JPH0830470B2 - Scroll compressor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a scroll compressor used for air conditioning.

2. Description of the Related Art A conventional compressor of this type has a structure as shown in FIG. 4, for example, as shown in JP-A-58-190591.

That is, in FIG. 4, a back pressure chamber 11 surrounded by the end plate 501 of the orbiting scroll 5 and the frame 8 is formed on the side opposite to the wrap of the orbiting scroll 5, and the end plate 501 is provided with a compression chamber 10 and a back pressure chamber 11. A communication hole 503 for communicating with Then
During operation, the pressure in the back pressure chamber 11 becomes an intermediate pressure between the suction pressure and the discharge pressure, and the orbiting scroll 5 is pressed against the fixed scroll 4. By this force, the fixed scroll 4
The clearance between the end plate 401 of the orbiting scroll 5 and the tip of the wrap of the orbiting scroll 5 and the clearance between the end plate 501 of the orbiting scroll 5 and the tip of the wrap of the fixed scroll 4 are kept to a minimum, and a good compression process proceeds. Further, in the present configuration, the end plate 501 of the orbiting scroll 5 is sandwiched and supported by the fixed scroll 4 and the frame 8. Now, since the pressure in the back pressure chamber 11 is low within a fixed time at the start, the end plate of the orbiting scroll 5 is
501 slides in contact with the frame 8. Therefore, in order to quickly start the present compressor, the end plate 501 of the orbiting scroll 5 is sandwiched with a slight clearance (about 30 μ) between the fixed scroll 4 and the frame 8.

Problems to be Solved by the Invention However, with such a structure, there is a problem that the compression function is impaired by the abnormally high pressure generated by the liquid compression because the liquid compression of the refrigerant cannot be dealt with.

That is, when the liquid refrigerant is sucked into the compression section 2 from the suction pipe 403 for some reason, liquid compression occurs in the compression chamber 10. At this time, the orbiting scroll 5 can move only a small amount in the axial direction, so that the liquid refrigerant in the compression chamber 10 cannot escape completely, and the compression chamber 10 has an abnormally high pressure (about 100 kg / cm ² ).
Occurs. Due to this abnormal high pressure, the laps 402 and 502 may be plastically deformed, the metal bearing 9 or the crankshaft 7 may be damaged, and the compression action may not be performed again.

Therefore, the present invention is to prevent the abnormal high pressure generated by liquid compression by promptly discharging the liquid refrigerant to the outside of the compression chamber 10 even if the liquid refrigerant is sucked into the compression chamber 10 for some reason.

Means for Solving the Problems And the technical means of the present invention for solving the above problems include pressure means for sliding the orbiting scroll end plate on the fixed scroll end plate, and at the fixed scroll from the wrap tip. Drill a plurality of holes to penetrate the end plate,
The reed valve is attached to the end of the end plate opposite the lap facing the hole.

Action The action of this technical means is as follows.

That is, in the case of a normal refrigerant gas compression process, since the end plate of the orbiting scroll is pressed against the end plate of the fixed scroll by the pressurizing means, both end plates slide in contact with each other,
The seal of the compression chamber is maintained, and good compression can be performed as in the conventional case. Also, when the liquid refrigerant is sucked into the compression chamber, the orbiting scroll only moves slightly in the axial direction, and a gap is created between the wrap tip of one scroll and the end plate of the other scroll. The liquid refrigerant is promptly discharged into the closed container through the hole penetrating from the wrap tip to the end plate, or into the back pressure chamber through the hole penetrating from the lap tip of the orbiting scroll to the end plate.

As a result, even if the liquid refrigerant is sucked into the compression chamber, abnormal high pressure does not occur in the compression chamber as in the conventional case, and safe operation can be performed.

Embodiment One embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, a scroll compression unit 2 is provided in a closed container 1.
And the motor 3 are built in. The scroll compression unit 2
The main components are a fixed scroll 4, an orbiting scroll 5, a rotation preventing mechanism (Oldham ring) 6, a crankshaft 7, a frame 8, and a metal bearing 9.

