JP2568610B2 - Rotary compressor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary compressor used for a refrigeration cycle and the like, and more particularly to lubrication of a sliding portion such as a bearing.

2. Description of the Related Art A conventional configuration will be described with reference to FIGS. Reference numeral 1 denotes a closed casing, and 2 denotes an electric motor unit, which is connected via a shaft 3 to a machine unit main body 9 constituted by a cylinder 4, rollers 5, vanes 6, a main bearing 7, and an auxiliary bearing 8. The shaft 3 comprises a main shaft 3a, a sub shaft 3b, and a crank 3c.
Oil supply holes 3d, 3e, 3f are provided in 3a, the countershaft 3b, and the crank 3c, respectively, and a hole 3q is formed in the center of the shaft. 10 is a spring provided on the back of the vane. 11
Reference numeral denotes a compression chamber formed of a roller 5, a vane 6, a main bearing 7, and an auxiliary bearing 8 in the cylinder 4. Reference numeral 12 denotes a lubrication mechanism, which is a first passage communicating with a pump chamber 12a formed by the cylinder 4, the main bearing 7, the sub-bearing 8, and the closed casing 1 on the back side of the vane 6, and a lubricating oil 13 at the bottom of the closed casing 1. 14 and a second communication passage 16 formed in the sub bearing 8 and a cover 15 fixed to the sub bearing 8. Reference numeral 17 denotes a suction pipe, which communicates with the compression chamber 11 via the auxiliary bearing 8 and the cylinder 4. Reference numeral 18 denotes a discharge pipe, which is a closed casing 1
Open to the inside.

The operation of the compressor configured as described above will be described below. Refrigerant gas from a cooling system (not shown) is led through a suction pipe 17 and a compression chamber in a cylinder 4.
Reaches 11. The refrigerant gas that has reached the compression chamber is gradually compressed by the rotation motion of the shaft 3 accompanying the rotation of the electric motor unit 2 in the compression chamber 11 partitioned by the roller piston 5 fitted to the crank 3c of the shaft 3 and the vane 6. You. The compressed refrigerant gas is once discharged into the closed casing 1 and then discharged through the discharge pipe 18 to the cooling system.

Next, the flow of the lubricating oil 13 will be described. Lubricating oil 13
It is stored in the lower part of the closed casing 1. Shaft 3
The vane 6 reciprocates due to the movement of the roller 5 accompanying the rotation of. At this time, when the volume of the pump chamber 12a changes from small to large and large to small with the movement of the vane 6, or when the volume changes from small to large, the lubricating oil 13 Flows into the pump chamber 12a. Then, when the volume changes from large to small, the lubricating oil 13 in the pump chamber 12a reaches the shaft hole 3q from the pump chamber 12a via the second passage 16. However, at this time, the first lubricating oil 13 does not flow back through the first
The passage resistances of the passage 14 and the second passage 15 are set.
The lubricating oil that has reached the hole 3q of the shaft reaches the sliding surface from the oil supply holes 3d, 3e, and 3f by the rotation of the shaft 3, and the sliding portion of the main bearing 7 and the sub-bearing 8 with the shaft 3, the roller 5, After lubricating the sliding portion with the crank 3c, it collects in the lower part of the closed casing 1. Further, part of the high-pressure lubricating oil on the inner peripheral side of the roller 5 reaches the compression chamber 11 due to the differential pressure between the inner peripheral side of the roller 5 and the compression chamber 11 and mixes with the refrigerant to be discharged into the closed casing 1. Accumulate in

However, in the above configuration, the configuration between the shaft and the bearing, and between the crank and the roller of the shaft is a configuration of a dynamic pressure bearing, that is, a configuration of a bearing that generates dynamic pressure by a wedge effect. For example, when the shaft diameter is reduced or the bearing length is reduced, sufficient bearing load resistance cannot be maintained only by the effect of dynamic pressure, and eventually the diameter cannot be reduced. There is a problem that the sliding loss increases.

The present invention has been made to solve the above problems, and has an object to reduce the sliding loss by providing a bearing with sufficient load resistance even when the shaft is reduced in diameter or the bearing length is configured to be short. It is.

Means for Solving the Problems The present invention arranges a plurality of radial passages formed of a throttle and a pressure receiving portion in a bearing portion, and guides lubricating oil from an oil supply mechanism to the radial passages. is there.

According to the present invention, the lubricating oil supplied to the sliding surface from each of the plurality of radial passages with respect to minute eccentricity of the shaft center of the shaft in the bearing in addition to the conventional dynamic pressure effect by the above configuration. Is smaller in the passage in the direction in which the shaft is eccentric, and conversely increases in the anti-eccentric side. As a result, the static pressure obtained by subtracting the dynamic pressure due to the lubricating oil flowing by the oil supply pressure is the eccentric side of the shaft. , And on the contrary, it becomes lower on the anti-eccentric side of the shaft, and this differential pressure adds a static pressure effect that a force is generated to push the shaft toward the center of the bearing. Therefore, even when the shaft diameter becomes small or the bearing length becomes short, sufficient load resistance can be maintained, and sliding loss can be reduced more than before.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. The same parts as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted. The arrows in FIG. 2 indicate the flow of the lubricating oil. Reference numeral 19 denotes a shaft, which comprises a main shaft 19a, a sub shaft 19b, and a crank 19c as in the prior art. A hole 19d is formed in the center of the shaft 19. 20, 21, 22, 23, 24, and 25 are radial passages that are respectively opened in the main shaft 19a, the counter shaft 19b, and the crank 19c, and communicate the hole 19d and the sliding portion.
The radial passages 20, 21, 22, 23, 24, and 25 are throttles 20a, 21 respectively.
a, 22a, 23a, 24a, 25a and oil introduction portions 20b, 21b, 22b, 23b, 24b, 25b having an area facing the sliding portion.

