JPH01227885A - Scroll compressor - Google Patents

Abstract

PURPOSE:To simplify the figure and select suitable material for a scroll compressor by forming a self-revolution inhibiting device in the form of an annular thin plate and placing the device between a lap supporting disk of a revolving scroll and a major body frame supporting a driving shaft. CONSTITUTION:The self-rotational inhibiting device (Oldham's ring) 24 of a scroll compressor is put between the lap supporting dish of a revolving scroll 18 and a major body frame 5 supporting a driving shaft 4. takes the form of an annular thin plate 24 and is molded from light alloy or reinforced fiber contained resin which are suitable in sintering shaping or injection molding. The outline of the annular plate 24a consists of the parts 25 of two parallel straight lines and the circular bent parts 26 succeeding thereto, is slidably engaged with a thrust bearing 20, is engaged with the hey groove 71 on the lap supporting disk of the scroll 18 and has recesses 24d and 24e forming lubricating oil passages. The self-rotation inhibiting device may be simplified in shape, light in weight, and is able to apply suitable material selected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a scroll compressor equipped with a rotation prevention device.

Conventional technology A scroll compressor has a suction chamber on the outer periphery, a discharge boat is provided at the center of the spiral, and the flow of n1 compressed fluid is sucked and compressed in a symmetrical spiral compression space centered on the discharge boat. It is generally known that n is unidirectional, the fluctuation in compression torque is smaller than that of reciprocating compressors or rotary compressors, and vibration and noise are also extremely small.

Since the orbiting scroll does not rotate but revolves around itself due to the crank mechanism and rotation prevention mechanism of the drive shaft, the centrifugal force generated on the orbiting scroll can be reduced by providing an appropriate balance weight on the drive shaft to maintain the dynamic balance of the drive system. balance,
No measures have been taken to reduce vibrations in the drive shaft system.

In a scroll compressor that has a compression section located only on one side of the drive shaft, the rotation prevention member of the orbiting scroll engages with the orbiting scroll and moves back and forth, and the center of gravity of the orbiting scroll portion is changes. In addition, it is known that it is necessary to reduce the weight of the rotation prevention member because of the problem that the dynamic balance cannot be completely balanced.

As for a specific rotation prevention mechanism for an orbiting scroll, a configuration as shown in FIGS. 15 to 17 has been considered for some time.

The figure shows key grooves 3096°30 on both sides of the annular plate 3091.
97 and key grooves 309B and 3099 are provided.

The keyways on both sides are orthogonal to each other at the center of the annular plate 3091,
In each keyway, an orbiting scroll 3020, a key 3100 fixed to a housing 3048, etc. are engaged and slid with a minute gap to form a rotation prevention mechanism (US Pat. No. 3,924,977).

As shown in Fig. 18, parallel key portions 4059 are provided on both sides of the annular plate 4061, and a keyway is provided in a mating member such as an orbiting scroll, as shown in Fig. 19. A combination of the above examples (F-shaped)
756 Publication), and furthermore, as shown in Figures 20 and 21 of the 1st edition, a part of the 18th evil wheel can be rotated at its center (Japanese Patent Application Laid-Open No. 53-34107), etc., to prevent rotation. Efforts have been made to reduce the weight of the parts and improve the wear resistance of some parts.

Problems to be Solved by the Invention However, the configurations shown in FIGS. 20 and 21 have a large number of parts, resulting in high costs and problems in reducing weight.

The rotation prevention members other than the circular plate are all parallel to each other on both sides of the annular plate, and the circular plate has a combination of key grooves to reduce the backlash in the rotational direction of the orbiting scroll and prevent compressed air. In order to reduce body temperature, high precision is required for the parallelism of the sliding surfaces and the width of the keyway. It is necessary to process the workpiece, attaching it to a jig, etc.
There is a problem in that the annular part cannot be made thinner because the removal and processing time is longer and the annular part tends to warp.

Also, in the production of component materials, because the annular plate has unevenness on both sides, there are constraints on the shape and dimensions in mass production methods such as stamping and sintering of the material, and there are many molding steps. Therefore, the material cost and processing cost are extremely high, and there is a limit to the weight reduction. It is arranged between the lamp support disk of the orbiting scroll and the main body frame and forms an annular thin plate shape,
A pair of protrusions are provided at symmetrical positions on an axis passing approximately at the center of the annular thin plate on the side of the lap support disk, and a pair of flat flat parts perpendicular to the axis are provided on both sides of the outer periphery of the annular thin plate. ,
The protruding portion is provided on the lap support disk and slidably engages with the pair of guide grooves, and includes a rotation preventing member.

