EP3159545A1 - Scroll fluid machine - Google Patents

Scroll fluid machine Download PDF

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Publication number
EP3159545A1
EP3159545A1 EP16194260.2A EP16194260A EP3159545A1 EP 3159545 A1 EP3159545 A1 EP 3159545A1 EP 16194260 A EP16194260 A EP 16194260A EP 3159545 A1 EP3159545 A1 EP 3159545A1
Authority
EP
European Patent Office
Prior art keywords
bush
scroll
radius
rotating shaft
fluid machine
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP16194260.2A
Other languages
German (de)
English (en)
French (fr)
Inventor
Masahiro Taniguchi
Yoshiyuki Kimata
Hajime Sato
Yogo Takasu
Youhei Hotta
Taichi Tateishi
Takuma YAMASHITA
Akihiro KANAI
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Heavy Industries Thermal Systems Ltd
Original Assignee
Mitsubishi Heavy Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Heavy Industries Ltd filed Critical Mitsubishi Heavy Industries Ltd
Publication of EP3159545A1 publication Critical patent/EP3159545A1/en
Pending legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
    • F04C18/02—Rotary-piston pumps specially adapted for elastic fluids of arcuate-engagement type, i.e. with circular translatory movement of co-operating members, each member having the same number of teeth or tooth-equivalents
    • F04C18/0207—Rotary-piston pumps specially adapted for elastic fluids of arcuate-engagement type, i.e. with circular translatory movement of co-operating members, each member having the same number of teeth or tooth-equivalents both members having co-operating elements in spiral form
    • F04C18/0215—Rotary-piston pumps specially adapted for elastic fluids of arcuate-engagement type, i.e. with circular translatory movement of co-operating members, each member having the same number of teeth or tooth-equivalents both members having co-operating elements in spiral form where only one member is moving
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
    • F01C17/00—Arrangements for drive of co-operating members, e.g. for rotary piston and casing
    • F01C17/06—Arrangements for drive of co-operating members, e.g. for rotary piston and casing using cranks, universal joints or similar elements
    • F01C17/063—Arrangements for drive of co-operating members, e.g. for rotary piston and casing using cranks, universal joints or similar elements with only rolling movement
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
    • F04C29/0021—Systems for the equilibration of forces acting on the pump
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
    • F04C29/0042—Driving elements, brakes, couplings, transmissions specially adapted for pumps
    • F04C29/005—Means for transmitting movement from the prime mover to driven parts of the pump, e.g. clutches, couplings, transmissions
    • F04C29/0057—Means for transmitting movement from the prime mover to driven parts of the pump, e.g. clutches, couplings, transmissions for eccentric movement
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2240/00—Components
    • F04C2240/50—Bearings
    • F04C2240/52—Bearings for assemblies with supports on both sides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2240/00—Components
    • F04C2240/60—Shafts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2240/00—Components
    • F04C2240/80—Other components
    • F04C2240/807—Balance weight, counterweight

