JPH0737794B2 - Scroll compressor - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an improvement of a scroll type compression device in which a scroll type compression mechanism is housed in a closed case.

[Technical background of the invention and its problems] Conventionally, a scroll type compression device is known as a low pressure compression device. This compressor has a combination of a pair of scroll blades in the axial direction to form a compression mechanism, and has advantages such as small size, high efficiency, and low vibration.

By the way, in such a scroll type compression device, generally, a frame is fixed at a position slightly upward in the closed case so as to vertically partition the inside of the closed case, and the scroll type compression mechanism is arranged above the frame. In addition, a motor for providing driving power to the scroll type compression mechanism is arranged below the frame, and lubricating oil is contained in the bottom of the hermetic case. The scroll-type compression mechanism is usually composed of a fixed element and a movable element arranged below the fixed element. A bearing hole is provided through the frame in the vertical direction, and the rotary shaft of the motor described above is rotatably supported by the bearing hole.
Further, a joint composed of an eccentric connecting mechanism and an Oldham mechanism is provided between the upper end of the rotary shaft and the movable element, and the action of this joint causes the movable element to perform a turning motion without rotation.

However, the conventional scroll type compression device configured as described above has the following problems. That is, the rotating shaft of the motor is passed through a bearing hole provided in the frame, and the radial load and the thrust load applied to the rotating shaft are supported by the bearing hole. Thus, if the means for supporting the rotary shaft has a so-called cantilever support structure, a bending moment is likely to act on the rotary shaft, and this force concentrates stress on the bearing surface, which causes seizure. There was a lot of fear. Such a phenomenon particularly occurs at high speed operation, and even a small unbalance becomes a large force at high speed operation and acts on the bearing surface. Therefore, usually, a structure is adopted in which the length of the bearing is increased to receive the above-mentioned force in a large area. And
In order to realize this method, generally, a structure is adopted in which a cutout portion is provided in a part of the motor, and a part of the bearing is fitted in the cutout portion to suppress the entire axial length. However, in such a structure, the efficiency of the motor is low, and thus there is a problem that high speed rotation cannot be realized.

Therefore, in order to eliminate such a problem, a so-called sub-bearing for supporting the lower end of the rotary shaft is arranged in the lower portion of the sealed case, and two bearings, that is, the sub-bearing and a bearing hole provided in the frame are provided. However, since it is necessary to align both bearings with high accuracy in the case of such a configuration, there is a problem in how to facilitate this alignment.

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide one end of a rotary shaft of a drive motor provided in a frame that divides the inside of a sealed case. The supporting main bearing and the sub-bearing supporting the other end of the rotary shaft can be easily and accurately aligned with each other, thereby achieving high-speed rotation and facilitating manufacture and assembly. An object of the present invention is to provide a scroll type compression device that can be achieved.

[Summary of the Invention] The present invention has a shape in which a hermetically sealed case, a frame provided so as to divide the hermetically sealed case into two chambers, and axially joined each other to form a compression chamber therebetween. A scroll-type compression mechanism provided in the one chamber, which is composed of a fixed element and a movable element, each of which is formed and has scroll blades that mesh with each other in the compression chamber, and a bearing hole provided in the frame. When,
A motor provided in the other chamber in a relationship in which one end side of a rotary shaft connected to the rotor by the bearing hole is supported, and a motor provided between the rotary shaft of the motor and the movable element. In a scroll type compression device provided with a joint for performing gas compression by rotating the movable element with power to rotate without rotation, an intermediate in which the closed case is formed in a tubular shape and the frame is fixed. A case and a pair of closing cases that finally close the openings of both ends of the intermediate case, the stator of the motor is fixed to the frame, and the frame or the stator is provided on the other end side of the rotating shaft. It is characterized in that a sub-bearing for supporting the other end side of the rotary shaft is provided by being screwed so that the position of the rotary shaft can be adjusted.