According to the above-mentioned structure, the present invention has a simple shape in which the annular plate has less warpage during material forming and processing, is lightweight, and has high sliding product dimensional accuracy. The reciprocating motion occurs as the drive shaft rotates, and the scroll functions to prevent rotation of the orbiting scroll, thereby performing a suction and compression action in the compression space. Lightweight for self-driving, it reduces the change in inertia force when the stop member reciprocates and changes the direction of movement, and the backlash in the gap between sliding parts.It also reduces the change in the center of gravity of the orbiting scroll (and reduces the change in the center of gravity of the orbiting scroll). It reduces the amount of unbalance in the system, reduces the excitation force applied to the compressor, and reduces vibration even when the compressor is operated at high speed.

Embodiments Hereinafter, scroll compressors according to embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a vertical cross-sectional view of a scroll refrigerant compressor according to a first embodiment of the present invention, FIG. 2 shows an exploded view of the main parts, and FIG. 3 shows a seal portion of the thrust bearing 20 in FIG. 1. A detailed partial sectional view is shown, Fig. 4 shows an external view of the Oldham ring, and Fig. 5 shows the main body frame, thrust bearing,
The assembled appearance of the Oldham ring is shown in Figure 61.
1 is a cross-sectional view taken along line A-A in FIG. A top view is shown, FIG. 9 shows an external view of the check valve used in the oil supply passage, and FIG.
Fig. 11 shows an explanatory diagram of the movement of the compression chamber at the suction port, Fig. 12 shows a characteristic diagram showing the pressure change of refrigerant gas from the suction stroke to the discharge stroke, and Fig. 1a shows the pressure at a fixed point in each compression chamber. A characteristic diagram showing changes is shown, and FIG. 14 shows an external view of an Oldham ring in another embodiment of the present invention.

In Fig. 1, reference numeral 1 denotes a closed case made of iron, the entire interior of which is in a high-pressure atmosphere that communicates with the discharge chamber 2, and a motor 3 mounted on the top.
The inside of the sealed case 1 is partitioned into a motor chamber 6 and a discharge chamber by a main frame 5 of the compression section which is fixed to the rotor 3 of the motor 3 and supports the drive shaft 4. I'm n.

The main body frame 5 is made of an aluminum alloy with excellent heat conduction properties, with the main purpose of reducing weight and dissipating heat from the bearing part, and a liner 8 made of iron with excellent weldability is fixed to the outer periphery by shrink fitting. The outer peripheral surface of the liner 8 is inscribed in the sealed case 1 all around and is partially fixed by welding.

The outer periphery of both ends of the stator 3b of the motor 3 is fixed internally to the sealed case 1, and supported and fixed by the bearing frame 9 and the main body 7 frame 5. The drive shaft 4 is a bearing frame 9
The r-section bearing 10. A lower bearing 11 is provided at the upper end of the main body frame 5, a main bearing 12 is provided at the center of the main body frame 5, and a main bearing 12 is provided between the upper end surface of the main body frame 5 and the lower end surface of the rotor 3a of the motor 3. This is supported by a thrust ball bearing 13, and an eccentric bearing 14 is provided eccentrically from the main axis of the drive shaft 4 at its lower end.

A fixed scroll 15 made of aluminum alloy is fixed to the lower end surface of the main body frame 5, and the fixed scroll 15 is
Consisting of a spiral fixed scroll wrap 15 and an end plate 15b, a discharge port 16 is provided in the center of the end plate 15b and opens at the beginning of winding of the fixed scroll wrap 15m, and is also open to the discharge chamber 2. lamp 15
A suction chamber 17 is provided on the outer periphery of m.

A spiral-shaped orbiting scroll lamp 18 that engages with a fixed scroll wrap 15m to form a compression chamber, and a rotary shaft 18b supported by an eccentric bearing 14 of a drive shaft 4 are made upright from a wrap support disk 18c. The orbiting scroll 18 made of aluminum alloy is the same as the fixed scroll 15.
A sleeve 19 made of high-tensile steel material is shrink-fitted to the outer periphery of the pivot shaft 18b, and the surface of the lap support disk 18o is hardened. I'm in San.

The nf fixed to the main body frame 5 is restrained by the parallel pin 19.
A spacer 21 is provided between the thrust bearing 20, which can move only in the axial direction, and the end plate 15b of the fixed scroll 15. For this purpose, the thickness is set approximately 0.015x0.02011M larger than the thickness of the lap support disk 18a.

