JP2010031732A - Rotary compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the efficiency of a compressor without increasing material cost from present cost by reducing leak loss while restraining friction resistance of a sliding surface of a roller end surface. <P>SOLUTION: A shallow spiral groove is provided on a roller inner surface part in a direction in which oil flows upward to rotation of a crankshaft. Leak quantity from the roller both end surfaces can be greatly reduced by a configuration in which section area of the spiral groove reduces toward the oil flow direction. Efficiency can be improved as compared to former compressors. Since sliding loss at the roller end surface is simultaneously reduced, reliability can be improved by inhibiting occurrence of wear, seizure and the like. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotary compressor used for an air conditioner, a refrigerator, a blower, a water heater, and the like.

  Conventionally, in refrigeration equipment and air conditioning equipment, a compressor that sucks in gas refrigerant evaporated in an evaporator, compresses it to the pressure necessary for condensation, and sends high-temperature and high-pressure gas refrigerant into the refrigerant circuit has been used. Has been. A rotary compressor is known as one of such compressors.

  For example, as shown in FIG. 8, the rotary compressor is one in which the electric motor 2 and the compression mechanism 3 are connected by a crankshaft 31 and housed in the hermetic container 1, and the compression mechanism 3 includes the cylinder 30 and the cylinder 30. A compression chamber 39 formed by an upper bearing 34 and a lower bearing 35 that close both end surfaces of the cylinder 30, and an eccentric portion 31 a of the crankshaft 31 supported by the upper bearing 34 and the lower bearing 35 in the compression chamber 39. The roller 32 is fitted, and a vane 33 that reciprocates following the eccentric rotation of the outer periphery of the roller 32 to partition the inside of the compression chamber 39 into a low pressure portion and a high pressure portion. The crankshaft 31 is provided with an oil hole 41 in the axial line portion, and oil supply holes 42 and 43 communicating with the oil hole 41 are provided in the wall portions for the upper bearing and the lower bearing, respectively. An oil supply hole 44 communicating with the oil hole 41 is provided in the wall portion of the crankshaft 31 with respect to the eccentric portion 31a, and an oil groove 45 is formed in the outer peripheral portion. On the other hand, the suction port 40 for sucking gas toward the low pressure portion in the compression chamber 39 is opened in the cylinder 30, and the upper bearing 34 has a high pressure portion formed by turning from the low pressure portion in the compression chamber 39. A discharge port 38 for discharging gas is opened, and the roller 32 is accommodated in a compression chamber 39 formed by the cylinder 30 being closed from above and below by an upper bearing 34 and a lower bearing 35.

  The discharge port 38 is formed as a circular hole passing through the upper bearing 34 in plan view, and a discharge valve 36 is provided on the upper surface of the discharge port 38 that is released when a pressure of a predetermined size or more is applied. And a cup muffler 37 that covers the discharge valve 36.

  On the low pressure portion side, the sliding contact portion of the roller 32 passes through the suction port 40 and gradually moves away from the suction chamber, and sucks gas from the suction port 40 into the suction chamber. On the other hand, on the high pressure portion side, the sliding portion of the roller 32 approaches the discharge port 38 while gradually reducing the compression chamber 39, and when the pressure is compressed to a predetermined pressure or higher, the discharge valve 36 opens and the gas is discharged from the discharge port 38. Is discharged from the cup muffler 37 into the sealed container 1.

  The outer periphery of the compression mechanism is a high-pressure discharge space 52. On the other hand, there is a space 46 between the upper end surface of the eccentric portion 31a and the inner peripheral surface of the upper bearing 34 and the roller 32, and between the lower end surface of the eccentric portion 31a, the lower bearing 35 and the inner peripheral surface of the roller 32. Has a space 47. Oil leaks into the spaces 46 and 47 from the oil hole 41 through the oil supply holes 42 and 43. The spaces 46 and 47 are almost always higher than the pressure inside the compression chamber 39.

  On the other hand, the height of the cylinder 30 must be set slightly larger than the height of the roller 32 so that the roller 32 can slide inside. As a result, the end face of the roller 32, the upper bearing 34, and the lower bearing There is a gap between the end face of 35. Therefore, oil leaks from the spaces 46 and 47 to the compression chamber 39 through this gap.