Definitions

  • the present invention relates to a scroll fluid machine.
  • a scroll compressor which is a scroll fluid machine
  • a fixed scroll an orbiting scroll, a rotating shaft, and a drive unit
  • Fluid is compressed, by the rotating shaft being rotated by the drive unit, and the orbiting scroll, to which this rotation is transmitted, engaging and orbiting with the fixed scroll.
  • a slide bush for adjusting, in a scroll fluid machine, an orbiting radius of an orbiting scroll, according to a spiral shape thereof has been disclosed.
  • Each of spirally shaped laps of the orbiting scroll and a fixed scroll is designed based on a predetermined optimum orbiting radius, but there is a problem that when a gap is generated between the engaged laps due to dimensional tolerance thereof, fluid leaks out from the gap.
  • the slide bush is formed of: a bush, which is inserted in a cylindrical boss of the orbiting scroll, and in which an eccentric pin of a rotating shaft is inserted; a connected portion connected with a side portion of the bush; and a balance weight integrally formed with the connected portion.
  • the bush is configured to be able to slidingly move in a radial direction of the rotating shaft with respect to the eccentric pin; the respective laps of the orbiting scroll and fixed scroll are caused to contact each other and generation of a gap between the laps is prevented, by the slide bush: slidingly moving in the radial direction due to action of gas pressure in a scroll compression chamber, centrifugal force on the orbiting scroll, and centrifugal force on the balance weight; and causing the orbiting radius of the boss, in which the bush has been inserted, to be changed.
  • Patent Literature 1 Japanese Patent Application Laid-open No. 2003-343454
  • the present invention solves the above described problems, and an object thereof is to provide a scroll fluid machine, which enables bending of an eccentric pin therein to be prevented.
  • a scroll fluid machine of the present invention includes:
  • an outer shape of the eccentric pin has: a first circular arc formed in a range of an outer shape of the rotating shaft, with a first radius Ra having a length exceeding a part of an outer edge of the rotating shaft, the first radius Ra having a center at a position of an eccentric center; and a second circular arc formed in a portion where the first radius Ra exceeds the outer edge, with a second radius Rb having a length equal to or less than a radius R forming the outer edge, the second radius Rb having a center at a position of the shaft center.
  • the outer shape of the eccentric pin since the outer shape of the eccentric pin has the first circular arc formed in the range of the outer shape of the rotating shaft, with the first radius Ra having the length exceeding the portion of the outer edge of the rotating shaft, the first radius Ra having the center at the position of the eccentric center, the outer shape of the eccentric pin is made to have a large diameter that exceeds the portion of the outer edge of the rotary shaft, and rigidity of the eccentric pin is improved. As a result, bending of the eccentric pin is prevented.
  • the outer shape of the eccentric pin since the outer shape of the eccentric pin has the second circular arc formed in the portion where the first radius Ra exceeds the outer edge, with the second radius Rb having the length equal to or less than the radius R forming the outer edge, the second radius Rb having the center at the position of the shaft center, the outer shape of the eccentric pin is prevented from going over the outer edge of the rotating shaft. If the outer shape of the eccentric pin goes over the outer edge of the rotating shaft, processing the rotating shaft requires labor with the eccentric pin being an obstacle, or assembly requires labor when the rotating shaft is inserted in the bearings with the eccentric pin being an obstacle, and such inconvenience is eliminated.
  • the first radius Ra, the second radius Rb, the radius R, and a distance p between the position of the shaft center and the position of the eccentric center satisfy a relation of (Ra 2 + ⁇ 2 ) 1/2 ⁇ Rb ⁇ R.
  • the second circular arc is formed with the second radius Rb having the length equal to or less than the radius R forming the outer edge of the rotating shaft, the second radius Rb having the center at the position of the shaft center, but if the second radius Rb becomes too much less than the radius R, a diameter of the outer shape of the eccentric pin becomes too small.
  • the lower limit of the second radius Rb is set by the relation, (Ra 2 + ⁇ 2 ) 1/2 ⁇ Rb ⁇ R, the diameter of the outer shape of the eccentric pin is prevented from becoming too small. As a result, the effect of increasing the rigidity of the eccentric pin, and preventing the bending of the eccentric pin, is achieved.
  • the bush assembly includes:
  • the moment having the starting point at the connected portion acts so that the weight is rotated towards the contact end surface, and in the stepped portion, this moment acts so that the connected portion is caused to approach the bush. Therefore, excessive load is not applied to the joining portion provided in the stepped portion, rigidity of the joining between the bush and the connected portion is increased, and removal of the connected portion from the bush, or positional displacement of the connected portion with respect to the bush is prevented.
  • the joining portion joining the bush and the connected portion together is provided in the stepped portion, the joining portion is prevented from protruding to the contact end surface of the bush coming into contact with the end surface of the rotating shaft, and thus the joining portion is prevented from interfering with the end surface of the rotating shaft and processing of the joining portion for preventing the interference is omitted.
  • the weight is provided in the direction going away from the contact end surface, so as to stick out from the connected portion in the cantilevered shape; and in the stepped portion, the joining portion is provided between the connected portion and the contact end surface at the side opposite to the side to which the weight sticks out: regardless of the presence of the weight, the joining portion is provided easily.
  • the joining portion is provided at plural positions in a circumferential direction of the bush.
  • the joining portion is formed by welding, when the joining portion is provided at plural positions in the circumferential direction of the bush, rather than being provided on the whole circumference in the circumferential direction of the bush, thermal deformation of the bush and the joining portion due to the welding heat is reduced.
  • the joining portion is evenly arranged in the circumferential direction of the bush.
  • an oil feeding groove is provided along an extending direction of a cylindrical shape, on an outer peripheral portion of the bush, and the joining portion is arranged separately from a radial direction range of the oil feeding groove.
  • the oil feeding groove is for feeding the lubricating oil, and when the joining portion is formed by welding, by the joining portion being arranged separately from the radial direction range of the oil feeding groove, thermal deformation of the oil feeding groove due to the welding heat is reduced, and the lubricating oil is fed smoothly by the oil feeding groove.
  • the bush is formed of a sintered material, and the balance weight is formed of a cast iron material.
  • the bush is a sliding member connected to the eccentric pin or the orbiting scroll
  • the bush is preferably formed of a sintered material having a hardness that is comparatively high.
  • the balance weight has the weight, which balances the dynamic unbalance generated due to the unbalanced weights associated with the orbiting motion of the orbiting scroll, the balance weight is preferably formed of a cast iron material having a density that is comparatively high.
  • the bush assembly in the bush assembly, the bush and the connected portion of the balance weight are fixed by shrinkage fitting or interference fitting.
  • the bush assembly is configured to slidingly move with respect to the eccentric pin, by a bush side slide surface, which comes into contact with a pin side slide surface provided on a side portion of the eccentric pin, being provided on an inner peripheral portion of the bush, and the joining portion is arranged separately from a radial direction range of the bush side slide surface.
  • the bush side slide surface is a portion supporting sliding movement of the bush assembly, and when the joining portion is formed by welding, by the joining portion being arranged separately from the radial direction range of the bush side slide surface, thermal deformation of the bush side slide surface due to the welding heat is reduced, and the sliding movement of the bush assembly is performed smoothly.
  • the maximum number of rotations per second of the rotating shaft exceeds 145 rps.
  • FIG. 1 is an overall cross sectional view of a scroll fluid machine according to this embodiment.
  • FIG. 1 as the scroll fluid machine, a scroll compressor 1, which compresses and discharges intaken fluid, is illustrated. Further, the scroll compressor 1 of this embodiment is interposed in a refrigerant flow channel, through which a refrigerant is circulated in an air conditioner, a freezer, or the like.
  • the scroll compressor 1 includes, inside a housing 3, a motor 5, which is a driving means, and a scroll compression mechanism 7, which is driven by the motor 5.
  • the housing 3 includes: a housing main body 3a, which extends vertically and is cylindrical; a bottom portion 3b, which closes a lower end of the housing main body 3a; and a lid portion 3c, which closes an upper end of the housing main body 3a, and the housing 3 forms a pressure vessel, the whole of which is closed.
  • a housing main body 3a which extends vertically and is cylindrical
  • a bottom portion 3b which closes a lower end of the housing main body 3a
  • a lid portion 3c which closes an upper end of the housing main body 3a, and the housing 3 forms a pressure vessel, the whole of which is closed.
  • a discharge cover 13 is provided, and the interior of the housing 3 is partitioned into a low pressure chamber 3A lower than the discharge cover 13, and a high pressure chamber 3B upper than the discharge cover 13.
  • an opening hole 13a which communicates the low pressure chamber 3A with the high pressure chamber 3B, is formed, and a discharge reed valve 13b, which opens and closes the opening hole 13a, is provided.
  • a bottom in the housing 3 is formed as an oil sump, where lubricating oil is stored.
  • the motor 5 includes a stator 15, a rotor 17, and a rotating shaft 19.
  • the stator 15 is fixed to an inner wall surface substantially at a vertical direction center of the housing main body 3a.
  • the rotor 17 is provided rotatably with resect to the stator 15.
  • a longitudinal direction of the rotating shaft 19 is arranged vertically, with respect to the rotor 17. The motor 5 rotates the rotor 17 when power is supplied from outside of the housing 3, and the rotating shaft 19 is rotated with the rotor 17.