The bottom of the eccentric bearing 14 of the drive shaft 4 and the orbiting scroll 18
The eccentric bearing space 36 between the end of the pivot shaft 18b and the outer peripheral space 37 of the lap support disk 18c are
b and Nf are connected to each other by an oil filled A38 provided on the lap support disk 18c.

As shown in FIGS. 2 and 6, the thrust bearing 20 is formed through a central portion into a shape consisting of two parallel straight portions 22 and two arcuate curved portions 23 connected thereto.

The rotating scroll rotation prevention member (hereinafter referred to as Oldham ring) 24 is suitable for sinter molding, injection molding, etc.
It is made of light alloy or reinforced fiber composite resin material, has oil-retaining properties, and is a 24 m thin annular plate with parallel surfaces as shown in Figure 4.
and a pair of parallel keys 24b provided on the negative surface thereof.
The outer contour of the annular plate 24a consists of two parallel straight parts 25 and two arcuate curved parts 26 connected to the straight parts 25, and the straight parts 25 are connected to the thrust bearing 2 as shown in FIG.
The side surface 24c of the parallel key part 24b is orthogonal to the straight part 25 at the center thereof, and can be rotated as shown in FIGS. 1 and 2. The wrap support disk 18a of the scroll 18 is provided with a shape that engages with a pair of key grooves 71 with a small gap and is slidable.

Note that the inner contour of the annular plate 24m is similar to the outer contour and has an r-shaped shape. The attachment of the parallel key portion 24b is provided at the root, and the recessed portion 24d also serves as a passage for lubricating oil.

The dented part 24e is provided in the arc-shaped curved part.
is a similar lubricating oil passage.

As shown in Figures 1 and 3, there is a release gap 2 of approximately 0.1WIR between the main body frame 5 and the thrust bearing 20.
An annular groove 28 is also provided in the main body frame 5 opposite to the release gap 27, and a rubber seal ring 70 surrounding the annular groove 28 is provided between the main body frame 5 and the thrust bearing 2o. It is attached to the

The upper part of the motor chamber 6 and the discharge chamber 2 communicate through a bypass discharge pipe 29 that passes through the side wall of the sealed case 1, and the opening position of the bypass discharge pipe 29 to the motor chamber 6 is as follows.
The discharge pipe 31 is connected to the side surface of the upper coil end 30 of the stator 3b and connected to a partial front end of the bypass discharge pipe 29 and the upper surface of the sealed case 1. 32, a large number of small holes arranged between the upper surface of the sealed case 1 and the bearing frame 9 are communicated via a punching metal 33.

A discharge chamber oil reservoir 34 is provided in the lower part of the motor chamber 6 and is communicated with the upper part of the motor chamber 6 by a cooling passage 35, which is provided by cutting a part of the outer periphery of the stator 3b of the motor 3. There is. The discharge chamber oil sump 34 is provided in the main body frame 5 and communicates with the annular groove 28 via an oil filler B58b, and the Oldham ring 24 is disposed and communicates with the back pressure chamber 39 of the orbiting scroll 18. The main bearing 12 also communicates with the sliding part through a small gap, and is further provided in the eccentric bearing 14 with an oil groove A4.
It also communicates with the eccentric bearing space 36 via the shaft.

The oil filler B58b provided in the main body frame 5 also communicates with the helical oil groove 41 provided on the surface of the lower shaft portion 4m corresponding to the lower bearing 11 of the drive shaft 4. The winding direction of the oil groove 41 is such that when the drive shaft 4 rotates forward, the viscosity of the lubricating oil is used to produce a screw pump action, and the end thereof is formed halfway into the lower bearing 4a.

The rotational unbalance caused by the uneven weight and eccentricity of the lower end of the drive shaft 4 and the heavy electricity of the orbiting scroll 18 is caused by the rotational unbalance of the rotor 3.
Balance weights 7 are attached to the ends and lower ends of a.
5.76.

As shown in FIGS. 6 and 7, the fixed scroll 15 is provided with an arc-shaped suction passage 42 that communicates both ends of the suction chamber 17, and a circular suction hole 43 that is perpendicular to the suction passage 42 is provided in the fixed scroll lap. Also provided in the direction perpendicular to the side of 15m n1
The bottom of the suction hole 43 is flat and reaches the side surface of the suction passage 42.

