JPH04246283A - Sealed type scroll compressor - Google Patents

Abstract

PURPOSE:To dissolve the deterioration of the performance and reliability of a compressor accompanied with the high speed revolution in a sealed type scroll compressor which is used as a coolant compressor for refrigerating air conditioner, refrigerator, etc. CONSTITUTION:A main bearing 40 for supporting a rotary shaft 14 is arranged at the center part of a frame, and a sealing member 9 for sealing an electric motor chamber 1b and a back pressure chamber 41 is installed under the vicinity of the main bearing 40, and an auxiliary bearing part 51 which supports the rotary shaft 14 and has a separate structure from a chamber member is arranged in the lower part of the electric motor. A cylindrical roller bearing is arranged in the main bearing part 40, and is lubricated by the oil which flows into the back pressure chamber 41 from a turning bearing 39 side. The sealing member 9 installed in the vicinity of the main bearing is a sealing bearing structure due to the combination of the structure having a circumferential groove on the inner peripheral surface of the beering and an oil feeding hole in the radial direction or a radial hole on the rotary shaft 14 for supplying the high pressure oil into the circumferential groove. Accordingly, the performance and the reliability of a compressor can be drastically improved in the high speed operation, and the operation range in the high speed range can be set wide, and the effect for reducing the vibration and noise of the compressor in the high speed operation can be realized, and the superhigh speed operation of the compressor can be achieved.

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 air conditioning, refrigerators, etc.

0002

[Prior art] A hermetic scroll compressor was developed in Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent No. 75094, the refrigerant gas compressed by the scroll compression mechanism reaches the motor room from the upper discharge chamber through the communication path. The refrigerant gas then flows around the motor and out of the compressor discharge pipe. The rotating shaft is supported by two bearings (main bearing and lower bearing) located at the center of the frame above the motor and placed at the upper and lower ends. Also, cited example JP-A-2
-9971 and JP-A-63-80038,
A scroll compressor with a vertical auxiliary bearing structure is disclosed.

0003

[Problem to be solved by the invention] Prior art JP-A-62
Publication No. 75094 states that when trying to achieve a high speed compressor such as a rotation speed of 10,000 rpm, the swing of the rotating shaft (radial displacement of the shaft) increases as the load on the compressor increases; As a result, the vibration of the compressor increases significantly. Further, since the two bearing spans arranged in the frame are small, the bearing load acting on these two bearings becomes large, and mechanical loss also increases. Furthermore, in the conventional structure described above, as the speed increases, the amount of bearing oil increases, and the oil agitation loss in the back pressure chamber also increases. These losses increase in proportion to the third or fourth power of the rotational speed, and the performance of the compressor decreases significantly. Further, in the cited Japanese Patent Application Laid-Open No. 2-9971, the auxiliary bearing is located above the compressor, and there is a problem that the lubrication of the auxiliary bearing becomes more difficult as the speed increases. In this way, the present invention aims to solve the problem of performance deterioration and reliability deterioration caused by speeding up the compressor. On the other hand, JP-A-63-
In Publication No. 80038, the auxiliary bearing part and the casing part have an integrated structure, and there is a problem in the method of centering the auxiliary bearing part and the shaft part. Further, the assembly method is not disclosed in detail.

0004

[Means for Solving the Problems] As shown in Fig. 1, a main bearing that supports the rotating shaft is provided in the center of the frame, and a sealing member that seals the motor chamber and the back pressure chamber is provided below the immediate vicinity of the main bearing. An auxiliary bearing part is disposed below the electric motor to support the rotating shaft and is structured separately from the chamber member. A highly reliable cylindrical roller bearing is placed in the main bearing section, and the bearing is lubricated by oil flowing into the back pressure chamber from the swing bearing side. The seal member installed near the main bearing has a structure in which a circumferential groove is provided on the inner circumferential surface of the bearing, and a radial oil supply hole or radial hole is attached to the rotating shaft to supply high-pressure oil to the circumferential groove. A sealed bearing structure is created by combining the following. Alternatively, in order to increase the sealing function, a threaded seal structure (Biisco threaded seal structure) that is effective in moving the oil in the back pressure chamber toward the high pressure side is added to the seal bearing. This provides a mechanism for adjusting the amount of oil flowing into the back pressure chamber into the seal bearing, which is a seal member.

