JPH0230997A - Rotary compressor - Google Patents

Abstract

PURPOSE:To enhance the durability of bearing parts by providing the oil guide grooves of a pair of sliding bearings in the range from 220 deg. to 325 deg. for the bearing near to the motor, and in the range from 190 deg. to 310 deg. for the bearing far from the motor, making the position of the blade as 0 deg. and measuring in the turning direction of the turning shaft. CONSTITUTION:A turning shaft 4 commonly supports the pistons 13, 33 of respective rotary compression mechanisms 5, 6 having been coaxially arranged so that the blades 16, 36 have the same phase, and it is supported by a pair of sliding bearings 18, 38, and is rotatingly driven by a motor 2. The oil guide groove 56 of the sliding bearing 18 on the motor 2 side is provided in the range from 220 deg. to 325 deg., making the position of the blade 16 as 0 deg. and measuring in the turning direction of the turning shaft 4; and the oil guide groove 60 of the sliding bearing 38 on the other side is provided in the range from 190 deg. to 310 deg.. Thus, lubricating oil smoothly flows in the axial direction of the bearing surface along the oil guide groove without preventing the pressure buildup of the oil film, and moves in the circumferential direction along the outer circumferential surface of the turning shaft due to its viscosity, and a good oil film can be always formed over the entire bearing surfaces, thereby the enhancement in durability can be achieved.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention comprises two rotary compression mechanisms driven in common by one rotating shaft, and the rotating shaft is connected by a sliding bearing. This invention relates to a rotary compressor that is supported.

(Prior Art) As is well known, refrigerators and air conditioners require gas compressors. Rotary compressors are often used as compressors for such applications because they are easy to downsize.

A rotary compressor usually has a structure in which a motor and a rotary compression mechanism driven by the motor are integrally built into a container. The rotary compression mechanism includes a cylinder and a rotary piston eccentrically arranged within the cylinder.

A blade is attached to the cylinder so as to be in constant sliding contact with the outer peripheral surface of the rotating piston and divides the inside of the cylinder into a suction chamber and a compression chamber, a gas suction port communicating with the suction chamber, and a gas discharge port communicating with the compression chamber. It consists of Second, the container also serves as a tank for storing gas compressed by a rotary compression mechanism.

In such a rotary compressor, two rotary compression mechanisms are provided, and these two rotary compression mechanisms are commonly driven by one rotating shaft. There is a so-called 2-cylinder type. This 2 cylinder type rotary compressor has 2
The rotary compression mechanisms are arranged coaxially with the blades aligned in phase, and the rotary pistons of each rotary compression mechanism are commonly fixed to the outer periphery of the rotating shaft with a phase difference of 180 degrees. ing. Therefore, this type of device pumps compressed gas 1 time during 1 revolution of the 5-rotation shaft.
Discharge twice at 80 degree intervals. Therefore, the torque fluctuation of the 7-rotation shaft is small, and compared to the 1-cylinder type, it has the advantage of low vibration and low noise.

Incidentally, recently, in the field of refrigerators and air conditioners, a method of variable speed control of compressors has been adopted in order to improve efficiency and expand controllability. Along with this, the two-cylinder type rotary compressors incorporated in these systems are also required to further improve their rotational performance. There are several points to keep in mind when improving the rotational performance of a two-cylinder rotary compressor. Among these, reducing vibration and improving reliability of the bearing section are the most important items. To reduce vibration, a balancer is fixed at a proper position on the rotating shaft to offset the one-rotation unbalance. In the two-cylinder type, two rotating pistons are fixed to a rotating shaft with a phase difference of 180 degrees. Therefore, it is relatively easier to reduce vibration in the 2-cylinder type than in the 1-cylinder type. On the other hand, 1 is usually used as a bearing for a two-rotation compressor.

