JPH1182327A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the fastening strength of a frame and a fixed scroll by effectively utilizing a dimensional difference between a screw part and a shaft part having a diameter smaller than that of the screw part, and reducing the inner diameter dimension of a through hole so as to secure a bolt seat surface. SOLUTION: In a scroll compressor for turning a turning scroll 4 in relation to a fixed scroll 3, the turning scroll 4 is locked inside a frame 5 freely to be slid, and an end surface of the frame 5 and an end surface of the fixed scroll 3 are made to abut on each other, and the frame 5 and the end surface of the fixed scroll 3 are fastened by plural bolts 8. At this stage, as a bolt 8, a rolling bolt having an under neck diameter smaller than the screw outer diameter (nominal diameter) is used, and a spot facing 5d having an appropriate depth and a diameter larger than the bolt nominal diameter is provided in the frame 5 at a bolt engagement side of a screw hole 5c. On the other hand, inner diameter of a bolt through hole of the fixed scroll 3 is formed into a dimension close to the bolt nominal diameter, and at the time of combining them so as to fasten the frame 5 and the fixed scroll 3 to each other, a rear end of a screw part of the bolt 8 is positioned within a range of the spot facing 5d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fastening structure between a frame and a fixed scroll, which forms a compression mechanism of a scroll compressor.

[0002]

2. Description of the Related Art A scroll compressor having low vibration and low noise characteristics used in a home air conditioner and the like is disclosed in
As shown in FIG. 1 of JP-A-32092, there is provided a orbiting scroll composed of a disk-shaped head plate and a spiral wrap integrally formed upright on the head plate, and a structure similar to the orbiting scroll. The fixed scroll having a discharge port at the center of the end plate is meshed with each other so that the side walls of the wrap are in contact with each other, and these are housed in a cylindrical closed container having a suction port, and the fixed scroll is fixed to the closed container. By rotating the motor on the crankshaft having an eccentric portion fitted to the orbiting scroll while preventing the orbiting scroll from rotating by the anti-rotation mechanism, the fixed scroll wrap is maintained while maintaining the contact state between the wraps of both scrolls. The orbiting scroll is driven so that the center of the spiral of the orbiting scroll wrap orbits around the center of the spiral.

FIG. 3 schematically shows a compression mechanism portion of this conventional scroll compressor, and its structure will be described in detail.

Reference numeral 20 denotes a compression mechanism, 21 denotes a revolving scroll, 21a denotes a wrap, 21b denotes a boss, 21c denotes a bearing, 21d denotes a keyway, 22 denotes a fixed scroll, 22a
Is a wrap, 22b flange portion, 22c is a bolt through hole,
22d is a head plate, 22e is a seat surface, 23 is a frame, 23a
Is a flange portion, 23b is a screw hole, 23c is a main bearing, 23d is a key groove, 24 is a bolt, 24a is a shaft portion, 2
4b is a screw portion, 24c is a rear end of the screw portion, 24d is a bolt seat surface, 25 is a crankshaft, 25a is an eccentric portion, 26 is an Oldham ring, 26a is an Oldham key, 27 is an electric motor, 27a is a rotor, and 27b is a stator. , 27c are air gaps, 28 is a closed container, and 28a is an inner wall of the closed container.

FIG. 3 is a side sectional view of a conventionally known scroll compressor.
Crankshaft 2 inserted in the main bearing 23c of No. 3
After the stator 27a of the electric motor 27 is mounted on the lower end side of the rotary shaft 5 by press fitting or the like, the bearing 2 provided on the eccentric portion 25a of the crankshaft 25 and the boss portion 21b of the orbiting scroll 21 is mounted.
1c, and the wrap 21a of the orbiting scroll 21;
The fixed scroll 22 contacted with and engaged with the wrap 22a is arranged as shown in the figure, and the key 26a of the Oldham ring 26, which is a rotation preventing mechanism of the orbiting scroll 21, is connected to the keyway 21d of the orbiting scroll and the keyway of the frame 23, respectively. 23d to prevent the rotation of the orbiting scroll 21 from rotating.
b, a plurality of bolts 24 are passed through through holes 22c provided in
Screw hole 23b provided in flange portion 23a of frame 23
And the tightening is performed while centering and adjusting the mutual wraps 21a and 22a, thereby completing the assembly of the compression mechanism 20.