The fixed scroll 4 is provided with an upright spiral wrap 402 on an end plate 401, and the wrap 402 is composed of an involute curve or a curve close thereto. or,
A refrigerant gas suction pipe 403 is provided at the outer peripheral portion, and a discharge hole 404 is provided at the central portion of the end plate 401. And fixed scroll 4
Is fixed to the frame 8. On the other hand, the orbiting scroll 5 includes an end plate 501 and a spiral wrap 502 standing upright on the end plate 501. The shapes of the wraps 402 and 502 of the fixed scroll 4 and the orbiting scroll 5 are mirror-symmetrical to each other. Further, the fixed scroll 4 and the orbiting scroll 5 are engaged with each other with the centers of their respective spirals displaced by the orbiting radius, so that the two laps 402 and 502 contact or approach at a plurality of points, and a plurality of compression chambers 10 are formed. It is formed. Also,
On the side opposite to the wrap of the orbiting scroll 5, the orbiting scroll 5
A back pressure chamber 11 surrounded by the end plate 501 and the frame 8 is formed.

As shown in FIG. 2 as well, the fixed scroll 4 is provided with a plurality of holes 405 penetrating from the wrap tip to the end plate 401. A reed valve 14 is attached. Further, a boss portion 504 into which the crankshaft 7 is inserted is provided at the center of the end plate 501 of the orbiting scroll 5 opposite to the wrap side. Further, the rotation preventing mechanism 6 is incorporated by engaging the end plate 501 of the orbiting scroll 5 and the frame 8. The crankshaft 7 is supported by the frame 8 via a metal bearing 9, and the rotor 301 of the motor 3 is attached to one end of the crankshaft 7.

In this structure, when the crankshaft 7 is rotated by the rotation of the rotor 301 of the motor, the orbiting scroll 5 orbits with respect to the fixed scroll 4 while maintaining its posture by the action of the rotation preventing mechanism 6. Then, the compression chamber 10 formed by the engagement of the fixed scroll 4 and the orbiting scroll 5 gradually moves from the outer peripheral portion of the scroll to the center portion by the orbiting motion, and the volume thereof decreases.

As a result, the low-pressure gas taken from the suction pipe 403 is compressed and discharged from the discharge hole 404 of the fixed scroll 4 into the closed container 1. After that, the high-pressure gas in the closed container 1 is sent to the outside through the discharge pipe 101.

Now, the lubricating oil during operation flows due to the differential pressure of the compressed gas. That is, the lubricating oil accumulated at the bottom of the closed container 1 is pushed up by the high-pressure gas into the lubricating oil passages 701 and 702 opened at the center of the crankshaft 7. After this, the lubricating oil
It reaches the back pressure chamber 11 through the boss portion 504 of the orbiting scroll 4 and the bearing clearance between the crankshaft 7 and the metal bearing 9 and the bearing clearance between the crankshaft 7. The high-pressure lubricating oil is depressurized because it has passed through the narrow bearing clearance, and the back pressure chamber 11 has an intermediate pressure. After that, the lubricating oil flows from the first back pressure chamber 11a to the second back pressure chamber 11b, and finally, the contact sliding surface between the end plate 401 of the fixed scroll 4 and the end plate 501 of the orbiting scroll is lubricated and compressed. It flows into chamber 10. Then, after being discharged into the closed container 1 together with the discharge gas, it is separated and returns to the bottom of the closed container 1.

By such circulation of the lubricating oil, the back pressure chamber 11 is maintained at an intermediate pressure, and the orbiting scroll 5 is pressed against the fixed scroll 4. Due to this force, the end plate of the fixed scroll 4
The 401 and the end plate 501 of the orbiting scroll 5 slide in contact with each other, and the clearance between the wrap tip of one scroll and the end plate of the other scroll becomes almost zero, so that a good seal of the compression chamber 10 can be obtained. . Therefore, with respect to the normal compression of the refrigerant gas, a good compression process similar to the conventional one proceeds.

Now, also in the present embodiment, the end plate of the orbiting scroll 5
501 is sandwiched between the fixed scroll 4 and the frame 8 to a narrow gap similar to the conventional one.