Uses sliding bearings with excellent durability. As is well known, in a sliding bearing, an oil film is interposed between a rotating shaft and a bearing surface, and the rotating shaft is supported by the pressure of this oil film. Therefore, in order to perform the bearing function well, it is necessary to always stably supply lubricating oil to the bearing clearance. For this reason, 2. Normally, an oil guide groove extending in the axial direction is provided on the outer circumferential surface of the rotating shaft or the inner circumferential surface of the bearing, and lubricating oil is supplied to the bearing clearance through this oil guide groove. .

However, in a one-rotation compressor, it is difficult to completely eliminate the one-rotation unbalance, and furthermore, since a fluctuating lateral load due to the compressed gas is applied to the rotation shaft, the swing of the two-rotation shaft is relatively large. This also applies to the 2-cylinder type. When whirling occurs in this way, pressure fluctuations occur within the bearing clearance.

For this reason, it is difficult to stably supply lubricating oil to the bearing clearance, which often results in reduced operating efficiency and direct contact between the sliding bearing and the rotating shaft, which can damage the rotating shaft and bearings. It was there.

(Problems to be Solved by the Invention) As mentioned above, it has been desired to improve the durability of the bearing portion and the operating efficiency by some means even in the two-cylinder type motor.

Therefore, the present invention satisfies the above-mentioned demands by two methods.
The purpose is to provide a cylinder type rotary compressor.

[Invention/) Configuration (Means for solving the problem) The present invention is a rotary compressor in which two rotary compression mechanisms are coaxially arranged with blades aligned in phase, and each of the 16-rotation compression mechanisms A rotating shaft that commonly supports the rotating piston with a phase difference of 180 degrees and is rotationally driven by a motor, and a pair of slides that respectively support both parts of the rotating shaft that protrude outside of the rotary compression mechanism. bearing and
Oil guide grooves are formed on the inner surface of each of these slide bearings to move the supplied lubricating oil to the entire bearing surface.

and means for supplying the lubricating oil to the entrance of the second oil guide groove, wherein the oil guide groove is formed in one of the pair of slide bearings that is closer to the motor; 2220 to 325 when the position of the blade is 0 degrees and the direction in which the rotating shaft rotates is a reference.
It is set within the range of Further, the oil guide groove formed in the other sliding bearing that is far from the motor is provided in a range of 190 to 310 degrees when the position of the blade is 0 degrees and the direction in which the rotating shaft rotates is a reference. There is.

(Function) According to the results of experiments and analysis, in the case of a two-cylinder type rotary compressor, there is almost no pressure increase due to supporting the shaft in the bearing clearance within the above-mentioned angular range on the bearing surface of each sliding bearing. . Therefore, if the oil guide groove is provided in the above angle range, the lubricating oil will smoothly flow in the axial direction of the bearing surface along the oil guide groove without hindering the pressure generation of the oil film. This flowing lubricating oil moves in the circumferential direction along the outer peripheral surface of the rotating shaft due to its viscosity. Therefore, it is possible to always form a good oil film over the entire bearing surface.

(Example) An embodiment will be described below with reference to one drawing.

FIG. 1 shows a longitudinal sectional view of a rotary compressor according to an embodiment of the present invention.

In the figure, 1 has a cylindrical space inside.

It shows a container arranged with its axis parallel to the direction of gravity. A motor 2, typically an induction motor, is arranged above the container 1, and below it are rotary compression mechanisms 5, 6 that are commonly driven by a rotating shaft 4 directly connected to the rotor 3 of the motor 2. There are nine coaxially arranged. Further, a predetermined amount of lubricant/lh7 is stored at the bottom of the container 1.

The rotary compression mechanisms 5 and 6 are arranged vertically adjacent to each other with a partition wall 9 having a hole 8 in the center as a boundary. The one-rotation shaft 4 is provided so as to pass through the two-rotation compression mechanism 5.6 and the hole 8 of the partition plate 9.