In general, refrigeration oil dissolves refrigerant, and its solubility increases as the pressure increases. Therefore, when oil leaks from the high-pressure spaces 46 and 47 to the low-pressure compression chamber 39, the solubility of the refrigerant decreases, so that the dissolved refrigerant evaporates. This eventually results in a gas leak and contributes to a reduction in compressor efficiency.

  Therefore, by reducing the difference between the height of the cylinder 30 and the height of the roller 32, gas leakage can be suppressed, but sliding of the end face of the roller 32 becomes severe, and problems such as wear and seizure occur. On the other hand, by increasing the difference between the height of the cylinder 30 and the height of the roller 32, wear and seizure are eliminated, but the efficiency of the compressor is reduced due to leakage.

Therefore, conventionally, it has been required to reduce leakage from the gap between the end faces of the roller 32 and to reduce sliding. FIG. 7 shows a conventional rotary compressor described in Patent Document 1. In FIG. As shown in FIG. 7, the lower end of the crankshaft thrust bearing that transmits the rotational force of the electric motor to the compression section is supported by the lower bearing and supported, and the lower end is immersed in the lubricating oil stored on the bottom surface of the sealed container. In the rotary compressor in which the lubricating oil is pumped up through the hollow part of the crankshaft as it rotates, and the pumped lubricating oil is supplied to each part, the lower bearing is made of ferrous metal, and the crankshaft thrust bearing Further, an impregnated and sintered sliding member in which any one of PEEK resin, polyimide resin and polyamideimide resin mixed with solid lubricant is mixed on the bimetal which has been sintered together, or a combination thereof, is provided. Thereby, even if the sliding area is small and it is difficult to form an oil film, self-lubricating action reduces sliding loss and wear, the roller floats up by the sliding member, and automatically adjusts to a uniform gap between the top and bottom, The leakage loss was reduced.
JP 2002-195180 A

  In recent years, since higher efficiency of an air conditioner or the like that circulates refrigerant using a compressor is desired, it is important to further improve the efficiency of the compressor in order to achieve these. In the structure of the conventional rotary compressor described above, the processing method and accuracy cannot be easily maintained, and the sliding surface frictional resistance of the sliding member may increase due to temperature change. Moreover, since a sliding member is newly added, the material cost of a compressor will also become high.

  Therefore, the present invention has been made in view of the above circumstances, and reduces the leakage loss while suppressing the frictional resistance of the sliding surface of the roller end surface, and increases the efficiency of the compressor without increasing the material cost. It aims to plan.

  In order to solve the above-described conventional problems, a rotary compressor according to the present invention includes an electric motor and a compression mechanism connected by a crankshaft and housed in a sealed container. The compression mechanism includes a cylinder, a cylinder, A compression chamber formed by an upper bearing and a lower bearing for closing both end surfaces of the roller, a roller fitted in an eccentric part of a crankshaft provided in the cylinder, and provided in the cylinder following the eccentric rotation of the roller. In a rotary compressor comprising a vane that reciprocates in the slot and partitions the compression chamber into a low pressure portion and a high pressure portion, oil is applied to the inner surface of the roller that slides with the eccentric portion of the crankshaft against the rotation of the crankshaft. A shallow spiral groove is provided in the upward flow direction, and the groove cross-sectional area of the spiral groove is reduced in the oil flow direction.

  With this configuration, it is possible to greatly reduce the amount of leakage from both end faces of the roller, and the efficiency can be improved as compared with a conventional compressor. At the same time, since the sliding loss of the roller end face is reduced, the occurrence of wear and seizure can be suppressed, and the reliability can be improved.

The rotary compressor of the present invention applies a force in the direction of floating the roller and makes the gap between the upper and lower end surfaces of the roller uniform, thereby greatly reducing the amount of leakage from both end surfaces of the roller. The efficiency can be improved compared to the machine. At the same time, since the sliding loss of the roller end face is reduced, the occurrence of wear and seizure can be suppressed, and the reliability can be improved.