  • the rotating shaft 19 is provided, such that its end portions protrude upward and downward from the rotor 17, and the upper end portion is supported by an upper bearing 21 and the lower end portion is supported by a lower bearing 23, rotatably around a shaft center CE extending in the vertical direction, with respect to the housing main body 3a.
  • an eccentric pin 25 which protrudes upward along an eccentric center LE eccentric with respect to the shaft center CE, is formed.
  • the scroll compression mechanism 7 is connected to the upper end of the rotating shaft 19 having this eccentric pin 25. A detailed configuration of this eccentric pin 25 will be described later. Further, inside the rotating shaft 19 and the eccentric pin 25, an oil feeding hole 27 penetrating vertically therethrough is formed.
  • a lower end of the rotating shaft 19 is provided to reach the oil sump, and an oil feeding pump 29 is provided at that lower end.
  • the oil feeding pump 29 feeds the lubricating oil stored in the oil sump with the rotation of the rotating shaft 19, to the oil feeding hole 27 of the rotating shaft 19.
  • the upper bearing 21 rotatably supports the rotating shaft 19 with the upper end portion of the rotating shaft 19 penetrating therethrough.
  • a recessed portion 21a is formed to surround the upper end portion of the rotating shaft 19 penetrating through the upper bearing 21.
  • the recessed portion 21a accommodates therein a bush assembly 37, which will be described later, and stores therein the lubricating oil fed by the oil feeding pump 29 through the oil feeding hole 27. The stored lubricating oil is supplied to the scroll compression mechanism 7.
  • a notch 21b is formed such that a gap is formed between an inner wall surface of the housing main body 3a of the housing 3 and the upper bearing 21, and an oil discharging hole 21c that provides communication between the notch 21b and the recessed portion 21a is formed in the upper bearing 21.
  • a cover plate 31 is provided below the notch 21b of the upper bearing 21 below the notch 21b of the upper bearing 21. The cover plate 31 is provided to extend in the vertical direction.
  • the cover plate 31 is formed such that both side ends of the cover plate 31 face the inner wall surface of the housing main body 3a to cover a periphery of the notch 21b, and is formed such that a lower end of the cover plate 31 is bent to gradually approach the inner wall surface of the housing main body 3a.
  • the oil discharging hole 21c discharges the lubricating oil stored excessively in the recessed portion 21a to an outer periphery of the upper bearing 21 from the notch 21b.
  • the cover plate 31 receives the lubricating oil discharged from the notch 21b and guides the received lubricating oil towards the inner wall surface of the housing main body 3a.
  • the lubricating oil guided towards the inner wall surface by the cover plate 31 goes along the inner wall surface and returns to the oil sump at the bottom inside the housing 3 by the cover plate 31.
  • the scroll compression mechanism 7 is arranged above the upper bearing 21 in the low pressure chamber 3A below the discharge cover 13 inside the housing 3, and includes a fixed scroll 33, an orbiting scroll 35, and the bush assembly 37.
  • a fixed lap 33b which is spiral, is formed.
  • a discharge hole 33c is formed at a central portion of the fixed end plate 33a.
  • a movable lap 35b On an inner surface (upper surface in FIG. 1 ) of a movable end plate 35a facing the inner surface of the fixed end plate 33a of the fixed scroll 33, a movable lap 35b, which is spiral, is formed.
  • a compression chamber partitioned by the respective end plates 33a and 35a and the respective laps 33b and 35b is formed.
  • the orbiting scroll 35 is caused to orbit with its rotation prevented, based on the eccentric rotation of the eccentric pin 25, by a rotation preventing mechanism 39, such as a known Oldham link, which is arranged between the outer surface of the movable end plate 35a and the upper bearing 21.
  • a rotation preventing mechanism 39 such as a known Oldham link
  • the bush assembly 37 is accommodated in the above described recessed portion 21a of the upper bearing 21, is interposed between the eccentric pin 25 of the rotating shaft 19 and the boss 35c of the orbiting scroll 35, and transmits the rotational movement of the eccentric pin 25 as orbital movement of the orbiting scroll 35. Further, the bush assembly 37 is provided to be slidingly movable in a radial direction of the eccentric pin 25 in order to maintain the engagement between the movable lap 35b of the orbiting scroll 35 and the fixed lap 33b of the fixed scroll 33. A detailed configuration of this bush assembly 37 will be described later.
  • a low pressure refrigerant introduced into the low pressure chamber 3A in the housing 3 via the inlet pipe 9 is compressed while being intaken in the compression chamber between the fixed scroll 33 and orbiting scroll 35, by the orbiting scroll 35 orbiting.
  • the compressed high pressure refrigerant is discharged to an outer surface side of the fixed end plate 33a from the discharge hole 33c of the fixed scroll 33, opens the discharge reed valve 13b of the discharge cover 13 by its own pressure, reaches the high pressure chamber 3B from the opening hole 13a, and is discharged outside the housing 3 via the discharge pipe 11.
  • FIG. 2 is a plan view of the rotating shaft in the scroll fluid machine according to this embodiment.
  • FIG. 3 is a sectional side elevation of a combination of the rotating shaft and the bush assembly in the scroll fluid machine according to this embodiment.
  • the eccentric pin 25, which has the eccentric center LE eccentric with respect to the shaft center CE, is formed, as described above.
  • the eccentric pin 25 is formed so as to protrude upward from an upper end surface 19a of the rotating shaft 19.
  • An outer shape of this eccentric pin 25, the outer shape projected in an extending direction of the shaft center CE (or eccentric center LE), is mainly formed of a first circular arc 25a, a second circular arc 25b, and a pin side slide surface 25c.
  • the first circular arc 25a corresponds to a range of P1 to P2 in FIG. 2 , and is formed in a range of an outer shape of the rotating shaft 19, with a first radius Ra having a length exceeding a part of an outer edge 19b of the outer shape of the rotating shaft 19, the first radius Ra having a center at a position of the eccentric center LE.
  • the second circular arc 25b is formed in a portion where the first radius Ra exceeds the outer edge 19b of the outer shape of the rotating shaft 19, the portion being a range of P2 to P3 in FIG. 2 , with a second radius Rb having a length equal to or less than a radius R forming the outer edge 19b of the rotating shaft 19, the second radius Rb having a center at a position of the shaft center CE.
  • the outer shape of the eccentric pin 25 of the rotating shaft 19 is configured to have: the first circular arc 25a formed in the range of the outer shape of the rotating shaft 19, with the first radius Ra having the length exceeding the part of the outer edge 19b of the rotating shaft 19, the first radius Ra having the center at the position of the eccentric center LE; and the second circular arc 25b formed in the portion where the first radius Ra exceeds the outer edge 19b, with the second radius Rb having the length equal to or less than the radius R forming the outer edge 19b, the second radius Rb having the center at the position of the shaft center CE.
  • the outer shape of the eccentric pin 25 since the outer shape of the eccentric pin 25 has the first circular arc 25a formed in the range of the outer shape of the rotating shaft 19, with the first radius Ra having the length exceeding the part of the outer edge 19b of the rotating shaft 19, the first radius Ra having the center at the position of the eccentric center LE; the outer shape of the eccentric pin 25 has a large diameter that exceeds the part of the outer edge 19b of the rotating shaft 19 and rigidity of the eccentric pin 25 is increased. As a result, bending of the eccentric pin 25 is prevented.
  • the outer shape of the eccentric pin 25 since the outer shape of the eccentric pin 25 has the second circular arc 25b formed in the portion where the first radius Ra exceeds the outer edge 19b, with the second radius Rb having the length equal to or less than the radius R forming the outer edge 19b, the second radius Rb having the center at the position of the shaft center CE; the outer shape of the eccentric pin 25 is prevented from going over the outer edge 19b of the rotating shaft 19. If the outer shape of the eccentric pin 25 goes over the outer edge 19b of the rotating shaft 19, processing the rotating shaft 19 requires labor with the eccentric pin 25 being an obstacle, or assembly requires labor when the rotating shaft 19 is inserted in the bearings 21 and 23 with the eccentric pin 25 being an obstacle, and such inconvenience is eliminated.
  • the first radius Ra, the second radius Rb, the radius R, and a distance p between the position of the shaft center CE and the position of the eccentric center LE preferably satisfy a relation of (Ra 2 + ⁇ 2 ) 1/2 ⁇ Rb ⁇ R.
  • the second circular arc 25b is formed with the second radius Rb having the length equal to or less than the radius R forming the outer edge 19b of the rotating shaft 19, the second radius Rb having the center at the position of the shaft center CE, but if the second radius Rb becomes too much less than the radius R, the diameter of the outer shape of the eccentric pin 25 becomes too small.
  • this scroll compressor 1 by setting a lower limit of the second radius Rb with the relation, (Ra 2 + ⁇ 2 ) 1/2 ⁇ Rb ⁇ R, the diameter of the outer shape of the eccentric pin 25 is prevented from becoming too small. As a result, the effect of increasing the rigidity of the eccentric pin 25, and preventing the bending of the eccentric pin 25 is achieved.
  • FIG. 4 is a plan view of the bush assembly in the scroll fluid machine according to this embodiment.
  • the bush assembly 37 includes a bush 41 and a balance weight 43.
  • the eccentric pin 25 is inserted in a hole portion 41a cylindrically formed in the bush 41.
  • the bush 41 has a contact end surface 41b, which comes into contact with the upper end surface 19a of the rotating shaft 19 when the eccentric pin 25 is inserted into the hole portion 41a.
  • the bush 41 is inserted into the boss 35c of the orbiting scroll 35, as illustrated in FIG. 3 . Therefore, an outer shape of the bush 41 is circularly formed according to the cylindrical shape of the boss 35c.
  • an orbiting bearing 45 which is cylindrical, is interposed, in order to smoothly transmit eccentric rotation of the bush 41 to the orbiting of the orbiting scroll 35.
  • a bush side slide surface 41c facing the pin side slide surface 25c of the eccentric pin 25 is provided in an internal shape of the hole portion 41a of the bush 41. Furthermore, in the bush 41, a diameter of the internal shape of the hole portion 41a is formed more largely than that of the outer shape of the eccentric pin 25 in a direction along the radial direction of the eccentric center LE on the pin side slide surface 25c. Therefore, correspondingly with the hole portion 41a having the diameter larger than that of the outer shape of the eccentric pin 25, the bush side slide surface 41c slides along the pin side slide surface 25c, and thereby, the bush 41 is configured to be able to slidingly move along the pin side slide surface 25c.
