JPH04214976A - Scroll compressor - Google Patents

Abstract

PURPOSE:To smooth rotation of a main spindle so as to prevent the performance of a scroll compressor installed in e.g. a refrigerating machine, etc., from being deteriorated by preventing a sub-frame supporting the main spindle from being affected by welding of an end shell. CONSTITUTION:The starting point 16a of continuous welding by which to fix together a center shell 4a and an end shell 4b both of which constitute a sealed shell 4 is disposed on the circumference of the center shell 4a and in the same direction as one of welding points 14a, 14b, 14c for spot welding by with to fix a sub-frame 8 to the center shell 4a.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a scroll compressor installed in, for example, a refrigeration system, and relates to welding between a closed container that constitutes a main part and a frame that supports a main shaft that drives an oscillating scroll. be.

0002

2. Description of the Related Art Conventionally, there is a scroll compressor in which a subframe supporting a bearing supporting one end of a main shaft that drives an oscillating scroll is fixed to a side wall of a hermetic shell by spot welding. FIG. 4 is a sectional view showing the configuration of a conventional scroll compressor of this type.

In the figure, 1 is a spiral body 1b on a base plate 1a.
2 is a base plate 2a;
An oscillating scroll 3 having a spiral body 2b projecting thereon has a flange 3a on one side, fixedly supports the base plate 1a on its upper end surface, and has a recess formed in the center by the flange 3a. Place 3
This is a frame in which the swinging scroll 2 is rotatably mounted, and has a bearing portion 3c on the other side that projects in the axial direction and supports one end of a main shaft, which will be described later.

4 is formed into a cylindrical shape and has a flange 3 on the upper inner circumferential wall.
A sealed shell 5 consisting of a center shell 4a fixed by shrink fitting, and a dish-shaped end shell 4b fixed to both ends of the center shell 4a by continuous welding to close each open end.
6 is a compression chamber formed between the spiral bodies 1b and 2b, 6 is a high pressure chamber formed between the base plate 1a and the end shell 4b, and 7 is a compression chamber formed between the spiral bodies 1b and 2b.
is a discharge port that passes through the center of the base plate 1a and communicates the compression chamber 5 and the high pressure chamber 6.

As shown in FIG. 5, which shows a cross section taken along the line V-V in FIG.
The sub-frame has a bearing part 8a paired with c and a plurality of ribs 8b formed radially on the outer surface, and the outer surface of each rib 8b is fixed to the lower inner circumferential wall of the center shell 4a by spot welding. ing. 9 has frame 3 on one end
A pump device 10 provided in the subframe 8 in the center thereof is a main bearing whose other end is supported by the bearing portion 3c of the subframe 8, and whose other end is supported by the bearing portion 8a of the subframe 8, and whose one end side is rotatably connected to the oscillating scroll 2. A hole 9a is formed through the hole 9a through which lubricating oil supplied through the hole 9a flows.

11 is a low-pressure chamber formed below the frame 3; 12 is an electric motor disposed within the low-pressure chamber 11 for rotating the main shaft 9; the electric motor rotor is fixed to the main shaft 9 by press-fitting or the like; , and a motor stator fixed to the inner surface of the side wall of the center shell 4a. A glass terminal 13 is attached to the side wall of the center shell 4a and is used to supply power to the electric motor 12.

[0007] Here, the fixing of the subframe 8 and the end shell 4b to the center shell 4a by welding will be explained in more detail. As shown in Figure 5, first,
Insert the outer surface of each rib 8b of the subframe 8 along the inner circumferential wall of the center shell 4a to a predetermined position, and
and the center shell 4a are fixed by arc spot welding. The welding points of this arc spot welding are 14a, 14
b, 14c. In addition, when fixing this subframe 8, the subframe 8 is several μm to the frame 3.
The precision of each component is controlled to ensure coaxiality on the order of several tens of micrometers.

Next, after lightly press-fitting the end shell 4b into the center shell 4a, normally one welding torch is used to continuously weld the entire circumference by moving the torch or rotating both shells 4a and 4b. arc welded and sealed. The starting point of this arc welding is indicated by 15a.

The conventional scroll compressor constructed as described above operates as follows, as is generally well known. That is, the main shaft 9 driven by the electric motor 12 is supported by the bearing part 3c of the frame 3 and the bearing part 8a of the sub-frame 8 and rotates, causing the swinging scroll 2 to orbit. As a result, the low-pressure refrigerant gas in the low-pressure chamber 11 is
, 2b, and after being compressed into high-pressure refrigerant gas, it is discharged from the discharge port 7 into the high-pressure chamber 6 and sent out to the outside of the sealed shell 4.

0010

[Problems to be Solved by the Invention] Since the conventional scroll compressor is constructed as described above, the end shell 4
When arc welding is performed between the center shell 4a and the center shell 4a, the molten metal begins to solidify near the welding start point 15a. Therefore, the end shell 4b is attracted to the welding start point 15a side of the center shell 4a. however,
At this point, the end shell 4b can freely move in the radial direction within the center shell 4a, so a gap is created between the end shell 4b and the center shell 4a on the opposite side of the welding start point 15a, as shown in FIG. , no internal stress occurs due to welding.