In the above configuration, when operated, the refrigerant gas flowing from the suction pipe 17 is compressed and discharged from the discharge pipe 18 as in the conventional case.

Further, the lubricating oil 13 is supplied to the first passage 14
a to the hole 19d of the shaft through the second passage 16.
The lubricating oil 13 in the hole 19d passes through the radial passages 20, 21, 22, 23, 24, 25
Are supplied to the respective sliding parts via the. However, unlike the conventional case, for example, taking the main bearing 7 part as an example, the shaft
The load acting on 19, with respect to the bearing center O ₁ of the main bearing 7 when the center O ₂ of the main shaft 19a is eccentric, the clearance of the main shaft 19a and the main bearing 7 is wider in the radial passage 20, with radial passages 21 Narrows. Therefore, in the radial passages 20 and 21, 20
It is becomes possible to flow many lubricating oil, the oil inlet portion 20b which is obtained as a static pressure obtained by subtracting the dynamic pressure pressure P _V due to the lubricating oil flows from the supply pressure P _T, the pressure of the surrounding 21b are radial passages 21 P _S 21 on the side is higher than P _S 20 on the side of the radial passage 20. Thus by taking the oil introduction portion 20b acting of P _S 20 and P _S 21, the area of the 21b moderate, it is possible to generate a force that pushes back the shaft 19 in the center of the main bearing 7 by the pressure difference. Further, since lubricating oil is supplied between the main bearing 7 and the main shaft 19a, a dynamic pressure is generated as in the prior art in a place where the radial passages 20 and 21 are not provided. Can be. Therefore, the load-bearing capacity of the bearing can be improved more than before, and the diameter of the shaft can be reduced, so that the sliding loss can be reduced.

The throttles 20a, 21a, 22a, 23a, 24a, and 25a prevent lubricating oil from flowing back to the hole 19d of the shaft due to dynamic pressure or static pressure at the sliding portion.

In the present embodiment, the description has been given of the vane pump type oil supply mechanism. However, in the vane pump type, since the supply pressure of the lubricating oil is higher than in other systems, the present embodiment supplies the lubricating oil by a differential pressure. In this case, the most advantageous method is used. However, it goes without saying that other methods using springs or blades are effective as long as the pressure inside the closed casing is high.

In this embodiment, the case where the space and the radial passage are provided in the shaft has been described. However, it goes without saying that the same effect can be obtained even in the bearing side.

Effect of the Invention As is clear from the above description, the present invention provides a cylinder and
A main bearing and a sub-bearing fixed to both ends of the cylinder, a shaft rotatably housed in the main bearing and the sub-bearing and having a crank, a roller fitted to the crank of the shaft and eccentrically rotating in the cylinder, and a groove in the cylinder Mechanism body composed of a vane reciprocating inside and abutting on a roller, an oil supply mechanism connected to the machine body, a sliding portion between a main bearing and a sub bearing and a shaft, and a sliding portion between a crank and a roller. And a plurality of radial passages communicating with the space and the sliding portion and including a throttle and an oil introduction portion, so that the dynamic pressure and the static pressure are provided. And a bearing configuration utilizing both of them can be obtained, and there is an effect that the load resistance of the bearing can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a rotary compressor showing one embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a bearing section taken along line II-II 'of FIG. FIG. 3B is a cross-sectional view showing the flow and pressure of lubricating oil from the radial direction of the shaft, FIG. 3 is a cross-sectional view of a conventional rotary compressor, and FIG. FIG. 4 is a sectional view taken along line IV-IV ′ of FIG. 4 ... Cylinder, 5 ... Roller, 6 ... Vane, 7 ...
Main bearing, 8 ... Bearing bearing, 9 ... Mechanical part body, 12 ... Lubricating mechanism, 19 ... Shaft, 19d ... Hole, 20,21,22,23,24,25
... radial passages, 20a, 21a, 22a, 23a, 24a, 25a ... throttles, 20b, 21b, 22b, 23b, 24b, 25b ... oil introduction section.

Claims (1)

(57) [Claims] 1. A cylinder, a main bearing and a sub-bearing fixed to both ends of the cylinder, a shaft rotatably housed in the main bearing and the sub-bearing, having a crank, and fitted to a crank of the shaft. A mechanical unit main body composed of a roller eccentrically rotating in the cylinder, a vane reciprocating in the groove of the cylinder and abutting on the roller, an oil supply mechanism connected to the mechanical unit main body, the main bearing and the auxiliary A space provided near a sliding portion between a bearing and the shaft and a sliding portion between the crank and the roller and connected to an oil supply mechanism, a space communicating with the sliding portion, a throttle, and an oil introducing portion. Rotary compressor having a plurality of radial passages.