JP3518305B2 - Fluid machinery - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid machine represented by, for example, a scroll compressor, a rotary compressor, a reciprocating compressor and the like.

[0002]

2. Description of the Related Art FIG. 7 is a vertical sectional view showing a structure of a conventional scroll compressor disclosed in Japanese Patent Laid-Open No. 4-234592. In FIG. 7, 1 is a fixed scroll of a scroll compressor, 2 is an orbiting scroll which constitutes a fluid compression mechanism 25 for compressing a refrigerant gas together with the fixed scroll 1.
Is a discharge port, 4 is a suction port, 5 is a suction pipe communicating with the suction port 4, 10 is a discharge pipe, 6 is a drive shaft which is a crankshaft, and 7 is a bearing 7a which rotatably supports the drive shaft 6 in a radial manner. Then, 8 is a main frame for thrust-supporting the orbiting scroll 2, 8 is an electric motor rotor, 9 is an electric motor stator that constitutes the motor 21 together with the electric motor rotor 8, and 11 is a hermetically-sealed housing that houses the fluid compression mechanism 25 and other drive elements. It is a shell. Further, 14 is a sub-frame for supporting the bearing 15 which is located under the shell 11 and rotatably and radially supports the drive shaft 6 on the shell 11, and is a sub-frame holder fixed to the positioning portion 11 a of the shell 11. It is fixed to 12 with a bolt 13. Further, 30 is an oil pump for pumping lubricating oil such as refrigerating machine oil, and 31 is an oil reservoir provided under the shell 11 for storing lubricating oil.

Next, the operation of the above conventional scroll compressor will be described. In FIG. 7, the drive shaft 6 driven by the electric motor stator 9 supported in the middle part of the shell 11 and the electric motor rotor 8 fixed in the middle part of the drive shaft 6.
While being supported by the bearing 7a of the main frame 7 and the bearing 15 of the sub-frame 14, the orbiting scroll 2 is caused to orbit to form a compression chamber between the fixed scroll 1 and the orbiting scroll 2. The refrigerant gas flowing from the suction pipe 5 into the shell 11 is sucked into the compression chamber through the suction port 4 by the compression action of the fixed scroll 1 and the orbiting scroll 2 and compressed into high pressure refrigerant gas, and then discharged from the discharge port 3. Then, it is sent out of the shell 11 through the discharge pipe 10.
In such a compression process, a centrifugal force due to the gas load due to the refrigerant and the rotational balance is generated, and the force acts on the bearing 7a of the main frame 7 and the bearing 15 of the sub frame 14 via the drive shaft 6, respectively.

Thus, in the conventional scroll compressor,
In order to ensure the reliability of the bearing life with respect to the load, the bearing 15 with respect to the bearing 7a is aimed to minimize the relative inclination between the bearing sliding surface of the drive shaft 6 and the bearing 7a and the bearing 15. The sub-frame 14 is positioned with respect to the sub-frame holder 12 so that the parallelism (degree of parallelness of each axis) and the degree of coaxiality (degree of matching of each axis) have a predetermined relationship. After performing the aligning work, the subframe 14 was fixed to the subframe holder 12 with the bolt 13.

[0005]

However, the conventional scroll compressor has a poor assembling efficiency because it requires a time-consuming aligning process as described above. Moreover, since the sub-frame 14 and the sub-frame holder 12 are independent separate parts, the number of parts increases. Therefore, as the number of parts increases, the assembling work becomes more troublesome, and the number of parts increases, resulting in higher cost.

On the other hand, when the air conditioning unit or the refrigerating unit is left for a long period of time, the refrigerant in the unit circuit flows into the compressor and is liquefied, resulting in a so-called "refrigerant stagnation" state. In that case, the inflowing refrigerant is dissolved in the oil stored in the oil sump 31 in the compressor to reduce the oil concentration.
In this state, when starting the low pressure shell type compressor,
The refrigerant is sucked into the compression chamber and the pressure inside the compressor drops,
The refrigerant lying in the oil foams all at once. Therefore, the oil in the oil sump 31 is sucked into the compression chamber together with the foamed refrigerant,
It is discharged as it is and flows out of the compressor. As a result, the oil in the compressor may be depleted, resulting in poor oil supply, and eventually seizure of the bearing may occur. That is, in order to prevent oil carry-out and oil depletion due to the foaming of the refrigerant at the time of starting the sleeping, the "foam prevention plate" that separates the motor 21 side space and the oil sump 31 side space so as to be capable of defoaming is required separately. In addition, the number of parts and the assembling work are increased, resulting in an increase in cost and a decrease in work efficiency.

