JPH01187388A - Scroll compressor - Google Patents

Abstract

PURPOSE:To aim at the promotion of simplification in structure and miniaturization and lightweightiness by superposing respective end plate peripheral parts of both fixed and swirl scrolls and making them come into slidingly contact with each other, while opposing a projection, formed in the end plate peripheral part of the swirl scroll, to a base surface of a frame. CONSTITUTION:In the inner part of a hermetically sealed vessel 1, a compressor part with both fixed and swirl scrolls 5, 6 is housed in the upper part and an electric motor part 3 in the lower part, respectively. In this case, each seat surface between an end plate peripheral part of the fixed scroll 5 and another end plate peripheral part 6k of the swirl scroll 6 is superposed at a crescent part F and made slidingly contact with each other. In addition a crescent clearance E is formed between an end plate outer circumferential wall 6j of the swirl scroll 6 and an inner circumferential wall 5k of the fixed scroll 5. With this constitution, a pressure sealing function among a back pressure chamber 20, a side space 6f and a suction chamber 5f is secured by a projection formed in the end plate peripheral part 6k of the swirl scroll 6 and a base surface of a frame 6 being opposed to this projection.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a scroll compressor used as a refrigerant compressor for refrigeration and air conditioning or an air compressor.

[Prior Art] A scroll compressor has an orbiting scroll consisting of a disc-shaped end plate and a spiral wrap integrally formed upright on the end plate, and has a similar configuration to the orbiting scroll. Fixed scrolls having a discharge hole in the center of the end plate are engaged with each other so that the side walls of the wraps are in contact with each other, and these are housed in a cylindrical sealed casing having an inlet.The fixed scroll is fixed to the casing and rotates. While the rotation of the scroll is prevented by an anti-rotation mechanism, by rotating a crankshaft with an eccentric crank pin fitted to the orbiting scroll using a prime mover, the wrap of the fixed scroll is kept in contact with the side walls of the wraps of both scrolls. The orbiting scroll is driven so that the center of the spiral of the wrap of the orbiting scroll revolves around the center of the spiral. This turning radius is equal to the eccentricity of the crank pin of the crankshaft. When the orbiting scroll is driven in this manner, a closed space (compression chamber) is formed by the end plates and wraps of the orbiting and fixed image scrolls, and this compression chamber increases in volume while being driven toward the center as the orbiting scroll rotates. It gradually reduces in size and finally comes to communicate with the above-mentioned discharge hole located at the center of the end plate of the fixed scroll. Therefore, the gas that is sucked into the compression chamber from the suction port through the suction chamber in the peripheral portion of the fixed scroll and is confined therein is compressed to a discharge pressure higher than the suction pressure and discharged from the discharge hole.

For conventional scroll compressors, Japanese Patent Application Laid-Open No. 59-11088
As described in Japanese Patent Application No. 6, the sheet surface of the outer circumferential portion of the end plate of the orbiting scroll is always in full sliding contact with the end surface of the fixed scroll facing thereto. Gas at an intermediate pressure between suction pressure and discharge pressure is introduced to the back side of the end plate of the orbiting scroll, but the seat surface on the outer periphery of the end plate of the above-mentioned orbiting scroll acts on the back side of the end plate of the orbiting scroll. It has the function of a thrust receiver that receives the gas pressure load at the intermediate pressure, and the function of sealing between the back side of the orbiting scroll head plate and the suction chamber side.

[Problems to be Solved by the Invention] In the above conventional technology, the seat surface of the outer peripheral portion of the end plate of the orbiting scroll has the functions of both a thrust receiver and a pressure seal, and in order to maintain these functions, the seat surface of the orbiting scroll It is necessary to secure a certain amount of sheet width on the surface. For this reason, the outer diameter of the end plate of the orbiting scroll becomes relatively large, which leads to problems in that the outer diameter of the entire compressor increases and the overall weight increases.

Furthermore, in the prior art, oil compression occurs in the side space of the outer periphery of the end plate of the orbiting scroll, resulting in an increase in compressor power. In the side space of the orbiting scroll, as disclosed in Japanese Patent Laid-Open No. 59-110886, multiple oil drainage grooves are provided on the frame pedestal surface to prevent oil from stagnation. There was also the problem that the structure was complicated and the cost was relatively high.

