JPH06317269A - Closed type scroll compressor - Google Patents

Abstract

PURPOSE:To improve performance, or simplify work by setting a clearance between a lap tooth tip surface of a turning scroll member and a lap tooth bottom surface of a fixed scroll member uniformly at a scroll lap winding angle (an involute expanding angle). CONSTITUTION:In a closed type scroll compressor, a clearance (deltaak) between a lap tooth tip surface 6p of a turning scroll member 6 and a lap tooth bottom surface 5n of a fixed scroll member 5 is set uniformly at a scroll lap winding angle (an involute expanding angle). On the other hand, delicate steps are set uniformly at the scroll lap winding angle on a tooth bottom surface 6n of a turning scroll lap 6b to the outer peripheral part of a scroll end plate between the fixed side 5m and the turning side 6m being a slidingly movable thrust part. Assuming that a shaft directional clearance between a lap tooth bottom surface 6n of the turning scroll member 6 and a tooth tip surface 5p of the fixed scroll member 5 is (deltaas), a step dimension is set in the relationship of (deltaak)>(deltaas) or is set equally to (deltaak)=(deltaas).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic scroll compressor used as a refrigerant compressor for refrigeration and air conditioning, refrigerators and the like.

[0002]

2. Description of the Related Art A hermetic scroll compressor is disclosed in Japanese Patent Laid-Open No.
As disclosed in Japanese Patent No. 67902, the refrigerant gas compressed by the scroll compression mechanism portion reaches the electric motor chamber from the upper discharge chamber through the communication passage. Then, the refrigerant gas flows around the electric motor and flows out from the discharge pipe of the compressor.
Then, this known technique discloses a structure in which a gap in the central portion is larger than that in the outer peripheral portion of the scroll member in order to reduce contact of the scroll member due to deformation due to pressure of the end plate portion of the fixed scroll member.

[0003]

In the above-mentioned known technique, since the tapered gap distribution is set so that the gap in the central portion of the wrap is set larger than the gap in the outer peripheral portion of the wrap of the scroll member, the taper of the tip end surface of the scroll wrap is formed. The processing method becomes difficult. As a result, the processing time is long and the processing cost is relatively high, which limits the mass productivity of the scroll wrap. Further, the size of the taper of the tip end surface of the scroll wrap also tends to vary, and as a result, the performance of the compressor also varies, which causes a problem in maintaining the quality of the compressor.

An object of the present invention is to solve the above problems.

[0005]

As shown in FIGS. 1 to 4 and 9, in the present invention, a scroll compressor and an electric motor are continuously provided in a closed container via a rotary shaft supported by a frame. It is housed and the closed container chamber is divided into an upper chamber and a lower chamber, and the scroll compressor is fixed by interlocking the fixed scroll member and the orbiting scroll member, which stand the spiral wrap upright on the disk-shaped end plate, with the wrap inside. The disk-shaped end plates on the rotating side and the orbiting side have the same thickness and engages with the eccentric shaft part that connects the orbiting scroll member to the rotating shaft, and fixes the orbiting scroll member without rotating. The scroll member is caused to orbit, and the fixed scroll member is provided with a discharge port that opens in the center and an intake port that opens in the outer periphery. Move around Revolving in a hermetic scroll compressor that reduces the amount of gas and compresses it, discharges the compressed gas from the discharge port to the upper container chamber, guides it to the lower container chamber through a passage, and discharges it outside the unit through a discharge pipe. The gap δ _ak between the wrap tooth tip surface 6p of the scroll member 6 and the tooth bottom surface 5n of the fixed scroll member 5 is set uniformly with respect to the scroll wrap winding angle (involute extension angle, λ), and With respect to the outer periphery of the scroll end plate on the fixed side 5m and the orbiting side 6m, a minute step is uniformly provided on the tooth bottom surface 6n of the orbiting scroll wrap 6b with respect to the scroll wrap winding angle.
The step size is the axial clearance δ _as between the wrap tooth bottom surface 6n of the orbiting scroll member 6 and the tooth top surface 5p of the fixed scroll member 5.
In this case, the relation is set _as δ _ak > δ _as , or δ _ak = δ _as . Further, as shown in FIG. 3, the wrap tooth bottom surface 6s of the orbiting scroll member 6 engaging with the side wall surface 6g forming the outer wrap curve 6f from the wrap outer end portion 6y of the orbiting scroll member 6 to the wrap portion 6z on the inner side of the half circumference. Is the same height as the outer peripheral portion 6m of the end plate of the annular orbiting scroll that serves as the thrust sliding portion, and has a uniform surface. Alternatively, the dimensionless gap δ _as / H _so , which is the ratio of the reference height H _so of the orbiting scroll wrap to the step size δ _as provided on the wrap tooth bottom surface of the orbiting scroll member, is defined _as (1.2 to
The feature is that the range is set to 3.5) / 1000.

