JPH0541838B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an oil-fed scroll fluid machine used as a refrigerant compressor or an air compressor for refrigeration and air conditioning, refrigerators, etc.

[Prior Art] Taking a refrigerating and air conditioning compressor as an example of a refrigerating scroll fluid machine, its basic structure, lubrication method, etc. will be explained with reference to FIGS. 1 to 9. In addition,
To facilitate explanation, solid line arrows indicating the flow direction of working gas and broken line arrows indicating the flow direction of lubricating oil are included in each figure. FIG. 1 shows an example of the structure of a vertical compressor which is a closed type and has a scroll compression element section at the upper part of the main body and an electric motor section at the lower part of the main body.

FIG. 1 shows the overall structure of a conventional hermetic scroll compressor for air conditioners. The compressor includes both scroll members, a fixed scroll member 1 and an orbiting scroll member 2, which are compression element portions, a rotation prevention member 3 that prevents rotation of the orbiting scroll member 2, and a main shaft 6.
Three bearing parts that support this, namely the swing bearing 12
It is composed of a bearing 11, an auxiliary bearing 10, an electric motor 9, a stationary member 4 (hereinafter referred to as "frame") that fixes the fixed scroll member 1, and the like. These components are housed inside the closed container 23.
Note that FIG. 1 is a structural example of a high-pressure chamber type in which the inside of the closed container 23 is in an atmosphere of discharge pressure (high-pressure side pressure).

The operation of the compressor will be explained according to the flow of refrigerated gas and the flow of lubricating oil.

The low-temperature, low-pressure refrigerant gas is guided from the suction pipe 19 and reaches the suction chamber 1f in the fixed scroll member 1. As shown in FIG. 2, the refrigerant gas that has reached the compression element part is caused by the revolution movement of the orbiting scroll member 2, which is prevented from rotating, so that the closed spaces 5a and 5b formed by both scroll members gradually shrink, and the refrigerant gas reaches the center of the scroll. The refrigerant gas increases its pressure and is discharged from the central discharge hole 1d. The discharged high-temperature, high-pressure refrigerant gas fills the space around the electric motor, that is, the electric motor chamber 17, through the upper space 1b in the closed container 23 and the passages 13 and 14, and then flows into the discharge pipe 2.
0 to the outside. (This high discharge pressure is indicated by the symbol Pd.) On the other hand, in a space 18 (referred to as a "back pressure chamber") surrounded by the back surface of the orbiting scroll member 2 and the frame 4, there are both orbiting and fixed scrolls. Gas force in the thrust direction due to gas pressure in a plurality of sealed spaces formed by the members (this force is applied to the orbiting scroll member 2
It becomes a separation force that tries to push down. ), a pressure between the suction pressure (low pressure side pressure) and the discharge pressure (indicated by the symbol Pm) acts. This intermediate pressure is set by providing fine holes 2c and 2d in the end plate 2a of the orbiting scroll member 2, and through these fine holes, the gas inside the scroll which is being compressed is pumped into the back pressure chamber 18.
This is done by applying gas force to the back surface of the orbiting scroll member 2. How to apply this intermediate pressure is disclosed in JP-A-53-119412 and JP-A-55-37520, so a detailed explanation will be omitted.

Next, the detailed structure of the automatic prevention member 3 is shown in FIGS. 3 and 4. An example of the anti-rotation member 3 configured with an Oldham ring 30 and Oldham keys 31 and 32 is illustrated. This Oldham ring 30
is sandwiched between the orbiting scroll member 2 and the flume 4 (strictly speaking, the key pedestal 4a of the frame 4), and is provided with an Oldham key 32a,
32b, 31a, and 31b to prevent the orbiting scroll member 2 from rotating. 37 (37
a, 37b) are fixing grooves for the Oldham key 31 provided on the back of the orbiting scroll member 2. Therefore, the Oldham ring 30 has locations 33, 34, 35, 36.
It is sliding.