Thereafter, the molten metal gradually hardens along the welding path, and each part of the center shell 4a is drawn to the end shells 4b and deformed so as to fall inward. The amount of inward deformation of the center shell 4a is approximately proportional to the size of the gap between the end shell 4b and the center shell 4a. The deformation in the welding point 14a direction is the largest, and at this time, as shown in FIG. 7, along with this deformation (indicated by the arrow in the figure), the subframe 4b also moves slightly toward the welding start point 15a, so that the subframe relative to the frame 3 If the coaxiality of the shaft 4b deteriorates and exceeds a permissible limit, the rotation of the main shaft 9 supported by the bearings 3c and 8a will deteriorate, resulting in a problem that performance will be affected.

[0012] This invention was made in order to solve the above-mentioned problems, and it is possible to achieve smooth rotation of the main shaft without deteriorating the coaxiality of the subframe with respect to the frame even if the end shell is welded, thereby improving performance. The purpose of this invention is to provide a scroll compressor that does not cause any problems.

[0013]

[Means for Solving the Problems] A scroll compressor according to the present invention has a welding start point for continuous welding that fixes a center shell and an end shell to one of the welding points for spot welding that fixes a subframe to the center shell. They are arranged in the same direction on the circumference of the center shell.

[0014]

[Operation] The center shell of the scroll compressor in this invention deforms mainly at a position away from the spot welding point where the subframe is fixed, and prevents deterioration of coaxiality without affecting the subframe. .

[0015]

[Embodiments] Examples of the present invention will be described below. FIG. 1 is a sectional view showing the main parts of a scroll compressor according to an embodiment of the present invention, and corresponds to FIG. 5 of the conventional example. The scroll compressor of this embodiment is different from the conventional scroll compressor shown in FIG. 4, as shown in FIG. This is done in the same direction as the welding point 14a of spot welding for fixing to the center shell 4a.

In the embodiment of the present invention constructed as described above, as in the conventional one, first, the outer surface of each rib 8b of the subframe 8 is placed at a predetermined position along the inner circumferential wall of the center shell 4a. The rib 8b and the center shell 4a are fixed by arc spot welding. next,
After the end shell 4b is lightly press-fitted into the center shell 4a, using one welding torch, the torch is moved or both shells 4a and 4b are rotated to continuously arc weld the entire circumference and seal the shell.

When the end shell 4b and the center shell 4a are arc welded as described above, the molten metal begins to solidify near the welding start point 16a. therefore,
The end shell 4b is the welding start point 1 of the center shell 4a.
It is attracted to the 6a side. However, at this point, the end shell 4b can freely move in the radial direction within the center shell 4a, so the welding starting point 1
A gap is created between the end shell 4b and the center shell 4a on the opposite side from the welding point 14a and the welding point 14a, and no internal stress is generated due to welding.

Thereafter, the molten metal gradually hardens along the welding path, and each part of the center shell 4a is drawn to the end shells 4b and deformed so as to fall inward. The amount of inward deformation of the center shell 4a is approximately proportional to the size of the gap between the end shell 4b and the center shell 4a.
The deformation in the direction intermediate between 4b and 14c is the largest,
As shown in FIG. 3, the side wall of the center shell 4a is deformed (indicated by an arrow in the figure), but not only the welding point 14a between the subframe 8 and the center shell 4a but also the welding point 14b
, 14c are located far apart from each other, so the influence on the subframe 8 is small, and deterioration of the coaxiality of the subframe 8 with respect to the frame 3 is also prevented.

Note that the end shell 4 in the above embodiment
Although the welding start point 16a in b is shown in the same direction as the arc spot welding point 14a of the subframe 8, the same effect can be obtained even if it is in the same direction as the other arc spot welding points 14b and 14c. Needless to say.

[0020]

As described above, according to the present invention, the welding start point of the continuous welding that fixes the center shell and the end shell is set to one welding point of the spot welding that fixes the subframe to the center shell. are arranged in the same direction on the circumference, so even if the center shell is deformed due to welding of the end shells, it does not affect the subframe, and the main shaft rotates smoothly, providing a scroll compressor that does not affect performance. can do.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing essential parts of a scroll compressor in an embodiment of the present invention.

FIG. 2 is a sectional view showing the state of the subframe in FIG. 1 during welding.

FIG. 3 is a sectional view showing a state of deformation of the center shell in FIG. 1 during welding.

FIG. 4 is a sectional view showing the overall configuration of a conventional scroll compressor.

FIG. 5 is a cross-sectional view showing a cross section taken along line V-V in FIG. 4;

FIG. 6 is a sectional view showing a state of a conventional subframe during welding.

FIG. 7 is a sectional view showing a state of deformation of a conventional center shell during welding.

[Explanation of symbols]

1 Fixed scroll 2. Oscillating scroll 3 Frame 8 Subframe 9 Main shaft 14a Welding point 14b Welding point 14c Welding point 16a Welding start point

Claims (1)

[Claims] Claim 1: A hermetic shell consisting of a cylindrical center shell whose both ends are covered with dish-shaped end shells and the periphery of which is fixed by continuous welding; A fixed and oscillating scroll that gradually compresses and discharges in a compression chamber formed by combining, a main shaft that is rotated by an electric motor and drives the oscillating scroll, and an outer peripheral part fixed to the center shell and one end of the main shaft. A scroll compressor comprising a supporting frame and a sub-frame whose outer peripheral portion is fixed to the center shell by spot welding and which supports the other end of the main shaft, wherein continuous welding is performed to fix the center shell and the end shell. A crawl compressor characterized in that a welding start point is arranged in the same direction on the circumference of the center shell as one of the welding points for spot welding that fixes the subframe to the center shell.