[0006]

The operation of the present invention will be described with reference to FIGS. 1 to 4 and 9. As shown in FIG. 9, in the operating state, when the fixed side and the orbiting side disk-shaped end plates have the same thickness, the end plate part (ceiling plate part) of the fixed scroll is affected by the load due to the pressure difference and the temperature. , Tends to bend to the orbiting scroll side of about a dozen μm in the axial direction. Since the initial gap corresponding to the amount of deformation is set between the scroll wraps, it is possible to reduce the contact between the tip of the wrap and the bottom surface of the revolving tooth that is the partner of the wrap, which is caused by the deformation on the fixed scroll side. FIG. 1 is a perspective view of an orbiting scroll member 6 having a step on the bottom surface of the lap teeth. The step portion is indicated by diagonal lines. Figure 2
FIG. 6 is a vertical cross-sectional view showing a state in which a fixed scroll 5 and an orbiting scroll 6 are engaged with each other. As shown in FIG. 2, the gap is δ
_Since the relation of _ak > δ _as is established, the end plate surfaces on the fixed side 5 m and the orbiting side 6 m of the scroll end plate outer peripheral portion can surely fulfill the function as the thrust sliding portion. The axial clearance between the orbiting scroll tooth tip surface and the fixed scroll tooth bottom surface (hereinafter referred to as “orbiting tooth tip clearance” δ _ak ) is from several μm to more than 10 μm.
The gap is uniform around m. In the prior art, since this gap was unclear, the function as the thrust sliding portion was insufficient. FIG. 6 shows the relationship between the step size and the performance. Step difference δ _as provided on the wrap tooth bottom surface of the orbiting scroll member with respect to the reference height H _so of the orbiting scroll wrap
The performance of the compressor can be further improved by appropriately setting the dimensionless clearance δ _as / H _so which is the ratio of This range is experimentally determined by the dimensionless gap δ _as / H _so = (1.2
It was known to be in the range of ~ 3.5) / 1000.

