JP2020112143A - Scroll type fluid machine - Google Patents

Abstract

To reduce energy loss, and to reduce load imbalance in a thrust direction of a scroll.SOLUTION: In a scroll-type fluid machine 100, a back pressure chamber H3 is partitioned into a plurality of regions (H3a, H3b, H3c) by a back face 3a1 of a movable scroll 3, a thrust receiving face 24c, and a plurality of annular seal members 19 (19a, 19b, 19c) disposed into a multiple annular shape between the back face 3a1 and the thrust receiving face 24c, and blocked in communication with the region having a pressure lower than the pressure in the back pressure chamber H3. Through holes 3d penetrated through a second bottom plate 3a of the movable scroll 3 in a plate thickness direction, are opened corresponding to each of the regions (H3a, H3b, H3c) of the plurality of regions. Each region of the plurality of regions is communicated with a sealed space S to which the through hole 3d is opened, among the plurality of sealed spaces S through the through hole 3d corresponding to the region.SELECTED DRAWING: Figure 1

Description

The present invention relates to a scroll type fluid machine that has a fixed scroll and a movable scroll that are meshed with each other, and that compresses or expands a fluid by changing the volume of a sealed space formed by these.

The scroll type fluid machine has a first scroll and a second scroll which are meshed with each other, and at least one scroll of the first scroll and the second scroll revolves with respect to the other scroll, thereby A scroll unit is formed between the first scroll and the second scroll, the scroll unit forming a plurality of hermetically sealed spaces whose volumes change in accordance with the revolution orbiting motion, and the bottom plate of the one scroll is formed on the opposite side of the other scroll. And a back pressure chamber. The scroll fluid machine compresses or expands the fluid while pressing the one scroll toward the other scroll side by the back pressure chamber pressure (back pressure).

As this type of scroll type fluid machine, for example, a scroll type compressor described in Patent Document 1 (hereinafter referred to as a scroll type fluid machine) is generally known. The scroll type fluid machine described in Patent Document 1 has an orbiting scroll as the one scroll and a fixed scroll as the other scroll, and the plurality of hermetic seals are provided between the orbiting scroll and the fixed scroll. It forms a space. Further, in this scroll type fluid machine, the volume of the closed space is reduced in accordance with the revolution revolving motion, thereby compressing the refrigerant as the fluid flowing into the closed space from the suction chamber and passing through the discharge chamber to the outside. Is being discharged to. The back pressure chamber is provided as an annular space on the back surface side of the bottom plate of the orbiting scroll. By decompressing the refrigerant in the discharge chamber to an intermediate pressure and supplying it intermittently to the back pressure chamber, the compression reaction force in the axial direction of the drive shaft of the scroll unit acting on the bottom plate of the orbiting scroll is generated. A back pressure load is generated to resist the load (that is, the load in the thrust direction). Specifically, a refrigerant supply path for supplying a part of the refrigerant in the discharge chamber to the back pressure chamber and a refrigerant discharge path for discharging the refrigerant in the back pressure chamber to the suction chamber area are provided. It can be said that the back pressure in the entire back pressure chamber is set to a predetermined value by balancing the supply flow rate and the discharge flow rate. Similarly, in the scroll compressor described in Patent Document 2, a back pressure supply passage for supplying a part of the refrigerant in the compression chamber to the back pressure chamber and a throttle for discharging the refrigerant in the back pressure chamber to the suction chamber region. And a passage is provided.

JP, 2005-201173, A JP, 2018-168757, A

However, in the scroll-type fluid machine described in Patent Document 1 or Patent Document 2, the back pressure chamber is communicated with the low pressure region lower than the pressure in the back pressure chamber by the refrigerant discharge path and the throttle passage. Therefore, a part of the fluid in the discharge chamber is supplied to the back pressure chamber, and the fluid in the back pressure chamber is dripped from the back pressure chamber to the low pressure region by the refrigerant discharge path and the throttle passage. Therefore, the amount of energy loss is generated by the amount of this drift.

Further, the scroll type fluid machine described in Patent Document 1 or Patent Document 2 is a compressor, and the pressure in the closed space progresses from the spiral outer end side of the orbiting scroll and the fixed scroll to the spiral center portion side. According to. Therefore, the entire pressure distribution of the plurality of closed spaces shows a distribution that rises from the outer peripheral portion of the bottom plate of the orbiting scroll toward the central portion. Therefore, the load due to the compression reaction force in the axial direction acting on the orbiting scroll generally increases from the outer peripheral portion of the bottom plate of the orbiting scroll toward the central portion.