FIGS. 5 and 6 show the appearance of the Oldham ring, which is an anti-rotation member. Figure 5 is a combination of Figures 3 and 4.
As shown in the figure, this is an embodiment in which two Oldham key grooves 30d are provided on each surface of the upper end surface 30b and lower end surface 30c of the main body 30a of the Oldham ring 30 to engage with the Oldham key in directions perpendicular to each other. . FIG. 6 shows an embodiment of an integrated Oldham ring in which an Oldham key groove is provided on the orbiting scroll member side and the frame side, an Oldham key is provided on the Oldham ring side, and the Oldham key 38b and the main body portion 38a are integrated.

In addition, the outer diameter of the Oldham ring 30 is D _pr and the width is
t _pr , thickness is displayed in h _pr .

The structure around the outer peripheral portion 2f of the end plate of the orbiting scroll member 2 will be explained with reference to FIGS. 7 to 9.
The head plate thickness of the end plate 2a of the orbiting scroll member 2 has a uniform thickness regardless of the outer peripheral part 2f of the end plate and the center part 2g of the end plate (in FIG. 8, this end plate thickness is indicated by the dimension _Hs ). . Further, the outer peripheral portion 2f of the end plate of the orbiting scroll member 2 is sandwiched between the outer peripheral portion 1c of the end plate of the fixed scroll member 1 and the pedestal 4b of the frame 4 with a slight gap being maintained. In the case of FIG. 8, the minute distance is expressed as (H _f −H _s ). (Here, _Hf : the dimension between the frame upper surface 4c and the upper surface of the pedestal 4b, which coincide with the lower surface of the outer periphery of the end plate of the fixed scroll member 2) Oil supply holes 41 (41a to 41d) on the outer periphery of the end plate 2a of the orbiting scroll member 2 A radial oil supply path 40 (40a to 40d) is provided which communicates with the. These oil supply holes 41 engage with oil grooves 42 provided in the end plate 1a of the fixed scroll member 1. The orbiting scroll member 2 is positioned at the frame center point (or the fixed scroll center point) with the end plate outer circumferential portion 2f sandwiched between the end plate outer circumferential portion 1c of the fixed scroll member 1 and the pedestal 4b of the frame _4. The positional relationship between the frame 4 and the orbiting scroll 2 is as shown in FIG.

FIG. 8 shows a cross-sectional view of the frame 4. The frame 4 is provided with two key pedestals 4a each having a key fixing groove 4f for mounting an Oldham key 31 thereon. 4e is a bolt hole for attaching the fixed scroll member 1 to the frame 4. in this way,
In addition to the back pressure chamber 18 at the back of the orbiting scroll 2, around the outer peripheral portion 2f of the end plate of the orbiting scroll member 2,
A space 43 is formed by the outer circumferential portion 2f of the end plate, the fixed scroll member 1 opposing it, the outer circumferential portion 1c of the end plate, and the frame 4. Hereinafter, this space 43 will be referred to as a "frame chamber."

Note that the outer peripheral portion 2f of the end plate of the orbiting scroll member 2
The fixed scroll end plate outer peripheral part 1c which is a stationary member
A structure in which the frame pedestal 4b is sandwiched between the frame pedestal 4b and the frame pedestal 4b while maintaining a slight gap is disclosed in Japanese Patent Application Laid-open No. 142902/1982, so the purpose, effects, etc. of this structure will not be explained. Reference numerals 8 and 24 shown in FIG. 1 are balance weights, which are balancing components for canceling the centrifugal force acting on the orbiting scroll member 2, and swing around the main shaft 6.

Next, the flow of lubricating oil will be explained using FIG. 1, FIG. 7, and FIG. 8.

The lubricating oil 7 is stored in the lower part of the closed container 23.
The lower end of the main shaft 6 is immersed in oil at the bottom of the container, and the main shaft 6
The upper portion is provided with an eccentric shaft portion 6a, and the eccentric shaft portion 6a engages with the orbiting scroll member 2, which is a scroll compression element portion, via an orbit bearing 12. The main shaft 6 has an eccentric vertical hole 6 for supplying oil to each bearing.
b is formed from the lower end of the main shaft to the upper end surface of the main shaft.

