JPH07332258A - Scroll compressor - Google Patents

Abstract

PURPOSE:To reduce the size of the whole of a compressor and reduce the occurrence of resistance of a delivery flow passage, in a through-shaft type scroll compressor wherein an upsetting moment is prevented from occurring to a revolving scroll. CONSTITUTION:A crank shaft 4 is supported on the side closer to an eccentric shaft part and coupled to a drive source 3 and the tip part of the crank shaft is structured in such a manner to be positioned closer to the end plate side of the revolving scroll than the lap tip surface of the revolving scroll 6. Thus, the diameter of the eccentric shaft part of the crank shaft 4 can be suppressed to a necessary minimum limit to reduce the size of a compressor. Further, the occurrence of flow passage resistance of a delivery port is reduced and high efficiency is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft penetrating scroll compressor, and more particularly, to a refrigerant compressor for air conditioners and refrigerators, and a shaft penetrating scroll compressor most suitable for an expander or an air compressor. is there.

[0002]

2. Description of the Related Art As a conventional shaft penetrating scroll compressor, as described in JP-A-57-131896, a radial load point by compressed gas in an orbiting scroll and a supporting point of an eccentric shaft portion of a crankshaft are provided. To prevent the overturning moment from occurring in the orbiting scroll and to improve the performance of the compressor, the eccentric shaft of the crankshaft is inserted to the tip of the orbiting scroll wrap and the tip of the eccentric shaft is inserted. Further, there is a structure in which the shaft core shaft portion is extended through a discharge hole, and a bearing portion for supporting the extended shaft core shaft portion is formed in the fixed scroll.

[0003]

In the above-mentioned known technique, it is necessary to design the extension shaft core diameter smaller than the eccentric shaft diameter.

That is, in FIG. 5, assuming the diameter D1 of the extension shaft core portion 19, the diameter D2 of the eccentric shaft portion 21, the gap G between them, and the turning radius E, the diameter of the eccentric shaft portion 21 is , D2 ≧ D1 + 2E + 2G ... (1). Therefore, when the specified value of the bearing surface pressure formed on the fixed scroll is secured, the crankshaft has sufficient rigidity necessary for processing, and the extension shaft core diameter D1 is determined to maintain processing accuracy, From (1), the minimum value of the eccentric shaft diameter D2 is determined. Therefore, the eccentric shaft diameter cannot be selected by the specified value of the surface pressure of the eccentric shaft portion 22 alone, and the eccentric shaft diameter may be unnecessarily increased due to the restriction of the extension shaft core shaft diameter D1. Therefore, when the orbiting bearing boss portion 6c in the central portion of the orbiting scroll becomes large and the scroll wrap is designed so as to obtain the required compression ratio, the size of the innermost compression chamber in the central portion becomes large, so that the outer diameter of the scroll member is increased. However, there is a problem that the outer diameter of the entire compressor is increased accordingly.

Further, in order to secure the surface pressure of the extension shaft bearing,
It is possible to increase the bearing width or to increase the distance between the bearing and the compressed gas load point of the orbiting scroll so as to reduce the bearing load. There is also a problem that it is necessary to lengthen it and it is difficult to maintain sufficient strength.

Further, in the above-mentioned known technique, since the extension shaft core shaft portion has a structure of penetrating the inside of the discharge hole provided in the fixed scroll, the resistance of the discharge flow path becomes large and a high efficiency can be obtained. There was a problem of not having.

The present invention has been made in view of the above problems, and an object thereof is a shaft penetrating structure in which an overturning moment does not act on an orbiting scroll, and the size of a compressor can be reduced. An object is to provide a through scroll compressor. Another object of the present invention is to provide a highly efficient shaft-penetrating scroll compressor having a small discharge flow path resistance.

[0008]

In order to achieve the above-mentioned object, in a shaft-through type scroll compressor, the crankshaft is swung with its eccentric shaft tip end portion being rotated from the orbiting scroll wrap tip end surface. The structure is such that it is on the flat plate side. Further, the crankshaft is supported by at least one bearing portion on the side connected to the drive source with respect to the eccentric shaft portion. The bearing portion that supports the crankshaft is composed of a main bearing portion provided in the center of the frame and an auxiliary bearing portion provided on the opposite side of the drive source from the frame.

[0009]

According to the present invention, since the tip of the shaft is located lower than the tip surface of the orbiting scroll wrap, the bearing reliability and processing of the extended shaft core extended further than the eccentric shaft of the crankshaft. Since the diameter of the slewing bearing is not increased more than necessary in order to ensure accuracy, the entire compressor can be downsized. Further, since the crankshaft is supported on both sides of the drive source, the distance between bearings can be increased, the bearing load can be reduced, and high reliability and performance can be obtained. Further, the discharge flow path resistance is reduced, and thus high performance is obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1, 2 and 3.