Specifically, the rotary compression mechanism 5 is configured as follows. That is, on the upper surface of the partition plate 9, a cylinder 11 having a cylindrical space 10 in the center with a larger diameter than the aforementioned hole 8 and through which the rotating shaft 4 passes is closely arranged.
The outer peripheral surface of the container 1 is fixed to the inner peripheral surface of the container 1. An eccentric portion 12 is integrally provided on the outer peripheral surface of the rotating shaft 4 located within the space 10, and a ring-shaped piston 13 is mounted on the outer peripheral surface of the eccentric portion 12. In addition, the opening on one end side is the space 10.
A guide groove 1 extending radially in the cylinder 11 in a relationship leading to the
4, and a blade 16 is mounted in the guide groove 14, which is always urged in the direction of the rotation axis by a spring 15.

Furthermore, the upper surface of the cylinder 11 is provided with a flange portion 17 that closes the upper end opening of the space 10, and the rotating shaft 4
A sliding bearing 18 is mounted to rotatably support the.

Blade 16 on one side in the circumferential direction with blade 16 as a boundary
A suction port 19 is provided at a position close to the cylinder 11 in a relationship that communicates with the space 10 as shown in FIG. It is connected to the gas suction pipe 21. Similarly, a discharge port 22 is provided in a portion of the flange portion 17 near the blade 16 on the other side in the circumferential direction with the blade 16 as a boundary, as shown in FIG. It communicates with the internal space of the container 1.

The rotary compression mechanism 6 is also configured in substantially the same manner.

That is, a cylinder 31 having a cylindrical space 30 in the center having the same diameter as the above-mentioned space 10 and through which the rotating shaft 4 passes is closely arranged on the lower surface of the partition plate 9.
Ko. The outer peripheral surface of the container 1 is fixed to the inner peripheral surface of the container 1. An eccentric portion 12 is provided on the outer peripheral surface of the rotating shaft 4 located within the space 30.
An eccentric part 32 is integrally provided with a phase difference of 180 degrees, and a ring-shaped piston 3 is attached to the outer peripheral surface of this eccentric part 32.
I am wearing 3. Further, a guide groove 34 extending radially in the cylinder 31 is provided in the same phase as the guide groove 14 so that the opening at one end communicates with the space 30, and a spring 3 is disposed in the guide groove 34.
A blade 36 that is always urged in the direction of the rotational axis by the blade 5 is attached. moreover.

A flange portion 37 that closes the lower end opening of the space 30 is provided on the lower surface of the cylinder 31, and a slide bearing 38 that rotatably supports the rotating shaft 4 is mounted. On the other hand, a suction port 39 is provided at a position close to the blade 36 on one side in the circumferential direction with the blade 36 as a boundary, and communicates with the space 30 as shown in FIG. It is connected to the gas suction pipe 21 through a guide path 40 and a hole provided in the container 1 . Similarly.

The flange portion 3 is located on the other side in the circumferential direction with the blade 36 as a boundary.
As shown in FIG. 4, a discharge port 42 is provided in a portion of the container 7 near the blade 36, and this discharge port 42 is communicated with the internal space of the container 1 via a discharge valve 43.

The radial load of the rotating shaft 4 is supported by two slide bearings 18.38, and the thrust load is supported by a thrust bearing 44 attached to the lower end of the slide bearing 38. The rotating shaft 4 is formed hollow. The cavity formed in the one-rotation shaft 4 has a large diameter in the portion located below the one-rotor 3. In this large diameter part.

A vane 51 is attached to draw up the lubricating oil 7 by a screw pump action. The blades 51 are formed by twisting a band-shaped plate material in the direction of rotation of the rotating shaft 4. The so-called peripheral wall of the one-rotation shaft 4 is located at the boundary between the sliding bearing 18 and the cylinder 11, and at the boundary between the sliding bearing 38 and the cylinder 31. Some sliding bearings 18.3
Lubricating hole 52 guided toward the 8 side. 53 is formed.

As shown in FIG. 5, the slide bearing 18 has an annular stepped portion 55 extending in the circumferential direction on the edge of the bearing surface 54 located on the cylinder 11 side, and also has an annular stepped portion 55 extending in the circumferential direction on the bearing surface 54 along the rotational direction of the rotating shaft 4. It has an oil guide groove 56 extending in the axial direction.

The oil guide groove 56 is in this embodiment.