The present invention has been made in order to solve the above-mentioned problems, and reduces the number of parts of the bearing portion to improve and improve the assembling property, the bearing reliability is high, and the refrigerant stagnation start-up is performed. It is an object of the present invention to provide a highly reliable fluid machine which does not run out of oil and does not run out of oil even when it is used.

[0008]

In order to achieve the above object, a fluid machine according to the present invention comprises a shell formed in a hermetically sealed state, a fluid compression mechanism arranged on one side of the shell, and a shell. A motor disposed on the other side of the inside, a drive shaft provided by drivingly connecting the fluid compression mechanism and the motor, a bearing that rotatably supports the drive shaft in the radial direction, and a frame that holds the bearing, In a machine including a holder fixed to the inner peripheral surface of the shell and supporting the frame,
The frame and the holder are integrally connected to form an integrated frame, and a cutout portion that is separated from the inner peripheral surface of the shell is provided on the outer peripheral portion of the integrated frame, and the integrated frame is fixed to the inner peripheral surface of the shell. In the fan-shaped region formed by connecting the frame portion and the shaft center of the bearing, a space portion penetrating the front and back is formed so as to cross the fan-shaped region in the circumferential direction.

Further, the integrated frame having the above-mentioned structure integrally includes a sub-frame that holds a bearing that rotatably supports the drive shaft in the radial direction and a sub-frame holder that supports the sub-frame on the inner peripheral surface of the shell. And a step portion that covers at least the cutout portion is provided on the outer peripheral portion of the integrated frame with a predetermined minute gap between the stepped portion and the inner peripheral surface of the shell.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. First Embodiment of the Invention FIG. 1 is a plan view showing an integrated subframe of a scroll compressor according to an embodiment of the present invention. However, FIG.
The same components as those of the conventional machine shown in are designated by the same reference numerals and detailed description thereof will be omitted. In FIG. 1, an integral sub-frame 20 (an example of the integral frame of the present invention) holds the lower bearing 15 of the scroll compressor (an example of the fluid machine of the present invention) in FIG. Frame part 20a for fixing and holding 15
And the three holder parts 20 fixed to the inner peripheral surface of the shell 11 by shrink fit or the like to support the frame part 20a.
b, and three notches 2 formed on the outer peripheral portion of the subframe with a predetermined amount of clearance from the inner peripheral surface of the shell 11.
0c and. The frame portion 20a is formed as a cylindrical housing having a shaft center 15c of the bearing 15 as a center, and the bearing 15 is fixed to the inner peripheral surface thereof by press fitting or the like. Further, the holder portion 20b is provided with three space portions 20d penetrating the front and back of the integral subframe 20 in a fan-shaped region 20h formed by both ends of the holder portion 20b and the shaft center 15c of the bearing 15. The space 20d has an axis 15c.
Is formed as a circular arc shape having a larger angle than the fan-shaped angle with respect to the center of the fan-shaped region 20h in the circumferential direction.

As shown in FIG. 2, the integrated sub-frame 20 having the above-mentioned structure is arranged in the lower part of the shell 11 of the scroll compressor. First, the main frame 7 and the electric motor stator 9 are sequentially arranged in the shell 11. Shrink fit fixed. Separately, the frame portion 20a of the integrated subframe 20
A bearing 15 is press-fitted into the drive shaft 6, and an electric motor rotor 8 is also shrink-fitted and fixed to the drive shaft 6. Then, by shrink-fitting the holder portion 20b with respect to the workpiece in which one end of the drive shaft 6 is inserted into the bearing 7a of the main frame 7, and inserting the other end of the drive shaft 6 into the bearing 15 at the same time,
The integral sub-frame 20 serves as the positioning portion 11 of the shell 11.
It is fixedly supported by a.

When the integral sub-frame 20 is shrink-fitted to the shell 11 and spot welded, the integral sub-frame 20 contracts (compresses) toward the center of the integral sub-frame 20 due to shell shrinkage.
Is exerted, the bearing 15 contracts due to the force. Therefore, the bearing 15 is deformed to reduce the bearing clearance, or the roundness of the bearing 15 is deteriorated, resulting in deterioration of the bearing reliability.