In the closed casing 1, the scroll compression mechanism 2 is housed in the upper part and the electric motor 3 is housed in the lower part.
The scroll compression mechanism section 2 and the electric motor 3 are connected via a crankshaft 4. The compression mechanism section 2 is
An orbiting scroll 6 which vertically moves a flat wrap portion 6a on a flat plate portion or end plate portion 6a, and a spiral wrap portion 7b on the flat plate portion or end plate portion 7a which is fixed to the frame 5 with bolts or the like. The fixed scrolls 7 are formed by meshing with each other with the wraps inside.
An eccentric shaft portion 4a is formed at one end of the crankshaft 4, and the eccentric shaft portion 4a is inserted and arranged in a boss portion 6c provided at the center of the orbiting scroll 6. An intermediate pressure chamber 11 is provided between the frame 5 and the orbiting scroll 6, and the intermediate pressure chamber 11 is isolated from the inner chamber of the hermetic casing 1 by a seal ring 5b provided on the frame 5 to maintain airtightness. Is dripping Gas in the middle of compression is introduced into the intermediate pressure chamber 11, and the orbiting scroll 6 is caused by this pressure.
A pressing force is applied to the fixed scroll 7 side to maintain the seal between the scroll wrap and the end plate surface and stabilize the behavior of the orbiting scroll 6. Along with the rotation of the crankshaft 4, the orbiting scroll 6 coupled to the eccentric shaft portion 4a makes an orbiting motion without being rotated by a rotation preventing mechanism 8 such as an Oldham ring arranged in the intermediate pressure chamber 11.

When the contact points on the wrap side surface of the orbiting scroll 6 and the fixed scroll 7 take the direction of the orbiting motion in the direction of moving to the inside of the spiral, the suction gas entering the spirally shaped outer chamber is centered on the compression space. The gas is compressed by moving it to reduce the volume, and is discharged into the closed casing 1 through the discharge port 15 provided in the central portion of the fixed scroll 7. Thereafter, the discharge gas is guided to the lower space inside the hermetic casing through a passage (not shown) provided on the outer periphery of the frame 5 and a passage 14 provided on the outer periphery of the electric motor 3, and rises between the rotor and the stator of the electric motor. Then, after cooling the electric motor 3, it is discharged to the outside of the compressor through the discharge pipe 13.
The passage (not shown) and the passage 14 provided on the outer periphery of the frame 5 and the air suction portion of the discharge pipe 13 are located at different positions in the horizontal cross section of the compressor and communicate with each other. Absent.

The crankshaft 4 has its shaft portion 4d whose electric motor 3
Of the eccentric shaft portion 4a is located closer to the orbiting end plate than the wrap tip portion of the orbiting scroll 6, and the tip portion substantially protrudes from the wrap tip portion. do not do. Further, the shaft portions 4b and 4e of the crankshaft 4
Are supported by a main bearing 5a provided on the frame 5 and an auxiliary bearing 16a provided on a lower frame 16 located below the electric motor 3 in the closed casing 1.
Further, the lower frame 16 is provided with a thrust bearing 16b so that the thrust force acting on the orbiting scroll 6 is received via the crankshaft 4. Further, an oil supply passage 9 is formed in the crankshaft 4, and an oil supply pipe 10 is attached to the lower end of the shaft, and the oil is collected in an oil sump 18 at a lower portion of the closed casing 1 by a centrifugal pump action. Lubricating oil is supplied to the oil supply pipe 10 and the oil supply passage 9
The structure is such that the inside of the crankshaft 4 rises through and is supplied to each bearing portion.

The bearing shaft portion of the crankshaft 4 is an eccentric shaft portion 4.
a and a shaft core shaft portion 4b below the eccentric shaft portion 4a. Of these, the diameter D2 of the eccentric shaft portion 4a determines the outer diameter of the orbiting scroll 6 as described above, and thus determines the outer diameter of the entire compressor. Since this diameter is designed only by the desired performance of the slewing bearing, the eccentric shaft diameter is more than necessary in order to secure sufficient rigidity for machining the extension shaft core shaft portion and the bearing surface pressure as in the past. It doesn't have to be very large. Therefore, the outer diameter of the entire compressor can be suppressed to the necessary minimum.