[Advantages of the Invention] With the above configuration, generally, the frame, the stator of the motor, the rotating shaft, and the like are manufactured with high accuracy, and the auxiliary bearing itself is also manufactured with high accuracy. The sub bearing can be assembled easily and with high accuracy, as compared with the case in which the inner surface of the closed case is fixed by welding, press fitting, or the like. In addition, even if the swing of the rotary shaft is large after assembly, it can be easily corrected by re-tightening the screw or inserting a spacer. In this case, since the sub bearing is screwed only to the frame or the stator, the sub bearing and the stator will not be unduly applied after the straightening due to the structure, and the straightened state can be maintained accurately. it can. Further, since the stator and the sub bearing of the motor are fixed to the frame, they can be assembled before being assembled in the closed case, and the assembling work can be facilitated. Therefore, by supporting the rotary shaft of the motor with the two bearings, it is possible to realize high-speed rotation and also to facilitate the assembly.

Embodiments of the Invention Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 11 in the drawing denotes a vertically long closed case, and this closed case 11 includes a cylindrical intermediate case 12 and
The intermediate case 12 is composed of closed cases 13a and 13b welded to close both ends. Closed case
A frame 14 is fixed to a position in the upper part of the inside of the housing 11 so as to vertically partition the inside of the closed case 11. A scroll type compression mechanism 15 is arranged above the frame 14, a motor 16 for giving driving power to the scroll type compression mechanism 15 is arranged below the frame 14, and the bottom of the hermetic case 11 is lubricated. Oil 17 is contained.

The scroll type compression mechanism 15 includes a fixed element 21 and a movable element arranged below the fixed element 21 as in the known one.
It is composed of 22 and. The fixing element 21 is a disk-shaped end plate 23.
And an annular wall 24 protruding from the peripheral edge of one surface of the end plate 23.
And a scroll blade 25 projecting at a height substantially equal to that of the annular wall 24 in a portion surrounded by the annular wall 24, and a discharge port 26 provided at a substantially central portion of the end plate 23. . The inner edge of the annular wall 24 is formed as a curved surface having an appropriate curvature or a notch surface 27 such as a tapered surface as shown in FIGS. 2 (a) and 2 (b). In the fixing element 21 configured as described above, the peripheral edge of the annular wall 24 is hermetically fixed to the peripheral edge of the upper surface of the frame 14 by the bolt 28 with the protruding direction of the annular wall 24 and the scroll blade 25 facing downward. A cap 29 is applied to the upper surface of the fixing element 21 during fixing, and the cap 29 is also integrally fixed by the bolt 28. The cap 29 is formed in such a size that a gap 30 having a predetermined thickness can be formed between the cap 29 and the upper surface of the end plate 23, and a hole 31 is formed in a part of the wall forming the gap 30. Further, a hole 32 for guiding a lubricating oil described later is formed in a part of the side wall thereof. Meanwhile, the movable element 22
Is an end plate 33 having an outer diameter slightly larger than the inner diameter of the annular wall 24.
And a scroll blade 34 provided on one surface of the end plate 33 so as to project at a height substantially equal to the height of the scroll blade 25, and the end plate.
It is composed of a cylindrical portion 35 protruding from the center of the other surface of 33. As shown in FIGS. 3 (a) and 3 (b), the peripheral portion of the surface of the end plate 33 on the side where the scroll blades 34 project is provided with a notch surface 36 such as a tapered surface. And
The movable element 22 configured as described above has a scroll wing 34.
Of the scroll blade 34 and the scroll blade 25 are meshed with each other, and the peripheral portion of the end plate 33 and the end surface of the annular wall 24 and the end surface of the scroll blade 34 and the end plate 23 and the end surface of the scroll blade 25 and the end plate. 33 are mounted so as to be in sliding contact with each other, and this mounted state is held by an Oldham mechanism 40 provided between the end plate 33 and the frame 14.