At the lower part of the eccentric shaft part 6a, a balance weight 8 is formed so as to be engaged with and integrated with the main shaft 6, on the upper part of the main bearing 11 facing the lower end surface of the orbiting scroll boss part 2e. The lower end of the main shaft 6 immersed in the lubricating oil 7 is in an atmosphere of high discharge pressure Pd, while the area around the downstream swing bearing 12 is in an atmosphere of intermediate pressure Pm. −
Pm), the lubricating oil 7 at the bottom of the container rises inside the eccentric vertical hole 6b. Further, due to the rotation of the main shaft 6, centrifugal force acts on the oil in the eccentric vertical hole 6b,
The amount of oil supplied to each bearing is further increased. In this way, each bearing can be lubricated using the eccentric hole lubricating method.
This is done using the partial pressure lubrication method.

The lubricating oil 7 rising inside the eccentric vertical hole 6b is supplied to the auxiliary bearing 10 and the main bearing 11, and is also supplied to the upper space 25 of the eccentric shaft portion 6a (orbiting scroll boss portion 2).
The space between e and the bottom surface of the boss hole and the upper end surface of the eccentric shaft portion 6a becomes a hydraulic chamber. Hereinafter, it will be referred to as the "hydraulic chamber" 25. ). The lubricating oil in the hydraulic chamber 25 has a pressure approximately equal to the discharge pressure Pd, and as shown in FIG. 7 and FIG.
The oil reaches an oil groove 42 provided in the outer peripheral portion 1c of the fixed scroll member 1 through a radial oil supply passage 40 and an oil supply hole 41 provided in the end plate 2a.

The lubricating oil that has reached the oil groove 42 is transferred to the frame chamber 43.
or to the suction chamber 1f inside the scroll. In addition, the lubricating oil that has reached the swing bearing 12 and the main bearing 11 passes between the respective bearings into the back pressure chamber 1.
Oil is drained to 8. The lubricating oil that has reached the back pressure chamber 18 is
After lubricating the Oldham ring 30 and the like, the refrigerant gas is injected into the working chamber formed by both scroll members 1 and 2 through the pores 2c and 2d, and then mixed with the refrigerant gas inside the scroll wrap.

Next, the lubricating oil along with the refrigerant gas is subjected to a pressure increasing action, and the discharge hole 1d, the discharge chamber 16, and the passages 13, 1
4 to the electric motor room 17. Electric motor room 1
7, the flow rate of the lubricating oil is greatly reduced due to the large space, and it falls to the bottom of the closed container 23 due to its own weight. That is, the refrigerant gas and lubricating oil are separated in the motor room 17. The fallen lubricating oil was collected again at the bottom of the container and used to lubricate various parts.

In addition, in Japanese Utility Model Application Publication No. 55-177089, the orbiting scroll is rotated by an Oldham coupling, and the back surface of the orbiting scroll is rotated by a floating thrust ring to which an axial thrust force is applied by hydraulic pressure. A scroll compressor is disclosed that generates an axial sealing force to overcome the thrust force generated by the scroll.

[Problems to be Solved by the Invention] Next, problems with the prior art will be explained using the above-mentioned FIGS. 3 and 4 and FIGS. 10 to 12.

Figure 10 shows frame 4, Oldham key 31
a, A vertical sectional view around the Oldham ring 30 of the scroll compressor showing a state in which the Oldham ring 30, the orbiting scroll member 2, and the fixed scroll member 1 are assembled. The Oldham ring 30 rests on the Oldham key 31a provided on the key pedestal 4a of the frame 4, and the orbiting scroll member 2 is mounted on the upper end surface 30b of the Oldham ring 30.
It's on top.