Assuming that the rotational direction of the rotational shaft 4 is the direction shown by the solid line arrow 57 in the figure, the blade 16 is formed over a range of 240 to 290 degrees in the rotational direction of the rotational shaft 4, with the position of the blade 16 being 0 degrees. ing. On the other hand, as shown in FIG. 6, the slide bearing 38 has an annular step 59 extending in the circumferential direction at the edge of the bearing surface 58 located on the cylinder 31 side, and also extends linearly in the axial direction on the bearing surface 58. It has an oil guide groove 60. In this embodiment, the oil guide groove 60 is arranged so that the direction of rotation of the one-rotation shaft 4 is indicated by the solid line arrow in the figure.
1, the above-mentioned blade 36
It is formed at a position of 300 degrees in the rotational direction of the rotary shaft 4, with the position of 0 degrees. In addition, 62 in FIG. 1 indicates a passage for communicating the upper and lower spaces with the rotary compression mechanism 5.6 as a boundary, 63 indicates a gas exhaust pipe for discharging high-pressure gas, and 64 indicates a passage connected to the motor 2. A power feeding mechanism for feeding power is shown.

Next, the operation of the rotary compressor configured as described above will be explained.

When power is supplied to the motor 2, the first rotor 3 rotates and the rotating shaft 4 starts rotating. As a result, the pistons 13, 33 of each rotary compression mechanism 5, 6 rotate eccentrically. piston 1
As shown in FIGS. 2 and 3, the tip of the blade 16.36 is always in sliding contact with the outer peripheral surface of the blade 3.33.

Each space 10.30 communicates with the suction port 19.39 and the discharge port 22.42 with the blade 16.36 as the boundary. Therefore, in FIGS. 2 and 3, the solid line arrow 6
Assuming that the piston 13.33 is rotating as shown at 5, there is a blade 16.36 in each space 10.30.
Therefore, the suction chamber 66 is formed at the upper side in the figure, and the compression chamber 67 is formed at the lower side. The gas compressed in each compression chamber 67 is as follows.

They are discharged into the container 1 via a discharge opening 22,42 and a discharge valve 23.43, respectively. in this case.

The pistons 13.33 are eccentric with a phase difference of 180 degrees, and the blades 16.36 are arranged in the same phase, so that, for example, when the piston 13 starts compression, the piston 33 is already halfway through the compression stroke. This means that it has ended. Therefore, while the rotating shaft 4 rotates once, the container 1
The compressed gas will be discharged twice. The high-pressure gas in the container 1 is then guided to necessary equipment through the gas exhaust pipe 63.

During such compression operation, the plain bearing 18.38
Lubrication between the rotary shaft 4 and the rotary shaft 4 is performed as follows. That is, the lubricating oil 7 contained in the bottom of the container 1 is pumped up into the rotating shaft 4 by the screw pumping action of the vanes 51 contained in the rotating shaft 4 . A portion of this pumped up lubricating oil flows through the oil fill hole 53.52 to an annular step 59.55 formed at the edge of the bearing surface 58.54 of the plain bearing 38.18. As shown in FIG. 6, an oil guide groove 60 is provided in the bearing surface 58 of the slide bearing 38 in a straight line in the axial direction. Therefore, the lubricating oil that has flowed into the annular step portion 59 flows downward within the oil guide groove 60. Since the rotating shaft 4 is rotating, the lubricating oil flowing down in the oil guide groove 60 is distributed over the entire bearing surface 58, and an annular oil film is formed between the rotating shaft 4 and the inside of the bearing 58. Become. On the other hand, on the sliding bearing 18 side, the bearing surface 54
An oil guide groove 56 is formed in the direction in which the rotating shaft 4 rotates. Therefore, the lubricating oil that has flowed into the annular step portion 55 is 1
The oil moves upward in the oil guide groove 56 due to the relative motion between the rotating shaft 4 and the plain bearing 18, and thereby spreads over the entire bearing surface 54, forming an annular oil film between the rotating shaft 4 and the bearing surface 54. That will happen.

