JP2011174407A - Scroll fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll fluid machine actualizing a cost reduction, common use of components and speeding-up of development to reduce the size and increase the capacity of the scroll fluid machine while solving problems resulting from the deflection and deformation of a crank shaft. <P>SOLUTION: In the scroll fluid machine, a crank pin 12 whose axis is eccentric by a predetermined size is provided at one end of a driving shaft 11 rotatably supported via a bearing member, and a turning scroll member is connected to the outer periphery of the crank pin 12 via a drive bush and/or a turning bearing in a turn-driven manner. At least one circumferential groove 29 is provided around the crank pin 12. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a scroll fluid machine that can be widely used in compressors, pumps, expanders, and the like.

  The scroll fluid machine includes a fluid intake / exhaust mechanism including at least a pair of a fixed scroll member and a turning scroll member. The orbiting scroll member constituting the fluid intake / exhaust mechanism is connected to a crank pin provided at one end of a crank shaft rotatably supported on the housing side via a bearing member via a drive bush and / or an orbiting bearing. It is connected and is configured to be driven to rotate by rotation of the crankshaft.

  In such a scroll fluid machine, a crankshaft that is rotatably supported at two upper and lower positions by a main bearing and a sub-bearing across an electric motor receives a radial force due to a compressive load or the like. Since the crankshaft has a cantilever structure with respect to the main bearing and the sub-bearing, the crankshaft is deformed flexibly between the main bearing and the sub-bearing, and the one-side contact mainly occurs in the sub-bearing. As a result, it is known that the local surface pressure increases abnormally on the bearing surface, causing metal transfer to the shaft, deterioration of the roughness of the shaft, abnormal wear, seizure, and the like.

  Therefore, in order to relieve the one-side contact in the auxiliary bearing caused by the bending and deformation of the crankshaft, Patent Document 1 discloses that one end portion of the crankshaft supported by the auxiliary bearing has a minute convex barrel shape or a minute amount. A taper shape having an inclination angle is presented. Japanese Patent Application Laid-Open No. H10-228667 proposes a sub-bearing provided with an annular groove or a thin wall portion to reduce the rigidity of the bearing or to provide a crowning on the bearing surface.

Japanese Patent No. 3154623 JP 2003-206872 A

  However, in those described in Patent Documents 1 and 2 above, against abnormal wear, seizure, and the like caused by abnormal increase in local surface pressure due to a single contact in the sub-bearing supporting the crankshaft. Is effective, but requires a significant structural change in structure, and such a structure has a problem that the influence on the cost is unavoidable from the machining surface. Furthermore, according to the above configuration, it is effective for bending deformation of the entire crankshaft, but against a single contact between the crankpin and a drive bush and / or a slewing bearing fitted to the crankpin. However, there is a problem that no effect is obtained.

  In particular, in recent years, there is a high need for a small size and a large capacity for a scroll fluid machine due to high speed, etc., and various problems due to bending deformation of the crankshaft are more likely to occur. It is a problem how to solve the above-mentioned problems related to the above, and to reduce costs, share parts and speed up development.

  The present invention has been made in view of such circumstances, and can solve one of the problems caused by the bending deformation of the crankshaft. At the same time, the cost of the scroll fluid machine can be reduced in size and capacity. It is an object of the present invention to provide a scroll fluid machine capable of sharing parts and speeding up development.

In order to solve the above problems, the scroll fluid machine of the present invention employs the following means.
That is, the scroll fluid machine according to the present invention is provided with a crank pin whose shaft center is eccentric by a predetermined dimension at one end of a drive shaft that is rotatably supported via a bearing member. In the scroll fluid machine in which the orbiting scroll member is connected so as to be capable of orbiting drive via the drive bush and / or the orbiting bearing, at least one circumferential groove is provided around the pin of the crank pin. It is characterized by.

  According to the present invention, the shaft center is eccentrically provided by a predetermined dimension at one end of the drive shaft that is rotatably supported via the bearing member, and the orbiting scroll member is orbitally driven via the drive bush and / or the orbiting bearing. Since at least one circumferential groove is provided around the pins of the crank pins that are connected to each other, the drive shaft including the crank pins may cause a radial force due to a gas pressure load, etc. Even if a moment is applied, the rigidity of the crank pin is reduced by providing the circumferential groove, and the flexibility is increased and the bending becomes easy to be deformed. As a result, the crank pin and the drive bush and / or the slewing bearing and the crank pin are It is possible to reduce the local surface pressure due to the contact of each piece. Accordingly, metal transfer to the shaft, deterioration of the roughness of the shaft, abnormal wear, seizure, etc. can be prevented, and the quality and reliability of the product can be improved. In addition, when the scroll fluid machine is reduced in size and capacity, the drive shaft can be shared by the presence or absence of a circumferential groove, so that cost reduction and development speed can be realized. In addition, since the configuration is such that only a groove is provided around the crankpin, it is only necessary to process one or a plurality of grooves at the time of lathe processing, the processing is easy, and there is no need to change the basic shape on the bearing side. Can be implemented.