  According to a first aspect of the present invention, an electric motor and a compression mechanism are connected by a crankshaft and stored in a sealed container. The compression mechanism includes a cylinder, an upper bearing and a lower bearing that close both end surfaces of the cylinder. A compression chamber formed in the cylinder, a roller fitted in an eccentric portion of a crankshaft provided in the cylinder, and a reciprocating motion in a slot provided in the cylinder following the eccentric rotation of the roller to thereby form a compression chamber. In a rotary compressor comprising a vane that divides a low-pressure part and a high-pressure part, a shallow spiral groove is provided on the inner surface of the roller in a direction in which oil flows upward with respect to rotation of the crankshaft, and the spiral groove is directed toward the direction of oil flow The groove cross-sectional area is reduced. As a result, as the oil flows through the spiral groove, the pressure of the oil increases, so that a force for pushing the roller upward from below is generated. Therefore, since the roller floats in the direction in which the gap between both end faces of the roller is made uniform, the amount of leakage from the both end faces of the roller can be greatly reduced, and efficiency can be improved as compared with the conventional compressor. . Since the sliding loss of the roller end face is reduced, the occurrence of wear and seizure can be suppressed, and the reliability can be improved. In addition, since the upward force can be adjusted freely according to the reduction amount of the cross-sectional area, by selecting a reduction amount of the cross-sectional area that balances with the weight of the roller, the gaps on both end faces of the roller are made more uniform. It becomes possible to reduce leakage loss.

  The second invention is characterized in that the angle of the upper end opening is made larger than the angle of the lower end opening of the spiral groove with respect to the axial direction of the crankshaft. As a result, the oil entering from the lower end opening of the roller inner surface is bent from the axial direction to the end face as the oil flows to the upper end opening. As a reaction force of this oil flow, the roller receives an upward component force. Therefore, since the roller floats in the direction in which the gap between both end faces of the roller is made uniform, the amount of leakage from the both end faces of the roller can be greatly reduced, and efficiency can be improved as compared with the conventional compressor. . Since the sliding loss of the roller end face is reduced, the occurrence of wear and seizure can be suppressed, and the reliability can be improved. In addition, since the upward force can be adjusted freely according to the angle of the lower end opening and the angle of the upper end opening, by selecting an angle that balances with the weight of the roller, the gap between both end faces of the roller is made more uniform. And leakage loss can be reduced.

  The third invention is characterized in that the spiral groove is closed in the sliding portion between the roller and the crankshaft. As a result, the oil flow is blocked, so that the pressure at the blocking portion increases, and a force is generated that pushes the roller upward from below. Therefore, since the roller floats in the direction in which the gap between both end faces of the roller is made uniform, the amount of leakage from the both end faces of the roller can be greatly reduced, and efficiency can be improved as compared with the conventional compressor. .

  In particular, the fourth invention is characterized in that a plurality of spiral grooves are provided in the rotary compressors of the first to third inventions. This makes it possible to apply an upward force to the roller in a balanced manner by arranging the spiral grooves evenly compared to when there is only one spiral groove, and it is possible to suppress the inclination of the roller and the like. . Therefore, the gas can be prevented from leaking from the high pressure to the low pressure caused by the inclination of the roller with respect to the inner surface of the cylinder and the gap between the inner surface of the cylinder and the outer periphery of the roller becoming larger, leading to an improvement in the efficiency of the compressor.

A fifth invention is, in particular, in the rotary compressor of the first to fourth invention, the use of CO ₂ as the working fluid, in particular, the pressure difference is large, even in the leakage loss is large CO _2, more effectively High efficiency can be achieved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a rotary compressor according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of the compression mechanism portion in the first embodiment of the present invention. 1 and 2, the rotary compressor is one in which the electric motor 2 and the compression mechanism 3 are connected by a crankshaft 31 and housed in the sealed container 1. The compression mechanism 3 includes a cylinder 30 and the cylinder 30. A compression chamber 39 formed by an upper bearing 34 and a lower bearing 35 that close both end surfaces of the upper shaft 34 and an eccentric portion 31 a of the crankshaft 31 supported by the upper bearing 34 and the lower bearing 35 in the compression chamber 39. And a vane 33 that abuts the outer periphery of the roller 32 and reciprocates following the eccentric rotation of the roller 32 to partition the compression chamber 39 into a low pressure portion and a high pressure portion. The crankshaft 31 is provided with an oil hole 41 in the axial line portion, and oil supply holes 42 and 43 communicating with the oil hole 41 are provided in the wall portions for the upper bearing and the lower bearing, respectively. An oil supply hole 44 communicating with the oil hole 41 is provided in the wall portion of the crankshaft 31 with respect to the eccentric portion 31a, and an oil groove 45 is formed in the outer peripheral portion. On the other hand, the suction port 40 for sucking gas toward the low pressure portion in the compression chamber 39 is opened in the cylinder 30, and the upper bearing 34 has a high pressure portion formed by turning from the low pressure portion in the compression chamber 39. A discharge port 38 for discharging gas is opened, and the roller 32 is accommodated in a compression chamber 39 formed by the cylinder 30 being closed from above and below by an upper bearing 34 and a lower bearing 35.

