JP3109275B2 - Scroll compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor used for air conditioners for business use and home use.

[0002]

2. Description of the Related Art Electric compressors for refrigeration include a reciprocating type compressor and a rotary type compressor, and both types have been used in the home and commercial air conditioning fields. The reciprocating type is gradually decreasing in terms of cost and performance. The scroll type has been put to practical use in place of the reciprocating type and the rotary type, taking advantage of its low noise and low vibration characteristics.

[0003] Generally, the reciprocating type is called a low pressure type because a low pressure acts in a closed container, and the rotary type is called a high pressure type because a high pressure acts.

[0004] At present, both types of the scroll type are conceivable, but in the case of the low pressure type, since the motor is in a low pressure refrigerant gas atmosphere, the motor can be easily cooled and the reliability of the motor is high. Further, there is an advantage that the weight can be reduced, including the fact that a low-pressure shell container can be adopted.

FIG. 7 shows an example of a longitudinal sectional view of a conventional low-pressure scroll compressor. A compression mechanism 2 in which a fixed scroll 2a and a movable scroll 2b orbiting with respect to the fixed scroll 2a are engaged, a thrust bearing 3 for supporting the movable scroll 2b, and a bearing component for supporting the thrust bearing 3 inside the closed container 1. 4 is provided on the upper part. Then, the shaft 2c of the movable scroll 2b is connected to the end 5 of the crank shaft 5.
The orbiting scroll 2 b is inserted into the eccentric bearing 6 of the hole 5 b provided in the a and is driven to turn by the crankshaft 5.
A rotor 7a of an electric motor 7 is attached to the crankshaft 5, and is supported by a main bearing 8a and a sub-bearing 8b of the bearing component 4 together with a stator 7b fixed to the closed casing 1 by shrink fitting. An oil reservoir 10 for storing a lubricating oil 9 is provided at a lower bottom portion of the closed container 1, and a gas suction pipe 11 is provided on a side portion of the closed container 1. The gas pressure on the suction side acts on the oil sump 10. Reference numeral 15 denotes an upper shell 1a which is a part of the closed container 1 and a fixed scroll 2
a discharge chamber provided between the compression mechanism 2
Temporarily accumulates the gas compressed by and serves as a projecting muffler. Reference numeral 16 denotes a projecting pipe for emitting a compressed gas to the outside of the closed vessel 1. The high-pressure gas in the projecting chamber 15 and the low-pressure gas acting on the oil sump 10 are separated by the fixed scroll 2a and the bearing component 4 via the spacer 17. They are connected by bolts. The entire periphery of the spacer 17 is fixed to the closed container 1 by welding. Reference numeral 20 denotes an Oldham ring for preventing the movable scroll 2b from rotating with respect to the fixed scroll 2a, and reference numeral 21 denotes a suction port provided in the bearing component 4 for sucking low-pressure gas into the compression mechanism 2.

Next, a description will be given of the compression action having the above configuration. The low-pressure gas returns from the suction pipe 11 and partially
Is cooled and guided to the compression mechanism 2 from the suction port 21 of the bearing component 4. Movable scroll 2 with respect to fixed scroll 2a
As a result, the sucked gas is compressed by the compression mechanism 2 to become a high-pressure gas, and the protruding chamber 1
Enter 5. Then, the gas is returned from the protruding tube 11 to circulate the gas, thereby constituting a known compression cycle.

Next, the operation principle of the scroll compressor is shown in FIG.
This will be described with reference to FIGS. FIG. 4A shows the movable scroll 2 in a state in which the compression is started simultaneously with the completion of the suction.
FIG. 4 shows the relationship phase between “b” and the fixed scroll 2a.
4 (b), FIG. 4 (c), and FIG.
4A shows a state in which the orbiting scroll 1 has been rotated by 90 degrees in the counterclockwise direction from the states shown in FIGS. 4B and 4C.

4 (b) and 4 (b) from the state of FIG.
As the state shifts to the state of (c), both scrolls 2a, 2a
b, the enclosed space is reduced, the fluid is compressed and at some rotational angle between FIGS. 4 (c) and 4 (d),
The compressed fluid is discharged by the winding start wall surface portion of the movable scroll wrap being separated from the fixed scroll wall surface and the closed space communicating with the discharge port 22. Then, the movable scroll 2b rotates counterclockwise 90 degrees from the state of FIG. 4D, thereby returning to the original state, that is, the state of FIG. 4A. When the discharge port allows high-temperature and high-pressure gas to flow, the orbiting scroll 2b rotates clockwise. At this time, FIGS. 4 (d), 4 (c), 4 (b), 4 (a)
It becomes in order. 4 (a) to 4 (d), the closed space is formed by the radial contacts of both scrolls 2a, 2b.