[0005]

[Operation] In the present invention, since the seal member is provided near the main bearing portion, high-pressure oil is prevented from flowing from this portion. Therefore, in the conventional machine, high-pressure oil flows into the back pressure chamber from both bearings from the swing bearing side and the lower bearing side of the frame, but in the present invention, oil flows only from the swing bearing side. Therefore, according to the configuration of the present invention, the conventional machine JP-A-62-750
Compared to the one in Publication No. 94, the amount of oil flowing into the back pressure chamber can be suppressed to about half or less, and the oil agitation loss due to the balance weight swinging around in this back pressure chamber can be greatly reduced. . On the other hand, since the bearing structure is such that the electric motor is sandwiched between the upper and lower ends, the span between the main bearing and the auxiliary bearing is longer, and the load applied to the main bearing for each bearing is reduced to a fraction of that of conventional machines. be done. Coupled with the reduction in bearing load, this also suppresses the rise in oil temperature in the bearing.

Furthermore, since the whirling of the rotating shaft can be kept within the bearing gap of the auxiliary bearing, vibrations of the compressor during high speed rotation can be reduced under conditions where the auxiliary bearing is properly lubricated. Noise reduction is achieved. In addition, the lower end support bearing structure has the effect of reducing fluctuations in the gap between the motor rotor and the stator during rotation at high speeds. Therefore, the effect of improving the motor efficiency and the significant reduction in the electromagnetic attraction force can further reduce the bearing load applied to the above-mentioned two bearing parts. Since a differential pressure oil supply system is adopted, the amount of oil is always ensured even during low-speed rotation or high-speed rotation, and there is no problem of poor lubrication of the auxiliary bearing shown in Japanese Patent Application Laid-Open No. 2-9971. In addition, since the auxiliary bearing part is structured separately from the chamber member,
Radial adjustment becomes possible during centering work between the auxiliary bearing and the shaft. Therefore, the problem of the method of centering the auxiliary bearing part and the shaft part, which was found in Japanese Patent Application Laid-Open No. 63-80038, can be solved.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention are shown in FIGS. 1 to 12. FIG. 1 is a longitudinal sectional view of a hermetic scroll compressor showing the overall configuration of the present invention.

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

The compressor section 100 has a fixed scroll member 5 and an orbiting scroll member 6 that are engaged with each other to form a compressor (closed space) 7. The fixed scroll member 5 consists of a disc-shaped end plate 5a and a wrap 5b that stands upright and is formed into an involute curve or a curve similar to this. Mouth 16
It is equipped with The orbiting scroll member 6 has a disc-shaped mirror plate 6.
a, a wrap 6b standing upright thereon and formed in the same shape as the wrap of the fixed scroll, and a boss 6c formed on the surface opposite to the wrap of the end plate. The frame 11 has a bearing part formed in the center thereof, and the rotating shaft 14 is supported in this bearing part, and the eccentric shaft 14a at the tip of the rotating shaft is inserted into the boss 6c so as to be able to rotate. Further, a fixed scroll member 5 is fixed to the frame 11 by a plurality of bolts, and a rotating Ekroll member 6 is attached to the frame 11 by an Oldham mechanism 12 consisting of an Oldham ring and an Oldham key.
The orbiting scroll member 6 is supported by the fixed scroll member 5 and is formed to perform an orbiting motion without rotating on its own axis relative to the fixed scroll member 5. A motor shaft 14b fixed to the rotor 3b is integrally connected to the rotating shaft 14 at its lower part, and the motor section 3 is directly connected thereto. 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 18a,
It communicates with the upper motor chamber 1b via 18b. This upper motor chamber 1b includes a motor stator 3a and a sealed container 1.
It communicates with the lower motor chamber 1c via a passage 19 between it and the side wall. Further, the upper motor chamber 1b communicates with a discharge pipe 20 passing through the closed container 1.