  • the balance weight 43 includes a connected portion 43A and a weight 43B.
  • the connected portion 43A is formed in a ring shape, and a hole portion 43Aa thereof is joined to an outer peripheral portion of the bush 41. As described above, since the bush 41 is inserted in the boss 35c of the orbiting scroll 35, the connected portion 43A is joined to the bush 41 at a position near the rotating shaft 19 (contact end surface 41b) in order to prevent interference between the connected portion 43A and the boss 35c of the orbiting scroll 35.
  • the weight 43B is provided in a portion of an outer periphery of the connected portion 43A, so as to stick out, in a direction going away from the contact end surface 41b of the bush 41 (upward in FIG. 3 ), in a cantilevered shape. As illustrated in FIG. 3 and FIG. 4 , the weight 43B is arranged in a direction reverse to a direction in which the eccentric pin 25 is eccentric with respect to the rotating shaft 19, in a state where the eccentric pin 25 of the rotating shaft 19 has been inserted in and attached to the bush assembly 37. Positioning upon this arrangement of the weight 43B is performed by causing the bush side slide surface 41c of the hole portion 41a of the bush 41 to face the pin side slide surface 25c of the eccentric pin 25. That is, the bush assembly 37 is attached to be able to slidingly move with respect to the eccentric pin 25 in a state of being prevented from rotating.
  • the weight 43B is arranged with a gap from the bush 41, the gap allowing the boss 35c (and the orbiting bearing 45) to be inserted therethrough, and is arranged in a circular arc shape (or a fan shape) along an outer shape of the bush 41.
  • the rotational movement of the eccentric pin 25 is transmitted as the orbiting movement of the orbiting scroll 35; and upon this transmission, in the bush assembly 37, since the weight 43B arranged at a side opposite to the eccentricity of the eccentric pin 25 with respect to the shaft center CE rotationally moves with the eccentric pin 25, dynamic unbalance generated due to unbalanced weights of the orbiting scroll 35, the boss 35c, the orbiting bearing 45, the bush assembly 37, and the like, the dynamic unbalance associated with the orbiting motion of the orbiting scroll 35, is balanced by centrifugal force acting on the weight 43B.
  • the connected portion 43A is arranged to be displaced in a lengthwise direction (upward in FIG. 3 ) of the bush 41 with resect to the bush 41, and a stepped portion 47 is formed between the contact end surface 41b of the bush 41, the contact end surface 41b facing the upper end surface 19a of the rotating shaft 19, and a lower surface 43Ab of the connected portion 43A.
  • the connected portion 43A is formed to be attached to the bush 41, such that the lower surface 43Ab of the connected portion 43A is a little separate from the upper end surface 19a of the rotating shaft 19, more than the contact end surface 41b of the bush 41.
  • a joining portion 49 which joins the bush 41 and the connected portion 43A together, is provided.
  • the joining portion 49 is formed on the lower surface 43Ab of the connected portion 43A and on a side surface of the bush 41, in the stepped portion 47, and is formed such that the joining portion 49 does not protrude towards the upper end surface 19a of the rotating shaft 19, more than the contact end surface 41b of the bush 41.
  • the joining portion 49 is formed by laser welding. Not being limited to laser welding, the joining portion 49 may be formed by other welding.
  • the scroll compressor 1 of this embodiment has the bush assembly 37 including: the bush 41, into which the eccentric pin 25 is inserted, which has the contact end surface 41b that comes into contact with the end surface 19a of the rotating shaft 19, and which is inserted in the cylindrically shaped boss 35c provided at the bottom surface of the orbiting scroll 35; the balance weight 43 having the connected portion 43A and the weight 43B, the connected portion 43A arranged in the outer peripheral portion of the bush 41 and near the contact end surface 41b, and the weight 43B provided, in the cantilevered shape, in the portion of the outer periphery of the connected portion 43A, so as to stick out in the direction going away from the contact end surface 41b; the stepped portion 47 provided between the connected portion 43A and the contact end surface 41b of the bush 41; and the joining portion 49, which is provided in the stepped portion 47 and joins the bush 41 and the connected portion 43A together.
  • the joining portion 49 joining the bush 41 and the connected portion 43A together is provided in the stepped portion 47, the joining portion 49 is prevented from protruding to the contact end surface 41b of the bush 41 coming into contact with the end surface 19a of the rotating shaft 19, and thus the joining portion 49 is prevented from interfering with the end surface 19a of the rotating shaft 19 and processing of the joining portion 49 for preventing the interference is omitted.
  • the joining portion 49 is provided between the connected portion 43A and the contact end surface 41b at the side opposite to the side to which the weight 43B sticks out; regardless of the presence of the weight 43B, the joining portion 49 is provided easily.
  • FIG. 5 is a bottom view of the bush assembly in the scroll fluid machine according to this embodiment.
  • the joining portion 49 may be provided on the whole circumference in a circumferential direction of the bush 41, but as illustrated in FIG. 5 , the joining portion 49 is preferably provided at plural positions (three positions in FIG. 5 ) in the circumferential direction of the bush 41.
  • the circumferential direction of the bush 41 refers to a circumferential direction with reference to the position of the eccentric center LE of the eccentric pin 25.
  • the joining portion 49 is formed by welding, when the joining portion 49 is provided at plural positions in the circumferential direction of the bush 41, rather than being provided on the whole circumference in the circumferential direction of the bush 41, thermal deformation of the bush 41 and the connected portion 43A due to the welding heat is reduced.
  • the joining portion 49 when the joining portion 49 is provided at plural positions in the circumferential direction of the bush 41, the joining portion 49 is preferably arranged evenly in the circumferential direction of the bush 41.
  • the joining portion 49 is provided at three positions in the circumferential direction of the bush 41, and is evenly arranged at 120° intervals with reference to the eccentric center LE of the eccentric pin 25.
  • this scroll compressor 1 when the joining portion 49 is formed by welding, by the joining portion 49 being arranged evenly in the circumferential direction of the bush 41, even if thermal deformation of the bush 41 or the connected portion 43A due to the welding heat is caused, the thermal deformation is equalized and local deformation is prevented.
  • the joining portion 49 when the joining portion 49 is provided at plural positions in the circumferential direction of the bush 41, more of the positions of the joining portion 49 are preferably situated near where the weight 43B is provided.
  • the joining portion 49 is evenly arranged in the circumferential direction of the bush 41, as illustrated in FIG. 5 , in a configuration where the joining portion 49 is provided at an odd number of positions in the circumferential direction of the bush 41, more of the positions of the joining portion 49 are situated near where the weight 43B is provided.
  • an oil feeding groove 51 is provided in the outer peripheral portion of the bush 41 and along the extending direction of the cylindrical shape, and the joining portion 49 is arranged to be separate from a radial direction range of the oil feeding groove 51.
  • the oil feeding groove 51 is for feeding the lubricating oil to the scroll compression mechanism 7, and when the joining portion 49 is formed by welding, by the joining portion 49 being arranged separately from the radial direction range of the oil feeding groove 51, thermal deformation of the oil feeding groove 51 due to the welding heat is reduced, and the lubricating oil is fed smoothly by the oil feeding groove 51.
  • the bush 41 is formed of a sintered material
  • the balance weight 43 is formed of a cast iron material.
  • the bush 41 is a sliding member connected to the eccentric pin 25 of the bush 41 and the boss 35c of the orbiting scroll 35, the bush 41 is preferably formed of a sintered material having a hardness that is comparatively high.
  • the balance weight 43 has the weight 43B, which balances the dynamic unbalance generated due to the unbalanced weights of the orbiting scroll 35, the boss 35c, the orbiting bearing 45, the bush assembly 37, and the like, in association with the orbiting motion of the orbiting scroll 35; the balance weight 43 is preferably formed of a cast iron material having a density that is comparatively high.
  • the bush 41 and the connected portion 43A of the balance weight 43 are preferably fixed by shrinkage fitting or interference fitting.
  • the bush 41 and the connected portion 43A of the balance weight 43 are fixed by shrinkage fitting or interference fitting, synergistically with the inclusion of the joining portion 49, the effect of increasing the rigidity of the joining between the bush 41 and the connected portion 43A is achieved.
  • an inner diameter of the hole portion 43Aa of the connected portion 43A is formed smaller than the outer diameter of the bush 41, the bush 41 and the connected portion 43A are fitted to each other by shrinkage fitting or interference fitting, and thereafter, the joining portion 49 is formed by welding.
  • the joining portion 49 is formed by welding without causing any displacement between the bush 41 and the connected portion 43A.
  • the joining portion 49 when the joining portion 49 is provided at plural positions in the circumferential direction of the bush 41, as illustrated in FIG. 5 , the joining portion 49 is preferably arranged separately from a radial direction range of the bush side slide surface 41c.
  • the bush side slide surface 41c is a portion supporting sliding movement of the bush assembly 37, and when the joining portion 49 is formed by welding, by the joining portion 49 being arranged separately from the radial direction range of the bush side slide surface 41c, thermal deformation of the bush side slide surface 41c due to the welding heat is reduced, and the sliding movement of the bush assembly 37 is performed smoothly.
  • the maximum number of rotations per second of the rotating shaft 19 exceeds 145 rps.
  • FIG. 7 is an overall cross sectional view of another example of the scroll fluid machine according to this embodiment.
  • FIG. 8 is a sectional side elevation of a combination of a rotating shaft and a bush assembly of the another example of the scroll fluid machine according to this embodiment.