The Oldham mechanism 40 is located on the peripheral edge of the lower surface of the end plate 33, and
As shown in FIG. 4, key grooves 41a, 41b are provided at two points on the same line drawn through the center of the frame, and on a line orthogonal to the arrangement direction of the key grooves 41a, 41b and on the upper surface of the frame 14. And the key grooves 42a, 42b provided on the one side, and the keys 43a, 43b fitted into the key grooves 41a, 41b on one surface as shown in FIG. 4 and the key grooves 42a, 42b fitted on the other surface. And a ring 45 having keys 44a and 44b. Actually, for example, a mesh-shaped oil groove 46 for reducing sliding resistance is formed on both surfaces of the ring 45 as shown in FIG. Also, the key grooves 42a, 42b,
On the inner surface of 41a, 41b, as shown by a key groove 42b in FIG. 6, a widening step portion for reducing the sliding area with the key is formed.
47 are formed.

The frame 14 is provided with a projecting peripheral wall 49 having an outer diameter smaller than the inner diameter of the intermediate case 12 at the peripheral portion of the lower surface. Further, in the central portion of the frame 14, the tubular portion 35 of the movable element 22 is provided.
A bearing hole 51 that is eccentric with respect to the axial center line is provided so as to penetrate in the vertical direction, and the portion of the bearing hole 51 that is located on the cylinder portion 35 side is formed to have a large diameter. The frame structure on the large diameter side is specifically configured as shown in FIG. That is, an annular wall 52 having an outer diameter substantially equal to the inner diameter of the hermetically sealed case 11 and having an inner diameter larger than the inner diameter of the annular wall 24 is formed so that the annular wall 24 is fixed by bolts 28. An annular receiving surface 55 for receiving the ring 45 is formed on the inner side of the annular receiving surface 55, and an annular receiving surface 56 is formed on the inner side of the annular receiving surface 55 for receiving a thrust force reducing mechanism 59 described later.
Each of the receiving surfaces is divided into a plurality of pieces in the circumferential direction by radially extending grooves 57, and at least one of the grooves 57 is communicated with a hole 58 provided in the wall of the frame 14 for directly communicating the inside and the outside. There is. The key grooves 42a and 42b are formed on the receiving surface 55.

Specifically, the thrust force reducing mechanism 59 is, as shown in FIGS. 7A, 7B, and 7C, an annular body 60 fitted and supported on the annular receiving surface 56, and the annular body 60. An annular groove 61 formed on the upper surface, and annular grooves 62, 63 shallower and thinner than the annular groove 61 formed inside and outside the annular groove 61 on the upper surface, and in the annular grooves 62, 63, respectively. A part of the seal rings 64 and 65 is made of, for example, tetrafluoroethylene and is mounted so as to project outward. A taper surface 66 is formed at the lower end of the outer peripheral surface of the seal ring 64 as shown in FIG. 7C, and a similar tapered surface is formed at the lower end of the inner peripheral surface of the seal ring 65. ing. Further, at four positions in the circumferential direction of the annular groove 61,
A bottomed hole 67 is formed at the same depth as the annular groove 61 so that the annular groove 61 communicates with the annular grooves 62, 63. Inside the end plate 33, the thrust force reduction mechanism 59 is mounted as shown in FIG. 1 and surrounded by the annular body 60, the seal rings 64 and 65, and the lower surface of the end plate 33. Holes 68 and 69 are formed to allow the space to communicate with the medium pressure ports S and S'of the compression chamber P at all times.

The bearing hole 51 of the frame 14 has a rotating shaft of the motor 16.
70 is rotatably supported. The motor 16 fixes its rotor 71 to the outer circumference of the rotary shaft 70, and fixes the stator core 73 of the stator 72 to the lower end surface of the projecting peripheral wall 49 provided on the frame 14 with screws 74. It is a squirrel cage induction motor. The rotating shaft 70 has a large diameter portion 75 formed at a portion located in the large diameter portion of the bearing hole 51, and a small shaft 76 which is fitted into the cylindrical portion 35 is projectingly provided on the large diameter portion 75. ing. The lower end of the rotating shaft 70 is formed so as to penetrate into the lubricating oil 17, and the lower end of the rotating shaft 70 is the stator.
It is supported by an auxiliary bearing 77 fixed to the stator core 73 of 72.