In the orbiting scroll member 2, the end plate outer peripheral part 2f is sandwiched between the end plate outer peripheral part 1c of the fixed scroll member 1 and the pedestal 4b of the frame 4 with a distance (H _f - H _s ) maintained, It is also sandwiched between the fixed scroll member 1 and the orbiting scroll member 2 (strictly speaking, the upper surface of the end plate of the orbiting scroll member 2 placed on the upper end surface 30b of the Oldham ring 30) with a slight distance δ ₀₁ . ing.

In FIG. 10, from the pedestal surface 4 _b1 of the pedestal 4b of the frame 4, the main body portion 30 of the Oldham ring 30 is
The case where the upper end surface 30b of a is located upward is shown. The positional relationship between these is the depth of 4 _b1 in front of the pedestal.
H _f , the mirror plate thickness H _s of the orbiting scroll member 2, the depth H _z of the Oldham key seat surface 4 _a1 on the frame 4 side, the thickness h _pr of the Oldham ring 30, etc. Note that the first
FIG. 0 shows a state in which the Oldham ring 30 is subjected to the gravity of the orbiting scroll member 2 when the compressor is not operating.

When the compressor is driven from the state shown in FIG. 10, the following problems occur.

FIG. 11 shows the positional relationship around the Oldham ring immediately after the compressor is started. (The scroll wrap part is not shown.) At the moment of startup, the axial gas force F _a due to the gas pressure generated in the closed space formed by the fixed scroll member 1 and the orbiting scroll member 2 is , is larger than the gas force F _b due to the gas pressure (back pressure) in the back pressure chamber 18, so the orbiting scroll member 2 is pressed downward as shown in FIG. In such a state, a force (F _a −F _b ) acts on the upper end surface 30b and eventually the lower end surface 30c of the Oldham ring 30, and the rear surface 2k of the end plate of the orbiting scroll member 2 and the upper end surface 30b of the Oldham ring 30 are Causes sliding movement with strong contact. Therefore, mechanical friction loss increases in the Oldham ring portion, and as a result, starting torque increases. In the worst case, an abnormal axial gas force acts on the upper end surface of the Oldham ring 30,
There is a fear that friction of the Oldham ring 30 due to excessive surface pressure accompanying this may cause damage (fatigue fracture). Naturally, a sound (strong impact sound) is also generated due to the strong contact between the orbiting scroll member 2 and the Oldham ring 30 at the initial stage of startup.

FIG. 12 shows the behavior of the orbiting scroll member 2 and the Oldham ring 30 when the compressor enters a steady state.
A vertical cross-sectional view showing the circumferential positional relationship is shown.

In a steady state, the relationship between the magnitudes of the gas forces F _a and F _b is F _b >F _a >, so the orbiting scroll member 2 floats toward the fixed scroll member 1 and is pressed against it.

In addition, in a steady state, the gas pressure in the sealed space formed by both scroll wraps acts as a concentrated force at a position half the height of the teeth of the orbiting scroll, while the driving force is applied to the orbiting scroll boss portion 2e. As shown in FIG. 12, the moment that tends to overturn the orbiting scroll, which is generated due to the force acting on the rotor, causes the orbiting scroll 2 to perform an orbiting motion in an inclined state within the range of the minute distance δ ₀₁ . Therefore, the inner end 30e of the upper end surface 30b of the Oldham ring 30
and the end plate rear surface 2k of the orbiting scroll 2 come into contact with each other, even if only on one side. In such a situation,
Since the edge load acts on the Oldham ring 30, problems arise such as an increase in mechanical friction loss in this part and generation of noise due to uneven contact.

Japanese Utility Model Application Publication No. 55-177089 describes that the function of preventing rotation is performed by an Oldham joint, and the thrust force of the orbiting scroll member, such as gas force or self-gravity, is performed by a floating thrust ring. No consideration was given to preventing thrust force from being applied to the joint and preventing edge load from acting even if the orbiting scroll was tilted.

This invention was invented in view of the above-mentioned problems, and aims to provide a scroll fluid machine that prevents thrust force and edge load from being applied to the Oldham ring, ensures reliability against wear and breakage of the anti-rotation member, and provides a scroll fluid machine. .