By the way, in the case of 2 cylinder type, pistons 13 and 3
3 and is fixed to the rotating shaft 4 with a phase difference of 180 degrees. Therefore, the rotational unbalance force acting on the rotating shaft 4 due to the presence of the piston 13°33 is small. However, the differential pressure of the compressed gas compressed by each piston 13, 33 acts greatly on the rotating shaft 4. This differential pressure is generally
A force as shown by C in FIG. 7 is generated and acts on the rotating shaft 4.

When a differential pressure is generated in such a direction, the oil guide grooves 56, 60 of the slide bearings 18, 38 are provided in the above-mentioned angular range as in this embodiment.

Lubricating oil can be reliably supplied to the bearing clearance.

This can prevent damage.

The reason for this will be explained below. The inventors.

An experiment was conducted to examine how the oil film pressure within each sliding bearing 18.38 changes in the circumferential direction when the above-mentioned differential pressure acts on the rotating shaft 4. That is, the sliding bearing 18
Twelve pressure sensors are installed at 30 degree intervals on the outer circumferential surface of the motor 2, the outer circumferential surface of the cylinder 11, and the outer circumferential surface of the sliding bearing 38 located on the cylinder side. The circumferential pressure distribution of the oil film inside the bearing was measured by passing it through the bearing clearance through the hole. As a result, the characteristics shown in FIGS. 8, 9, and 10 were obtained. Here, FIG. 8 shows the characteristics of the portion of the sliding bearing 18 located on the motor 2 side, FIG. 9 similarly shows the characteristics of the portion of the sliding bearing 18 located on the cylinder 11 side, and FIG. 10 shows the characteristics of the sliding bearing 18 located on the cylinder 11 side. 38 shows the characteristics of the portion located on the cylinder 31 side. In addition, in these figures, the horizontal axis shows the circumferential position of the bearing with the position of the blade 16.36 being 0 degrees, and the piston 13 is
The rotation axis 4 is set with the rotation angle φ-0 degrees at the position where the
It shows pressure distribution characteristics in the circumferential direction every 30 degrees during one rotation. Note that the straight line portion of the pressure distribution in FIGS. 8 to 10 represents that the inside of the bearing is under negative pressure with respect to the outside of the bearing. As can be seen from these figures, the sliding bearing 18 side (see Figures 8 and 9)
Well then.

It can be seen that no pressure increase occurs in the range of 215 to 330 degrees, and the temperature is in a negative pressure region. Similarly, on the sliding bearing 38 side (see FIG. 10), it can be seen that the negative pressure region is in the range of 185 to 315 degrees. In addition.

The difference in the range between the two bearings is due to the difference in whirling characteristics of the rotating shaft 4, which has the rotor 3 on one end side.

Lubricating oil tends to flow into this negative pressure region inside the bearing from outside the bearing. In the embodiments shown in Figures 6 to 6,
On the sliding bearing 18 side, an oil guide groove 56 is provided in a range of 240 to 2"l (1 degree, and on the sliding bearing 38 side, an oil guide groove 60 is provided in a 300 degree position. Therefore, the sliding bearing 18 As a result, the lubricating oil can be reliably entered between the bearing surface 54.58 of 38 degrees and the rotating shaft 4.

Direct contact between the slide bearing 18.38 and the rotating shaft 4 can be reliably prevented. Also.

In the part where the oil guide grooves 56 and 60 are provided.

During one rotation of the rotating shaft 4, the pressure of the oil film is always negative and never positive, so lubricating oil can be actively introduced from the outside of the bearing into the inside of the bearing through the oil guide grooves 56 and 60. However, it is possible to reliably supply lubricating oil.

Further, as in the embodiment, an annular stepped portion 55.59 is provided at a position facing the oil filling hole 52.53 on the bearing surface 54.58 of each sliding bearing 18°38.

It is possible to improve lubrication performance.

Note that the present invention is not limited to the embodiments described above. That is, the positions of the oil guide grooves 56 and 60 provided in the plain bearing 1838 are in the range of 240 to 290 degrees and in the range of 3
It is not limited to the 00 degree position, but taking misalignment into consideration, the position is 220 to 32 degrees on the sliding bearing 18 side.
It may be in the range of 5 degrees, and in the range of 190 to 310 degrees on the sliding bearing 38 side.