The sub bearing 77 is roughly divided into a radial bearing material 78 and a thrust bearing material fixed to the bearing material 78 with screws 79.
It is composed of 80 and. The radial bearing member 78 includes a tubular portion 81 that supports the rotary shaft 70 and a lower end radial load, and the tubular portion 81.
A support portion 82 extends radially outward from 81, then extends toward the stator core 73, and is commonly fastened and fixed to the stator core 73 by the screws 74. A plurality of holes 83 are formed in the support portion 82 in the circumferential direction. On the other hand, the thrust bearing member 80 is composed of an annular plate that is in sliding contact with the lower end surface of the rotating shaft 70.

A hole 90 for pumping the lubricating oil 17 to the bearing surface and the fitting portion between the small shaft 76 and the tubular portion 35 by a centrifugal pump action is formed in the rotating shaft 70. The shape of the inlet portion of the hole 90, that is, the portion located at the lower end portion of the rotating shaft 70, is that the portion 91 extends upward from the central portion of the lower end surface of the rotating shaft 70, and the tubular portion in the radial direction from this portion 91. A portion 92 extending to the inner surface of 81 and a portion 93 extending vertically in the peripheral position of the rotary shaft 70 so as to intersect the portion 92 at a right angle are combined.

Further, a suction pipe 110 is connected to a portion of the side wall of the intermediate case 12 of the closed case 11 located between the scroll type compression mechanism 15 and the motor 16, and a suction port 110 is connected to a discharge port of the suction pipe 110. A hole 111 is formed in the opposing wall of the protruding peripheral wall 49. Further, a discharge pipe 113 is connected to a wall of the closed case 13a so as to communicate with a space 112 formed between the wall and the fixing element 21.

In FIG. 1, reference numeral 114 denotes a hole provided in the annular wall 24 and the frame 14 for returning the lubricating oil extruded into the space 112 to the lower side of the frame 14, 115 denotes a balance weight, and 116 denotes A connection mechanism for supplying power to the motor 16 is shown, and 117 is a hole for passing lubricating oil.

Next, the operation of the compression device configured as described above will be described.

First, when power is supplied to the motor 16, the rotating shaft 70 starts rotating. This rotation is smoothly held by both the bearing hole 51 and the sub bearing 77. Then, the rotational force of the rotating shaft 70 is transmitted to the movable element 22. Since the tubular portion 35 of the movable element 22 is fitted with the small shaft 67 provided eccentrically with respect to the rotating shaft 70 and is supported by the Oldham mechanism 40, the movable element 22 does not rotate. Perform a turning motion. Therefore, the scroll vanes 34 provided on the movable element 22 also perform the orbiting motion. Along with this orbiting motion, scroll wings 25
The volume of the compression chamber P formed between the scroll vane 34 and the scroll vane 34 is periodically reduced, and the compressed gas is discharged from the discharge port 26. The discharged high-pressure gas is a cap
It is sent out from the discharge pipe 113 through the gap 30 formed by 29-the hole 31 provided in the cap 29-the space 112. On the other hand, when the movable element 22 pivots as described above, the peripheral edge of the upper surface of the end plate 33 of the movable element 22 and the annular wall 24 of the fixed element 21.
The notched surfaces 36 and 27 are effectively formed with the inner edge of the compression chamber P so that the peripheral edge of the compression chamber P is always in communication with the space above the receiving surface 55 formed in the frame 14. Becomes The space is a groove formed radially in the frame 14.
57 and the like, and this hole 58 communicates with the suction pipe 110 through the hole 111, so that the low-pressure gas is eventually the suction pipe 110-hole 111-hole 58-receiving surface 55. It will be sucked into the low pressure port in the compression chamber P via the upper space,
The function as a compression device is exhibited here. In this case, even if a liquid such as a refrigerant is mixed in the low-pressure gas flowing through the suction pipe 110, this liquid drops downward while moving to the hole 58, and the lubricating oil 17 is accumulated. Try to move to the bottom. Since the motor 16 is self-heated, the dropped liquid is gasified by the heat and mixed into the flow of the gas which has already been gasified, and moves into the compression chamber P. Therefore, the space where the motor 16 is installed has exactly the same function as the gas-liquid separator.