Therefore, in the scroll compressor according to the embodiment of the present invention, the force acting on the integral sub-frame 20 after shrink-fitting and spot-welding on the shell 11 will be described with reference to FIGS. 3 and 4. . The contracting force of the shell 11 generated after the holder portion 20b of the integral subframe 20 is shrink-fitted and spot-welded as described above acts as a force toward the center from the holder portion 20b in contact with the shell 11. These forces F ′ change direction in the vicinity of the space portion 20d provided in the middle of the force F ′, and the other holder portion 20
The opposite forces from b cancel each other out. Therefore, the force does not reduce the diameter of the frame portion 20a and the bearing 15. Therefore, the contracting force does not reduce the clearance of the bearing portion.

In the integrated sub-frame 20, as shown in FIG. 3, R portions 20e and 20f are formed at both ends of the holder portion 20b and the space portion 20d, respectively. The radii of curvature of these R portions exceed the radiation connecting each of them with the shaft center 15c, and the contraction force of the shell 11 is set to such a value that the shell 11 does not act on this radiation toward the shaft center 15c.

When the integral sub-frame 20 as described above is manufactured, the notch 20c may be processed by an end mill, or molded by a mold, but it is generally made by the mold from the viewpoint of cost. Often formed as a casting. In that case, the notch 20c becomes large due to dimensional accuracy and variation of the mold, and as a result, an excessive space is provided between the outer circumference of the integral subframe 20 and the inner circumference of the shell 11. Therefore, the integral sub-frame 20 has a role of a “foaming prevention plate” that separates the space on the motor 21 side and the space on the oil sump 31 side so that bubbles cannot pass therethrough and prevents the oil from being taken out due to the foaming of the refrigerant that occurs at the time of start-up. I couldn't do it, so I had to install a separate "foam prevention plate." On the other hand, by forming the notch 20c with a mold and setting the clearance between the outer peripheral portion of the integral subframe 20 and the inner peripheral surface of the shell 11 to a predetermined clearance, the effect of the "foam prevention plate" is obtained. A means for providing the above will be shown in the following second embodiment.

Second Embodiment of the Invention FIG. 5 is a plan view showing an integrated subframe having a function of a “foaming prevention plate”, and FIG. 6 is a sectional view taken along the line BB in FIG. The integrated sub-frame 20 shown in each drawing has the holder portion 20b and the notch portion 20c as described above, and further has a predetermined amount smaller than the outer diameter ΦD1 of the holder portion 20b on the outer periphery near the lower surface thereof and the shell. An entire circumferential step portion 20g (an example of the step portion of the present invention) having an inner diameter 11 and an outer diameter ΦD2 having a predetermined small gap δ is formed over the entire circumference. Since the entire circumferential step portion 20g covering the cutout portion 20c can be machined (lathe) with the outer diameter of the holder portion 20b and a minute gap δ, a predetermined amount of minute gap δ with the inner peripheral surface of the shell 11, that is, passage. It is possible to control the clearance that can break the bubbles that are formed. Further, since lathe processing can be performed instead of end mill processing, it is possible to perform processing in the same process when processing the outer diameter of the holder portion 20b. Further, it goes without saying that the entire circumferential step portion 20g is not in contact with the inner peripheral surface of the shell 11 and is not related to the deformation of the integrated subframe 20 (due to the shrinkage force of the shell 11) due to shrink fitting or the like.

Therefore, when the integral sub-frame 20 is fixed to the shell 11 by shrink fitting or the like, the frame portion 20a due to the contracting force from the holder portion 20b as described above.
Of the space portion 20 provided in the integrated sub-frame 20
The frame portion 20 is absorbed or offset by d.
The a and the bearing 15 are not deformed. Further, apart from the holder portion 20b and the cutout portion 20c, the entire circumferential step portion 20g having an outer diameter portion having a minute gap δ between the shell portion 11 and the inner peripheral surface thereof.
Since the shell 11 is provided, the subframe 2 integrated with the shell 11 is provided.
Since the clearance between 0s can be managed and the space of the motor 21 side and the space of the oil sump 31 side are separated by the integrated sub-frame 20, the integrated sub-frame 20 has a function of a “foam prevention plate”. You can However, as the step portion of the present invention, it is sufficient that it covers at least the notch portion 20c, and it is not necessary to form the holder portion 20b as in the case of the above-mentioned entire circumferential step portion 20g.