[Means for Solving the Problems] In order to achieve the above object, the present invention is designed to prevent the axial gas force formed by both scroll members or the self-gravity of the orbiting scroll from acting on the Oldham ring, which is an anti-rotation member. The structure is such that the edge load does not act even if the orbiting scroll is tilted. Therefore, in the scroll fluid machine according to the present invention, a fixed scroll member and an orbiting scroll member, each having an end plate and a spiral wrap standing upright thereon, are engaged with each other with the wraps inside to form a sealed space. The orbiting scroll member is configured such that its axial movement and tilting are restrained by the mirror plate surface of the fixed scroll member and the pedestal surface of the frame with a required axial distance, and one end surface of the Oldham ring main body The orbiting scroll member is rotated by the anti-rotation member of the Oldham mechanism, the other end surface of which has a key and keyway engagement portion between the surface on the opposite lap side of the end plate of the orbiting scroll member and the Oldham key seating surface of the frame. In a scroll fluid machine that compresses fluid by reducing the volume of the closed space to move from the outside to the center, one end surface of the Oldham ring main body is Axial direction between the plane including the pedestal surface of the frame
and an axial distance between the end plate of the orbiting scroll member and the opposite-to-lap side surface, and a gap between the key and the keyway on the opposite-to-lap side surface of the end plate of the orbiting scroll member. The engaging portion is characterized by having an axial distance between the head of the key and the bottom of the key groove.

That is, the present invention provides an appropriate and large axial distance between the Oldham ring portions, thereby preventing the Oldham ring from receiving an axial load, and furthermore, prevents the Oldham ring from receiving an edge load even when the orbiting scroll member is tilted. It is characterized by maintaining a free state in the axial direction.

[Function] In a scroll fluid machine that assumes a configuration in which the orbiting scroll member is restrained from axial movement and tilting with a required axial distance by the end plate surface of the fixed scroll member and the pedestal surface of the frame. , regardless of the axial movement and tilting of the orbiting scroll member, one end surface of the Oldham ring main body has an axial distance between it and a plane including the pedestal surface of the frame, and The structure is such that there is also an axial gap between the end face of the end plate on the side opposite to the lap, and there is always a gap between one end face of the main body of the Oldham ring and the side opposite to the lap of the end plate of the orbiting scroll member. Moreover, since the structure is such that there is always a gap in the axial direction between the engaging Oldham key and the bottom surface of the Oldham key groove, even if the orbiting scroll member is pressed downward by gas pressure, the pedestal surface on the outer periphery of the frame There is no sliding contact with the Oldham ring body under the thrust force, and no sliding contact occurs in the axial direction between the key head surface and the bottom surface of the key groove at the engagement portion between the Oldham key and the Oldham key groove. Furthermore, even if the orbiting scroll member is tilted due to a moment, since the outer peripheral portion of the end plate of the orbiting scroll member is supported by the frame pedestal surface, the tilt of the orbiting scroll member is small.
Edgelord has no effect on Oldham Ring.

[Embodiments of the Invention] Examples of the present invention are shown in FIGS. 13 to 19.

Figure 13 shows the Oldham ring 30 when the compressor is stopped or when the scroll compressor has been assembled.
Indicates the positional relationship of the surroundings. oldham ring 30
is placed on the upper end surface _31a1 of the Oldham key 31a on the frame 4 side. In order to maintain the Oldham ring 30 in a free state in the axial direction, there is always a gap between the Oldham ring 30, the upper end surface 30b of the main body 30a, and the rear surface 2k of the end plate of the orbiting scroll 2 that faces this. δ ₀₂ is provided. On the other hand,
The lower end surface 30 of the main body portion 30a of the Oldham rig 30
The distance δ ₀₃ is provided so that there is always a distance between c and the seat surface 4 _a1 of the Oldham key pedestal surface 4 a on the side of the frame 4 facing this. In order to provide the distances δ ₀₂ and δ ₀₃ , the following dimensional relationship is required, as shown in the cross section of FIG.