However, in the scroll-type fluid machine described in Patent Document 1, the back pressure chamber is provided as one annular space of the intermediate pressure in the outer peripheral portion of the bottom plate on which the lowest compression reaction force acts. It's just Further, the back pressure chamber is not positively provided in the central portion of the bottom plate where the highest compression reaction force acts, and in the central portion, at most, the pressure of the refrigerant lower than the intermediate pressure is maintained. The pressure in the suction area can act as a back pressure. Further, in the scroll type fluid machine described in Patent Document 2, high-pressure refrigerant in the compression chamber on the central side of the plurality of closed spaces is supplied to the back pressure chamber via the back pressure supply passage. However, the total pressure of the back pressure chamber is substantially constant throughout. In other words, in these scroll type fluid machines, the pressure distribution of the entire plurality of sealed spaces and the pressure distribution of the entire back pressure are completely different. Therefore, the pressure and back pressure of the closed space are not balanced between the outer peripheral portion and the central portion of the bottom plate, and the load due to the compression reaction force and the back pressure load are unbalanced, that is, A load imbalance in the axial direction (thrust direction) of the orbiting scroll is likely to occur. Due to this load imbalance, excessive sliding loss or excessive gap occurs between the bottom plate of the orbiting scroll and the protruding end of the wrap of the fixed scroll, or the orbit of the orbiting scroll. The bottom plate may be distorted.

Further, in the scroll type fluid machine described in Patent Document 1, the flow path for adjusting the pressure of the back pressure chamber is relatively moved through the block forming the discharge chamber, the fixed scroll and the orbiting scroll. Since it has a long flow path length and its flow path path is complicated, pressure loss is likely to occur in the process of flowing the refrigerant. Therefore, the load imbalance is more likely to occur. The same applies to the scroll type fluid machine described in Patent Document 2. Although the scroll type fluid machines described in Patent Documents 1 and 2 are compressors, reduction of the energy loss and reduction of the load imbalance are also required in the case of expanders.

The present invention has been made in view of the above problems, and is a scroll type that can reduce energy loss and can effectively reduce load imbalance in the thrust direction that acts on at least one scroll of a scroll unit. An object is to provide a fluid machine.

According to one aspect of the present invention, the first scroll and the second scroll are meshed with each other, and at least one scroll of the first scroll and the second scroll revolves with respect to the other scroll. Thus, between the first scroll and the second scroll, a scroll unit that forms a plurality of sealed spaces that change in volume due to the revolution orbiting motion, and the other scroll in the bottom plate of the one scroll are And a back pressure chamber formed on the opposite side, wherein the scroll unit compresses or expands the fluid while pressing the one scroll toward the other scroll side by the back pressure chamber pressure. Will be provided. The back pressure chamber includes a back surface of the bottom plate of the one scroll, a thrust receiving surface that faces the back surface and receives a thrust force from the one scroll, and a plurality of back surface and the thrust receiving surface. It is divided into a plurality of regions by a plurality of annular seal members arranged in an annular shape, and communication with a region of lower pressure than the pressure in the back pressure chamber is blocked. A through hole that penetrates the bottom plate of the one scroll in the plate thickness direction is opened corresponding to each of the plurality of regions. Each region of the plurality of regions communicates with the sealed space in which the through hole opens among the plurality of sealed spaces via the through hole corresponding to the region.

In the scroll type fluid machine according to the one aspect, the back pressure chamber has a lower pressure region than the pressure in the back pressure chamber (that is, a suction chamber in the case of a compressor, an expanded low pressure region in the case of an expander). It does not communicate with the discharge area where the fluid is discharged. That is, the escape passage (pressure release passage) such as the refrigerant discharge passage of Patent Document 1 and the throttle passage of Patent Document 2 for releasing the pressure in the back pressure chamber is positive in the scroll type fluid machine having the one side surface. Not provided in. Therefore, in the scroll type fluid machine according to the one aspect, in the case of the compressor, it is assumed that a part of the high-pressure fluid obtained by the compression operation is supplied to the back pressure chamber through the through hole to form the back pressure. However, the fluid does not flow down to a region lower than the pressure in the back pressure chamber. Further, in the scroll type fluid machine according to the one aspect, in the case of an expander, even if a part of the high pressure fluid that flows in is supplied to the back pressure chamber through the through hole to form a back pressure, that fluid Will not be spilled into a region of lower pressure than the pressure in the back pressure chamber. As a result, energy loss can be reduced in both the compressor and the expander.