FIG. 4 shows details of an example of a tightening portion of the bolt 24 shown in FIG. 3. In the conventional scroll compressor, a bolt shaft portion 24a has an effective diameter and a screw portion 24b formed by plastic working. Is formed by the rolling method.
It is customary to use a general rolled bolt to form the fastening portion as shown in FIG. That is, the fixed scroll 22
Bolts 22c in the flanges 22b of the frame 2
3, a plurality of screw holes 23b are provided in the flange 23a (not shown), and bolts 24 are inserted through the through holes 22c with the respective end faces in contact with each other as shown in FIG.
And tighten it. At this time, the screw portion 24 of the bolt 24
b is located in the through hole 2 of the fixed scroll 22.
2c.

On the other hand, a stator 27b of the electric motor 27 is joined to an arbitrary position below the closed casing 28, and an inner diameter of the stator 27b and a rotor previously joined to the crankshaft 25 of the compression mechanism 20 described above. The closed container 28 and the fixed scroll 22 are locked by a plurality of spot weldings while appropriately holding the air gap 27c between the outer diameter 27a and the outer diameter 27a.

[0008]

In a high-pressure container type scroll compressor that stores a high-pressure discharge gas in a closed container 28, a deformation load is applied from the outside to the compression chamber (the meshing portion of the wrap). Therefore, it is necessary to increase the thickness of the end plate 22d of the fixed scroll 22 and the weight increases. For this reason, an inertial force is generated by an impact (hereinafter referred to as a lateral impact) from a direction perpendicular to the bolt tightening direction,
There is a drawback that the fixed scroll 22 shifts in the horizontal direction.

For this reason, in a conventionally known bolt tightening structure, a through hole 22 having an inner diameter corresponding to the bolt screw portion 24b is provided.
c (in the case of a plurality of bolt tightening structures, it is necessary to increase the inner diameter of the through hole 22c which is compatible with assembly in order to absorb the screw hole pitch tolerance), and to the fixed scroll 22 of the bolt seat surface 24d. And the bolt seating surface 22e of the fixed scroll 22 is easily buckled, and as a result, the bolt 24 is designed to increase the number of tightening bolts as much as possible and to increase the tightening force by increasing the diameter of the bolt. ing.

As a result, it is necessary to increase the cost due to the increase in the number of parts and to enlarge the flanges 22b and 23b for securing the bolt seating surface which leads to an increase in the size of the compressor. There is a drawback that goes against the needs of scroll compressors used in harmonizers and the like.

[0011]

SUMMARY OF THE INVENTION The present invention makes effective use of the difference in dimension between a shaft portion and a thread portion, which are smaller in diameter than the thread portion, which is a characteristic of a general rolled bolt, and uses the inside diameter of a through hole. It is an object of the present invention to improve the fastening strength between the frame and the fixed scroll by reducing the size and securing the bolt bearing surface.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

Here, 1 is a closed container, 2 is a compression mechanism,
3 is a fixed scroll, 3a is a head plate, 3b is a wrap, 3c
Is a discharge port, 3d is a suction port, 3e is a flange, 3f is a bolt through hole, 3g is a bearing surface, 4 is a revolving scroll, 4a is a head plate, 4b is a wrap, 4c is a boss, 4d is a bearing, 4e is a keyway, 5 is a frame, 5a is a main bearing, 5b is a flange,
5c is a screw hole, 5d is a counterbore, 5e is a keyway, 6 is a crankshaft, 6a is an eccentric part, 7 is an Oldham ring, 7
a is an Oldham key, 8 is a bolt, 8a is a shaft, 8b is a screw, 8c is a rear end of a screw, 8d is a seat surface, 9 is a motor, 9
a is a stator, 9b is a rotor, 9c is an air gap, 10
Is a suction pipe, and 11 is a contact surface between the fixed scroll and the frame.

In FIG. 1, a compression mechanism 2 having a fixed scroll 3 and an orbiting scroll 4 is accommodated in an upper portion of a closed container 1. The fixed scroll 3 and the orbiting scroll 4 are engaged with each other to form a compression chamber (closed space). The fixed scroll 3 is composed of a disk-shaped end plate 3a and a spiral wrap 3b standing upright, and has a discharge port 3c at the center and a suction port 3d at the outer periphery.