As shown in FIG. 8, the center of the suction hole 43 is aligned with the bottom surface 44 of the suction passage 42, and the opening dimension W to the suction passage 42 is
45 is provided to be smaller than the diameter of the suction hole 43. The suction pipe 47 of the accumulator 46 is connected to the suction hole 43, and between the bottom surface 44 of the suction hole 43 and the suction pipe end surface 48, the inner diameter dimension of the suction pipe 47 and the suction pipe end surface 48 are connected. Suction hole depth dimension L4 between and bottom surface 44
9 and a circular thin steel plate check valve 50 having an opening size W45 larger than the opening size W45 is disposed. The surface of the check valve 50 has poor oil temperature retention (it is coated with highly elastic Teflon).

A second compression chamber 51 that does not communicate with either the suction chamber 17 or the discharge chamber 2
The outer peripheral space 37 is an injection groove 52 with a small diameter that opens into the second compression chamber 51 and is provided on the end plate 15b.
An injection groove 54 formed by the mirror plate 15b and a heat insulating cover 53 made of resin is communicated with an injection passage 55 consisting of an oil filler C38a which opens into the outer peripheral space 37 and has a two-step shape. The large diameter portion 56 includes
As shown in FIG. 9, a check valve 58 made of a thin steel plate having a notch 57 in a part of its outer periphery and a coil spring 59 are arranged, and the coil spring 59 is held down by a heat insulating cover 53 to complete the check valve. 58 is always energized. As shown in FIGS. 10 and 11, the opening position of the oil filling C38c into the outer peripheral space 37 is such that the orbiting scroll 18 is close to the end of the volume reduction stroke of the third compression chamber 60 communicating with the discharge boat 16. When moving (see Figure 10), the outer peripheral space 37 and oil filler C3
8c, and at other times (see FIG. 11), it is provided at a position where it is blocked by the wrap support disk 18a.
ing.

In FIG. 12, the horizontal axis indicates the rotation angle of the drive shaft 4,
The vertical axis shows refrigerant pressure. A solid line 62 and a dotted line 63 represent changes in the pressure of the refrigerant gas during the suction, compression, and discharge processes. A solid line 62 represents the pressure change during normal pressure operation, and a dotted line 63 represents the pressure change during abnormal pressure and increased operation.

In FIG. 13, the horizontal axis indicates the rotation angle of the drive shaft 4,
The vertical axis indicates the refrigerant pressure, and the solid line 64 indicates the second compression chambers 51m and 51b that do not communicate with either the discharge chamber 2 or the suction chamber 17.
Injection hole 52m.

The dotted line 65 represents the pressure change at the opening position of 52b.
is a first compression chamber 61a communicating with the suction chamber 17;

61b (see FIG. 6), the - dotted chain line 66 represents the pressure change at a fixed point in the third compression chamber Bo communicating with the discharge chamber 2.
The two-dot chain line 67 represents the pressure change at fixed points a and 60b, and the double-dashed line 67 indicates the first compression chamber 61.

It represents the pressure change at a fixed point between stb and the second compression chambers 51a, 51b, and the double dotted line 68 represents the pressure change in the back pressure chamber 39.

The operation of the scroll refrigerant compressor constructed as follows will be explained.

1 to 13, the drive shaft 4 is driven by the motor 3.
When is driven to rotate, the orbiting scroll 18 is rotated around the main axis of the drive shaft 4 by the crank mechanism of the drive shaft 4.
The parallel key portion 24b of the Oldham ring 24 engages with the keyway 71 of the orbiting scroll 18, and the linear portion 25 is prevented from rotating.Since the parallel key portion 24b of the Oldham ring 24 is engaged with the linear portion of the thrust bearing 20, rotation is prevented. It rotates and changes the volume of the compression chamber together with the fixed scroll 15, allowing refrigerant gas to be sucked and
Performs a compressive action.

At this time, the Oldham ring 24 is affected by the torque produced by the pressure difference in the compression chambers in the symmetrically arranged compression space and which attempts to rotate the orbiting scroll 18, and the mutual torque of the inertia of the orbiting scroll. This affects the friction of the sliding parts of the ring 24 and the warping deformation of the annular plate. As the Oldham ring 24 reciprocates, its inertial force becomes an excitation force to the main body frame 5 via the thrust bearing 20, and this movement changes the center of gravity of the orbiting scroll 18 and changes the position of the drive shaft system. creating an imbalance.

