the differential pressure between the discharge pressure and the intermediate pressure, the same phenomenon as described above occurs. In general bearings, the heat generated by sliding loss is cooled with oil, so the oil supply temperature is higher than the exhaust oil temperature, but scroll compressors use the differential pressure between discharge pressure and intermediate pressure to supply oil. In this case, the reduction due to the latent heat due to evaporation of the refrigerant in the oil is much larger than the amount of heat generated due to sliding loss, and the drain oil temperature becomes lower than the oil supply temperature.

The present invention takes advantage of the above phenomenon, and lubricates the bearing and cools the upper part of the main bearing, where surface pressure is particularly high, with the low-temperature oil discharged into the intermediate chamber, contributing to improved bearing reliability. It is something to do.

Embodiments of the present invention will be described below with reference to FIGS. 2 and 3. In this embodiment, except for the housing portions of the main bearing 13 and lower bearing 14 of the frame 5, the structure and operation are the same as the conventional one. Therefore, the explanation will be omitted except for the parts related to the present invention. The inside of the container 1 is maintained at a discharge pressure, and the inside of the container 8 is maintained at an intermediate pressure as described above. 9 is oil, and refrigerant is dissolved in the pond. The oil is pushed up through the oil hole in the υ shaft 4 due to the differential pressure between the intermediate pressure and the discharge pressure, lubricates the main bearing 13 and the like, and is discharged into the intermediate pressure chamber 8. However, as mentioned above, the temperature of the drained oil is lower than the oil supply temperature due to the vaporization of the refrigerant in the oil. On the other hand, the outer periphery of the housing of the main bearing 13 of the frame 5 is provided with a recess so that the drained oil can collect therein, and the upper part of the housing of the main bearing 13 can be cooled by the drained oil. The shape of the oil reservoir 9 portion 5b of this frame 5 is preferably a ring shape all around the circumference, because the oil discharged from the bearing enters the oil reservoir portion, and the oil reservoir portion 5b is ring-shaped. This is because, by the rotation of the balance weight 15 that rotates together with the crankshaft 4, the waste oil is agitated as it rotates around the housing of the main bearing 13, making it possible to effectively cool the main bearing.

Fig. 3 is a model representation of the bearing surface pressure of this embodiment.As shown in the figure, the surface pressure at the upper end of the main bearing 13 is high and a lot of heat is generated due to sliding loss, so this part was This shows that cooling is highly effective in increasing bearing reliability. Furthermore, as shown in this example, in a cantilever bearing structure in which the shaft is supported at an angle within the bearing, the surface pressure is biased towards the one end of the bearing under relatively severe load conditions;
It is possible to indirectly investigate the surface pressure distribution.The bearing has a strong bulge, which indicates that the main bearing...
If the above range is cooled, there will be little practical effect.In addition, if the oil removed in the intermediate royal chamber 8 accumulates in excess of a certain amount, it will be turned into a mist by the balance weight 15, and
0, mixes with the refrigerant gas in the middle of compression, and transfers it to the 7C container 1.
It is discharged inside and returns to the inside of the lower part of the container 1. If the outer circumferential portion of the housing at the upper end of the main bearing, which has strong uneven contact, is thinned out in a ring shape, the rigidity of the tip of the bearing housing is reduced, and the degree of uneven contact at the end of the bearing can be reduced. This improves bearing reliability.

Since the present invention has the above-described configuration, it is possible to cool the portion of the main bearing of the scroll compressor where the surface pressure is particularly high, and the reliability of the bearing is improved.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional structural diagram of a conventional scroll compressor, Fig. 2 is a cross-sectional structural diagram of a scroll compressor showing an embodiment of the present invention, and Fig. 3 is a model showing surface pressure distribution of the main bearing of the scroll compressor. The figure shows a surface pressure model especially when the main bearing has a cantilevered structure. 1... Airtight container 2... Scroll compressor section 3.
...Electric motor 4...Crankshaft 5...Frame
6'... Orbiting scroll 7... Fixed scroll
8...Intermediate pressure chamber 9...Oil 10...Communication hole 11
... Suction pipe 12 ... Discharge pipe 13 ... Main bearing
14...Lower bearing 15...Balance weight 5b
...Frame oil reservoir Vum

Claims (1)

[Claims] 1. In a closed type scroll compression system in which a discharge unit is arranged in a continuous manner at the bottom in a closed container with a discharge pressure atmosphere,
An oil drain is provided on the outer periphery of the main bearing housing, and the bearing is supplied with oil by the differential pressure between the discharge pressure and the intermediate pressure within the oil drain, and the drained oil after lubrication is collected as bearing coolant. A scroll compressor featuring: 2. The scroll compressor according to claim 1, wherein the oil drain is provided continuously on the outer periphery of the main bearing housing, and its depth is approximately one or more of the length of the main bearing metal.