[Effects of the Invention] As described above, according to the present invention, the support performance and durability of a pair of sliding bearings can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a rotary compressor according to an embodiment of the present invention, FIG. 2 is a local cross-sectional view taken along line A-A in FIG. 1 and viewed in the direction of the arrow, and FIG. is B- in Figure 1
Local sectional view taken along line B and viewed in the direction of the arrow, No. 4
The figure is a vertical cross-sectional view of the rotary compression mechanism section taken at a different angle from that shown in Figure 1, and Figure 6 is a partially cutaway perspective view of the underbelly bearing installed near the motor. , 6th
The figure is a partially cutaway perspective view of a slide bearing located far from the motor, and FIG. 7 is a diagram for explaining the load applied to the slide bearing and the installation range of the oil guide groove specified by the present invention. , FIG. 8 to FIG. 10 are diagrams showing the experimental results for deriving the installation range of the oil guide groove. 1... Container, 2... Motor, 3... Rotor, 4...
··Axis of rotation. 5.6...Rotary compression mechanism 17...Lubricating oil, 9...
Temporary partition, 10.30...space, 11.31...cylinder. 12.32...B small part, 13.33...piston. 16.36...Blade, 18.38...Slide bearing. 19.39...Suction port, 22.42...Discharge port. 2343...Discharge valve, 51...Blade, 52.53.
...Oil filling hole, 54.58...Bearing surface, 55.59...
- Annular stepped portion, 56.60...Oil guide groove, 66...Suction chamber. 67...Compression chamber. Applicant's representative Patent attorney Takehiko Suzue @1 Figure Figure Figure Figure Figure Figure Figure Figure Whistle Figure 215e 335゜Tanzu Inou ○ Tanzu 1゜Town Drawing Procedure Amendment Band 1゜Indication of Case Patent Application 1986- No. 304640 2゜Name of the invention Rotary compressor 3゜Relationship with the person making the amendment case

Claims (4)

[Claims] (1) A cylinder, a rotating piston eccentrically arranged within the cylinder, and a rotating piston attached to the cylinder such that it is always in sliding contact with the outer circumferential surface of the rotating piston, dividing the inside of the cylinder into a suction chamber and a compression chamber. A rotary compression mechanism comprising two blades, a gas suction port communicating with the suction chamber, and a gas discharge port communicating with the compression chamber, arranged coaxially with the blades aligned in phase. a rotary shaft that commonly supports the rotary pistons of the rotary compression mechanisms with a phase difference of 180 degrees and is rotationally driven by a motor; A pair of sliding bearings that respectively support both protruding parts, an oil guide groove formed on the inner surface of each of these sliding bearings to move the supplied lubricating oil to the entire bearing surface, and an inlet of the oil guiding groove. In a rotary compressor comprising means for supplying lubricating oil, the oil guide groove formed in one of the pair of sliding bearings that is closer to the motor has a position of the blade at 0 degrees,
and 220 when based on the direction in which the rotating shaft rotates.
The oil guide groove is provided in the range of ~325 degrees, and is formed in the other sliding bearing that is far from the motor, when the position of the blade is 0 degrees and the direction in which the rotating shaft rotates is taken as a reference. A rotary compressor characterized in that it is installed in a range of 190 to 310 degrees. (2) The rotary compressor according to claim 1, wherein the rotating shaft is arranged with its axis line parallel to the direction of gravity. (3) The rotating shaft is formed hollow, and a mechanism for pumping up the lubricating oil is installed in the hollow part, and a part of the pumped lubricating oil is transferred to the entrance of the oil guide groove of the pair of sliding bearings. The rotary compressor according to claim 2, characterized in that the rotary compressor has a hole for supplying oil to the rotary compressor. (4) The rotary compressor according to claim 1, wherein the pair of sliding bearings has a groove-shaped portion on an inner circumferential surface that communicates with an entrance of the oil guide groove.