The orbiting scroll 4 has a disk-shaped end plate 4a,
It is composed of a wrap 4b formed upright on the same shape as the wrap 3b of the fixed scroll 3, and a boss 4c formed on the opposite wrap surface of the end plate 4a. The frame 5 has a main bearing 5a formed at the center thereof. A crankshaft 6 is supported by the main bearing 5a. An eccentric portion 6a at the tip of the crankshaft 6 is inserted into the bearing 4d in the boss 4c so as to be pivotable. I have.

The fixed scroll 3 passes a bolt 8 through a through hole 3f provided in the flange 3e, and
b, and is screwed and fastened to a screw hole 5c provided. The orbiting scroll 4 is regulated so that the key 7a of the Oldham ring meshes with the key groove 4e of the orbiting scroll 4 and the key groove 5e of the frame 5, respectively, so that the orbiting scroll 4 does not rotate with respect to the fixed scroll 3 and orbits. A suction pipe 10 is connected to a suction port 3d of the fixed scroll 3, and a rotor 9b of an electric motor 9 is attached to the lower end of the crankshaft 6 by press-fitting or the like, thereby completing the assembly of the compression mechanism unit 2.

On the other hand, a stator 9a of the electric motor 9 is accommodated in a lower portion of the closed container 1 by shrink fitting or the like.

In the compression mechanism 2 of the present invention, the fixed scroll 3 and the frame 5 are fastened as shown in FIG. That is, the bolt 8 used for tightening is a general rolled bolt formed by forming the shaft portion 8a as an effective diameter and rolling the screw portion 8b by plastic working. The fixed scroll 3 is provided on its flange 3e with a through hole 3f having an inside diameter small enough to allow the screw portion 8b of the bolt 8 to pass therethrough, and the frame 5 is provided with a plurality of screw holes 5c (not shown). In addition, a counterbore 5d having an arbitrary depth is formed on the screw biting side of the screw hole 5c. The fixed scroll 3 and the frame 5 are brought into contact with each other, and the bolt 8 is screwed into the screw hole 5c of the frame 5 through the through hole 3f of the fixed scroll 3 and fastened as shown in FIG. then,
The position of the rear end 8c of the screw portion 8b of the bolt 8 is accommodated in a range of a counterbore 5d of the frame 5 as shown in the figure.

[0019]

According to the present invention described above, the inner diameter of the through-hole 3f of the fixed scroll 3 is adjusted to the screw portion 8b and the through-hole 3 assuming simultaneous tightening at a plurality of places as in the conventional compressor.
There is no need to make large dimensions to avoid f interference,
Since the bolts can be formed to have a small diameter that allows the opposed outer diameters of the screws (for each position) to pass simply, the bolt bearing surface 8d hits the bearing surface 3g portion of the fixed scroll 3 widely, and the buckling of the frame 5 is reduced. It is possible to improve the fastening force proportionally. As a result, it is possible to provide a compact and low-cost compressor which is a need for a scroll compressor mounted on a home air conditioner or the like.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of a scroll compressor according to the present invention.

FIG. 2 is an enlarged side sectional view illustrating a bolt fastening portion of FIG. 1;

FIG. 3 is a side sectional view showing an embodiment of a conventionally known scroll compressor.

FIG. 4 is an enlarged side sectional view illustrating a bolt fastening portion of FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Closed container, 2 ... Compression mechanism part, 3 ... Fixed scroll,
4 orbiting scroll, 5 ... frame, 6 ... crankshaft, 7 ... Oldham ring, 8 ... bolt, 9 ... electric motor,
10: suction pipe, 11: contact surface between fixed scroll and frame.

Claims (1)

[Claims] A fixed scroll and an orbiting scroll, each comprising a head plate and a spiral wrap standing upright, are engaged with each other with the wrap inside, and the orbiting scroll is caused to orbit with respect to the fixed scroll. Scroll compressor that obtains the desired performance by compressing it, slidably locks the orbiting scroll inside the frame, abuts the end surface of the frame and the end surface of the fixed scroll, and uses a plurality of bolts to fix the frame and the fixed scroll. Using a rolled bolt with a neck lower shaft diameter smaller than the screw outer diameter (hereinafter referred to as the nominal diameter), set the bolt to a desired depth on the biting side of the screw hole of the frame into which the bolt is inserted. A counterbore larger than the nominal diameter of the bolt is provided. On the other hand, the inner diameter of the fixed scroll's bolt through hole should be close to the nominal diameter of the bolt so that the bolts can individually pass through. A scroll compressor characterized by being located within the range of counterbore.