  • FIG. 9 is a bottom view of the bush assembly of the another example in the scroll fluid machine according to this embodiment.
  • a scroll compressor 101 which compresses and discharges intaken fluid, is illustrated. Further, the scroll compressor 101 is interposed in a refrigerant flow channel, through which a refrigerant is circulated in an air conditioner, a freezer, or the like, and is used, in particular, in an air conditioner for a vehicle.
  • a housing 103 an inverter motor 105, a fixed scroll 133 and an orbiting scroll 135 that compress the refrigerant, a rotating shaft 119 that drives the orbiting scroll 135, and a bush assembly 137, are provided.
  • the fixed scroll 133, the orbiting scroll 135, and the bush assembly 137 form a scroll compression mechanism 107 driven by the inverter motor 105.
  • the housing 103 is a case accommodating therein the fixed scroll 133, the orbiting scroll 135, the rotating shaft 119, the inverter motor 105, and the like, and a first housing 103a, a second housing 103b, and a motor case 103c, are provided therein.
  • the first housing 103a is a member formed in a bottomed cylindrical shape, and the fixed scroll 133 is fixed to a bottom surface thereof. Between the fixed scroll 133 and the first housing 103a, a discharge chamber 103A, into which the refrigerant compressed by the fixed scroll 133 and the orbiting scroll 135 flows, is formed.
  • first housing 103a In the first housing 103a, a discharge portion (not illustrated) that guides the refrigerant in the discharge chamber 103A to outside, and a first flange portion 103aa, are provided.
  • the first flange portion 103aa is used when the first housing 103a, the second housing 103b, and the motor case 103c are integrally fixed by use of a housing bolt 104, and is a member extending outward in a radial direction, at an end portion of the first housing 103a, the end portion at an opening side.
  • the second housing 103b is, as illustrated in FIG. 7 , a member, in which a first bearing 121 cylindrically formed, and a flange portion 103ba extending outward in the radial direction from an end portion of the second housing 103b, the end portion at the first housing 103a side, are provided.
  • the flange portion 103ba of the second housing 103b is arranged to be sandwiched between the first housing 103a and the motor case 103c.
  • a radial bearing 122 rotatably supporting the rotating shaft 119 is provided in the first bearing 121 of the second housing 103b.
  • An inlet flow channel 124 extending along the shaft center CE of the rotating shaft 119 is provided in a wall surface of the first bearing 121.
  • a second flange portion 103bb which is used when the first housing 103a, the second housing 103b, and the motor case 103c are integrally fixed by use of the housing bolt 104, is provided in the flange portion 103bb.
  • the second flange portion 103bb is a member extending outward in a radial direction from the flange portion 103ba.
  • the motor case 103c is, as illustrated in FIG. 7 , a member formed in a bottomed cylindrical shape, and a stator 115 of the inverter motor 105 is fixed inside the motor case 103c.
  • an inlet portion (not illustrated), into which the refrigerant flows from outside; a box 103ca; and a case flange portion 103cb, are provided.
  • the box 103ca opens outward in a radial direction of the motor case 103c, and an inverter unit 179 of the inverter motor 105 is accommodated inside the box 103ca.
  • the case flange portion 103cb is used when the first housing 103a, the second housing 103b, and the motor case 103c are integrally fixed by use of the housing bolt 104, and is a member extending outward in a radial direction, from an end portion of the motor case 103c, the end portion at the opening side.
  • the inverter motor 105 is a motor rotationally driven by alternating electric current subjected to frequency control, and is an electrically powered unit that orbitally drives the orbiting scroll 135.
  • a rotor 117 and the stator 115 which cause the orbiting scroll 135 to orbit via the rotating shaft 119 and the bush assembly 137, and the inverter unit 179, which controls alternating electric current supplied to the stator 115, are provided.
  • the rotor 117 generates rotational drive power with an alternating magnetic field formed by the stator 115, and is a permanent magnet formed cylindrically.
  • the rotating shaft 119 is fixed to the rotor 117.
  • the stator 115 rotates the rotor 117 by generating the alternating magnetic field, based on the alternating electric current supplied from the inverter unit 179.
  • the stator 115 is fixed to an inner peripheral surface of the motor case 103c, by use of a fixing method, such as shrinkage fitting.
  • the inverter unit 179 controls the alternating electric current supplied to the stator 115, and is arranged inside the box 103ca.
  • a capacitor (condenser) 181 plural substrates 185 including electronic elements, such as power transistors 183, and a terminal 187, are provided.
  • the capacitor 181 temporarily stores electric current.
  • the electronic elements such as the power transistors 183, included in the substrates 185, control frequency of alternating electric current supplied from outside.
  • the terminal 187 supplies the alternating electric current to the stator 115.
  • the substrate 185 including the power transistors 183 is configured to be fixed by contacting with the motor case 103c in the box 103ca, and to release heat generated from the power transistors 183 to the motor case 103c.
  • the other substrates 185 are fixed at positions separate from the motor case 103c. In other words, the substrates 185 are fixed in a state of being layered over one another.
  • the terminal 187 supplies the alternating electric current controlled by the power transistors 183 and the like, to the stator 115.
  • the inverter motor 105 may be used as the electrically powered unit as described above, but not being particularly limited thereto, any other known motor may be used as the electrically powered unit.
  • the fixed scroll 133 and the orbiting scroll 135 compress the refrigerant by forming a closed compression chamber C.
  • a fixed end plate 133a, and a fixed lap 133b which extends towards the orbiting scroll 135 from the fixed end plate 133a and is spiral, are provided.
  • the fixed scroll 133 is fixed to a bottom surface of the first housing 103a.
  • a discharge hole 133c is provided at a central portion of the fixed end plate 133a.
  • the refrigerant compressed in the compression chamber C is discharged to the discharge chamber 103A via the discharge hole 133c.
  • a movable end plate 135a, and a movable lap 135b which extends toward the fixed scroll 133 from the movable end plate 135a and is spiral, are provided.
  • the orbiting scroll 135 is orbitably supported by the rotating shaft 119 and a rotation preventing portion 139.
  • a boss 135c which extends toward the rotating shaft 119 and is cylindrical, is provided on a surface (also referred to as "bottom surface") of the movable end plate 135a, the surface facing the rotating shaft 119.
  • Orbital drive power by the rotating shaft 119 is transmitted to the boss 135c via the bush assembly 137.
  • the rotating shaft 119 is, as illustrated in FIG. 7 , a member, which extends toward the orbiting scroll 135 from the inverter motor 105, and is cylindrical. With respect to the housing 103, one end portion of the rotating shaft 119 is supported by the first bearing 121, and the other end portion thereof is supported by the second bearing 123, rotatably, based on the shaft center CE extending in a horizontal direction (left-right direction in FIG. 7 ).
  • the rotating shaft 119 has, as illustrated in FIG. 8 , a disk portion 119A, an eccentric pin 125, and a limit hole 126.
  • the disk portion 119A is provided at one end of the rotating shaft 119, and has a diameter formed more largely than that of the rotating shaft 119, with the shaft center CE centered therein.
  • This disk portion 119A is arranged inside a penetrating portion 121a formed in the first bearing 121, a peripheral surface of the disk portion 119A is supported by the bearing 122, which is fixed in the penetrating portion 121a, and the disk plate portion 119A is rotatably provided, with the shaft center CE centered therein, with respect to the first bearing 121.
  • the eccentric pin 125 is formed in a cylindrical shape extending along the eccentric center LE eccentric with respect to the shaft center CE from an end surface 119Aa of the disk portion 119A.
  • the limit hole 126 is a hole recessed from the end surface 119Aa of the disk portion 119A, and is formed along another eccentric center LE' eccentric with respect to the shaft center CE.
  • the bush assembly 137 is accommodated in the penetrating portion 121a of the first bearing 121, is interposed between the eccentric pin 125 of the rotating shaft 119 and the boss 135c of the orbiting scroll 135, and transmits rotational movement of the eccentric pin 125 as orbital movement of the orbiting scroll 135.
  • the bush assembly 137 includes a bush 141, a limit pin 142, and a balance weight 143.
  • the eccentric pin 125 is inserted in a circular hole portion 141a cylindrically formed in the bush 141.
  • the bush 141 has a contact end surface 141b, which comes into contact with the end surface 119Aa of the disk portion 119A of the rotating shaft 119 by the eccentric pin 125 being inserted in the circular hole portion 141a.
  • the bush 141 is inserted in the boss 135c of the orbiting scroll 135. Therefore, an outer shape of the bush 141 is circularly formed according to the cylindrical shape of the boss 135c.
  • an orbiting bearing 145 which is cylindrical, is interposed, in order to smoothly transmit eccentric rotation of the bush 141 to the orbiting motion of the orbiting scroll 135.
  • the limit pin 142 is arranged between the bush 141 and the disk portion 119A, and is a member, which adjusts, together with the limit hole 126, orbiting radius of the orbiting scroll 135, and which is cylindrical. As illustrated in FIG. 8 , the limit pin 142 is provided by being fitted in a fitting hole 141c formed in the bush 141, and is provided so as to protrude from the contact end surface 141b along the eccentric center LE', to be inserted in the limit hole 126 when the eccentric pin 125 is inserted in the circular hole portion 141a of the bush 141. A gap is formed between peripheral surfaces of the limit pin 142 and the limit hole 126 when the limit pin 142 is inserted in the limit hole 126.
  • a fitting groove 142a which is recessed, is formed over a circumferential surface of a side portion of a portion of the limit pin 142, the portion of the limit pin 142 being inserted in the limit hole 126.
  • An elastic portion 142b is fitted in the fitting groove 142a.
  • the limit pin 142 is not particularly limited thereto, and may be formed as a cylindrical member, or may be formed as a columnar member having another cross sectional shape.
  • the elastic portion 142b is a substantially cylindrical elastic member that is arranged to contact an outer peripheral surface of the limit pin 142 and an inner peripheral surface of the limit hole 126, when the elastic portion 142b has been fitted in the fitting groove 142a of the limit pin 142 and the limit pin 142 has been inserted in the limit hole 126.