The purpose of the present invention is to reduce the outer diameter of a scroll compressor,
The objectives are to reduce the weight, to prevent oil compression in the side space of the outer periphery of the end plate of the orbiting scroll, and to simplify the structure around the frame pedestal surface.

[Means for Solving the Problems] The present invention has a fixed scroll and an orbiting scroll, each consisting of an end plate and a spiral wrap provided upright thereon, which are engaged with each other with the wraps inside, and the orbiting scroll is By rotating the fixed scroll without rotating, the gas taken in from the suction chamber at the periphery of the fixed scroll into the compression chamber formed by both scrolls is compressed and transferred to the center of the end plate of the fixed scroll. In a scroll compressor, gas pressure is applied to the rear surface of the end plate of the orbiting scroll to press it toward the fixed scroll. The outer periphery of the end plate overlaps only a portion of the end plate so that they are in sliding contact with each other, and the outer periphery of the end plate of the orbiting scroll has a convex portion extending over the entire circumference on the back side. The outer periphery of the end plate of the scroll is sandwiched with a small gap between the outer periphery of the end plate of the fixed scroll and the pedestal surface of the frame fixed thereto, and rotates between the convex portion and the pedestal surface of the frame opposite thereto. The present invention is characterized in that a sealing function against the gas pressure on the back side of the end plate of the scroll is ensured.

[Function] The thrust force of the orbiting scroll relative to the fixed scroll is received by the sliding contact portion and the tooth tip surface of the wrap, which overlap only in the above-mentioned portion of the outer peripheral portion of the end plate of both scrolls. A seal between the gas pressure on the back surface of the end plate of the orbiting scroll and the suction gas pressure in the suction chamber of the fixed scroll is achieved by the convex portion on the outer periphery of the end plate of the orbiting scroll and the pedestal surface of the frame opposite thereto. The suction chamber and the side space of the outer periphery of the end plate of the orbiting scroll are always in communication via the non-overlapping portion of the outer periphery of the end plate of the fixed scroll and the outer periphery of the end plate of the orbiting scroll. Oil compression effects in the space are prevented.

[Embodiment] An embodiment of the present invention will be described below with reference to FIG. 1 and FIGS. 2 to 8.

In FIG. 1, a compressor section having a fixed scroll 5 and an orbiting scroll 6 is housed in an upper part of a closed container 1, and an electric motor part 3 is housed in a lower part. The inside of the airtight container 1 is divided into an upper chamber 2a (discharge chamber) and a motor chamber 2b.

The fixed scroll 5 and the orbiting scroll 6 are engaged with each other to form a compression chamber (sealed space) 7. fixed scroll 5
consists of a disc-shaped end plate 5a and a spiral wrap 5b standing upright thereon and formed into a circular impolied curve or a curve similar to this, with a discharge port 10 at the center and an inlet port 16 at the outer periphery. It is equipped with The orbiting scroll 6 is composed of a disc-shaped end plate 6a, a wrap 6b standing upright thereon and formed in the same shape as the wrap of the fixed scroll, and a boss 6c formed on the opposite surface of the end plate. frame 4
forms main bearings 31 and 32 in the center, and this main bearing 31
．． 32 supports a rotating shaft 15, and an eccentric crank pin 15a at the tip of the rotating shaft 15 is inserted into a swing bearing 30 in the boss 6c so as to be able to swing. The frame 4 is fixed to the fixed scroll 5 with a plurality of bolts,
The fixed scroll 5 is fixed to the closed container 1.

The orbiting scroll 6 is regulated by an Oldham ring 12 having an Oldham key so as not to rotate relative to the fixed scroll 5 but to rotate.

A suction pipe 17 is connected to the suction port 16 of the fixed scroll 5 through the closed container 1 . The upper chamber 2a in which the discharge port 10 is open communicates with the motor chamber 2b via a passage 14. The motor chamber 2b communicates with a discharge pipe 19 passing through the closed container 1. 43 is a hermetic terminal portion for the electric motor 3, and there is an oil reservoir at the bottom of the closed container 1.