  Furthermore, the scroll fluid machine according to the present invention is characterized in that, in the above scroll fluid machine, the circumferential groove is an arc-shaped concave groove.

  According to the present invention, since the circumferential groove is an arc-shaped concave groove, stress concentration in the circumferential groove can be reduced. Therefore, the required shaft strength can be ensured while reducing the rigidity of the crankpin, and the drive shaft can be shared when the scroll fluid machine is reduced in size and capacity.

  Furthermore, the scroll fluid machine according to the present invention is characterized in that, in any of the scroll fluid machines described above, the circumferential groove is provided at a base side of the crank pin.

  According to the present invention, since the circumferential groove is provided on the base side of the crankpin, the gas pressure load from the side of the orbiting scroll member connected to the tip side of the crankpin, the overturning moment, etc. The crankpin can be effectively bent and deformed from the root side. As a result, the contact between the crank pin and the drive bush and / or the slewing bearing is reliably reduced, and the local surface pressure is effectively reduced to prevent deterioration of shaft roughness, abnormal wear, seizure, etc. Can do.

  Furthermore, in the scroll fluid machine of the present invention, in any one of the above scroll fluid machines, the circumferential groove is provided at a base side of the crankpin and not on the orbiting bearing. Features.

  According to the present invention, since the circumferential groove is provided at a position on the root side of the crankpin and not on the orbiting bearing, the gas from the orbiting scroll member connected to the tip end side of the crankpin is provided. The crankpin can be flexed and deformed effectively against pressure load, overturning moment, etc., and the oil film breaks on the sliding surface between the crankpin and the drive bush and / or the slewing bearing via the circumferential groove. Can be prevented. Accordingly, not only the contact between the crankpin and the drive bush and / or the slewing bearing can be eased, the local surface pressure can be effectively reduced, but also the reliability of lubrication around the crankpin is ensured. be able to.

  According to the present invention, even if the drive shaft including the crank pin is subjected to a radial force due to a gas pressure load or the like or a tipping moment of the orbiting scroll member, the rigidity is reduced due to the provision of the circumferential groove in the crank pin. As a result of increasing flexibility and facilitating bending deformation, local surface pressure due to contact between the crank pin and the drive bush and / or the slewing bearing and the crank pin can be reduced, so that metal transfer to the shaft, shaft Roughness deterioration, abnormal wear, seizure, etc. can be prevented, and product quality and reliability can be improved. In addition, when the scroll fluid machine is reduced in size and capacity, the drive shaft can be shared by the presence or absence of a circumferential groove, so that cost reduction and development speed can be realized. In addition, since the configuration is such that only a groove is provided around the crankpin, it is only necessary to process one or a plurality of grooves at the time of lathe processing, the processing is easy, and there is no need to change the basic shape on the bearing side. Can be implemented.

1 is a longitudinal sectional view of a scroll fluid machine (sealed electric scroll compressor) according to an embodiment of the present invention. It is a side view of the drive shaft (crankshaft) of the scroll fluid machine shown in FIG. FIG. 3 is a perspective view (A) and a partially enlarged view (B) of the crankshaft side of the drive shaft shown in FIG. 2.

Embodiments according to the present invention will be described below with reference to FIGS. 1 to 3.
FIG. 1 shows a longitudinal sectional view of a scroll fluid machine according to an embodiment of the present invention. In the present embodiment, an example of the scroll fluid machine will be described using the hermetic electric scroll compressor 1 as an example, but the present invention is not limited to this.
The hermetic electric scroll compressor 1 includes a hermetic housing 2 that is made of a steel plate and has a bottom shape that is long in the vertical direction. The upper portion of the sealed housing 2 is sealed by a discharge cover 3 and an upper cover 4, and a discharge chamber 5 is formed between the discharge cover 3 and the upper cover 4.

  An upper bearing member (frame member) 6 is fixed in the upper portion of the hermetic housing 2, and a scroll compression mechanism 7 is installed via the upper bearing member 6, and a stator 8 and a rotor 9 are disposed in the lower portion thereof. The electric motor 10 consisting of the following is installed by fixing the stator 8 to the hermetic housing 2. A drive shaft (crank shaft) 11 is fixed to the rotor 9 of the electric motor 10, and a crank pin 12 whose shaft center is eccentric by a predetermined dimension is provided at the upper end of the drive shaft 11. The scroll compression mechanism 7 can be driven by connecting the crank pin 12 to the scroll compression mechanism 7.