The gas pressure and centrifugal force generated by this compression act on the movable scroll. The main forces are the centrifugal force Fe of the movable scroll, the gas pressure Fpt in the tangential direction, and the gas pressure Fpa in the thrust direction.

The centrifugal force Fe and the tangential gas pressure F
pt is received by the main bearing, and the gas pressure Fpa in the thrust direction is normally received by a circular thrust bearing.

As shown in FIG. 5, when the direction of the resultant force of the centrifugal force and the thrust force is within the thrust bearing surface, the operation is stable without rolling over.

Generally, the thrust force has a tendency shown in FIG. 6 with respect to the crank angle.

[0013]

In such an operating state, the conventional circular thrust bearing inside the Oldham ring cannot provide a sufficient area and receives a large thrust force, so that the surface pressure increases and the oil film breaks. May occur.

Further, when a high-speed operation such as an inverter is performed, the centrifugal force increases, and when the combined force of the thrust force and the centrifugal force is out of the thrust plane, the movable scroll may be overturned, and the operation range is limited. Was.

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention approximates an outer peripheral shape of a sintered thrust bearing to an inner envelope generated by reciprocating motion of an Oldham ring.

Further, the outer peripheral shape of the thrust bearing is made elliptical, and the major axis direction of the thrust bearing is arranged in the eccentric direction of the movable scroll when the thrust force due to the gas compression force is minimized.

[0017]

According to the technical means of the present invention, the area of the thrust bearing can be increased. The large surface area reduces surface pressure and increases reliability. When the long-diameter portion of the thrust bearing goes outside, it is difficult to overturn, and the operating range can be expanded.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The vertical sectional view of the scroll compressor of the present invention shown in FIG. 1 is almost the same as the vertical sectional view of the conventional scroll compressor shown in FIG. 7 except for the thrust bearing. Use the same number.

In FIGS. 1 to 7, a compression mechanism 2 in which a fixed scroll 2a and a movable scroll 2b orbiting with respect to the fixed scroll 2a are engaged, and a thrust bearing for supporting the movable scroll 2b are provided inside the closed casing 1. 3. A bearing component 4 for supporting the thrust bearing 3 is provided at an upper portion. Then, the shaft 2c of the movable scroll 2b is inserted into the eccentric bearing 6 of the hole 5b provided at the end 5a of the crankshaft 5, and the movable scroll 2b is driven to rotate by the crankshaft 5. The rotor 7 a of the electric motor 7 is mounted on the crankshaft 5.
Are mounted, and a main bearing 8a and a sub-bearing 8b of the bearing component 4 together with a stator 7b fixed by shrink-fitting in the closed casing 1.
And is supported by. An oil reservoir 10 for storing a lubricating oil 9 is provided at a lower bottom portion of the closed container 1.
A gas suction pipe 11 is provided on the side of the gas supply pipe. The gas pressure on the suction side acts on the oil sump 10. Reference numeral 15 denotes a discharge chamber provided between the upper shell 1a, which is a part of the closed vessel 1, and the fixed scroll 2a, and serves as a projecting muffler for temporarily storing gas compressed by the compression mechanism 2. Reference numeral 16 denotes a projecting pipe for emitting a compressed gas to the outside of the closed vessel 1. The high-pressure gas in the projecting chamber 15 and the low-pressure gas acting on the oil sump 10 are separated by the fixed scroll 2a and the bearing component 4 via the spacer 17. They are connected by bolts. The entire periphery of the spacer 17 is fixed to the closed container 1 by welding. An Oldham ring 20 for preventing rotation is provided outside the thrust bearing 3 for orbiting the movable scroll 2b with respect to the fixed scroll 2a.
Reference numeral 1 denotes a suction port provided in a bearing component 4 for sucking low-pressure gas into the compression mechanism 2. Here, the outer peripheral shape of the thrust bearing approximates an inner envelope generated by reciprocation of the Oldham ring. Further, the outer peripheral shape of the thrust bearing is made elliptical, and the long diameter portion of the thrust bearing is arranged in the eccentric direction of the movable scroll when the thrust force due to the compression force is minimized. FIG. 6 shows a change in the thrust force with respect to the crank angle in the present embodiment. The winding start wall surface portion of the movable scroll is separated from the fixed scroll wall surface at the broken line portion.
A crank angle 180 ° ahead of this point has the least thrust force. At this crank angle, the movable scroll is most easily overturned. The rollover can be prevented by bringing the major axis of the thrust bearing in the direction of this angle.