  • a material forming the elastic portion 142b is desirably rubber, which has suitability with respect to and does not swell in the refrigerant and lubricating oil of the scroll compressor 101.
  • HNBR hydrogenated nitrile butadiene rubber
  • any suitable rubber may be used.
  • the elastic portion 142b is formed such that a diameter of an outer peripheral surface thereof is equal to or greater than a diameter of the limit hole 126, and a diameter of an inner peripheral surface thereof is equal to or less than a diameter of the limit pin 142. Over an inner peripheral surface of the elastic portion 142b, a ridge shaped convex portion, which fits in the fitting groove 142a, is provided.
  • the elastic portion 142b at least has rigidity to support the own weight of the orbiting scroll 135 and to hold the limit pin 142 separately from the inner peripheral surface of the limit hole 126, when the orbiting scroll 135 is not being orbitally driven.
  • the rigidity of the elastic portion 142b is limited to an extent where the elastic portion 142b is squashed and the limit pin 142 directly contacts the inner peripheral surface of the limit hole 126, when the orbiting scroll 135 is being orbitally driven and the centrifugal force and reaction force due to the compression of the refrigerant are working.
  • FIG. 9 An example of a relative positional relation between the circular hole portion 141a and the limit pin 142 is, as illustrated in FIG. 9 , a case where the limit pin 142 is arranged in an eight o'clock direction when the circular hole portion 141a is arranged in a two o'clock direction, when the bush assembly 137 is viewed from the disk portion 119A side (left side in FIG. 7 and FIG. 8 ).
  • the balance weight 143 is a member that adjusts and balances pressing force of the orbiting scroll 135 against the fixed scroll 133. As illustrated in FIG. 8 and FIG. 9 , the balance weight 143 is a brim shaped member, which extends semi-circularly, outward in a radial direction from a circumferential surface of the bush 141, the circumferential surface of the bush 141 being at the disk portion 119A side. A range in which the balance weight 143 extends is, as illustrated in FIG.
  • the balance weight 143 includes a connected portion 143A and a weight 143B.
  • the connected portion 143A is formed in a ring shape, and a hole portion 143Aa thereof is joined to an outer peripheral portion of the bush 141.
  • the connected portion 143A is joined to the bush 141 at a position near the rotating shaft 119 (contact end surface 141b) in order to prevent interference between the connected portion 143A and the boss 135c of the orbiting scroll 135.
  • the weight 143B is provided, in a cantilevered shape, at a portion of an outer periphery of the connected portion 143A, so as to increase in thickness and stick out in a direction going away from the contact end surface 141b.
  • the rotating shaft 119 and the bush assembly 137 are combined together, such that the eccentric pin 125 is inserted in the circular hole portion 141a and the limit pin 142 is inserted in the limit hole 126.
  • the elastic portion 142b of the limit pin 142 is inserted, together with the limit pin 142, inside the limit hole 126, and contacts the inner peripheral surface of the limit hole 126. Because of such combination, the bush assembly 137 is able to rotate in a range restricted by the limit pin 142 and the limit hole 126, with the eccentric pin 125 being the center of rotation.
  • the compression chamber C formed between the orbiting scroll 135 and the fixed scroll 133 takes in and compresses the refrigerant that has flown into the scroll compressor 101 from the motor case 103c.
  • the compression chamber C takes in the refrigerant at an outer peripheral end of the fixed scroll 133 and orbiting scroll 135.
  • the refrigerant taken in is compressed, with volume of the compression chamber C becoming smaller towards the center from the outer peripheral edge along the fixed lap 133b and the movable lap 135b.
  • the refrigerant compressed by the compression chamber C is discharged to the discharge chamber 103A via the discharge hole 133c of the fixed scroll 133, and is discharged outside the first housing 103a from inside the discharge chamber 103A.
  • liquid refrigerant a liquid refrigerant
  • the orbiting radius of the orbiting scroll 135 is decreased and an escape passage for the liquid refrigerant or foreign matter is formed. That is, by the liquid compression reaction force generated when the liquid refrigerant is compressed and the resistance force generated when foreign matter is stuck, the bush assembly 137, together with the orbiting scroll 135, squashes the elastic portion 142b and rotates in a direction of decreasing the orbiting radius around the eccentric pin 125. By this rotation, the escape passage between the orbiting scroll 135 and the fixed scroll 133 is formed.
  • the elastic portion 142b which has been squashed between the limit pin 142 and the limit hole 126 due to the centrifugal force and the like during the operation of the scroll compressor 101, separates the limit pin 142 and the limit hole 126 from each other by a force of returning to the original form from the squashed form. Further, the elastic portion 142b holds the limit pin 142 in a state separated from the limit hole 126.
  • the orbiting radius of the orbiting scroll 135 is decreased. That is, the limit pin 142 and the limit hole 126 separate from each other and the orbiting radius of the orbiting scroll 135 is decreased.
  • the limit pin 142 separates from a predetermined region on the inner peripheral surface of the limit hole 126 and contacts (collides) with a region at an opposite side, the shape of the elastic portion 142b is deformed and momentum upon the contact between the limit pin 142 and the limit hole 126 is reduced.
  • clacking noise which is generated by the contact between the limit pin 142 and the limit hole 126 when the liquid refrigerant is present in the compression chamber C, is reduced.
  • the present invention is not limited to the configuration, in which the escape passage is formed between the orbiting scroll 135 and the fixed scroll 133 by the limit pin 142 and the limit hole 126.
  • the bush assembly 137 may be made movable in a radial direction of the eccentric pin 125 by providing a gap between the circular hole portion 141a of the bush 141 in the bush assembly 137 and the eccentric pin 125, and thereby, an escape passage may be formed between the orbiting scroll 135 and the fixed scroll 133.
  • FIG. 6 is a plan view of a rotating shaft of another example of the scroll fluid machine according to this embodiment.
  • an outer shape of the eccentric pin 125 in the configuration where the gap is formed between the circular hole portion 141a of the bush 141 in the bush assembly 137 and the eccentric pin 125, an outer shape of the eccentric pin 125, the outer shape projected in the extending direction of the shaft center CE (or eccentric center LE), is mainly formed of a first circular arc 125a and a second circular arc 125b.
  • the first circular arc 125a corresponds to a range of P11 to P12 in FIG. 6 , and is formed in a range of an outer shape of the rotating shaft 119 (the disk portion 119A, herein) with a first radius Ra having a length exceeding a part of an outer edge 119Ab of the outer shape of the disk portion 119A of the rotating shaft 119, the first radius Ra having a center at the position of the eccentric center LE.
  • the second circular arc 125b is formed in a portion where the first radius Ra exceeds the outer edge 119Ab of the outer shape of the rotating shaft 119, the portion being a range of P12 to P11 in FIG. 6 , with the second radius Rb having a length equal to or less than the radius R forming the outer edge 119Ab of the rotating shaft 119, the second radius Rb having a center at the position of the shaft center CE.
  • the outer shape of the eccentric pin 125 of the rotating shaft 119 is configured to have: the first circular arc 125a, which is formed in the range of the outer shape of the rotating shaft 119 with the first radius Ra having the length exceeding the part of the outer edge 119Ab of the rotating shaft 119 (disk portion 119A herein), the first radius Ra having the center at the position of the eccentric center LE; and the second circular arc 125b formed in the portion where the first radius Ra exceeds the outer edge 119Ab, with the second radius Rb having the length equal to or less than the radius R forming the outer edge 119Ab, the second radius Rb having the center at the position of the shaft center CE.
  • the outer shape of the eccentric pin 125 since the outer shape of the eccentric pin 125 has the first circular arc 125a formed in the range of the outer shape of the rotating shaft 119, with the first radius Ra having the length exceeding the part of the outer edge 119Ab of the rotating shaft 119 (disk portion 119A herein), the first radius Ra having the center at the position of the eccentric center LE; the outer shape of the eccentric pin 125 has a large diameter that exceeds the part of the outer edge 119Ab of the rotating shaft 119 and rigidity of the eccentric pin 125 is improved. As a result, the eccentric pin 125 is prevented from being bent.
  • the outer shape of the eccentric pin 125 since the outer shape of the eccentric pin 125 has the second circular arc 125b formed in the portion where the first radius Ra exceeds the outer edge 119Ab, with the second radius Rb having the length equal to or less than the radius R forming the outer edge 119Ab, the second radius Rb having the center at the position of the shaft center CE, the outer shape of the eccentric pin 125 is prevented from going over the outer edge 119Ab of the rotating shaft 119.
  • the processing of the rotating shaft 119 requires labor with the eccentric pin 125 being an obstacle in the processing, and the assembly requires labor with the eccentric pin 125 being an obstacle in inserting the rotating shaft 119 in the bearings 121 and 123, and thus such inconvenience is eliminated.
  • the first radius Ra, the second radius Rb, the radius R, and the distance p between the position of the shaft center CE and the position of the eccentric center LE preferably satisfy the relation of (Ra 2 + ⁇ 2 ) 1/2 s Rb ⁇ R.
  • the second circular arc 125b is formed with the second radius Rb having the length equal to or less than the radius R forming the outer edge 119Ab of the rotating shaft 119, the second radius Rb having the center at the position of the shaft center CE, and if the second radius Rb becomes too much less than the radius R, a diameter of the outer shape of the eccentric pin 125 becomes too small.
  • a lower limit of the second radius Rb is set by the relation, (Ra 2 + ⁇ 2 ) 1/2 ⁇ Rb ⁇ R, the diameter of the outer shape of the eccentric pin 125 is prevented from becoming too small.
  • an effect of enabling the rigidity of the eccentric pin 125 to be improved, and the bending of the eccentric pin 125 to be reduced, is achieved.