Further, in the structure in which the crankshaft 4 is supported by the main bearing 5a and the auxiliary bearing 16a, the compressed gas load point and the distance between the bearings are increased, and the bearing load can be reduced, so that the bearing diameter and width can be reduced. Is small,
It also has the effect of improving the reliability of the bearing. or,
If the width of the main bearing 5a is reduced, the distance between the counterweight 17 provided on the shaft portion 4c and the orbiting scroll 6 can be shortened by that amount, so that the outer diameter of the counterweight 17 can be reduced. It is possible to reduce the outer diameter of the entire compressor.

The crankshaft 4 is structured such that its tip end position is closer to the orbiting end plate side than the tip end face of the orbiting scroll wrap. Therefore, the extension shaft core of the discharge port 15 provided in the central portion of the fixed scroll 7 is provided. There is no increase in flow path resistance due to the shaft. Therefore, high efficiency can be obtained. or,
There is also an effect that the shape and size of the discharge port 15 can be freely determined.

Further, since the bearing on the fixed scroll side is eliminated, the number of parts is reduced and the cost can be reduced.
Further, since there is no bearing on the rear side of the fixed scroll, the centering of the shaft is facilitated, so that the assemblability and productivity are improved, and the height of the compressor can be reduced. is there.

[0018]

As described above, according to the present invention,
It is possible to reduce the size of the compressor with a shaft penetrating structure in which an overturning moment does not act on the orbiting scroll. Further, the discharge flow path resistance can be reduced, and high efficiency can be achieved.

[Brief description of drawings]

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

FIG. 2 is a partial sectional view showing an embodiment of the present invention.

FIG. 3 is a front view of a crankshaft showing an embodiment of the present invention.

FIG. 4 is a partial cross-sectional view showing a conventional method.

FIG. 5 is a partial front view of a crankshaft according to a conventional method.

[Explanation of symbols]

1 ... hermetic casing 2 ... compression mechanism 3 ...
・ Electric motor 4 ・ ・ ・ Crankshaft 4a ・ ・ ・ Eccentric shaft
4b, 4c, 4d ... Shaft core shaft portion 5 ... Frame
5a ... Main bearing 5b ... Seal ring 6 ...
Orbiting scroll 6a ... flat plate portion 6b ... lap portion 6c ... boss portion 7 ... fixed scroll 7a ... flat plate portion 7
b ... Wrap portion 8 ... Rotation preventing mechanism 9 ... Oil supply passage 10 ... Oil supply pipe 11 ...
Intermediate pressure chamber 12 ... Suction pipe 13 ... Discharge pipe 14 ... Gas passage 15 ... Discharge port 16 ...
・ Lower frame 16a ・ ・ ・ Sub bearing 16b ・ ・ ・ Thrust bearing 17 ・ ・ ・ Counter weight 18 ・ ・
・ Oil sump 19 ・ ・ ・ Fixed scroll side sub-frame
19a ... Sub-bearing on fixed scroll side 20 ... Extension shaft core shaft

Front page continued (72) Inventor Kenji Tojo 390 Muramatsu, Shimizu-shi, Shizuoka Hitachi Air Conditioning Systems Division (72) Inventor Kazutaka Suto 502 Jinmachi, Tsuchiura-shi, Ibaraki Hiritsu Seisakusho Co., Ltd.

Claims (3)

[Claims] 1. A fixed scroll member and an orbiting scroll member in which a spiral wrap is erected on a flat plate in an airtight casing are engaged with each other with the wrap inside, and a drive source is provided for a crankshaft for driving the orbiting scroll member. Combine,
The orbiting scroll is orbited against the fixed scroll fixed to the frame without rotating, and is moved around the compression space formed by both scroll members to reduce the volume and compress the gas. In a shaft penetrating scroll compressor in which a slewing bearing portion is provided in the center of the eccentric shaft portion, and the eccentric shaft portion of the crankshaft is inserted into the wrap portion in the slewing bearing portion. On the side of the coupled shaft core, the main bearing is provided in the center of the frame and the auxiliary bearing is provided on the opposite side of the drive source from the frame, and the tip of the eccentric shaft of the crankshaft is supported. The scroll compressor is characterized in that the position is on the side of the orbiting end plate with respect to the tip end face of the orbiting scroll wrap. 2. The scroll compressor according to claim 1, wherein the crankshaft is supported by at least one bearing on the side connected to the drive source with respect to the eccentric shaft. 3. The bearing portion for supporting the crankshaft,
A scroll compressor comprising a main bearing portion provided in a central portion of a frame and a sub bearing portion provided on a side opposite to a frame with respect to a drive source.