Further, in the scroll type fluid machine according to the one aspect, the back pressure chamber includes a back surface of the bottom plate of the one scroll, a thrust receiving surface facing the back surface and receiving a thrust force from the one scroll, It is divided into a plurality of regions by a plurality of annular seal members arranged in a multiple annular shape between the back surface and the thrust receiving surface. Then, a through hole penetrating the bottom plate of the one scroll in the plate thickness direction is opened corresponding to each region of the plurality of regions, each region of the plurality of regions, in the region concerned. Through the corresponding through holes, the plurality of closed spaces communicate with the closed space where the through holes open. Thereby, the pressure distribution of the entire back pressure acting on the back surface of the bottom plate can be generally matched with the pressure distribution of the entire closed spaces acting on the end face of the bottom plate on the sealed chamber side. Further, since the through hole simply penetrates the bottom plate in the plate thickness direction, the flow path is shorter than the conventional flow path and the flow path is simple. Therefore, the pressure loss in the process of flowing the fluid through the through hole is lower than that in the conventional case. Accordingly, in the scroll type fluid machine according to the one aspect, it is possible to effectively reduce the load imbalance between the load in the thrust direction and the back pressure load acting on the one scroll.

In this way, it is possible to provide a scroll type fluid machine capable of reducing energy loss and effectively reducing the load imbalance in the thrust direction of at least one scroll in the scroll unit.

It is a schematic sectional drawing of the scroll type fluid machine in a 1st embodiment of the present invention. FIG. 2 is a sectional view taken along the line AA of FIG. 1. It is a front view of the crankshaft of the scroll type fluid machine. It is a front view of a rocking member of the scroll fluid machine. It is a front view of the thrust receiving part of the scroll type fluid machine. It is a rear view of the movable scroll of the scroll type fluid machine. It is a schematic sectional drawing of the principal part of the said scroll type fluid machine. FIG. 8 is a sectional view taken along the line BB shown in FIG. 7. It is a conceptual diagram for demonstrating the load of the thrust direction which acts on the said movable scroll. It is a schematic sectional drawing of the scroll type fluid machine in a 2nd embodiment of the present invention. It is a schematic sectional drawing of the scroll type fluid machine in 3rd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail. The scroll type fluid machine according to the present invention can be used as a compressor or an expander. Here, an example of the compressor will be described.

First, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic sectional view showing an overall configuration of a scroll type fluid machine in the present embodiment, and FIG. 2 is a sectional view taken along the line AA of FIG. 3 to 6 are each a component diagram of a scroll type fluid machine, FIG. 3 is a front view of a crankshaft, FIG. 4 is a front view of a rocking member, FIG. 5 is a front view of a thrust receiving portion, and FIG. It is a rear view of a scroll.

The scroll fluid machine 100 in the present embodiment is, for example, a compressor that is incorporated in a refrigerant circuit of a vehicle air conditioner and that compresses and discharges a refrigerant (fluid) drawn from a low pressure side of the refrigerant circuit. The scroll fluid machine 100 includes a scroll unit 1, a housing 10, and a drive mechanism 20 that transmits a driving force to the scroll unit 1. The scroll unit 1 and the drive mechanism 20 are housed inside the housing 10. In the present embodiment, the scroll fluid machine 100 also includes the electric motor 30 that is the drive source of the scroll unit 1 in the housing 10. Further, the scroll fluid machine 100 has an inverter 40 for controlling the drive of the electric motor 30 housed inside the housing 10, and an example of a so-called inverter-integrated electric compressor will be described.

As shown in FIG. 1, the scroll unit 1 has a fixed scroll 2 and a movable scroll 3 which are meshed with each other. In the scroll fluid machine 100, the orbiting scroll 3 is in contact with the fixed scroll 2 and revolves around the axis X′ of the fixed scroll 2, and the volume of the movable scroll 3 changes along with the revolving movement, which will be described later. It is configured to form a plurality of closed spaces S. Further, in the present embodiment, the scroll unit 1 is configured to compress and discharge the refrigerant in the closed space S. For example, the fixed scroll 2 and the movable scroll 3 are made of aluminum alloy.

Specifically, the fixed scroll 2 is formed in a substantially disc shape, and has a first bottom plate 2a having a discharge hole 2a1 opened in the center thereof, and a spiral scroll first member provided upright on one end surface of the first bottom plate 2a. 1 wrap 2b. The movable scroll 3 includes a substantially disk-shaped second bottom plate 3a having one end face facing the one end face of the first bottom plate 2a, and a spiral second wrap 3b erected on the one end face of the second bottom plate 3a. Have and. The first bottom plate 2a of the fixed scroll 2 has a larger diameter than the second bottom plate 3a of the movable scroll 3.