On the other hand, when the motor 16 is rotated as described above, a part of the lubricating oil 17 is struck by the centrifugal pump action accompanying the shape of the hole 90.
The information in 90 is drawn up. The pumped lubricating oil lubricates the inner peripheral surface of the bearing hole 51, and then the small shaft 76 and the cylindrical portion.
The fitting portion with 35 is lubricated, and then the portion where the Oldham mechanism 40 is provided is lubricated through the hole 117, and then a part of the oil flows down from the hole 58 and the rest is in the compression chamber P. To slide in and lubricate the sliding portion in the pressurizing chamber P. Then, the lubricating oil that has entered the compression chamber P is finally discharged from the discharge port 26 and then flows downward through the holes 32 and 114 provided in the cap 29. Therefore, the high pressure gas containing no lubricating oil is discharged from the discharge pipe 113.

Further, as described above, when the movable element 22 performs the turning motion and the compression operation is performed, the pressure inside the compression chamber P becomes high, so that the movable element 22 receives the downward thrust force, and this force is applied to the Oldham mechanism. 40, the receiving surface 55 of the frame 14 and the like may be added, and a seizure phenomenon may occur in these elements.
However, in the case of this embodiment, the thrust force reducing mechanism 59 prevents the occurrence of the seizure phenomenon as follows. That is, the annular body 60 and the seal ring 6 of the thrust force reducing mechanism 59.
The annular space surrounded by 4,65 and the end plate 33 is always connected to the so-called intermediate pressure ports S, S'of the compression chamber P via the holes 68, 69. Therefore, the end plate 33 receives a force directed upward due to the gas pressure in the annular space, and the presence of this force reduces the downward thrust force applied to the end plate 33. This reduction prevents the occurrence of a seizure phenomenon. The downward thrust force applied to the movable element 22 is
Pulsates with a change in the position of the compression space. For this reason,
High-pressure gas may leak from the thrust force reducing mechanism 59 to the low-pressure side, but in this embodiment, as shown in FIG. 7, the annular groove 61 and the annular grooves 6 in which the seal rings 64 and 65 are mounted are used.
Since the bottomed hole 67 for communicating with 2, 63 is provided, the seal rings 64, 65 always have a force as indicated by a solid arrow in FIG. 7C, that is, the seal rings 64, 65 are attached to the end plate 33. The force that presses against the bottom surface of. Therefore, this pressing prevents the high-pressure gas from leaking.

Thus, the upper end of the rotary shaft 70 is supported by the bearing hole 51 provided in the frame 14, and the lower end is supported by the sub bearing 77. Then, the sub bearing 77 is fixed to the frame 14 via the stator core 73 of the motor 16. Frame 14,
The stator core 73, the rotary shaft 70, etc. are generally manufactured with high precision because of their functions. Therefore, if the manufacturing accuracy of the sub bearing 77 is raised to some extent, the axis line of the sub bearing 77 and the bearing hole
The sub-bearing 77 can be assembled semi-automatically so that the axis line of the shaft 51 coincides and the thrust bearing material 80 also functions well. Therefore, the support of the rotary shaft 70 can be stabilized, and high-speed rotation can be realized. Further, in particular, since the auxiliary bearing 77 is fixed in the above-mentioned relationship, the closed case 11
The sub-bearing 77 and the motor 16 can be assembled at a stage before being assembled inside. Therefore, not only the assembling work can be greatly facilitated, but even if the swinging of the rotary shaft 70 is large after the assembling, the correction work such as the re-tightening of the screw 74 can be easily performed, and as a result, the above-mentioned effect is obtained. Will be obtained.