The suction refrigerant gas containing lubricating oil from the refrigeration cycle connected to the compressor is connected to the accumulator 46.
The suction pipe 47, the suction hole 43, and the suction passage 42 are sequentially flown into the suction chamber 17, and a first compression chamber 61 m, 61 is formed between the orbiting scroll 18 and the fixed scroll 15.
2nd compression chamber 51 m, 51 b s 3rd compression chamber B
It is sequentially transferred to OA and SOB, compressed, and discharged into the discharge chamber 2 via the discharge boat 16 in the center.

The discharged refrigerant gas containing lubricating oil returns to the motor chamber 6 inside the compressor via a bypass discharge pipe 29, which is connected to the outside of the compressor, and then returns to the motor chamber 6 in the compressor, and then to the discharge pipe 3 to the external refrigeration cycle.
1, but when flowing into the motor chamber 6, it collides with the side surface of the upper coil end 30 of the motor 3 and adheres to the surface of the motor winding. After separating a portion of the lubricating oil, the flow direction is changed when passing through the punched hole 32 provided in the bearing frame 9, and the lubricating oil is separated when passing through the small hole in the punched metal 3a. The lubricating oil is effectively separated due to the inertial force and surface adhesion.

A part of the lubricating oil separated from the discharged refrigerant gas partially lubricates the sliding surfaces of the bearings, and then passes through the cooling passage 35 along with the remaining lubricating oil and cools the motor 3 while flowing into the lower discharge chamber. The oil is collected in the oil sump 34.

The lubricating oil in the discharge chamber oil sump 34 is supplied to the thrust ball bearing 13 by the screw pump action of the nf spiral oil groove 41 provided on the surface of the lower shaft portion 4a of the drive shaft 4, and is supplied to the thrust ball bearing 13 at the end of the lower bearing 4m. When the lubricating oil passes through the minute bearing gap, the sealing action of the oil film blocks the discharged refrigerant gas atmosphere of the motor chamber 6 from the upstream space of the main bearing 12.

The lubricating oil containing the dissolved discharged refrigerant gas in the discharge chamber oil sump 34 is
When passing through the small gap of the main bearing 12, the pressure is reduced to an intermediate pressure between the discharge pressure and the suction pressure. , the eccentric bearing space 36, the oil filler A38 that passes through the orbiting scroll 18, flows into the outer circumferential space 37, and furthermore, the oil filler 38c that opens intermittently, and the oil filler A38 that passes through the orbiting scroll 18.
, flows into the second compression chambers 51 m, 51 b via the injection holes 52 m, 52 b, and lubricates the sliding surfaces in the middle of the passages.

The lubricating oil that flows into the back pressure chamber 39 flows into the Oldham ring movement spaces 77a and 77b between the Oldham ring 24 and the thrust bearing 20, and due to the pumping action caused by the reciprocating motion of the Oldham ring 24, Apply an appropriate amount of oil to the sliding part of the ring 24.

Since the discharge chamber oil reservoir 34 also communicates with the annular groove 28 and the release gap 27, the thrust bearing 20 is urged by the back pressure and comes into contact with the end surface of the spacer 21. The lap support disk 18c of the orbiting scroll 18 is connected to the thrust bearing 20 and the end plate 15b of the fixed scroll 15.
A small gap is maintained between the
End face of fixed scroll wrap 15m and wrap support disk 1
8c, as well as between the end face of the orbiting scroll wrap 18m and the end plate 15b, are kept small to reduce gas leakage between the opening and adjacent compression chambers.

Injection hole 52m of second compression chamber 51m, 51b
, 52b undergoes a pressure change 64 as shown in FIG. As a result, the average pressure is lower than the back pressure chamber pressure 68, which changes according to the pressure in the discharge chamber 2, although it is instantaneously higher.
The lubricating oil from the back pressure chamber 39 is intermittently opened and closed by the sliding surface of the lap support disk tea at the opening end of the end plate of the oil tank 38a, and is intermittently supplied to the second compression via the injection passage 55 while being refilled. It flows into chambers 51m and 51b. The compressed refrigerant gas in the second compression chambers 51m, 5Ib, which is instantaneously higher than the back pressure chamber pressure 68 during normal operation, is attenuated by the small diameter injection holes 52m, 52b and then flows into the injection hole 54. No instantaneous backflow, injection groove 5
The pressure of 4 yen does not become higher than the back pressure chamber pressure 68.

Note that the amount of lubricating oil flowing from the outer peripheral space 37 into the oil filler C38a per rotation of the drive shaft 4 increases when the rotation speed of the drive shaft 4 is slow, and decreases when the rotation speed of the drive shaft 4 is fast. As the flow rate is adjusted, the amount of oil injected into the second compression chambers 51m and 51b is also increased or decreased accordingly.