The fixed scroll 2 and the movable scroll 3 are arranged so that the first wrap 2b and the second wrap 3b mesh with each other. Specifically, the fixed scroll 2 and the movable scroll 3 are arranged such that the circumferential angle of the first wrap 2b and the circumferential angle of the second wrap 3b are deviated from each other and the side wall of the first wrap 2b and the second wrap are different from each other. The side walls of 3b are arranged so as to partially contact each other. Thereby, a plurality of closed spaces S (compression chambers in the present embodiment) are formed between the first wrap 2b and the second wrap 3b. That is, a plurality of closed spaces S are formed between the fixed scroll 2 and the movable scroll 3. Further, the fixed scroll 2 and the movable scroll 3 have a gap (hereinafter, referred to as a first lap end gap) between the projecting end portion of the first wrap 2b and the second bottom plate 3a, and the projecting end of the second wrap 3b. It is arranged so as to have a gap (hereinafter, referred to as a second lap end gap) between the portion and the first bottom plate 2a. In the present embodiment, the tip seal member 4 is fitted into the groove formed on the protruding end of the first wrap 2b and the groove formed on the protruding end of the second wrap 3b. The chip seal member 4 appropriately maintains the airtightness of the closed space S, and as a result, the compression performance of the refrigerant in the scroll fluid machine 100 is maintained. The plurality of closed spaces S will be described later in detail.

More specifically, the fixed scroll 2 has a cylindrical cylindrical portion 2c that is erected on the outer edge of the one end surface of the first bottom plate 2a. The cylindrical portion 2c has an outer diameter that matches the inner diameter of the opening on one end side (upper side in FIG. 1) of the center housing 11 of the housing 10 described later. The fixed scroll 2 is fitted in the center housing 11 so that the first wrap 2b and the cylindrical portion 2c are directed to the inside of the center housing 11 and the one end opening of the center housing 11 is closed.

In the present embodiment, the back surface 3a1 of the second bottom plate 3a of the movable scroll 3 is formed in a flat plane shape. It should be noted that the back surface 3a1 of the second bottom plate 3a can be said in other words as the other end surface of the second bottom plate 3a or the end surface of the second bottom plate 3a opposite to the fixed scroll 2.

The movable scroll 3 is configured to be able to revolve around the axis X′ of the fixed scroll 2 through the drive mechanism 20 in a state where its rotation is blocked. As a result, the scroll unit 1 moves the closed space S between the fixed scroll 2 and the movable scroll 3 to the central portion, and gradually reduces the volume thereof. As a result, the scroll unit 1 compresses the refrigerant flowing into the closed space S from the spiral outer end side of the first wrap 2b and the second wrap 3b in the closed space S.

In this way, the movable scroll 3 has the fixed scroll 2 and the movable scroll 3 which are meshed with each other, and the movable scroll 3 revolves around the fixed scroll 2 so that the revolving scroll is moved between the fixed scroll 2 and the movable scroll 3. The scroll unit 1 is configured to form a plurality of closed spaces S whose volumes change with the orbiting motion.

In the case of the expander, the closed space S is moved in the opposite direction from the center of the first wrap 2b and the second wrap 3b toward the outer end of the spiral, so that the volume of the closed space S increases. The fluid that has changed and is taken into the closed space S from the central portion side of the first wrap 2b and the second wrap 3b is expanded. Further, in the present embodiment, the movable scroll 3 corresponds to “one scroll” of the “first scroll and the second scroll” according to the present invention, and the fixed scroll 2 corresponds to the “first scroll and the first scroll” according to the present invention. The second bottom plate 3a corresponds to the "bottom plate of one scroll" according to the present invention.

The housing 10 includes a center housing 11, a front housing 12, an inverter cover 13, and a rear housing 14. Then, these (11, 12, 13, 14) are integrally fastened by fastening members such as bolts 15 to form the housing 10 of the scroll fluid machine 100. The housing 10 is made of, for example, an aluminum alloy.

The center housing 11 has a substantially cylindrical peripheral wall portion 11a and an annular protruding portion 11b that is protruded inward along an inner peripheral surface of the peripheral wall portion 11a in the longitudinal direction. Inside the center housing 11, the scroll unit 1, the drive mechanism 20, and the electric motor 30 are mainly housed. The end surface of the outer edge portion 14a of the rear housing 14 is in contact with one end of the peripheral wall portion 11a. Further, the opening on the other end side (lower side in FIG. 1) of the peripheral wall portion 11 a is closed by the front housing 12.