Note that 22 indicates an oil reservoir at the bottom of the closed container. In the figure, solid line arrows indicate the flow direction of refrigerant gas, and dashed line arrows indicate the flow direction of oil. In addition, 8 and 21 are orbiting scrolls 6
These are the first and second balance weights to offset the centrifugal force caused by the rotational movement of the robot.

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

The lubricating oil 22a is stored in the lower part of the closed container 1 as an oil reservoir 22. 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 connected to an orbiting bearing 39 in the boss portion 6c of the end plate 6a of the orbiting scroll 6.
It engages with the orbiting scroll 6, which is a scroll compression element portion, through the. A central vertical hole 13 for supplying oil to each bearing portion is formed in the rotating shaft 14 from the lower end to the upper end surface of the rotating shaft 14. 13a is an oil lifting pipe that connects the lower end of the rotating shaft 14 and the bottom oil reservoir 22. At the lower part of the eccentric shaft part 14a, a balance weight 8 is integrally formed with the rotating shaft 14 at the upper part of the main bearing 40, which faces the front end surface of the boss part 6c of the orbiting scroll 6. Lubricating oil 22
The lower end of the oil lift pipe 13a immersed in the oil reservoir 22 of a is receiving a high discharge pressure Pd, while the area around the downstream swing bearing 39 (see FIG. 2) and main bearing 40 is Since the lubricating oil 22a in the oil reservoir 22 at the bottom of the container receives an intermediate pressure Pm, which is the pressure during compression, through the small hole 6e provided in the center vertical hole 13 due to the pressure difference (Pd-Pm), rise. In this way, each bearing portion is supplied with oil by the differential pressure oil supply method using central vertical hole oil supply.

The lubricating oil 22a rising inside the central vertical hole 13 is supplied to the auxiliary bearing 51a and the swing bearing 39. The oil supplied to the swing bearing 39 flows into the back pressure chamber 41,
The oil that has flowed into the back pressure chamber 41 is mixed with refrigerant gas, and the oil flows into the back pressure hole 6.
It flows out into the compression chamber 7 via c. The oil that has reached the compression chamber 7 is pressurized together with the refrigerant gas, and moves to the discharge chamber 1a above the fixed scroll 5 and further to the motor chamber 1b. Refrigerant gas and oil are separated in the motor chamber 1b and the lower space 1c, and the oil falls into an oil reservoir 22 at the bottom of the closed container 1, and is again supplied to each sliding part.

Note that using an aluminum alloy for the orbiting scroll 6 is advantageous for increasing the speed of the compressor. In other words, as the centrifugal force acting on the swing bearing is reduced, it becomes even more effective in improving performance and reliability, such as reducing bearing loss.

As shown in FIG. 1, a main bearing 40 supporting the rotating shaft 14 is provided in the center of the frame, and a sealing member 9 is provided below near the main bearing 40 to seal the motor chamber 1b and the back pressure chamber 41. The rotary shaft 14 (1
4c), and is provided with an auxiliary bearing part 51 which is a separate structure from the casing part 2b, which is a chamber member. Main bearing part 40
A cylindrical roller bearing is placed in the
The oil flowing into the back pressure chamber 41 from the 9 side is supplied. In Figure 2,
An enlarged view of the area around the seal member 9 is shown. The seal member 9 provided near the main bearing 40 has a circumferential groove 9 formed on the inner peripheral surface of the bearing 9a.
On the other hand, b is a sealed bearing structure in which a radial oil supply hole 52 (radial hole) is attached to the rotating shaft 14 in order to supply high pressure oil to the circumferential groove 9b. A higher hydraulic pressure is applied to the circumferential groove 9b due to the action of the centrifugal pump as the oil supply hole 52 rotates. As shown in FIG. 2, the lower end of the seal bearing 9 is positioned at the upper end of the end ring of the rotor portion 3b. This prevents the bearing 9 from being affected by heat generated from the electric motor. This is preferable in terms of bearing reliability. In FIG. 3, in order to increase the sealing function, a threaded seal portion 9d (Biisco threaded seal structure) is added to the seal bearing portion 9, which is effective in moving the oil in the back pressure chamber 41 to the high pressure side. Although the figure shows a right-handed thread direction, this thread direction is determined by the direction of the rotating shaft 14. 9d is a thread groove structure with a rectangular cross section. The seal bearing part 9 has an auxiliary bearing at the lower end of the rotating shaft, so the rotating shaft 14
There is no need to support it, and the load carrying capacity at that part only needs to be small. Therefore, 9d only needs to have a sealing function. As a result, a mechanism can be provided in which the amount of oil flowing into the back pressure chamber 41 is adjusted by the seal bearing 9, which is a seal member. As described above, since the seal member 9 is provided near the main bearing portion 40, high pressure oil is prevented from flowing in from this portion. Therefore, in the conventional machine, high pressure oil flows into the back pressure chamber from both the bearings from the swing bearing side and the lower bearing side on the frame side, but in the present invention, oil flows only from the swing bearing 39 side. Therefore, according to the configuration of the present invention, the amount of oil flowing into the back pressure chamber can be suppressed to less than about half to a fraction of that of conventional machines, and the amount of oil swirling around inside this back pressure chamber 41 can be suppressed. The oil agitation loss caused by the balance weight 8 can be greatly reduced.