On the other hand, in a space 20 (referred to as a "back pressure chamber") surrounded by the back surface of the orbiting scroll member 6 and the frame 4, there is a force in the thrust direction due to the gas pressure in the compression chamber formed by the orbiting and fixed image scrolls. (This force is applied to the orbiting scroll member 6
In order to counteract the separation force that tries to push the gas downward, a pressure is set between the suction pressure and the discharge pressure.

This intermediate pressure is set by guiding the gas inside the compression chamber to the back pressure chamber 20 through the pores 22 provided in the end plate 6a of the orbiting scroll 6, and by applying the intermediate pressure to the back surface of the orbiting scroll, the orbiting Scroll 6 is fixed scroll 5
so that it is pressed against. The method of applying this intermediate pressure is disclosed in JP-A-53-119412 and JP-A-55-3.
Since it is disclosed in Japanese Patent No. 7520, etc., a detailed explanation will be omitted.

The thick arrows in FIG. 1 indicate the flow of refrigerant gas. The refrigerant gas passes through the suction pipe 17 and the suction port 16, enters the suction chamber 5f formed on the inner circumference of the fixed scroll 5, and then It is compressed in the compression chamber 7 and discharged from the discharge port 10 into the upper chamber 2a, passes through the passage 14, enters the motor chamber 2b, and is discharged from the discharge pipe 19 to the outside of the closed container 1.

Also, the dashed arrows in Figure 1 indicate the flow of oil.
The oil accumulated at the bottom of the container 1 flows through the central vertical hole 15c formed in the rotating shaft 15 due to the differential pressure between the high pressure (discharge pressure) in the motor chamber 2b and the intermediate pressure in the back pressure chamber 20. After ascending and lubricating the swing bearing 30 and the main bearing 31, the back pressure chamber 20
leak inside. The oil in the back pressure chamber 20 is discharged to the compression chamber 7 through the pores 22, and also moves to the side space 6f through the small gap between the orbiting scroll end plate back surface 6t and the frame 4. . The oil that has entered the side space 6f moves to the suction chamber 5f through a gap E shown in FIG. 2, which will be described later.

This prevents the conventional oil compression action in the side space 6f. The oil that has moved to the suction chamber 5f mixes with the suction refrigerant gas, is pressurized together with the refrigerant gas in the compression chamber 7, is discharged from the discharge port 10 to the upper chamber 2a, enters the motor chamber 2b through the passage 14, Return to the oil pool at the bottom of container 1.

3 is a longitudinal sectional view of the combined fixed scroll 5 and orbiting scroll 6 in FIG. 1, and FIG. 4 is a cross sectional view of FIG. 3. Suction chamber 5 of fixed scroll 5
The diameter D0 of the fixed scroll inner circumferential wall surface 5 forming f and the outer circumferential wall surface 6j of the end plate outer circumferential portion 6 of the orbiting scroll 6
The outer diameter of.

is Dsi-2εth<D. <D,,+2εth
...(1) Preferably, Dgl≦D. <Dsi+2ε... It is set to satisfy the relationship (2). Here, εth is the orbiting radius of the orbiting scroll. Due to the relationship in the above equation,
As shown in FIG. 2, the sheet surfaces of the outer peripheral portion 6 of the end plate 5a of the fixed scroll 5 and the outer circumferential portion 6 of the end plate 6a of the orbiting scroll 6 that oppose this overlap at a crescent-shaped portion F shown by diagonal lines. This part receives part of the thrust load of the orbiting scroll. The remaining thrust load will be received by the tooth tips of the wraps of both scrolls. According to the relationship of the above equation, there is a crescent-shaped gap E shown in FIG.
exists, and the side space 6f of the end plate outer periphery 6 of the orbiting scroll 6 and the suction chamber 5f of the fixed scroll are in a positional relationship in which they are always in communication through the gap E. The angle range β of the crescent-shaped sheet surface sliding contact portion F is preferably β≧180° from the viewpoint of stability of the behavior of the orbiting scroll. In addition,
In Fig. 2, of is the center of the end plate of the fixed scroll (the D
center of wl), 0. is the center of the end plate of the orbiting scroll (described above, the center of .), 0 and 01 coincide with the center of the spiral of the fixed scroll's wrap and the center of the spiral of the orbiting scroll's wrap, respectively; Om revolves around it with a turning radius εth. In addition, Figure 3,
As shown in FIG. 4, a groove 5C for taking in suction pressure is formed in the seat surface of the outer periphery of the end plate of the fixed scroll.