A low pressure side port (suction port) C1 into which the refrigerant flows is formed in the peripheral wall portion 11a. Refrigerant from the low pressure side of the refrigerant circuit is sucked into the center housing 11 via the low pressure side port C1. Therefore, the space inside the center housing 11 functions as the suction chamber H1. The electric motor 30 is cooled by circulating the refrigerant around the electric motor 30 in the suction chamber H1. In FIG. 1, the space above the electric motor 30 communicates with the space below the electric motor 30 and constitutes one suction chamber H1 together with the space below the electric motor 30. In addition, an appropriate amount of lubricating oil is stored in the suction chamber H1 in order to lubricate sliding parts such as the drive mechanism 20. Therefore, in the suction chamber H1, the refrigerant flows as a mixed fluid with the lubricating oil.

An end surface 11b1 of the protruding portion 11b on the rear housing 14 side is formed as an annular surface orthogonal to a rotation axis X of a drive shaft 21a of the drive mechanism 20 described later. A thrust receiving portion 24, which will be described later, of the drive mechanism 20 is brought into contact with the end surface 11b1. The fixed scroll 2 is fixed in the center housing 11 together with the thrust receiving portion 24 by sandwiching the fixed scroll 2 between the thrust receiving portion 24 and the rear housing 14.

The front housing 12 is formed in a box shape with one end opening as a whole, and is provided so as to protrude from the box bottom portion 12a that closes the opening on the other end side of the peripheral wall portion 11a of the center housing 11 and the outer edge portion of the box bottom portion 12a. It has the side wall part 12b and accommodates the inverter 40 inside. At the center of the box bottom portion 12a, a cylindrical support portion 12a1 holding a front bearing 16 for supporting the end portion (lower end portion in FIG. 1) of the drive shaft 21a is provided so as to project toward the inside of the center housing 11. There is.

The inverter cover 13 is formed in a plate shape and closes the one end opening of the front housing 12, and is fastened to the side wall portion 12b of the front housing 12 with a bolt 15.

The rear housing 14 is formed in a substantially disc shape having an outer diameter matching the outer diameter of the peripheral wall portion 11a of the center housing 11, and a central portion 14b thereof is formed so as to bulge outward. The outer edge portion 14a of the rear housing 14 is fastened to one end portion of the peripheral wall portion 11a by a fastening member such as an appropriate number of bolts 15.

A radially inner portion 14a1 of the outer edge portion 14a of the rear housing 14 projects inward from the inner peripheral surface of the peripheral wall portion 11a of the center housing 11. When the inner portion 14a1 contacts the outer edge portion of the first bottom plate 2a of the fixed scroll 2, the fixed scroll 2 is sandwiched between the thrust receiving portion 24 and the rear housing 14 (specifically, the inner portion 14a1). The bulging central portion 14b of the rear housing 14 and the first bottom plate 2a define a refrigerant discharge chamber H2. A seal member 17 is provided at a portion (the outer edge portion) of the fixed scroll 2 that is in contact with the inner portion 14a1 of the rear housing 14. The discharge chamber H2 communicates with the closed space S via a discharge hole 2a1 formed in the center of the first bottom plate 2a. A one-way valve 18 is provided in the discharge chamber H2 so as to cover the opening of the discharge hole 2a1. The one-way valve 18 is a check valve that restricts the flow from the discharge chamber H2 to the closed space S. The refrigerant compressed in the closed space S is discharged into the discharge chamber H2 through the discharge hole 2a1 and the one-way valve 18. The compressed refrigerant in the discharge chamber H2 is discharged to the high pressure side of the refrigerant circuit via a discharge port (not shown) formed in the rear housing 14.

The drive mechanism 20 is a mechanism for preventing rotation of the movable scroll 3 and transmitting the revolution drive force around the axis X′ of the fixed scroll 2 to the movable scroll 3.

As shown in FIGS. 1 and 2, in the present embodiment, the drive mechanism 20 includes a crankshaft 21, a swivel bearing 22, an annular rocking member 23, a thrust receiving portion 24, and a rotation preventing mechanism portion 25. The rear bearing 26 and the connecting pin 25a are included.