As shown in FIG. 6, by increasing the step size (recess size) δ _as of the bottom surface of the orbiting scroll from 0, both the volume efficiency η _v and the total adiabatic efficiency η _ado are improved, and the end plate of the orbiting scroll is improved. The displacement Wk is decreasing. If the initial axial clearance δ _as during conventional assembly is small, deformation will make it easier for the scroll wrap tips to hit the scroll wrap tips, resulting in a smaller radius that supports the overturning moment acting on the orbiting scroll. It is considered that this is due to the increase in the end plate displacement W _k of the orbiting scroll. When the orbiting scroll easily moves in the axial direction and its end plate displacement increases, it can be determined that the performance deteriorates as a result of an increase in the amount of heating due to internal leakage and oil leakage from the back pressure chamber to the suction chamber. It has been found that the small displacement of the end plate of the orbiting scroll gives good results in terms of performance. In this way, the contact of the scroll member due to the deformation of the fixed scroll member due to the pressure of the end plate portion is mitigated by optimizing the set gap, and the set gap is uniformly provided with respect to the scroll wrap winding angle. The machining method becomes easy and the variation of the tooth profile accuracy becomes small. Therefore, it is effective in improving the performance of the compressor and reducing variations in the performance, and the scroll processing method is facilitated, resulting in a lower product cost.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention is shown in FIGS. FIG. 1 shows a perspective view of an orbiting scroll member 6 in which a step is provided on a wrap tooth bottom surface 6n of the orbiting scroll 6. Figure 2
FIG. 4 is a vertical cross-sectional view showing a state in which a fixed scroll 5 and an orbiting scroll 6 are meshed with each other. The size of the wrap and the size of the gap are exaggerated for clarity. 3 and 5 are plan views of the orbiting scroll 6. Further, FIG. 4 is a vertical sectional view taken along line A-Om-A in FIG. 3 and 5, the region in which the wrap tooth bottom surface 6n of the orbiting scroll 6 is provided with a step is shown by hatching. D _c in the drawing is a tooth groove size, and this value is represented by (turning radius × 2) + lap thickness t. As shown in FIG. 3, a step region is set by extending outwardly in an arc shape from the outer wrap portion P of the wrap portion 6z on the inner side of the wrap outer end portion 6y of the orbiting scroll member 6 by a dimension of D _c. ing. On the other hand, 6
The wrap tooth bottom surface 6s of the orbiting scroll member 6 that engages with the side wall surface 6g that forms f has a height equivalent to that of the end plate outer peripheral portion 6m of the annular orbiting scroll that is the thrust sliding portion, that is, a uniform surface. There is no minute step in the part. FIG. 5 shows an embodiment in which, as compared with the step area shown in FIG. 3, the step area is increased by a half circle in an arc shape having a line segment OmT as a radius R1 as shown in the figure. For this reason, a step portion is partially formed in an arc shape at the wrap outer end portion 6y.

FIG. 6 is an explanatory view of the function and effect of the present invention. FIG. 7 is an explanatory diagram showing the relationship between the clearance δ _as between the wrap bottom surface of the orbiting scroll member and the tooth top surface of the fixed scroll member and the scroll wrap winding angle λ.

In the figure, λ _L is the scroll wrap winding angle at the wrap outer end portion 6y, which is the scroll wrap winding end angle. Further, λ ₁ is the scroll wrap winding angle at the lap winding start portion of the lap center portion 6k, and is the scroll wrap winding start angle. The step size δ _as provided on the wrap tooth bottom surface of the orbiting scroll member is set within a range of 3 to 8 μm or a uniform value of about 10 μm with respect to the scroll wrap winding angle λ.
FIG. 8 is an explanatory diagram showing the relationship between the gap δ _ak between the tip of the wrap bottom of the orbiting scroll member and the bottom of the root of the fixed scroll member and the scroll wrap winding angle λ. The gap δ _ak is several μm to ten and several μ with respect to the scroll wrap winding angle λ.
It is set to a uniform value around m, and the gap between them has a relation of δ _ak > δ _as . Alternatively, the relation of δ _ak = δ _as . As described above, this range is practically expressed as a dimensionless gap, in general, δ _as / H _so = (1.2 to 3.
It was confirmed experimentally that the range was 5) / 1000.

FIG. 9 is a vertical sectional view of a hermetic scroll compressor incorporating the orbiting scroll of the present invention.

As shown in FIG. 9, the compressor section 100 is housed in the upper part of the closed container 1, and the electric motor section 3 is housed in the lower part. The closed container 1 is divided into an upper chamber 1a (discharge chamber) and electric motor chambers 1b and 1c.