  The drive shaft (crankshaft) 11 is supported by a journal lower bearing 13 whose upper portion is rotatably supported by the journal bearing portion 6A of the upper bearing member 6 and whose lower end portion is provided at a lower portion of the hermetic housing 2. It is supported freely. As is well known, a positive displacement oil pump 14 is provided between the lower bearing 13 and the lower end of the drive shaft 11, and the lubricating oil 15 filled in the bottom of the hermetic housing 2 is passed through the suction pipe 16. And is discharged into an oil supply hole 17 formed in the drive shaft 11 along the axial direction. The lubricating oil 15 is supplied to required portions such as the upper bearing member 6, the scroll compression mechanism 7, and the lower bearing 13 through the oil supply hole 17.

  The scroll compression mechanism 7 includes the upper bearing member 6 as one of the structural parts, and is slidable on a fixed scroll member 18 fixedly installed on the upper bearing member 6 and a thrust bearing portion 6B of the upper bearing member 6. The revolving scroll member 19 that is supported and meshed with the fixed scroll member 18 to form the compression chamber 20 is interposed between the upper bearing member 6 and the revolving scroll member 19, and prevents the revolving scroll member 19 from rotating. In addition, the rotation preventing mechanism 21 such as an Oldham ring that allows a revolving orbiting motion is interposed between the crank pin 12 of the drive shaft 11 and the rear boss of the orbiting scroll member 19. A drive bush 22 for transmitting rotational force and a slewing bearing (needle bearing) 23, and the center portion of the end plate of the fixed scroll member 18 is a disc. It is installed on the upper bearing member 6 in the connected state Yajikaba 3.

  The scroll compression mechanism 7 sucks the refrigerant gas sucked into the sealed housing 2 (low-pressure housing) through the suction pipe 24 into the compression chamber 20 from the suction port 25 opened in the sealed housing 2, and the high temperature. Compress to high pressure gas. This compressed gas is discharged into the discharge chamber 5 through the discharge port 26 provided in the center of the fixed scroll member 18 and the discharge valve 27 provided in the discharge cover 3, and is further connected to the discharge chamber 5. It is sent to the outside of the compressor through the discharge pipe 28.

  By this compression operation, the drive shaft 11 is loaded with a compression load or a load due to the overturning moment acting on the orbiting scroll member 19, and the crank pin 12 and the drive shaft 11 are bent and deformed. In the present embodiment, as shown in FIGS. 2 and 3, in order to mitigate an abnormal increase in local surface pressure due to a single contact within the drive bush 22 and / or the slewing bearing 23 caused by the bending deformation of the crank pin 12. Further, by providing a circumferential groove 29 around the pin on the base side of the crankpin 12, the rigidity of the crankpin 12 is lowered and the flexibility is increased.

  The number of grooves or the depth of the circumferential groove 29 is adjusted so that optimum rigidity can be obtained depending on the application model. Further, it is desirable that the circumferential groove 29 is provided at a position on the base side of the crankpin and not on the drive bush 22 and / or the slewing bearing 23. Particularly, the cross-sectional shape of the groove is a reduction in shaft strength due to stress concentration. In order to avoid this, as shown in FIG.

With the configuration described above, according to the present embodiment, the following operational effects can be obtained.
When the electric motor 10 is rotationally driven, the drive shaft 11 is rotated together with the rotation of the rotor 9, and the orbiting scroll member 19 connected to the crank pin 12 is prevented from rotating by the rotation preventing mechanism 21, and the fixed scroll member. 18 is revolved and rotated. By driving the scroll compression mechanism 7, the refrigerant gas sucked into the sealed housing 2 through the suction pipe 24 is sucked into the compression chamber 20 through the suction port 25 opened in the sealed housing 2. The compression chamber 20 is reduced in volume as it moves from the outer peripheral side to the center side, and compresses the refrigerant gas during this time. The compressed high-temperature and high-pressure refrigerant gas is discharged into the discharge chamber 5 through the discharge port 25 and the discharge valve 26 provided in the central portion of the fixed scroll member 18, and is discharged to the outside of the compressor through the discharge pipe 27. Is sent to.

  When the scroll compression mechanism 7 performs the compression action as described above, the radial force due to the compression load, the force due to the overturning moment acting on the orbiting scroll member 19, etc. are applied to the crank pin via the drive bush 22 and / or the orbiting bearing 23. 12 and the drive shaft 11 are loaded. As a result, the crankpin 12 and the drive shaft 11 are bent and deformed, and one-sided contact occurs between the crankpin 12 and the drive bush 22 and / or the slewing bearing 23.