  • the connected portion 143A is arranged displaced in a lengthwise direction (rightward in FIG. 8 ) of the bush 141 with respect to the bush 141, and a stepped portion 147 is formed between the contact end surface 141b of the bush 141, the contact end surface 141b facing the end surface 119Aa of the disk portion 119A of the rotating shaft 119, and an end surface 143Ab of the connected portion 143A.
  • the stepped portion 147 is formed by the connected portion 143A being attached to the bush 141, such that the end surface 143Ab of the connected portion 143A is a little separate from the end surface 119Aa of the disk portion 119A of the rotating shaft 119 more than the contact end surface 141b of the bush 141.
  • a joining portion 149 which joins the bush 141 and the connected portion 143A together, is provided.
  • the joining portion 149 is formed on the end surface 143Ab of the connected portion 143A and on a side surface of the bush 141, in the stepped portion 147, and is formed such that the joining portion 149 does not protrude towards the end surface 119Aa of the disk portion 119A of the rotating shaft 119, more than the contact end surface 141b of the bush 141.
  • the joining portion 149 is formed by laser welding. Not being limited to laser welding, the joining portion 149 may be formed by any other welding.
  • the bush assembly 137 includes: the bush 141, into which the eccentric pin 125 is inserted, which has the contact end surface 141b that comes into contact with the end surface 119Aa of (the disk portion 119A of) the rotating shaft 119, and which is inserted in the cylindrically shaped boss 135c provided at the bottom surface of the orbiting scroll 135; the balance weight 143 having the connected portion 143A and the weight 143B, the connected portion 143A arranged in the outer peripheral portion of the bush 141 and near the contact end surface 141b, and the weight 143B provided, in the cantilevered shape, in the portion of the outer periphery of the connected portion 143A, so as to stick out in the direction going away from the contact end surface 141b; the stepped portion 147 provided between the connected portion 143A and the contact end surface 141b of the bush 141; and the joining portion 149, which is provided in the stepped portion 147 and joins the bush 141 and the
  • the moment having the starting point at the connected portion 143A acts so that the weight 143B is rotated towards the contact end surface 141b, and in the stepped portion 147, this moment acts so that the connected portion 143A is caused to approach the bush 141.
  • the joining portion 149 joining the bush 141 and the connected portion 143A together is provided in the stepped portion 147, the joining portion 149 is prevented from protruding to the contact end surface 141b of the bush 141 coming into contact with the end surface 119Aa of the rotating shaft 119, and thus the joining portion 149 is prevented from interfering with the end surface 119Aa of the rotating shaft 119 and processing of the joining portion 149 for preventing the interference is omitted.
  • the joining portion 149 is provided between the connected portion 143A and the contact end surface 141b at the side opposite to the side to which the weight 143B sticks out; regardless of the presence of the weight 143B, the joining portion 149 is provided easily.
  • the joining portion 149 may be provided on the whole circumference in a circumferential direction of the bush 141, but as illustrated in FIG. 9 , the joining portion 149 is preferably provided at plural positions (three positions in FIG. 9 ) in the circumferential direction of the bush 141.
  • the circumferential direction of the bush 141 refers to a direction along a peripheral surface of the bush 141, with reference to a center O of the bush 141.
  • this scroll compressor 101 if the joining portion 149 is formed by welding, when the joining portion 149 is provided at plural positions in the circumferential direction of the bush 141, rather than being provided on the whole circumference in the circumferential direction of the bush 141, thermal deformation of the bush 141 and the connected portion 143A due to the welding heat is reduced.
  • the joining portion 149 when the joining portion 149 is provided at plural positions in the circumferential direction of the bush 141, the joining portion 149 is preferably arranged evenly in the circumferential direction of the bush 141.
  • the joining portion 149 is provided at three positions in the circumferential direction of the bush 141, and is evenly arranged at 120° intervals with reference to the center O of the bush 141.
  • this scroll compressor 101 when the joining portion 149 is formed by welding, since the joining portion 149 is arranged evenly in the circumferential direction of the bush 141, even if thermal deformation of the bush 141 or the joining portion 143A due to the welding heat is caused, the thermal deformation is equalized and local deformation is reduced.
  • the joining portion 149 when the joining portion 149 is provided at plural positions in the circumferential direction of the bush 141, more of the positions of the joining portion 149 are preferably situated near where the weight 143B is provided.
  • the joining portion 149 is evenly arranged in the circumferential direction of the bush 141, as illustrated in FIG. 9 , in a configuration where the joining portion 149 is provided at an odd number of positions in the circumferential direction of the bush 141, more of the positions of the joining portion 149 are situated near where the weight 143B is provided.
  • the moment having the starting point at the connected potion 143A acts near where the weight 143B is provided, and thus when the joining portion 149 is provided at plural positions in the circumferential direction of the bush 141, by more of the positions of the joining portion 149 being situated near where the weight 143B is provided, the effect of increasing the rigidity of the joining between the bush 141 and the connected portion 143A is achieved.
  • an oil feeding groove 151 is provided in the outer peripheral portion of the bush 141 and along the extending direction of the cylindrical shape, and the joining portion 149 is arranged separately from a radial direction range of the oil feeding groove 151.
  • the oil feeding groove 151 is for feeding the lubricating oil to the scroll compression mechanism 107, and when the joining portion 149 is formed by welding, by the joining portion 149 being arranged separately from the radial direction range of the oil feeding groove 151, thermal deformation of the oil feeding groove 151 due to the welding heat is reduced, and the lubricating oil is fed smoothly by the oil feeding groove 151.
  • the bush 141 is formed of a sintered material
  • the balance weight 143 is formed of a cast iron material.
  • the bush 141 is a sliding member connected to the eccentric pin 125 and the boss 135c of the orbiting scroll 135, the bush 141 is preferably formed of a sintered material having a hardness that is comparatively high.
  • the balance weight 143 has the weight 143B, which balances the dynamic unbalance generated due to unbalanced weights of the orbiting scroll 135, the boss 135c, the orbiting bearing 145, the bush assembly 137, and the like, in association with the orbiting motion of the orbiting scroll 135; the balance weight 143 is preferably formed of a cast iron material having a density that is comparatively high.
  • the bush 141 and the connected portion 143A of the balance weight 143 are preferably fixed by shrinkage fitting or interference fitting.
  • the bush 141 and the connected portion 143A of the balance weight 143 are fixed by shrinkage fitting or interference fitting, synergistically with the inclusion of the joining portion 149, the effect of obtaining the rigidity of the joining between the bush 141 and the connected portion 143A is achieved.
  • an inner diameter of the hole portion 143Aa of the connected portion 143A is formed smaller than the outer diameter of the bush 141, the bush 141 and the connected portion 143A are fitted to each other by shrinkage fitting or interference fitting, and thereafter, the joining portion 149 is formed by welding.
  • the joining portion 149 is formed by welding without displacement between the bush 141 and the connected portion 143A being caused.
  • the bush 141 is provided rotatably with respect to the eccentric pin 125; the limit pin 142, which is inserted in the limit hole 126 formed on the end surface 119Aa of the rotating shaft 119 and restricts the rotational range, is provided; and the joining portion 149 is arranged separately from the radial direction range of the part where the limit pin 142 is attached (the fitting hole 141c, in which the limit pin 142 is fitted).
  • this scroll compressor 101 when the joining portion 149 is formed by welding, since the joining portion 149 is arranged separately from the radial direction range of the part where the limit pin 142 is attached, thermal deformation of the part where the limit pin 142 is attached due to the welding heat is reduced, and the attachment of the limit pin 142 is prevented from being hindered.
  • the configuration, in which the limit hole 126 is formed on the end surface 119Aa of the rotating shaft 119 and the limit pin 142 is attached to the bush 141, is adopted, but limitation is not made thereto.
  • the limit pin 142 may be attached to the end surface 119Aa of the rotating shaft 119 and the limit hole 126 may be formed in the bush 141.
  • the bush 141 is provided rotatably with respect to the eccentric pin 125; the limit hole 126, in which the limit pin 142 fixed to the end surface 119Aa of the rotating shaft 119 is inserted and which restricts the rotational range, is provided; and the joining portion 149 is arranged separately from a radial direction range of a part where the limit hole 126 is formed.
  • this scroll compressor 101 when the joining portion 149 is formed by welding, since the joining portion 149 is arranged separately from the radial direction range of the part where the limit hole 126 is formed, thermal deformation of the part where the limit hole 126 is formed due to the welding heat is reduced, and accuracy of the rotational range restricted by the limit hole 126 is prevented from being reduced.
  • the maximum number of rotations per second of the rotating shaft 119 exceeds 145 rps.
  • the scroll fluid machine is not limited to the scroll compressor 1 or 101, and may be a scroll expander.
  • a scroll expander which is a scroll fluid machine
  • an orbiting scroll engaging with a fixed scroll is caused to orbit by compressed fluid, causing the fluid to expand and causing rotational drive power to be generated in a rotating shaft. That is, the above described configurations of the eccentric pin 25 or 125 of the rotating shaft 19 or 119 and configuration of the bush assembly 37 or 137 of the scroll compression mechanism 7 or 107 are also applicable to the scroll expander.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Rotary Pumps (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
  • Sliding-Contact Bearings (AREA)
EP16194260.2A 2015-10-20 2016-10-18 Scroll fluid machine Pending EP3159545A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2015206683A JP6685689B2 (ja) 2015-10-20 2015-10-20 スクロール流体機械