  The discharge port 38 is formed as a circular hole passing through the upper bearing 34 in plan view, and a discharge valve 36 is provided on the upper surface of the discharge port 38 that is released when a pressure of a predetermined size or more is applied. And a cup muffler 37 that covers the discharge valve 36.

  On the low pressure portion side, the sliding contact portion of the roller 32 passes through the suction port 40 and gradually moves away from the suction chamber, and sucks gas from the suction port 40 into the suction chamber. On the other hand, on the high pressure portion side, the sliding portion of the roller 32 approaches the discharge port 38 while gradually reducing the compression chamber 39, and when the pressure is compressed to a predetermined pressure or higher, the discharge valve 36 opens and the gas is discharged from the discharge port 38. Is discharged from the cup muffler 37 into the sealed container 1.

  The outer periphery of the compression mechanism is a high-pressure discharge space 52. On the other hand, there is a space 46 between the upper end surface of the eccentric portion 31a and the inner peripheral surface of the upper bearing 34 and the roller 32, and between the lower end surface of the eccentric portion 31a, the lower bearing 35 and the inner peripheral surface of the roller 32. Has a space 47. Oil leaks into the spaces 46 and 47 from the oil hole 41 through the oil supply holes 42 and 43. The spaces 46 and 47 are almost always higher than the pressure inside the compression chamber 39.

  On the other hand, the height of the cylinder 30 must be set slightly larger than the height of the roller 32 so that the roller 32 can slide inside. As a result, the end face of the roller 32, the upper bearing 34, and the lower bearing There is a gap between the end face of 35. Therefore, oil leaks from the spaces 46 and 47 to the compression chamber 39 through this gap.

  In the rotary compressor configured as described above, as shown in FIG. 3, a shallow spiral groove 48 is provided on the inner surface of the roller 32 in the direction in which oil flows upward with respect to the rotation of the crankshaft 31. I am doing.

Here, as shown in FIG. 4, since the spiral groove 48 reduces the groove cross-sectional area in the oil flowing direction, the oil pressure increases as the oil flows through the spiral groove 48. A force is generated that pushes 32 upward from the bottom. Therefore, since the roller 32 floats in the direction in which the clearance between both end faces of the roller 32 is made uniform, the amount of leakage from both end faces of the roller 32 can be greatly reduced, and the efficiency is improved as compared with the conventional compressor. I can do it. Since the sliding loss of the end face of the roller 32 is reduced, the occurrence of wear and seizure can be suppressed and the reliability can be improved. Further, since the upward force can be freely adjusted in accordance with the reduction amount of the cross-sectional area, the gap between the both end faces of the roller 32 is made more uniform by selecting the reduction amount of the cross-sectional area that balances with the weight of the roller 32. And leakage loss can be reduced.

  Further, as shown in FIG. 5, a shallow spiral groove is provided on the inner surface of the roller 32 in a direction in which oil flows upward with respect to the rotation of the crankshaft 31, and the angle of the lower end opening of the spiral groove with respect to the axial direction of the crankshaft 31. The angle (θ2) of the upper end opening is made larger than (θ1). As a result, the oil entering from the lower end opening of the inner surface of the roller 32 is bent from the axial direction to the end face as the upper end opening flows. As a reaction force of the oil flow, the roller 32 receives an upward component force. Therefore, since the roller 32 floats in a direction in which the clearance between both end faces of the roller 32 is made uniform, the amount of leakage from both end faces of the roller 32 can be greatly reduced, and the efficiency is improved as compared with the conventional compressor. I can do it. Since the sliding loss of the end face of the roller 32 is reduced, the occurrence of wear and seizure can be suppressed, and the reliability can be improved. In addition, since the upward force can be freely adjusted according to the angle of the lower end opening and the angle of the upper end opening, by selecting an angle that balances with the own weight of the roller 32, the gap between both end faces of the roller 32 is reduced. Furthermore, it becomes possible to make uniform and to reduce leakage loss.