The lubricating oil that is injected into the second compression chambers 51a and 51b flows into the compression chamber together with the suction refrigerant gas and merges with the lubricating oil, sealing the gap between adjacent compression chambers with an oil film to prevent compressed gas leakage. The compressed gas is discharged into the discharge chamber 2 together with the compressed gas while lubricating the sliding surfaces between the compression chambers. The lubricating oil in the discharged refrigerant gas during low-speed operation of the compressor is almost separated in the motor chamber 6, since the flow rate of the discharged refrigerant gas is slow and there is less lubricant mixed in, and during high-speed operation, some of the lubricating oil goes outside. Discharge.

The differential pressure lubricating oil is supplied to the threatening pressure chamber 39 by applying an intermediate pressure urging force to the orbiting scroll 18 together with the elastic force of the seal ring 70, and causing the lap support disk 18o to slide against the end plate 15b. The outer peripheral space 37 is sealed with a pressure oil film on the moving surface.
At the same time, the gap between the sliding surfaces of the thrust bearing 20 and the lap support disk 18c is also lubricated and sealed.

For a while after the compressor starts cold (see Fig. 9,
As can be understood from FIG. 10, since the pressure in the discharge chamber 2 is lower than the pressure in the second compression chambers 51a and 51b, the refrigerant gas that is being compressed is in the second compression chamber 51a.

51b to the back pressure chamber 39 via the injection passage 55.
However, the check valve 58 prevents the lubricating oil from flowing back into the outer space 37, and as the pressure in the discharge chamber 2 increases, the lubricating oil in the discharge chamber 2 flows into the back pressure chamber 39, Differential pressure oil is supplied to the outer peripheral space 37.

Therefore, a back pressure urging force is generated by the compression chamber pressure on the thrust bearing 2° at the initial stage of cold start, and the orbiting scroll 18
The thrust bearing 20 moves back slightly without resisting the thrust overcurrent, causing the orbiting scroll 18 and the fixed scroll 1 to move away from the fixed scroll 15.
Enlarge the axial clearance between 5 and 5.

This causes leakage in the compression space and lowers the compression chamber pressure.
Reduces compression load during initial startup.

Thereafter, as the pressure in the discharge chamber 2 increases, the lubricating oil in the outer circumferential space 37 flows through the injection holes 52m and 52b against the biasing force of the coil spring 59 so as to be inversely proportional to the rotational speed of the drive shaft 4. Metering controlled n1 second compression chamber 51
Inject to m, 51 b.

In this case, instantaneous liquid compression occurs due to oil injection or other causes during the initial cold start or stable operation. Although compression occurs, the increase in pressure in the discharge chamber is extremely small because the volume of the discharge chamber 2 and the high-pressure space communicating therewith is large.

Due to liquid compression, the injection groove 54 communicating with the second compression chambers 51m and 51b also experiences an abnormal pressure rise, but due to the throttling effect of the small diameter oil filler C38c and the check action of the check valve 58, the pressure on the outer periphery increases. The space 37 and the injection groove 54 are blocked, the pressure in the back pressure chamber 39 remains unchanged, and the back pressure urging force acting on the back surface of the thrust bearing 2o does not change.
As a result, when the liquid is compressed, an excessive thrust force acting on the orbiting scroll 18 causes the thrust bearing 2 to
0 retreats and the compression chamber pressure drops, after which normal operation continues.

In addition, as the thrust bearing 2o retreats during liquid compression, the pressure in the compression chamber drops midway as shown by the dashed line 63m in FIG.

After the compressor stops, the orbiting scroll 1
A reverse rotation torque is generated at 8, the orbiting scroll 18 rotates in the reverse direction, and the discharged refrigerant gas flows back to the suction side. Following this backflow of the discharged refrigerant gas, the check valve 50 moves from the position shown in FIG. 3 to the position shown in FIG. The reverse flow of the discharged refrigerant gas is stopped by sealing the refrigerant gas, the reverse rotation of the orbiting scroll 18 is stopped, and the space between the suction passage 42 and the discharge boat 16 maintains the discharge pressure.