δ ₀₂ = H _z − H _s − h _pr − δ ₀₃ ...(1) δ ₀₃ = h _pk −h _ps ...(2) Here, H _z : Seat surface of the Oldham key pedestal 4a from the upper end surface of the frame 4 Dimension up to _a1 H _s : Thickness of the mirror plate of the orbiting scroll h _pr : Thickness of the main body part 30a of the Oldham ring h _pk : Dimension from the seat surface 4 _a1 of the Oldham key 31a to the upper end surface 31 _a1 h _ps : Dimension of the Oldham ring 30 Oldham key groove depth Taking the Oldham key 32b on the orbiting scroll member 2 side as an example, in order to avoid contact with the Oldham ring 30 in the axial direction, the lower end surface 32 _b1 of the Oldham key 32 and the Oldham ring 30 opposite thereto
A certain distance δ ₀₄ is provided between the upper surface 30 of the Oldham key groove portion 30d.

The distance δ ₀₄ has a dimension expressed by the following formula.

δ ₀₄ = H _z −H _s −h _pk −h _pn −δ ₀₃ ...(3) Here, hom: Oldham key groove part 30 of Oldham ring
Thickness of the main body portion of d (=h _pr −h _ps ) FIG. 2f
The structure is such that the orbiting scroll member 2 is supported by a pedestal _4b that extends over the entire outer circumference of the frame 4, and the upper end surface 30b of the main body 30a of the Oldham ring 30 is
This is an embodiment in which the frame 4 is located below the pedestal surface 4 _b1 . FIG. 14 shows the positional relationship around the Oldham ring when the scroll compressor is stopped or when assembly is completed.

Even if the orbiting scroll member 2 falls downward due to its own gravity, the orbiting scroll member 2 is supported by the pedestal 4b of the frame 4, and the orbiting scroll member 2
Since the Oldham ring 30 and the Oldham ring 30 are separated by the axial distance δ ₀₂ , the self-gravity of the orbiting scroll member 2 does not act on the Oldham ring 30. 14th
In the illustrated embodiment, the axial distances δ ₀₂ and δ ₀₃ of the Oldham ring have the following relationship.

h _ff = δ ₀₂ + δ ₀₃ + h _pr ...(4) H _z =H _f +h _ff ...(5) In the conventional technology, h _ff h _pr ...(6) or H _z −h _pr ≦H _f ... ... Various problems have arisen due to the positional relationship in (7), but according to the present invention, the relationship in equations (6) and (7) is eliminated. Moreover, FIG. 14 is also a diagram showing an example of the behavior of the orbiting scroll of the present invention at the instant of startup of the scroll compressor, as shown in FIG. 11 described above.
That is, the orbiting scroll member 2 is pushed back downward by the axial gas force caused by the gas pressure in the closed space (such as 5a and 5b shown in FIG. 2) formed by both scroll members 1 and 2. , the load is not received by the Oldham ring 30, but is supported by the pedestal 4b of the frame 4.

15 and 16 show an example of the behavior of the orbiting scroll member 2 and the positional relationship around the Oldham ring 30 when the scroll compressor is in steady operation. Even if the orbiting scroll member 2 performs an orbiting motion (misosuri motion) with a certain inclination,
The orbiting scroll member 2 has the above-mentioned maximum in the axial direction.
Since it changes only within the range of δ ₀₅ (=H _f − H _s ),
The orbiting scroll member 2 and the Oldham ring 30 are separated from each other by gaps δ ₀₅ and δ ₀₇ and are always in a state of not contacting each other. As a result, the orbiting scroll member 2 is pressed downward during startup and operation, but even if the orbiting scroll member 2 is tilted, the orbiting scroll member 2 is pressed against the Oldham ring 30.
There is no uneven contact between the Oldham key and the Oldham key groove, and there is no uneven contact between the Oldham key and the Oldham key groove.
It can be expected to improve compressor performance and reduce noise by reducing mechanical friction loss.

17 and 18 illustrate an embodiment of the invention using the integral Oldham ring 38 shown in FIG. Both figures are integral Oldham ring 38
The upper end surface 38c of the main body portion 38a is located at a lower position than the pedestal surface _4b1 of the frame pedestal 4b. Further, a certain distance δ ₀₈ is maintained between the upper end surface 38c of the main body portion 38a of the Oldham ring 38 and the rear surface 2k of the end plate of the orbiting scroll member 2 opposing thereto,
and the Oldham key seat surface 4 _a1 of the Oldham key base 4 a on the frame 4 side opposite to this.
Keeping the gap δ ₀₉ , Oldham ring 38
The upper and lower end surfaces 38c and 38d of the upper and lower end surfaces 38c and 38d are prevented from coming into sliding contact with each other to prevent abrasion of these parts. The distance δ ₀₉ has the dimension shown by the following formula.

δ ₀₉ = h _i − h _o ...(8) where, h _i : Height of the Oldham key part of the integral Oldham ring _ho : Depth of the Oldham key groove on the frame side As shown in Figure 18, the integral Oldham ring 3
8 is used, a certain distance δ ₀₁₀ is maintained between the upper end surface 38f of the Oldham key 38b of the Oldham ring 38 and the groove bottom surface 37c of the Oldham key groove 38b of the orbiting scroll member 2 facing thereto. The distance δ ₀₁₀ is the Oldham key groove depth h _o ′ and the Oldham key 38b of the integral Oldham ring portion 38.
This can be obtained by adjusting each dimension such as the key height h ₁ '.

In this way, the axial distance δ ₀₂ of the Oldham ring,
By increasing δ ₀₃ , etc., even if the flatness (or waviness of the surface) of the upper end surface or lower end surface of the main body of the Oldham rings 30, 38 is greatly out of order, the orbiting scroll member due to the out of flatness may be and strong contact with the Oldham ring itself can be avoided. Therefore, the present invention can be expected to partially reduce the processing accuracy of the Oldham ring itself.

The structure of the Oldham ring 30 of the conventional machine is that, as shown in FIG.
pedestal 4 _a1 , but in the initial stage of startup and steady operation, the orbiting scroll 2 undergoes a scraping motion (orbiting motion in which the orbiting scroll member 2 is displaced in the axial direction). In order to do
Since the upper and lower end surfaces of the main body portion 30a of the Oldham ring 30 come into contact with the mirror plate back surface 2k and the pedestal surface _4a1 , in order to avoid this, the present invention provides a space between δ ₀₂ , δ ₀₃ , and δ ₀₇ with sufficient space in the axial direction. , δ ₀₈ , etc. Furthermore, if the gaps δ ₀₂ , δ ₀₃ , δ ₀₇ , and δ ₀₈ are too large, the Oldham ring 30 may move in the axial direction. is desirable.

δ ₀₂ ≒δ ₀₃ ≒0.5mm ...(9) δ ₀₅ ≒0.1mm (10) δ ₀₇ ≒ ₀₈ ≒δ ₀₁₀ ≒0.5mm ...(11) sinθ _pr ≒tanθ _pr = δ ₀₂ /D _pr ~ _{δ 03 /Dpr...(1}
2) _≒ (5 to ⁶ ₎ Shows an axial dance pattern. The Oldham ring 30 is displaced in the axial direction (axial direction dance phenomenon). The actual dimensions listed in equations (9) to (13) were given in consideration of the oil film reaction force not directly acting on the axial sliding surface of the Oldham ring. In other words, the distance in the axial direction is such that no oil film reaction force due to oil contamination occurs. The present invention is also characterized in that the Oldham ring is provided with a sufficient axial distance where excess axial force such as oil film reaction force (this force also acts as a load on the compressor) does not act on the Oldham ring.

[Effects of the Invention] According to the present invention, an excessive axial load on the Oldham ring (especially at the initial stage of startup) is avoided when the orbiting scroll member is pressed downward due to gas pressure, which was a problem in conventional scroll fluid machines. is not applied and no axial load is applied at all, so the starting torque can be reduced and the Oldham ring itself can be prevented from being destroyed. In addition, even if the orbiting scroll member is tilted during normal operation, the Oldham ring is free in the axial direction relative to the orbiting scroll, so there is no edge load effect, which reduces mechanical friction loss and improves the compressor. Overall performance is improved.

Further, in the inventions described in claims 2 to 4, the upper and lower end surfaces of the main body of the Oldham ring are in a state where the orbiting scroll member facing them and the Oldham key seating surface of the Oldham key pedestal are in a non-contact state, so that the main body Abrasion on the upper and lower end surfaces of the part can be completely suppressed.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional hermetic scroll compressor, Figure 2 is a cross-sectional view showing the meshing state of both scroll members, and Figures 3 and 4 are plan views showing the positional relationship between the Oldham ring and Oldham key. The figure, longitudinal sectional view, and FIGS. 5 and 6 are external perspective views of the Oldham ring. 7 and 8 are a plan view and a vertical cross-sectional view showing the structure around the outer periphery of the end plate of an orbiting scroll member according to the prior art, FIG. 9 is a plan view of a frame showing a broken closed container, and FIG. 10 12 are vertical sectional views showing the positional relationship between the orbiting scroll and the area around the Oldham ring. 1 from Figure 13
Fig. 8 shows one embodiment of the present invention, Fig. 13 shows the positional relationship around the Oldham ring and the Oldham key, Fig. a is a longitudinal sectional view, Fig. b is a sectional view taken along the - line, and Figs. FIG. 19 shows other embodiments, and is a vertical sectional view showing the positional relationship around the orbiting scroll and the Oldham ring. 1... Fixed scroll member, 1a... End plate of fixed scroll member, 2... Orbiting scroll member,
2a... End plate of orbiting scroll member, 4... Frame, 6... Main shaft, 7... Lubricating oil, 9... Electric motor, 10, 11, 12... Bearing, 18... Back pressure chamber, 23... Sealing Container, 30... Oldham ring, 31... Oldham key, 38... integral Oldham ring.

Claims (1)

[Scope of Claims] 1. A fixed scroll member and an orbiting scroll member, each having an end plate and a spiral wrap standing upright thereon, are engaged with each other with the wraps inside to form a sealed space, and the orbiting scroll member The mirror plate surface of the fixed scroll member and the pedestal surface of the frame are configured to restrain axial movement and tilting with a required axial distance, and one end surface and the other end surface of the Oldham ring main body. The orbiting scroll member is rotated by the anti-rotation member of the Oldham mechanism, which has a key-keyway engagement portion between the surface of the end plate of the orbiting scroll member on the anti-lap side and the Oldham key seat surface of the frame, respectively, to seal the orbiting scroll member. In a scroll fluid machine that compresses fluid by reducing a volume that moves a space from the outside to the center, one end surface of the Oldham ring main body portion is aligned with the pedestal surface of the frame regardless of the axial movement and tilting of the orbiting scroll member. has an axial distance between the end plate of the orbiting scroll member and a surface of the end plate of the orbiting scroll member on the opposite side of the wrap; A scroll fluid machine characterized in that the engagement portion between the key and the keyway on the side surface has an axial distance between the top surface of the key and the bottom surface of the keyway. 2. The scroll fluid machine according to claim 1, wherein there is also a space between the other end surface of the Oldham ring main body and the Oldham key seat surface of the frame that opposes the other end surface. 3. In the case where the orbiting scroll member has a key on the opposite surface of the end plate, and the Oldham ring has a keyway on the one end surface of the main body, the head surface of the key and the bottom surface of the keyway Scroll fluid machine according to claim 1 or 2, characterized in that there is an axial gap between them. 4. In the case where the orbiting scroll member has a key groove on the surface opposite to the lap of the end plate, and the Oldham ring has a key integrally on the one end surface of the main body, the bottom surface of the key groove and the head of the key The scroll fluid machine according to claim 1 or 2, characterized in that there is an axial distance between the scroll fluid machine and the surface.