  However, according to the present embodiment, the circumferential groove 29 is provided on the base side of the crankpin 12 to which the drive bush 22 and / or the slewing bearing 23 are fitted, and the rigidity of the crankpin 12 is reduced to be flexible. Therefore, it is possible to mitigate an abnormal increase in local surface pressure due to a single contact between the crankpin 12 and the drive bush 22 and / or the slewing bearing 23.

  Accordingly, it is possible to prevent metal transfer to the shaft, deterioration of the roughness of the shaft, abnormal wear, burn-in, and the like, and improve the quality and reliability of the product. In addition, when the scroll fluid machine 1 is reduced in size and capacity, the drive shaft 11 can be shared by the presence / absence of the circumferential groove 29, so that cost reduction and development speed can be realized. Furthermore, since only the groove 29 is provided around the crankpin 12, it is only necessary to process the groove 29 at one or several places during lathe processing, the processing is extremely easy, and there is no need to change the basic shape on the bearing side. Therefore, it can be easily implemented.

  In particular, in the scroll compressor 1, the crankpin 12 is usually connected to a boss portion provided on the back surface of the orbiting scroll member 19 via the drive bush 22 and / or the orbiting bearing 23. Since the correspondence on the side is substantially difficult, the present embodiment that can cope on the shaft side is effective. Further, since the circumferential groove 29 is an arc-shaped concave groove, there is no concentration of stress in the circumferential groove 29. Therefore, the required axial strength can be sufficiently obtained while reducing the rigidity of the crankpin. Therefore, even when the scroll fluid machine 1 is reduced in size and capacity, the drive shaft 11 can be shared.

  Furthermore, according to the present embodiment, the circumferential groove 29 is provided at a position on the root side of the crankpin 12 and at an axial position not on the drive bush 22 and / or the swing bearing 23. For this reason, the crankpin 12 can be effectively bent and deformed against the compressive load, the force of the overturning moment, etc. from the orbiting scroll member 19 connected to the tip end side of the crankpin 12, and the circumferential direction Oil film breakage on the sliding surface between the crank pin 12 and the drive bush 22 and / or the slewing bearing 23 via the groove 29 can be prevented.

  As a result, not only can the contact between the crankpin 12 and the drive bush 22 and / or the slewing bearing 23 be surely reduced, the local surface pressure can be effectively reduced, but also the lubrication around the crankpin 12 can be achieved. Can also be ensured.

  In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably. For example, in the above-described embodiment, the example in which the local surface pressure due to the one-side contact at the crank pin 12 is reduced has been described. Instead of forming an annular groove or thin portion on the bearing side of the conventional example, or providing a barrel-shaped portion or a tapered portion on the shaft side, the diameter supported by the lower bearing 13 of the drive shaft 11 is slightly reduced. One or a plurality of circumferential grooves 29A (see FIG. 2) similar to those of the above-described embodiment may be provided on the base portion side of the portion 11A (see FIG. 2) and not on the lower bearing 13.

  Moreover, although the said embodiment demonstrated the example applied to the sealed electric scroll compressor 1, as a compressor, it does not need to be a sealed type and can be applied similarly to an open type scroll compressor. it can. Needless to say, the present invention can be applied to a pump, an expander and the like in addition to the compressor. Furthermore, when adjusting to achieve optimum rigidity depending on the model, whether to adjust by the number of circumferential grooves 29 or the depth of the grooves 29 depends on the configuration of the scroll fluid machine to be applied. To decide.

1 Sealed electric scroll compressor (scroll fluid machine)
6 Upper bearing member (frame member)
7 Scroll compression mechanism 11 Drive shaft (crankshaft)
12 Crankpin 13 Lower bearing 18 Fixed scroll member 19 Orbiting scroll member 22 Drive bush 23 Orbiting bearing 29 Circumferential groove

Claims (4)

A crank pin whose shaft center is eccentric by a predetermined dimension is provided at one end of a drive shaft that is rotatably supported via a bearing member, and a drive bush and / or a swivel bearing is provided on the outer periphery of the crank pin. In a scroll fluid machine in which orbiting scroll members are connected so as to be capable of orbiting driving,
A scroll fluid machine, wherein at least one circumferential groove is provided around a pin of the crank pin.   The scroll fluid machine according to claim 1, wherein the circumferential groove is an arc-shaped concave groove.   The scroll fluid machine according to claim 1, wherein the circumferential groove is provided on a base side of the crank pin. 4. The scroll fluid machine according to claim 1, wherein the circumferential groove is provided at a position on a base side of the crank pin and not on the slewing bearing. 5.

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