The pressure sealing function between the back pressure chamber 20 and the side space 6f and eventually the suction chamber 5f is achieved by the outer peripheral portion 6k of the end plate of the orbiting scroll 6.
This is achieved between a convex portion 6t formed on the back side over the entire circumference and the pedestal surface of the frame 4 facing the convex portion 6t. This will be explained in detail with reference to FIGS. 1 and 5 to 8.

The convex portion 6t on the back surface of the end plate of the orbiting scroll 6 has a height hs slightly larger than the height of the Oldham ring 12 for preventing rotation. The Oldham ring 12 is designed to have a slight gap in the axial direction with respect to the pedestal surface 4b. This is to prevent thrust loads from acting on the Oldham ring 12. As shown in FIGS. 6 and 7. As shown, a lubricating oil groove 6p is provided on the end face of the convex portion 6t on the back surface of the end plate of the orbiting scroll 6, and a lubricating oil groove 4j is provided on the pedestal surface 4b of the frame 40 opposing this. ap, 4j are lubricated with oil leaking from the back pressure chamber 20 to the side space 6f of the orbiting scroll 6.

The height of the end plate outer peripheral part 6 of the orbiting scroll 6 (the above-mentioned convex part 6
The height of the end plate outer periphery 6 including t) is Isa, and the height of the side space 6f (the distance between the lower surface of the end plate outer periphery of the fixed scroll 5 and the pedestal surface 4b of the frame 4) is H. , when the outer peripheral part 6k of the end plate of the orbiting scroll 6 (the convex part 6t
) is a small gap δ (=Hr −H8,
), and this small gap δ is sealed with oil. In addition, 23 in Fig. 5 is the Oridum keyway,
48 in FIG. 7 is a boss portion forming the Oldham key groove 4f, and 12a in FIG. 8 is an Oldham key.

FIG. 9 shows an embodiment in which a slightly tapered surface 5p is formed at the intersection between the mirror plate surface 5q of the fixed scroll 5 and the inner wall surface 5 forming the suction chamber. This is to prevent the upper end surface of the outer periphery of the end plate 6 of the orbiting scroll 6 from coming into strong hard contact (riding effect) with the above-mentioned intersection during the orbiting movement, that is, it mainly acts on the orbiting scroll. This is to avoid hard contact between the inner peripheral wall surface 5 of the suction chamber of the fixed scroll and the outer peripheral wall surface of the end plate of the orbiting scroll at the intersections A and B shown in FIG. 2 due to the influence of the overturning moment caused by the overturning moment. .

FIG. 10 shows an embodiment in which an annular seal ring 27 for sealing the intermediate pressure in the back pressure chamber 20 is attached to the end face of the convex portion 6t on the back surface of the orbiting scroll end plate, thereby converting the intermediate pressure into suction pressure. It can be reliably sealed against.

In the above embodiments, the outer diameter of the end plate of the orbiting scroll I)
Let us calculate how much the outer diameter of the compressor will be smaller than the conventional machine when so is set equal to the inner diameter Dil of the suction chamber. In this case, D , o=D , . on the other hand,
The outer diameter of the end plate of the orbiting scroll in a conventional machine disclosed in Japanese Patent Application Laid-Open No. 59-110886. .

is approximately given by the following equation.

D3゜″=Dsi+2・εth+2・α.