The present invention is not limited to the above embodiment.

The sub-bearing may have a two-piece structure including a so-called sub-bearing main body and a support member connected to the main body.
Further, as shown in FIG. 8, the protruding peripheral wall 49 formed on the frame 14 is extended downward, the fixing core 73 is fixed to the inner surface of the protruding peripheral wall 49, and the auxiliary bearing is attached to the lower end surface of the protruding peripheral wall 49.
The 77a may be fixed by the screw 120. Of course, a part of the projecting peripheral wall may be formed by another member. Further, the projecting peripheral wall may be replaced with a plurality of support legs. Further, it goes without saying that the present invention can also be applied to a device in which a motor is arranged above and a scroll type compression mechanism is arranged below, and a device in which a shaft center line is horizontal.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a scroll type compression device according to an embodiment of the present invention, FIG. 2 (a) is a bottom view of a fixing element in the device, and FIG. 2 (b) is AA in (a). Sectional drawing of the installation condition cut | disconnected along the line and seen in the arrow direction, FIG. 3 (a) is a top view of the movable element in the same apparatus, FIG.
Is a sectional view taken along line BB in (a), FIG. 4 is a partially cutaway exploded perspective view showing only the upper part of the frame in the same device, and FIG. 5 is a plan view of the Oldham mechanism main part in the same device. , FIG. 6 is a view for explaining the shape of the keyway of the Oldham mechanism, FIG. 7 (a) is a top view of a thrust force reducing mechanism incorporated in the same device, and FIG. 7 (b) is (a). 8 is a view taken along the line CC in FIG. 7, FIG. 8C is a view for explaining the shape of a seal ring incorporated in the same mechanism, and FIG. 8 is a scroll type compression device according to another embodiment of the present invention. FIG. 11 …… Sealed case, 14 …… Frame, 15 …… Scroll type compression mechanism, 16 …… Motor, 17 …… Lubricating oil, 21 …… Fixed element, 22 …… Movable element, 25,34 …… Scroll blade, 26 ...
… Discharge port, 40 …… Oldham mechanism, 49 …… Casting wall, 51 ……
Bearing hole as main bearing, 70 ... rotating shaft, 71 ... rotor,
72 ... Stator, 77 ... Secondary bearing, 90 ... Hole for centrifugal pump, 110 ... Suction pipe, 113 ... Discharge pipe.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kanji Sakata 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Home Appliances Technology Laboratory, Inc. (72) Inventor Makoto Hayano 8 Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Incorporated company Toshiba Home Appliances Technology Laboratory (72) Inventor Hitoshi Hattori 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Incorporated Toshiba Electronics Appliances Research Laboratory (56) Reference JP 59-131702 (JP, A) )

Claims (1)

[Claims] 1. A hermetically sealed case, a frame fixed to the inner surface of the hermetically sealed case so as to divide the hermetically sealed case into two chambers, and one of the chambers partitioned by the frame, which are provided to each other. A scroll type compression mechanism comprising fixed elements and movable elements, each of which is formed into a shape that constitutes a compression chamber between them by joining in the axial direction and has scroll blades that mesh with each other in the compression chamber; Bearing holes provided in the frame, and provided in the other room partitioned by the frame,
One end of a rotary shaft connected to the rotor is supported by the bearing hole, and the motor is provided between the rotary shaft of the motor and the movable element of the scroll compression mechanism. In a scroll type compression device provided with a joint for rotating the movable element to perform gas compression by performing a rotational movement without rotation, the hermetically sealed case is formed in a tubular shape, and the intermediate case to which the frame is fixed and the intermediate case. The motor is fixed to the frame, and the other end of the rotary shaft is supported only by the frame. A scroll-type compression device, characterized in that a sub-bearing for supporting the other end of the rotary shaft is provided.