Although the above-mentioned integral frame is applied to a scroll compressor that compresses and discharges a refrigerant gas as a fluid machine, it is also applicable to, for example, a rotary compressor or a reciprocating compressor. is there. The fluid to be compressed may be air or the like. Further, it may be applied not only to the sub-frame near the motor but also to the main frame near the fluid compression mechanism. Further, although the vertical type fluid machine has been illustrated above, the present invention can be applied to a horizontal type fluid machine in which a motor and a fluid compression mechanism are arranged in the horizontal direction.
The bearing for rotatably supporting the drive shaft in the radial direction is not limited to the ball bearing, but may be a slide bearing or the like.

Further, in the above-mentioned embodiment, the method of fixing and supporting the integral type frame to the shell is shown by an example of shrink fitting.
A similar problem is caused by press fitting other than shrink fitting. That is, the present invention is also effective when the integral frame is fixedly supported to the shell by, for example, an interference fit.

[0020]

As described above, according to the fluid machine of the present invention, the frame and the holder are integrated to form an integrated frame, and the frame portion of the integrated frame and the shaft center of the bearing are connected. In this fan-shaped region, a space penetrating the front and back sides was formed so as to be laterally attached to the fan-shaped region in the circumferential direction. As a result, it is possible to reduce the number of parts, and it is possible to prevent the deformation of the bearing portion due to the shrinkage force of the shell during the shrink fitting of the integrated frame. Moreover, since the conventional aligning step can be omitted, the cost can be reduced and the assembling efficiency can be improved to enhance the productivity. Furthermore, a fluid machine with high bearing reliability can be obtained.

Further, since the step portion having a minute gap with the inner peripheral surface of the shell is provided in the cutout portion of the integral type frame, the step portion can separate the motor side space and the oil sump side space,
It can play an integral role of a "foaming prevention plate" that prevents the oil from being taken out due to the foaming of the refrigerant that occurs at the time of starting to sleep. Therefore, the number of parts is reduced and the assembling process is also reduced, so that the cost can be reduced and the productivity can be increased. In addition, a highly reliable fluid machine without oil depletion can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing an integrated subframe of a scroll compressor according to an embodiment of the present invention.

FIG. 2 is a plan view showing an integral subframe of a scroll compressor according to another embodiment of the present invention.

FIG. 3 is an explanatory diagram for explaining a force acting on the integrated subframe according to the embodiment of the present invention.

4 is a cross-sectional view taken along the line AA in FIG.

FIG. 5 is a plan view showing an integral subframe and shell cross section of a scroll compressor according to another embodiment of the present invention.

6 is a sectional view taken along the line BB in FIG.

FIG. 7 is a vertical cross-sectional view showing the structure of a conventional scroll compressor.

[Explanation of symbols]

6 drive shaft, 11 shell, 15 bearing, 15c shaft center, 20 integrated sub-frame, 20a frame part,
20b holder part, 20c notch part, 20d space part,
20g full circumference step section, 20h fan-shaped area, 21 motor,
25 fluid compression mechanism, 31 oil sump, δ minute gap.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-9-112474 (JP, A) JP-A-5-263773 (JP, A) JP-A-8-240191 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) F04C 29/00 F04C 18/02 311

Claims (2)

(57) [Claims] 1. A shell formed in a hermetically sealed manner, and the shell.
And a fluid compression mechanism disposed on one side of the shell
A motor disposed on the other side of the fluid compression mechanism,
A drive shaft provided by drivingly connecting a motor, and the drive
A bearing that rotatably supports the shaft in a radial direction, and the shaft
The frame that holds the bridge is fixed to the inner peripheral surface of the shell.
And a holder for supporting the frame.
In a body machine, the frame and the holder are integrally connected to form an integral type
A frame is formed, and the outer periphery of the integrated frame is
Providing a notch that is spaced apart from the inner peripheral surface of the shell
Together with the integral type fixed to the inner peripheral surface of the shell
It connects the frame part of the frame and the shaft center of the bearing.
A space that penetrates the front and back sides is surrounded by the fan-shaped area.
A fluid machine characterized in that it is formed so as to cross in the direction . 2. The integrated frame integrally connects a subframe that holds a bearing that rotatably supports a drive shaft in a radial direction, and a subframe holder that supports the subframe on an inner peripheral surface of a shell. And a step portion that covers at least the cutout portion is provided on the outer peripheral portion of the integral frame with a predetermined minute gap between the stepped portion and the inner peripheral surface of the shell. The fluid machine according to claim 1.