FIGS. 4 and 5 are a plan view and a longitudinal sectional view showing an embodiment of the auxiliary frame member 52. FIG. In the diagram of FIG. 4, a gas passage notch in the motor stator portion 3a is indicated by a two-dot broken line.

In order to prevent the gas that has passed through the gas passage notch 19 from blowing up the oil in the bottom chamber 22, the flow of the gas is blocked by the wall portion of the auxiliary frame 52. Therefore, a passage 52a for returning the oil circulating in the compressor to the bottom chamber 22 is provided on the opposite side of the passage 18 (18a, 18b). In this way, the auxiliary frame member 52 has the function of actively changing the flow of gas and separating oil from the gas. 52f is a threaded portion for fixing the auxiliary bearing portion 51. 6 and 7 are a plan view and a longitudinal sectional view showing other embodiments of the auxiliary frame member 52. FIG. As shown in FIGS. 1 and 7, an auxiliary frame 52 supporting the auxiliary bearing part 51
The auxiliary frame is fixed to the closed chamber member (casing portion 2b) by press-fitting, thereby making it possible to easily center the auxiliary frame. In addition, a hole 52a is provided in the auxiliary frame 52 in the circumferential direction of the auxiliary frame 52 through which an assembly thickness gauge 57 that maintains the gap 3e between the motor stator portion 3a and the rotor portion 3b uniformly can pass. In the assembled state, the auxiliary bearing 51 is connected to the rotating shaft 14c so that centering of the rotating shaft 14 can be easily performed. The assembly thickness gauge 57 is fixed to the jig 56 with a fixing bolt 57a. FIG. 8 shows the auxiliary bearing part 5
FIG. 9 is a cross-sectional view showing a case where a parallel groove 51e is provided in the shaft portion 14c. As shown in FIG. 8, since the auxiliary bearing part 51 has a separate structure from the chamber member, in order to attach it to the auxiliary frame 52,
A plurality of large holes 51f that can be adjusted in the radial direction are provided. The auxiliary bearing 51a is connected to the shaft portion 14 through the oil supply hole 14c.
It is lubricated by the oil in the parallel groove 51e of c. Parallel groove 51
The depth of the groove e may be sufficiently deep, around 0.5 mm. FIG. 10 shows an example in which the structure of a rolling bearing 51g is applied to the auxiliary bearing portion 51, and is a partial sectional view of the area around the bearing. Even if the rolling bearing 51g is used in this part, since it is structured separately from the chamber member as an auxiliary bearing, it is possible to align both members, and the centering of the rotating shaft 14 (14c) can be easily performed.

FIG. 11 is a longitudinal cross-sectional view of a hermetic scroll compressor showing the overall horizontal structure.

FIG. 12 is a partially enlarged view showing the structure around the auxiliary bearing 51a.