In the compressor section 100, a fixed scroll member 5 and an orbiting scroll member 6 are engaged with each other to form a compression chamber (closed space) 7. The fixed scroll member 5 is composed of a disk-shaped fixed scroll scroll end plate portion 5a and a wrap 5b which stands upright on the end plate 5a and is formed in an involute curve or a curve similar to this, and has a discharge port 10 at its center. A suction port 16 is provided on the outer peripheral portion. Orbiting scroll member 6
Is a disk-shaped end plate swivel scroll end plate portion 6a, a wrap 6b which is upright on the end plate and has the same shape as the wrap of the fixed scroll, and a boss 6c formed on the non-lap surface of the end plate.
It consists of The thickness of the disk-shaped end plate on the fixed side and that on the turning side are approximately the same. For example, when the rated output of the compressor is 3.75 kW, the thickness of the disk-shaped end plates on the fixed side and the turning side is about 13 mm and 11 mm, respectively. Also,
The material of the fixed scroll and the orbiting scroll is assumed to be cast iron material (FC25). The frame 11 has a bearing portion formed in the center thereof, and the rotary shaft 14 is supported by the bearing portion, and the eccentric shaft 14a at the tip of the rotary shaft is inserted into the boss 6c so as to be capable of turning motion. The fixed scroll member 5 is fixed to the frame 11 by a plurality of bolts, and the orbiting scroll member 6 is fixed to the frame 1 by an Oldham mechanism 12 including an Oldham ring and an Oldham key.
1, the orbiting scroll member 6 is formed so as to make an orbiting motion with respect to the fixed scroll member 5 without rotating. An electric motor shaft 14b fixed to the rotor 3b is integrally connected to the lower portion of the rotating shaft 14 to directly connect the electric motor unit 3. A vertical suction pipe 17 is connected to the suction port 16 of the fixed scroll member 5 through the closed container 1, and the upper chamber 1a where the discharge port 10 is open has a passage 18
It communicates with the upper electric motor room 1b through a and 18b.
The upper electric motor chamber 1b communicates with the lower electric motor chamber 1c via a passage 19 between the electric motor stator 3a and the side wall of the closed casing 1. Further, the upper electric motor chamber 1b communicates with a discharge pipe 20 penetrating the closed container 1.

Reference numeral 22 denotes an oil sump at the bottom of the closed container. In the figure, the solid line arrow indicates the flow direction of the refrigerant gas, and the broken line arrow indicates the flow direction of the oil. It should be noted that reference numerals 8 and 29 are first and second balance weights for canceling the centrifugal force caused by the orbiting movement of the orbiting scroll 6.

Next, the flow of lubricating oil will be described with reference to FIG.

The lubricating oil 22a is stored in the oil sump 22 below the closed container 1. The lower end of the rotating shaft 14 is provided with an eccentric shaft portion (crank pin) 14a, and the eccentric shaft portion 14a is a scroll compression element portion of the orbiting scroll 6 via an orbiting bearing 32 in a boss portion 6c of an end plate 6a of the orbiting scroll 6. Is engaged with. A central vertical hole 13 for supplying oil to each bearing is formed in the rotary shaft 14 from the lower end to the upper end surface of the rotary shaft 14. Reference numeral 13a is a pumping oil pipe that connects the lower end of the rotary shaft 14 and the bottom oil sump 22. A balance weight 8 is integrally formed on the lower part of the eccentric shaft part 14a by being coupled to the rotary shaft 14 and on the upper part of the main bearing 40 facing the tip surface of the boss part 6c of the orbiting scroll 6. The lower end of the oil pumping pipe 13a immersed in the oil sump 22 of the lubricating oil 22a receives a high discharge pressure Pd, while the slewing bearing 3 located downstream thereof.
2 and the area around the main bearing 40 receive the intermediate pressure Pm, which is the pressure during compression, due to the pores 6d and 6e (see FIG. 3 and FIG. 5) provided in the swivel end plate 6a (Pd-Pm).
Due to the pressure difference between the two, the lubricating oil 2 in the oil sump 22 at the bottom of the container
2a rises in the central vertical hole 13.

As described above, the oil is supplied to each bearing by the differential pressure oil supply method by the central vertical hole oil supply.

Lubricating oil 22a rising in the central vertical hole 13
Is supplied to the lower bearing portion 9 and further to the main bearing 40 and the slewing bearing 32. The oil supplied to the slewing bearing 32 is the back pressure chamber 4
The oil that has flowed into the No. 1 and has flowed into the back pressure chamber 41 is mixed with the refrigerant gas and flows into the frame chamber 11m. The orbiting scroll
If the end plate displacement of the orbiting scroll becomes small because it does not dance in the axial direction, internal leakage and back pressure chamber and eventually frame chamber 1
As a result, the heating amount due to oil leakage from 1 m to the suction chamber is reduced, and performance such as volumetric efficiency is improved. Next, the oil flowing into the back pressure chamber 41 flows out to the compression chamber 7 via the back pressure hole or the like. The oil reaching the compression chamber 7 is pressurized together with the refrigerant gas and is discharged above the fixed scroll 5 into the discharge chamber 1a.
Furthermore, it moves to the electric motor room 1b. Refrigerant gas and oil are separated in the electric motor chamber 1b and the lower space 1c, and the oil drops into an oil sump 22 below the closed container 1 and is supplied again to each sliding portion.