However, the passage that communicates with the compression chamber with the reverse ratio valve 58 of the injection passage 55 as a boundary has a discharge pressure, but the space between the outer circumferential space 37 and the back pressure chamber 39 has a The pressure is maintained and gradually approaches the discharge pressure due to a slight inflow of lubricating oil from the discharge chamber oil sump 34. When the compressor is stopped, the orbiting scroll 18 rotates in the opposite direction, and the third compression chambers 60m and 60b expand to apply reverse rotation torque. Stop at a position where it does not occur and fill with oil 03
The opening to the outer peripheral space 37 of 8c is the wrap support disk 18
It is blocked by c.

After the compressor is stopped, the biasing force of the coil spring 59 also causes the back pressure valve 58 to close to the injection passage Rudam ring 2.
4 and other sliding parts.

In addition, in the example described, Oldham ring 2 is used as shown in Fig. 4.
The bottom surface of the annular plate 24a of No. 4 is made flat, and by providing an oil groove 249 and a suitable relief groove 24f on the annular plate sliding surface of the orbiting scroll 18 and the main body frame 5,
It may also be formed into sheet metal using the fine planking method.

In the above embodiment, the flat part of the outer peripheral side of the Oldham ring 24 is engaged and slid into the flat part of the punched hole of the thrust bearing 2o, but the thrust bearing 2o is omitted and the main body frame is 5 may be provided with an engagement sliding hole.

As described above, according to the above embodiment, the Oldham ring 24
consists of a thin annular plate 24- disposed between the lap support disk 18a of the orbiting scroll 18 and the main body frame 5, and approximately centered on the annular plates 24a, l: on the side of the lap support disk 18c. A pair of parallel keys at symmetrical positions on the axis passing through part 2
4b is provided, and parallel parts 2 are provided on both sides of the outer periphery of the annular plate 24a.
The parallel key part 24b is provided on the lap support disc 18c and slidably engages with the pair of guide grooves 71, and the pair of parallel parts are parallel to the main body frame. By providing an Oldham ring 24 which is restrained in the rotational direction of the drive shaft 4 and is provided on the thrust bearing 20 and slidably engages with the flat surface of the drive shaft 4, the shape of the Oldham ring 24 is simplified and its As a result, there is a high degree of freedom in material selection during material production, and the 24m annular plate has less warpage (and can be made thinner) during part material molding and processing molding using sinter molding, injection molding, fine blanking press molding, etc. can.

As a result, it is possible to manufacture a wear-resistant Oldham ring that is lightweight, has a short machining time, and has high machining dimensional accuracy at a low cost because there are few parts to be attached and detached from the jig during the machining process.

However, even if such an Oldham ring 24 is installed, the orbiting scroll 18 performs a high-speed orbiting motion, the Oldham ring 24 follows and reciprocates, and even if the direction of movement is changed, the orbiting scroll 18 remains lightweight. The amount of movement of the center of gravity of the orbiting scroll 18 by the Oldham ring 24 is small (it has little effect on the unbalance of the drive shaft system. Since the dimensional accuracy of the sliding part of the Oldham ring 24 is high, the gap between the sliding parts can be reduced. By making the size smaller, the backlash of the Oldham ring 24 is reduced even when the rotational speed and load torque of the drive shaft 4 change. Noise can be reduced.

In addition, by selecting a low-friction material for the Oldham ring 24, it is possible to reduce the frictional resistance of the sliding parts during reciprocating motion (and thereby reduce the excitation force to the main body frame 5), thereby reducing vibration and noise. You can also do it.

Effects of the Invention As described above, in the present invention, the rotation prevention device is arranged between the lap support disk of the orbiting scroll and the main body frame supporting the drive shaft, and has an annular thin plate shape, and A pair of protruding portions are provided at symmetrical positions on the axis passing approximately through the center of the side annular thin plate, and a pair of parallel flat portions are provided on both sides of the outer periphery of the annular thin plate, which are perpendicular to the axis passing approximately through the center of the annular plate.
The protrusions on the annular thin plate are provided on the lamp support disc and are slidably engaged with a pair of guide grooves, and the pair of flat parts provided on both sides of the outer periphery are attached to the main body frame. By providing a rotation prevention device that is provided on a member that is restrained in the direction of rotation of the main shaft of the drive shaft and slidably engages with a guide groove, the shape of the rotation prevention device member can be simplified. In addition, there is a high degree of freedom in material selection when manufacturing parts, making it possible to select the most suitable material.
Mold costs are low when manufactured using fine blanking press molding, etc., and high-precision mold manufacturing is possible, and there is less warping of the annular plate at 2 o'clock for component material molding and processing molding, making it thinner and lighter. . Furthermore, since the attachment and detachment of parts to and from the jig during the machining process can be reduced, machining time can be shortened, and a rotation prevention member with high dimensional accuracy and wear resistance can be manufactured at low cost.