Here, α0 is the minimum pressure seal width dimension, which is usually 7~
It is 8m111. From the above equation, D. °〉D. It can be seen that in the embodiment of the present invention, the outer diameter of the orbiting scroll can be reduced by more than ten millimeters compared to the conventional machine. Thereby, the orbiting scroll itself can be made smaller and lighter, and the outer dimensions of the compressor can also be set smaller in accordance with the above-mentioned reduced dimensions.

[Effect of the invention] According to the present invention, there are the following effects.

(1) The outer diameter of the end plate of the orbiting scroll, and thus the outer diameter of the scroll compressor, can be made considerably smaller than in conventional machines. Therefore, the weight of the entire compressor can be significantly reduced.

(2) The performance of the compressor is improved because the oil compression effect in the side space of the outer circumference of the orbiting scroll end plate can be completely avoided.

Furthermore, the structure around the frame pedestal facing the back surface of the orbiting scroll end plate is simplified, and processing costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing an embodiment of the scroll compressor of the present invention, and FIG. 2 is an outer diameter D of the end plate of the orbiting scroll of the embodiment.
3 is a longitudinal cross-sectional view of the fixed scroll and the orbiting scroll in this embodiment. FIG. 4 is a cross-sectional view of FIG. 3, and FIG. 5 and 6 are a plan view and a vertical sectional view of the orbiting scroll in this embodiment, FIG. 7 is a plan view of the frame, and FIG. 8 is a sectional view of the Oldham ring.
FIG. 9 is a longitudinal sectional view of a fixed scroll and an orbiting scroll according to another embodiment of the present invention, and FIG. 10 is a longitudinal sectional view of an orbiting scroll, a fixed scroll, and a frame according to still another embodiment. 1... E-closed container 4... Frame 4b.
...Frame pedestal surface 5...Fixed scroll 5a...
・End plate 5b... Wrap 5f... Suction chamber 6... Orbiting scroll 6a... End plate
6b...Wrap 6f...Side space
6k... End plate outer periphery 6t... Convex portion 7.
...Compression chamber 10...Discharge port 12...Oldham ring 15...Rotating shaft 15a...Crank pin 16...Suction port 19...Discharge pipe 20...Back pressure chamber 27...・Seal ring 30...Swivel bearing 31.32...Main bearing. Figure 1 Figure 2 Figure 4 Figure 5 Figure B Figure 6

Claims (4)

[Claims] 1. By engaging the fixed scroll and the orbiting scroll, each consisting of an end plate and a spiral wrap provided upright therewith, with the wraps inside, and causing the orbiting scroll to orbit relative to the fixed scroll without rotating on its axis. , the gas taken in from the suction chamber in the periphery of the fixed scroll into the compression chamber formed by both scrolls is compressed and discharged from the discharge port provided in the center of the end plate of the fixed scroll, and the end plate of the orbiting scroll is In a scroll compressor in which gas pressure is applied to the back surface of the fixed scroll to push it toward the fixed scroll, the outer periphery of the end plate of the fixed scroll and the outer periphery of the end plate of the orbiting scroll only partially overlap and overlap each other. The outer periphery of the end plate of the orbiting scroll has a convex portion extending over the entire circumference on the back side, and the outer periphery of the end plate of the orbiting scroll having the convex portion is in sliding contact with the outer periphery of the end plate of the fixed scroll. and the pedestal surface of the frame fixed thereto with a small gap, and the convex part and the frame pedestal surface opposite thereto perform a sealing function against the gas pressure on the back side of the end plate of the orbiting scroll. A scroll compressor characterized by ensuring that 2. The diameter of the inner peripheral wall surface forming the suction chamber of the fixed scroll is D_s_i, the outer diameter of the outer peripheral part of the end plate of the orbiting scroll is D_s_o, and the orbiting radius of the orbiting scroll is ε_t_
When h, D_s_i−2ε_t_h<D_s_i<D_s_i+
The scroll compressor according to claim 1, which satisfies the dimensional relationship of 2ε_t_h. 3. D_s_i≦D_s_o<D_s_i+2ε_t_
The scroll compressor according to claim 2, which satisfies the dimensional relationship h. 4. D_s_i: D_s_o Claim 3
Scroll compressor as described in section.