[0019]

According to the present invention, (1) the performance of the compressor is improved and the variation in the performance is reduced.

(2) The scroll processing method becomes easy,
Product cost will be lower. In addition, mass productivity of manufacturing the scroll wrap is improved.

(3) Since the end plate displacement of the orbiting scroll is reduced and the inclination of the orbiting scroll is reduced, the degree of uneven contact on the thrust sliding surface is reduced and the lubricating performance in the sliding portion is also improved. It is possible to suppress abrasion of the sliding portion and prevent seizure from occurring.

[Brief description of drawings]

FIG. 1 is a perspective view of an orbiting scroll member in which a step is provided on a bottom surface of a wrap tooth of the orbiting scroll.

FIG. 2 is a vertical cross-sectional view showing a state in which a fixed scroll and an orbiting scroll are engaged with each other.

FIG. 3 is a plan view of an orbiting scroll.

FIG. 4 is a vertical sectional view taken along line A-Om-A in FIG.

FIG. 5 is a plan view of an orbiting scroll.

FIG. 6 is an explanatory diagram of a function and effect of the present invention.

FIG. 7 is an explanatory diagram showing a relationship between a gap δ _as between a wrap tooth bottom surface of an orbiting scroll member and a tooth crest surface of a fixed scroll member and a scroll wrap winding angle λ.

FIG. 8 is an explanatory diagram showing a relationship between a gap δ _ak between a tip of a wrap tooth bottom of an orbiting scroll member and a tooth bottom of a fixed scroll member and a scroll wrap winding angle λ.

FIG. 9 is a vertical cross-sectional view of a hermetic scroll compressor showing the overall configuration of the present invention.

[Explanation of symbols]

1 ... Airtight container, 5 ... Fixed scroll, 5a ... Fixed scroll end plate part, 5a, 6a ... Scroll end plate part, 5n, 6
n ... scroll wrap tooth bottom surface, 7 ... compression chamber, 11 ... frame, 22 ... oil sump, 32 ... slewing bearing, 40 ... main bearing.

Claims (1)

[Claims] 1. A scroll compressor and an electric motor are stored in a hermetically sealed container so as to be connected to each other through a rotary shaft supported by a frame.
The closed container chamber is divided into an upper chamber and a lower chamber, and the scroll compressor has a fixed scroll member and an orbiting scroll member engaged with each other, and the fixed side and the orbiting side disk-shaped end plates have the same thickness. , Engaging the orbiting scroll member with an eccentric shaft portion provided continuously with the rotating shaft to cause the orbiting scroll member to orbit with respect to the fixed scroll member without rotating, and to open in the center portion of the fixed scroll member. A discharge port and a suction port opening to the outer peripheral portion are provided, gas is sucked through the suction port, and the gas is compressed by moving it around the compression space formed by the scroll members to reduce the volume. In a hermetic scroll compressor that discharges compressed gas to an upper container chamber, guides it to a lower container chamber through a passage, and discharges it outside the device through a discharge pipe, the wrap tooth tip surface of the orbiting scroll member and the Set uniformly the gap [delta] _ak with root surfaces of constant scroll member with respect to the scroll wrap winding angle, scroll a minute level difference on the scroll wrap bottom land with respect to the end plate outer peripheral portion of the orbiting scroll as a thrust sliding surface Provided uniformly with respect to the wrap winding angle, when the step size is the axial gap δ _as between the wrap tooth bottom surface of the orbiting scroll member and the tooth crest surface of the fixed scroll member,
A hermetic scroll compressor characterized in that δ _ak > δ _as .