Then, if such a rotation prevention member is installed, the orbiting scroll will make a high-speed rotation movement, and the rotation prevention member will be installed.
Even if it makes a reciprocating motion following the direction of movement and changes its direction,
Due to the lightweight rotation prevention member, the fluctuation in the center of gravity of the orbiting scroll is small, and the influence on the unbalance of the drive shaft system is reduced.

In addition, since the dimensional accuracy of the sliding part of the rotation prevention member can be increased, the sliding part of the rotation prevention member can be backed up even when the rotational speed or load torque of the drive shaft changes by reducing the gap between the sliding parts. It is possible to provide a scroll compressor that has many excellent effects, such as low lash (low lash), and the ability to reduce vibrations, noise, and wear on sliding parts caused by collisions with the main body frame and orbiting scroll.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a scroll cooling system in an embodiment of the present invention, FIG. 4 is an explanatory diagram of the position of the check valve at the Oldham ring inlet pipe connection in the same compressor, and FIG. 8 is B--B in FIG. 7.
A vertical sectional view taken along line B, Figure 9 is an external view of the check valve used in the oil supply passage, Figures 10 and 11 are illustrations of movement of the compression chamber of the discharge boat, and Figure 12 is the discharge from the suction stroke. FIG. 13 is a characteristic diagram showing pressure changes of refrigerant gas up to the stroke; FIG. 13 is a characteristic diagram showing pressure changes at fixed points in each compression chamber; FIG. 14 is an external view of an Oldham ring in another embodiment of the present invention; FIG. The figure is a vertical sectional view of a scroll compressor using a conventional Oldham ring, Figures 16 and 17 are a plan view and cross-sectional view of the Oldham ring in Figure 15, and Figures 18 to 20 are a conventional scroll compressor. There are external views and plan views of different Oldham rings, and FIG. 21 is an exploded view of the Oldham ring shown in FIG. 20. 2...Discharge chamber, 3...Motor, 4...
... Drive shaft, 5 ... Body frame, 12.
...Main bearing, 15...Fixed scroll,
15a...Fixed scroll wrap, 16...
...Discharge port, 17...Suction chamber, 18...
...Orbiting scroll, 18 heat...Orbiting scroll wrap, 18o...Wrap support disk, 2
4...Oldham ring, 24a...Annular plate, 24b...Parallel key part, 34...
・Discharge chamber oil sump, 38c...Oil filled C139...
... Back pressure chamber, 52m, 52b ... Injection hole, 54 ... Injection groove, 55
...Injection passage, 58...
Check valve, 59... Coil spring. Name of agent: Patent attorney Toshio Nakao and 1 other person15
b-'r allowance 1 anti-18- Rotating shaft 0-2 π- Thrust bearing 21- Thrust 27- Resource boundary Z8-: Ei11 large is 1 3rd Fig. 4-・Drive shaft No. 411i111 ""- °
Body frame 2θ・~Thrust wH+ t''45 Fig. 42- Suction passage 61b Fig. 7'h54z Fig. 8!, and °-° Fixed scroll wrap Fig. 10 /6-Lt, t
Hoard 18LL°-10 Scroll Wrap Fig. 14 Z4f Fig. 15 Day Fig. 18 Fig. 20-59:

Claims (1)

[Claims] An orbiting scroll wrap on a wrap support disk that is a part of the orbiting scroll is engaged with a spiral fixed scroll wrap formed on one surface of an end plate that is a part of the fixed scroll, and the central part of the fixed scroll wrap is is provided with a discharge port, a suction chamber is provided on the outside of the fixed scroll wrap, and the orbiting scroll is disposed between a main body frame supporting a drive shaft and the fixed scroll to prevent rotation of the orbiting scroll. The spiral compression space formed between both scrolls is divided into multiple compression chambers that continuously move from the suction side to the discharge side, forming a scroll compression mechanism that compresses fluid. The rotation prevention device is disposed between the wrap support disk and the main body frame to form an annular thin plate shape, and is arranged on an axis passing approximately at the center of the annular thin plate on the side of the wrap support disk. A pair of protrusions are provided at symmetrical positions, a pair of flat surfaces perpendicular to the axis are provided on both sides of the outer periphery of the annular thin plate, and the protrusions are provided in a pair of guide grooves provided in the lap support disk. A scroll compressor having a slidably engaged rotation prevention member.