With this configuration, when the liquid refrigerant is sucked into the compression chamber 10, after the volume of the compression chamber 10 is reduced, the pressure tends to rise rapidly when the compression chamber 10 is filled with the liquid refrigerant. At that time, the orbiting scroll 5 has a slight pressure increase in the axial direction (opposite lap side).
Move to. Then, a slight gap is formed between the tip of the wrap of one scroll and the end plate of the other scroll. Due to this clearance, a hole 405 penetrating both scrolls faces the compression chamber 10, and the liquid refrigerant is discharged into the closed container 1 through the through hole 405 of the fixed scroll 4 as the pressure rises. Therefore, even if liquid compression occurs, the compression chamber 10
The internal pressure does not become an abnormally high pressure, and does not damage the fixed scroll wrap 402, the orbiting scroll wrap 502, the metal bearing 9, the crankshaft 7, and the like.

The method for setting the back pressure chamber 11 at the intermediate pressure may be the same as the conventional method shown in FIG.

 Next, another embodiment of the present invention will be described.

FIG. 3 shows another embodiment. In this embodiment, the end plate 501 of the orbiting scroll 5 is fixed by a ring 12 that comes into contact with the end plate 501 of the orbiting scroll 5 and a coil spring 13 that is fixed to the frame and applies a spring force to the sliding ring 12. It is configured to be pressed against the end plate 401 of No. 4. With this configuration, as is apparent from FIG. 3, the end plate 501 of the orbiting scroll 5 is the fixed scroll 4
It is held with a large gap between the end plate 401 and the frame 8.

That is, since the orbiting scroll 5 is supported by the spring force of the coil spring 13 even at the time of starting, it is possible to quickly rise even if the clearance is increased. When liquid compression occurs in this configuration, the orbiting scroll 5 can move largely in the axial direction, and at that time, the through hole 405 provided in the fixed scroll 4 largely faces the compression chamber 10. After passing through 405, the liquid refrigerant can easily escape, and the compression chamber 1
The pressure rise within 0 is even lower than in the previous example.

Further, in FIG. 3, the reed valve 14 is provided on the surface of the fixed scroll 4 on the side opposite to the lap side of the end plate 401 so as to close the through hole 405 formed in the fixed scroll 4. When the reed valve 14 is provided, it is possible to prevent the refrigerant gas from leaking into the compression chamber 10 from the inside of the closed container 1 through the through hole 405 during steady operation, which is advantageous in improving the compression efficiency. .

EFFECTS OF THE INVENTION The present invention provides at least one of a fixed scroll and an orbiting scroll of a scroll compressor with a hole penetrating from the wrap tip to the end plate, and presses the end plate of the orbiting scroll in contact with the end plate of the fixed scroll. Even if the liquid compression occurs, the orbiting scroll moves in the axial direction and the liquid refrigerant is discharged to the outside of the compression chamber through the through hole. Can be prevented, and safe driving can be performed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a scroll compressor according to an embodiment of the present invention, FIG. 2 is a transverse sectional view of a compression portion of the scroll compressor, and FIG. 3 is a scroll compressor according to another embodiment of the present invention. FIG. 4 is a longitudinal sectional view showing a conventional scroll compressor. 4 ... Fixed scroll, 5 ... Orbiting scroll, 6 ...
Anti-rotation mechanism, 8 ... Frame, 10 ... Compression chamber, 11 ...
Back pressure chamber, 12 …… Sliding ring, 13 …… Coil spring (elastic body), 405 …… Fixed scroll through hole.

Claims (1)

[Claims] 1. A spiral scroll wraps an orbiting scroll formed upright on an end plate with a fixed scroll having a wrap of substantially the same shape, and causes the fixed scroll to orbit without rotating the orbiting scroll. A rotation preventing mechanism is provided, and when the end plate of the orbiting scroll and the end plate of the fixed scroll are in contact with each other, the wrap tips of both scrolls are in contact with the end plate of the other scroll. From the end plate to the end plate, a reed valve is provided on the opposite lap side of the end plate facing this hole, and a scroll provided with a pressurizing means for sliding the end plate of the orbiting scroll into contact with the end plate of the fixed scroll. Compressor.