  Further, as shown in FIG. 6, a shallow spiral groove 48 is provided on the inner surface of the roller 32 in the direction in which oil flows upward with respect to the rotation of the crankshaft 31, and the spiral groove 48 is formed in the sliding portion between the roller 32 and the crankshaft 31. It is characterized by being blocked. As a result, the flow of oil is blocked, so that the pressure at the blocking portion increases, and a force that pushes the roller 32 upward from below is generated. Therefore, since the roller 32 floats in a direction in which the clearance between both end faces of the roller 32 is made uniform, the amount of leakage from both end faces of the roller 32 can be greatly reduced, and the efficiency is improved as compared with the conventional compressor. I can do it.

  Further, by providing a plurality of spiral grooves 48, it becomes possible to apply an upward force to the roller 32 in a balanced manner by arranging the spiral grooves 48 evenly compared to when there is only one spiral groove 48. The inclination of the roller 32 can be suppressed. As a result, the roller 32 is inclined with respect to the inner surface of the cylinder 30 and the gap between the inner surface of the cylinder 30 and the outer periphery of the roller 32 is increased, so that leakage of gas from the high pressure to the low pressure can be suppressed.

Further, by using CO ₂ as the working fluid, fluid leakage at the upper and lower end surfaces of the roller 32 can be reduced, and even in CO ₂ where the differential pressure is large and the influence of leakage loss and sliding loss is large, the roller 32 can be reduced. Since it is possible to avoid the force that strongly presses down, it is possible to increase the efficiency more effectively.

As described above, the rotary compressor according to the present invention can suppress deterioration of reliability such as wear and seizure, and simultaneously reduce leakage loss and sliding loss, thereby improving the efficiency of the compressor. It becomes. Thereby, in addition to the compressor for an air conditioner using an HFC refrigerant or an HCFC refrigerant, the present invention can be applied to uses such as an air conditioner using a natural refrigerant CO ₂ and a heat pump type hot water heater.

The longitudinal cross-sectional view of the rotary compressor in Embodiment 1 of this invention The expanded sectional view of the compression mechanism part of the rotary compressor in Embodiment 1 of this invention The perspective view which shows the relationship between the spiral groove of the roller in Embodiment 1 of this invention, and a crankshaft. Schematic diagram in which the spiral groove of the roller according to Embodiment 1 of the present invention shrinks toward the opening. The schematic diagram which made the angle of the upper-end opening part larger than the angle of the lower-end opening part of a spiral groove with respect to the axial direction of the crankshaft in Embodiment 1 of this invention Schematic diagram in which the spiral groove of the roller in Embodiment 1 of the present invention is closed in the sliding portion of the roller and the crankshaft Main part sectional drawing which shows the conventional rotary compressor Longitudinal sectional view of a conventional rotary compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Electric motor 3 Compression mechanism part 5 Upper shell 6 Oil reservoir 22 Stator 24 Rotor 26 Air gap 28 Notch part 30 Cylinder 30a Cylinder inner wall 31 Crankshaft 31a Eccentric part 32 Roller 32a Roller outer periphery 32b Roller inner periphery 33 Vane 34 Upper bearing 35 Lower bearing 36 Discharge valve 37 Cup muffler 38 Discharge port 39 Compression chamber 40 Suction port 41 Oil hole 42 Oil hole 43 Oil hole 44 Oil hole 45 Oil groove 46 Space 47 Space 48 Spiral groove 51 Refrigerant discharge pipe 52 Discharge space 100 Thrust bearing 101 Sliding member

Claims (5)

An electric motor and a compression mechanism portion are connected by a crankshaft and housed in a hermetically sealed container, and the compression mechanism portion is fitted to a cylinder and an eccentric portion of the crankshaft provided in the cylinder. A rotary that includes a roller, a vane that reciprocates in a slot provided in the cylinder following the eccentric rotation of the roller, and an upper bearing and a lower bearing that close both ends of the cylinder and support the crankshaft. In the compressor, the inner surface of the roller is provided with a shallow spiral groove in a direction in which oil flows upward with respect to rotation of the crankshaft, and the spiral groove has a groove cross-sectional area that decreases in the direction of oil flow. A featured rotary compressor. The rotary compressor according to claim 1, wherein the angle of the upper end opening is larger than the angle of the lower end opening of the spiral groove with respect to the axial direction of the crankshaft. The rotary compressor according to claim 1, wherein the spiral groove is closed in a sliding portion between the roller and the crankshaft. The rotary compressor according to any one of claims 1 to 3, wherein a plurality of spiral grooves are provided. Rotary compressor according to any one of claims 1 to 4, characterized by using the CO ₂ is high-pressure refrigerant as a working fluid.