The rotary shaft 13 is arranged horizontally, the electric motor 3 is disposed as a bearing portion supporting the rotary shaft 13, and the auxiliary bearing portion 51a located on the opposite side of the scroll compression element portions 5 and 6 is lubricated. An oil cover part 61 having an oil reservoir function as a source is connected to the support part 51 of the auxiliary bearing. 71
and 72 are oil passages connecting the discharge chamber 1a and the motor chamber. As described above, in the present invention, since the differential pressure oil supply system is used, oil easily rises from the bottom chamber part to the oil cover part 61.

The oil cover portion 61 is provided with a vertical pipe 62 that connects it to the oil 22 at the bottom. Note that the end portion 61a of the oil cover portion 61 has a press-fit structure for easy attachment to the support portion 51 of the auxiliary bearing. As can be seen from FIGS. 1 and 11, by using the present invention, by simply replacing the oil supply pipe 13a and the oil cover part 61, a generally vertical structure including the sharing of the compression mechanism part can be achieved. This makes it possible to use common parts for horizontal structures. The effect of using common parts for vertical and horizontal structures is as follows.
This is different from JP-A-2-9971.

[0022]

[Effects of the Invention] The present invention has the following effects.

(1) The performance of the compressor during high-speed operation can be significantly improved, and the operating range in the high-speed range can be widened.

(2) The effect of reducing vibration and noise of the compressor during high-speed operation can be achieved, and ultra-high speed of the compressor can be achieved.

(3) The reliability of the compressor at high speeds is improved by significantly reducing the bearing load.

(4) The lower end support structure of the main shaft has the effect of reducing the overall length (in the height direction) of the compressor, making it possible to reduce the weight of the compressor and the manufacturing cost.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a hermetic scroll compressor showing the overall configuration of the present invention.

FIG. 2 is a partial cross-sectional view showing the structure around the seal member.

FIG. 3 is a partial cross-sectional view showing the structure around the seal member.

FIG. 4 is a plan view showing an example of the auxiliary frame member.

FIG. 5 is a longitudinal sectional view showing an example of an auxiliary frame member.

FIG. 6 is a plan view showing another embodiment of the auxiliary frame member 52.

FIG. 7 is a longitudinal sectional view showing another embodiment of the auxiliary frame member 52.

FIG. 8 is a partial cross-sectional view showing the structure of the auxiliary bearing.

FIG. 9 is a cross-sectional view when parallel grooves are provided in the shaft portion.

FIG. 10 is a partial sectional view of the area around the bearing in an embodiment in which a rolling bearing structure is applied to the auxiliary bearing part.

FIG. 11 is a vertical cross-sectional view of a hermetic scroll compressor showing the overall horizontal structure.

FIG. 12 is a partially enlarged view showing the structure around the auxiliary bearing.

[Explanation of symbols]

1b...Motor room, 3...Electric motor, 5...Fixed scroll, 6
...Orbiting scroll, 9...Seal member, 22a...Oil, 39
...Swivel bearing, 40...Main bearing, 51...Auxiliary bearing, 52...Auxiliary frame member.

Claims (1)

[Claims] Claim 1: A scroll compressor and an electric motor are housed in a sealed container and are connected to each other via a rotating shaft supported on a frame,
The hermetic container is divided into upper and lower chambers, and the scroll compressor has a fixed scroll member having a spiral wrap standing upright on a disc-shaped end plate and an orbiting scroll member that are engaged with each other with the wrap inside, and the orbiting scroll member is The orbiting scroll member is engaged with an eccentric shaft portion connected to the rotating shaft and rotates relative to the fixed scroll member without rotating, and the fixed scroll member has a discharge port opening in the center and an outer peripheral portion. The gas is sucked in through the suction port, and the gas is moved around the compression space formed by the scroll members to reduce its volume and compressed, and the compressed gas is sent through the discharge port into the upper container. In a hermetic scroll compressor that discharges into a chamber, leads to a lower container chamber through a passage, and discharges out of the container through a discharge pipe, a main bearing supporting the rotating shaft is provided in the center of the frame, A sealing member for sealing the motor chamber and the back pressure chamber is provided below near the main bearing, and an auxiliary bearing part supporting the rotating shaft and having a separate structure from the sealed chamber member is disposed below the motor. A hermetic scroll compressor featuring: