JPH0211881A - Scroll compressor - Google Patents

Abstract

PURPOSE:To prevent an internal pressure from abnormally increasing, even when fluid is compressed, by fixing a thin plate of scroll shape along a side plate to the upper surface of a bed plate of each scroll. CONSTITUTION:Thin plates 31, 33 of scroll shape along volute side plates of bed plates 3a, 17b are fixed to their upper surface in a fixed scroll 3 and a swivel scroll 17. Each scroll 3, 17 provides in its upper surface center part recessed parts 3e, 17e engaging and stopping the thin plates 31, 33 which are elastically deformed so that at least a pair of compression chambers 19a in the inmost internal peripheral side of the compression chambers between both the side plates communicates with a delivery chamber 23 in the center part. When a condition is generated compressing fluid, the compression chamber 19a in the inmost internal peripheral side is placed in a condition communicating with the delivery chamber 23 of pressure lower than this compression chamber 19a, and an abnormal increase of pressure can be avoided.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a scroll compressor that compresses refrigerant gas by engaging a pair of spiral side plates with each other and rotating one of them. be.

[Conventional technology]

This type of scroll compressor is used in refrigerant compressors for refrigeration equipment and air conditioners.
The device disclosed in Japanese Patent No. 0-206989 and the like is constructed as shown in FIG. 6 in a longitudinal cross-sectional view. That is, at the upper end of the airtight container 2 fixed to the leg IF, there is a fixed scroll 3 (described in detail later) which is integrally formed with a disc-shaped base plate 3a and a spiral-shaped side plate 3b protruding from the lower surface of the base plate 3a. , is fixed with a plurality of bolts 5 to an upper bearing frame 4 on the side of the closed container l having an oil return hole 4a, and 1 part is fixed to the bearing frame 4 and a lower bearing frame 6 integrally connected thereto. A ball shaft 7 is rotatably supported via a top main bearing 8 and a lower main bearing 9. Reference numeral 10 denotes a motor stake formed in a cylindrical shape and fixed to the dome bearing frame 6 with a plurality of bolts 11, into which an upper shaft 71 is fixed by press-fitting and firing or the like. 12 are fitted, and the main shaft 7 is configured to rotate via the motor/rotor 12 by energizing the motor. Reference numeral 13 denotes an oil cap that is inserted into a hole in a cover 15 that covers an oil reservoir 14 at the bottom of the closed container 2 and fixed to the lower end of the main shaft 7 by press fitting, burning, etc. Oil 16 stored in reservoir 14
It is opened inward.

An eccentric hole 7a is formed in the upper end of the main shaft 7, and the eccentric hole 7a has an axis that is eccentric to the axis of the main shaft 7, that is, the axis of the upper main bearing 8. A shaft 17a of an oscillating scroll indicated by reference numeral 17 is rotatably supported via an oscillating bearing 18. The oscillating scroll 17 has a shaft 1
A base plate 17b is integrally formed with the fixed scroll 7a, and a side plate 17c protruding from the upper surface of the base plate 17b is formed in a spiral shape and engages with the side plate 3b of the fixed scroll 3. The swing scroll 17 will be explained in detail later. An inlet 20 and an outlet 21 are formed in the outer periphery and center of the crescent-shaped compression chamber 19 formed between the side plates 31) and 17c, respectively.
is connected to equipment outside the machine via a suction pipe 2a and a discharge pipe 22.

23 is a discharge chamber formed in the center of the compression chamber 19 in communication with the discharge port 21, and 24 is an oscillating scroll 17.
An Oldham joint 25 is a thrust bearing which is disposed between the upper bearing frame 4 and the rotary scroll 17 to restrict rotation of the oscillating scroll 17.

An oil supply hole 26 with an opening 26a at the lower end opened into the oil cap 13 is provided in the eccentric portion of the main shaft 7 with respect to the axis, and the oil supply hole 26 communicates with the eccentric hole 7a. The inside of the oil reservoir 14 and the rocking bearing 1 are connected through the oil hole 27.
8. The lower main bearing 9 is communicated with each other.

FIG. 7 is a cross-sectional view of a compression chamber formed by the fixed scroll and the swinging scroll, and the structure of both scrolls will be explained based on this figure.

Between the side plate 3b of the fixed scroll 3 and the side plate 17c of the swinging scroll 17, a pair of compression chambers 19a and 19b, which are symmetrical to each other, are formed on the innermost side, and the outer side thereof includes a pair of compression chambers 19 that are symmetrical to each other.
c, 19d are formed. Further, in the center, a discharge chamber 23 is in communication with the discharge port 21 and has the same internal pressure P0.
is formed. In the figure, the discharge chamber 23 and the compression chamber 19a.

19b shows the state immediately before communication is established.

With the above configuration, when the main shaft 7 rotates due to the driving force generated by the motor stator 10 and the motor rotor 12 when the motor is energized, the oscillating scroll 17 restricts its rotation by the Oldham joint 24. The refrigerant gas sucked in from the suction pipe 2a cools the motor rotor 12 and the motor stator 10, and then the scroll side plate 1 of the revolving oscillating scroll 17.
7c and the scroll side plate 3b of the fixed scroll 3 which is stationary, it is taken into the compression chamber 19 through the suction port 20 and compressed. The compressed refrigerant gas is discharged from the discharge pipe 22 to the outside of the compressor via the discharge chamber 23 and the discharge port 21 .

Furthermore, when the main shaft 7 rotates, the oil 16 in the oil reservoir 14 is drained from the suction port 13a of the oil cap 13 due to the action of centrifugal force.
Oil is supplied to the swing bearing I8 and the lower main bearing 9 through the oil supply hole 26, and then from the swing bearing 18 to the -L section main bearing 8. The thrust bearing 23 is lubricated in this order. Each of these bearings 18.9
, 8.23 falls down due to gravity and is returned to the oil sump 14.

In FIG. 7, the internal pressure of the discharge chamber 23 is P. , compression chamber 19
Assuming that the internal pressure of a and 19b is Pl, the internal pressure of compression chambers 19c and 19d is P2, and the internal pressure of the outermost circumferential side where no compression chamber has been formed is P3, during normal compression, Pa > PI >
P2>P, and the discharge chamber 23 and the compression chamber 19a.

19b communicated with P o = P l> P
z>P3.

[Problem to be solved by the invention]

However, in such a conventional scroll compressor, when it is started with a large amount of liquid refrigerant lying in the closed container 2, or when a large amount of liquid refrigerant is sucked during liquid banking, it enters a liquid compression state, and especially Innermost compression chamber 19a,
The pressure P1 immediately before the 19b communicates with the discharge chamber 23 becomes the maximum pressure, and may reach 100 to 200 aug in a pulsed manner, and at this time P1. (P + ) P 2
> P3.

In such a state, the differential pressure between Po and Pl and P
The differential pressure between P2 and P3 becomes abnormally large, and the stress at the roots of both spiral side plates 3b and 17c becomes large, resulting in deformation or damage, or the fixed scroll 3 and bearing frame 4, which are only connected by bolts, The side plate 3b of the fixed scroll 3 and the swinging scroll 17 is caused by a misalignment between the
There was a problem in that the relative position of 17c shifted, resulting in a locked state and generation of abnormal noise.

The present invention was made in view of the above points, and an object of the present invention is to provide a scroll compressor in which the internal pressure does not rise abnormally even during liquid compression.

[Means to solve the problem]

In order to achieve such an object, in the present invention, a spiral thin plate is fixed to the top surface of the base plate of the fixed scroll and the oscillating scroll along the spiral side plate thereof, and a spiral thin plate is fixed to the top surface of the base plate of the fixed scroll and the oscillating scroll, and a spiral thin plate is fixed to the top surface of the base plate of the fixed scroll and the oscillating scroll. A recess into which the elastically deformable thin plate is inserted is provided so that at least a pair of compression chambers on the innermost side of the compression chambers between the plates on both sides communicate with a discharge chamber in the center.

[For production]

When the oscillating scroll eccentrically revolves around its axis while its rotation is restricted as the main shaft rotates, the refrigerant gas taken from the suction port into the compression chamber between both spiral side plates is compressed, passes through the discharge chamber and the discharge port, and exits the compressor. is discharged to.

When a large amount of liquid refrigerant is sucked into a liquid compressed state, the thin plate elastically deforms and retreats into the recessed hole, and the innermost compression chamber, where the internal pressure is maximum, and the discharge chamber, which has a lower pressure, are separated. Since the closed state changes to the communicating state, the liquid flows from the innermost compression chamber to the discharge chamber, and abnormal pressure increase can be avoided.

〔Example〕

1 to 5 show an embodiment of a scroll compressor according to the present invention, FIG. 1(a) is a perspective view of a thin plate, and FIG.
b) is a perspective view of the oscillating scroll, FIG. 2 is a plan view of the oscillating scroll, FIG. 3 is a perspective view of the fixed scroll, and FIG. 4 is an enlarged vertical cross-section of the main parts of the scroll compressor in a normal compression state. FIG. 5 is an enlarged longitudinal sectional view of the main part of the scroll compressor shown in a liquid compressed state. The structure other than the fixed scroll and the swinging scroll is the same as the conventional scroll compressor shown in Fig. 6, so the explanation thereof will be omitted, and Fig. 6 will be used when necessary in explaining the structure and operation. explain. In the figure, the oscillating scroll 17 has a shaft 17 in the center.
A is provided with a base plate 17b integrally formed, and a side plate 17c formed in a spiral shape projects from the upper surface of the base plate 17b. Further, the upper end surface of the side plate 17c has the side plate 17
A chip seal 30 is attached to seal c in the axial direction.

31 is a thin plate formed into a spiral shape by providing a slit 31b having the same shape and size as the side plate 17c on a thin circular plate 31a made of an elastic steel plate such as spring steel, By engaging with the side plate 17c, the base plate 17b is brought into close contact with the OE surface of the base plate 17b along this, and lifting is restricted by a step 17d provided at the base of the inner wall of the side plate 17c. 31c is a small hole bored in the center of the thin plate 31. Further, on one surface of the base plate 17b, a recess 17e into which the thin plate 31 is inserted when it is elastically deformed due to internal pressure is provided at a location that will become the discharge chamber 23 and a location that will become the compression chamber 19b on the innermost peripheral side. The discharge chamber 23 and the compression chamber +9b are connected to the thin plate 31 by this elastic deformation.
The chip seal 30 is configured to communicate with the chip seal 30 through a gap between the chip seal 30 and the chip seal 30.

Note that the shape and depth of the recess 17e are determined by the shape and dimensions of the spiral, the rigidity of the thin plate 31, and the like.

On the other hand, the fixed scroll 3 fixed to the closed container 2 side is
It has a base plate 3a having a plurality of attachment holes 3C, and a side plate 3b formed in a spiral shape projects from the lower surface of the base plate 3a. Also, on the lower end surface of the side plate 3b, the side plate 3b
A chip seal 32 is attached to seal the shaft in the axial direction. 33 is a thin plate formed in a spiral shape by providing a slit 33b of the same shape and size as the plate 3b in a thin circular plate 33a made of an elastic steel plate such as spring steel. -33b is brought into close contact with the lower surface of the base plate 3a along this by engaging with the side plate 3b,
A step 3d provided at the base of the inner wall of the side plate 3b prevents it from floating upward. 33d is a through hole bored in the center of the thin plate 31, and communicates with the discharge port 21 on the side of the base plate 3a, which has the same diameter and diameter. Further, on the lower surface of the base plate 3a, a recess 3e into which dirt enters when the thin plate 33 is elastically deformed due to internal pressure is continuous between a location that will become the discharge chamber 23 and a location that will become the innermost compression chamber 19a. Due to this elastic deformation, the discharge chamber 23 and the compression chamber 19a are connected to the thin plate 33.
The chip seal 32 is configured to communicate with the chip seal 32 through a gap between the chip seal 32 and the chip seal 32. Reference numeral 20 denotes a suction port opened to the outermost compression chamber. Note that the shape and depth of the recess 3c are determined by the shape and dimensions of the spiral, the rigidity of the thin plate 33, and the like.

The oscillating scroll I7 and the fixed scroll 3 configured in this way have a side plate 17c and a side plate 3b as shown in FIG.
The swinging scroll 17 has a shaft 17a pivotally supported in an eccentric hole 7a of the main shaft 7, as shown in FIG. In addition, the fixed scroll 3 is connected to the closed container 2.
A stand +Fi3a is fixed to the upper bearing frame J and 4 on the side. As a result, a discharge chamber 23 that communicates with the discharge port 21 through the through hole 33d is formed in the center between the side plates 17c and 3b. Three sets of compression chambers 19a to 19F are on the side plate 17
It is formed between c and 3b, and the outermost compression chamber +9c
, 19f, an inlet 20 is opened. Chip seals 3 (1, 3
2 so that they are not electrically conductive to each other.

The other configurations are the same as the conventional scroll compressor shown in FIG.

The operation of the scroll compressor configured as described below will be explained. When the main shaft 7 rotates due to the start of the motor, the swinging scroll 17, which has a shaft 17a pivotally supported in the eccentric hole 7a, rotates eccentrically around its axis while being restrained from rotating by the Oldham joint 24.

As a result, the refrigerant gas taken from the suction port 20 into the compression chambers 19e, 19r is transferred to the compression chambers 19c, 19d to 19a.
, 19b and is compressed, and the discharge chamber 231 through hole 3
3d.

It is discharged outside the machine through the discharge port 21 and the discharge pipe 22.

In the compression section of the scroll compressor that operates in this manner, during normal operation, the discharge chamber 23 and the recess 3b17e are
The pressure is equalized to P0 by the through hole 33d and the small hole 31c, and the internal pressure of the discharge chamber 23 is 1).

Since the relationship between P0 and P of the compression chambers 19a and 19b is P0≧P, the thin plates 31 and 33 do not deform as shown in FIG.

If the engine is started with a large amount of liquid refrigerant stagnant, or a large amount of liquid refrigerant is sucked from the suction port 20 during liquid backup, etc.
The liquid is in a compressed state, and the compression chamber 19a.

The internal pressure P1 of 19b increases abnormally, but in this case, +
1. ) Po, the thin plates 31.33 are elastically deformed and inserted into the recesses 17e, 3e as shown in FIG. Since it flows into the discharge chamber 23 through the gap between the compression chambers 19a and 19b, abnormal pressure increase in the compression chambers 19a and 19b is prevented. The liquid refrigerant flows into the discharge chamber 23 through the thin plate 31.
33 elastically returns to normal compression.

In this embodiment, the recesses 3e and 17e are provided only in the portions corresponding to the innermost compression chambers 19a and 19b, but they may also be provided in the portions corresponding to the outer compression chambers 19c and 19f. good.

〔Effect of the invention〕

As is clear from the above description, in the scroll compressor according to the present invention, a thin plate along the spiral side plates is fixed to the top surface of the bed plate of the fixed scroll and the oscillating scroll, and the center of the top surface of each scroll is By providing a recess in which the thin plate, which is elastically deformed, is inserted so as to communicate at least a pair of compression chambers on the innermost side of the compression chambers between both side plates with a discharge chamber in the center, the liquid When a large amount of refrigerant is sucked into a liquid compressed state, the thin plate is elastically deformed into the recess and the discharge chamber and compression chamber are communicated, so the internal pressure does not rise abnormally and deformation and damage are prevented. improved durability and reliability.

[Brief explanation of the drawing]

1 to 5 show an embodiment of a scroll compressor according to the present invention, FIG. 1(a) is a perspective view of a thin plate, and FIG.
b) is a perspective view of the oscillating scroll, FIG. 2 is a plan view of the oscillating scroll, FIG. 3 is a perspective view of the fixed scroll, and FIG. 4 is an enlarged longitudinal section of the main parts of the scroll compressor shown in a normal compression state. Figure 5 is an enlarged vertical cross-sectional view of the main parts of a scroll compressor shown in a liquid compression state, Figure 6 is a vertical cross-sectional view of a conventional scroll compressor, and Figure 7 is also a fixed scroll and an oscillating scroll. It is a sectional view of a compression chamber and a discharge chamber which were formed. 3...Fixed scroll, 3a, 17b...Bed plate, 3b, 11c=--Side plate, 3e, 17e...
Recessed portion, 19a to 19f... Compression chamber, 20... Suction hole, 21... Discharge port, 23... Discharge chamber, 31
．． 33...Thin plate.

Claims (1)

[Claims] By engaging the side plates of a fixed scroll and an oscillating scroll, each consisting of a base plate and a spiral side plate protruding from the base plate, and rotating the oscillating scroll, the side plate is supplied to the compression chamber between the two side plates. In a scroll compressor configured to compress fluid taken in from a suction port on the outer periphery and discharge it from a discharge port through a discharge chamber in the center, a spiral shape along the side plate is formed on the top surface of the base plate of each scroll. In addition to fixing the thin plate, at the center of the upper surface of each scroll,
A scroll compressor comprising a recess into which the thin plate elastically deforms so as to communicate between at least a pair of innermost compression chambers of the compression chambers and the discharge chamber.