Publications (1)

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EP3159545A1 true EP3159545A1 (en) 2017-04-26

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ID=57144887

Family Applications (1)

Application Number Title Priority Date Filing Date
EP16194260.2A Pending EP3159545A1 (en) 2015-10-20 2016-10-18 Scroll fluid machine

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EP (1) EP3159545A1 (ja)
JP (1) JP6685689B2 (ja)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110735790A (zh) * 2018-07-18 2020-01-31 翰昂汽车零部件有限公司 涡旋式压缩机
CN112534138A (zh) * 2018-08-31 2021-03-19 三电汽车部件株式会社 涡旋压缩机

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* Cited by examiner, † Cited by third party
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JPH05288168A (ja) * 1992-04-10 1993-11-02 Sanyo Electric Co Ltd スクロール圧縮機
JPH07197890A (ja) * 1995-01-25 1995-08-01 Mitsubishi Electric Corp スクロール圧縮機
JPH0842467A (ja) * 1995-06-23 1996-02-13 Mitsubishi Electric Corp スクロール圧縮機
US5542830A (en) * 1994-08-09 1996-08-06 Mitsubishi Jukogyo Kabushiki Kaisha Bearing lubrication for scroll-type compressor
JP2003343454A (ja) 2002-05-29 2003-12-03 Daikin Ind Ltd スライドブッシュ及びスクロール型流体機械
US20100172781A1 (en) * 2007-12-27 2010-07-08 Mitsubishi Heavy Industries, Ltd. Scroll compressor
US20150037185A1 (en) * 2013-07-31 2015-02-05 Trane International Inc. Orbiting crankshaft drive pin and associated drive pin sleeve geometry
EP2913531A1 (en) * 2014-02-28 2015-09-02 Mitsubishi Heavy Industries, Ltd. Scroll compressor with balance weight

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JPS60206989A (ja) * 1984-03-30 1985-10-18 Mitsubishi Electric Corp スクロ−ル形流体機械
JPS61118579A (ja) * 1984-11-14 1986-06-05 Matsushita Electric Ind Co Ltd スクロ−ル圧縮機
JPH09329091A (ja) * 1996-06-13 1997-12-22 Daikin Ind Ltd スクロール型流体装置
US6682323B2 (en) * 2002-05-21 2004-01-27 Scroll Technologies Simplified stamped counterweight
JP4622242B2 (ja) * 2003-12-19 2011-02-02 ダイキン工業株式会社 スクロール圧縮機
JP2005201148A (ja) * 2004-01-15 2005-07-28 Daikin Ind Ltd スクロール流体機械
JP2008240597A (ja) * 2007-03-27 2008-10-09 Daikin Ind Ltd 可変クランク機構及び可変クランク機構を備えたスクロール流体機械
WO2015104863A1 (ja) * 2014-01-08 2015-07-16 三菱電機株式会社 回転式圧縮機

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05288168A (ja) * 1992-04-10 1993-11-02 Sanyo Electric Co Ltd スクロール圧縮機
US5542830A (en) * 1994-08-09 1996-08-06 Mitsubishi Jukogyo Kabushiki Kaisha Bearing lubrication for scroll-type compressor
JPH07197890A (ja) * 1995-01-25 1995-08-01 Mitsubishi Electric Corp スクロール圧縮機
JPH0842467A (ja) * 1995-06-23 1996-02-13 Mitsubishi Electric Corp スクロール圧縮機
JP2003343454A (ja) 2002-05-29 2003-12-03 Daikin Ind Ltd スライドブッシュ及びスクロール型流体機械
US20100172781A1 (en) * 2007-12-27 2010-07-08 Mitsubishi Heavy Industries, Ltd. Scroll compressor
US20150037185A1 (en) * 2013-07-31 2015-02-05 Trane International Inc. Orbiting crankshaft drive pin and associated drive pin sleeve geometry
EP2913531A1 (en) * 2014-02-28 2015-09-02 Mitsubishi Heavy Industries, Ltd. Scroll compressor with balance weight

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110735790A (zh) * 2018-07-18 2020-01-31 翰昂汽车零部件有限公司 涡旋式压缩机
CN110735790B (zh) * 2018-07-18 2022-03-04 翰昂汽车零部件有限公司 涡旋式压缩机
CN112534138A (zh) * 2018-08-31 2021-03-19 三电汽车部件株式会社 涡旋压缩机

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