FIG. 3 shows a front view of the thrust bearing and the Oldham ring. This thrust bearing is made by sintering, so that a thrust bearing having a different shape as shown in the figure can be made.

[0021]

As is apparent from the above description, the present invention approximates the outer peripheral shape of a thrust bearing made of a sintered body constituting a compression mechanism with the inner envelope shape generated by reciprocating motion of an Oldham ring. By using
The following effects are obtained.

(1) Since it is made by sintering (a) The shape of the thrust bearing can be easily made at low cost.

(2) Since the area of the thrust bearing increases, (a) the surface pressure can be reduced.

(B) Reliability is improved. (3) Since the thrust bearing can protrude to the outside, (a) the movable scroll can be prevented from overturning.

(B) It is possible to rotate at a higher speed by the inverter. (4) Since the long diameter portion of the thrust bearing is set in the eccentric direction of the movable scroll when the thrust force due to the compression force is minimized, (a) the movable scroll can be prevented from overturning.

(B) It is possible to rotate at a higher speed by the inverter.

[Brief description of the drawings]

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

FIG. 2 is an exploded perspective view of a main part of the compressor.

FIG. 3 is a front view of a thrust bearing and an Oldham ring.

FIG. 4 is a diagram showing the operation principle of a scroll compressor.

FIG. 5 is a diagram showing a relationship between main forces applied to a movable scroll.

FIG. 6 is a diagram showing a tendency of a thrust force and a crank angle.

FIG. 7 is a longitudinal sectional view of a conventional scroll compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed container 2 Compression mechanism 2a Fixed scroll 2b Movable scroll 3 Thrust bearing 4 Bearing part 5 Crankshaft 6 Eccentric bearing 7 Motor 8a Main bearing 8b Secondary bearing 9 Lubricating oil 10 Oil reservoir 11 Suction pipe 12 Oil outlet 13 Through hole 15 Discharge Chamber 16 Discharge pipe 17 Spacer 20 Oldham ring 21 Suction port 22 Discharge port

Continued on the front page (72) Inventor Hiroyuki Fukuhara 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) F04C 18/02 311

Claims (4)

(57) [Claims] 1. A compression mechanism in which a fixed scroll and a movable scroll orbiting relative to the fixed scroll are meshed with each other in an airtight container, an Oldham ring for preventing the movable scroll from rotating, and the movable scroll. Bearing, a bearing component for supporting the thrust bearing, an eccentric bearing whose shaft is fitted to the orbiting scroll, and a crankshaft for orbiting the orbiting scroll, and an attachment to the crankshaft. An electric motor comprising a rotor and a stator, an oil reservoir formed at the bottom of the hermetic container and storing lubricating oil, and a suction pipe opened at a side portion of the hermetic container. Wherein the outer peripheral shape of the scroll compressor is approximated to an inner envelope generated by reciprocation of the Oldham ring. 2. The scroll compressor according to claim 1, wherein the material of the thrust bearing is formed by sintering. 3. A compression mechanism in which a fixed scroll and a movable scroll orbiting relative to the fixed scroll are meshed with each other in an airtight container, an Oldham ring for preventing the movable scroll from rotating, and the movable scroll. Bearing, a bearing component for supporting the thrust bearing, an eccentric bearing whose shaft is fitted to the orbiting scroll, and a crankshaft for orbiting the orbiting scroll, and an attachment to the crankshaft. An electric motor comprising a rotor and a stator, an oil reservoir formed at the bottom of the hermetic container and storing lubricating oil, and a suction pipe opened at a side portion of the hermetic container. The shape of the thrust bearing in the eccentric direction of the movable scroll when the thrust force due to the gas compression force is minimized by making the outer peripheral shape of the Scroll compressor arranged direction. 4. The scroll compressor according to claim 3, wherein the material of the thrust bearing is formed by sintering.