As shown in FIGS. 1 and 3, the crankshaft 21 is a shaft for driving the scroll unit 1, and has a drive shaft 21a and an eccentric shaft 21b. The drive shaft 21a is driven to rotate about the rotation axis X. The rotation axis X of the drive shaft 21a is aligned with the axis X'of the fixed scroll 2. The eccentric shaft 21b is provided at one end (upper end in FIG. 1) in the axial direction of the drive shaft 21a so as to be eccentric with respect to the rotation axis X. The crankshaft 21 is made of alloy steel, for example.

At the one end of the drive shaft 21a, a flange-shaped flange portion 21a1 is provided integrally with the eccentric shaft 21b. The other end of the drive shaft 21a has a reduced diameter and is rotatably supported by a front bearing 16 fitted into the support 12a1.

In the present embodiment, a counterweight 27 for ensuring a weight balance with the movable scroll 3 is formed separately from the crankshaft 21 on the flange portion 21a1 formed integrally with the eccentric shaft 21b. The counterweight 27 is fixed to the flange portion 21a1 by a fastening member (not shown) such as a rivet. Specifically, the counterweight 27 is formed into a substantially fan shape, and is substantially flush with the flange surface of the flange portion 21a1 at the predetermined angle portion in the outer peripheral portion of the flange portion 21a1 at the one end portion of the drive shaft 21a. It has been fixed to be.

Specifically, the eccentric shaft 21b has a circular cross section centered on an axis eccentric to the rotation axis X of the drive shaft 21a, and extends toward the scroll unit 1 side.

In the present embodiment, the eccentric shaft 21b is formed with a circular hole 21b1 concentric with the rotation axis X. That is, the center of the outer diameter of the eccentric shaft 21b is located on the shaft center that is eccentric with respect to the rotation shaft center X of the drive shaft 21a, but the center of the inner diameter of the eccentric shaft 21b is the rotation shaft center X of the drive shaft 21a. Located on top. In other words, the eccentric shaft 21b is formed in a tubular shape, and the center of the outer diameter of the cylinder is such that the first wrap 2b of the fixed scroll 2 and the second wrap 3b of the movable scroll 3 slide appropriately. Eccentric to the center of.

In the present embodiment, the eccentric shaft 21b is formed separately from the drive shaft 21a. Specifically, the hole diameter of the circular hole 21b1 of the eccentric shaft 21b is matched with the outer diameter of the drive shaft 21a, and penetrates the eccentric shaft 21b. The flange portion 21a1 is formed in a flange shape on the outer periphery of one end of the eccentric shaft 21b. The eccentric shaft 21b is fixed to the one end of the drive shaft 21a by press-fitting the one end of the drive shaft 21a into the circular hole 21b1 of the eccentric shaft 21b while leaving the accommodation area of the rear bearing 26. In other words, the hole wall surface of the circular hole 21b1 and the end surface of the one end of the drive shaft 21a form a circular recess at one end (eccentric shaft side end) of the crankshaft 21. The convex portion 24b of the thrust receiving portion 24 described later is inserted into the circular concave portion.

The slewing bearing 22 is a bearing fitted to the eccentric shaft 21b, and is, for example, a bearing fitted onto the outer peripheral surface of the eccentric shaft 21b. In the present embodiment, the slewing bearing 22 is a cylindrical plain bearing. The slewing bearing 22 has a height that approximately matches the protruding height from the flange surface of the flange portion 21a1 of the eccentric shaft 21b.

The swing member 23 is fitted onto the outer peripheral surface of the slewing bearing 22. The rocking member 23 is formed in a disk shape having a thickness that matches the height of the slewing bearing 22, and is made of, for example, an aluminum alloy material. A swivel bearing mounting hole 23 a having an inner diameter matched with the outer diameter of the swivel bearing 22 is formed in the center of the swing member 23.

As shown in FIG. 4, a plurality of (six in FIG. 2) portions of the outer edge portion of the swinging member 23, which are spaced at equal intervals in the circumferential direction, are respectively inserted with connecting pins 25a described later. A hole (hereinafter, referred to as an insertion hole) 23b is penetrated. The rocking member 23 is formed such that the region between the insertion holes 23b at the outer edge of the rocking member 23 is recessed radially inward. As a result, the weight of the rocking member 23 is reduced. Further, the recess of the outer edge portion of the swinging member 23 is formed in the vicinity of the spiral outer end portions of the first wrap 2b and the second wrap 3b of the scroll unit 1 from the suction chamber H1 together with the through hole 24a of the thrust receiving portion 24 described later. It functions as a refrigerant introduction passage for introducing a refrigerant (specifically, a mixed fluid of the refrigerant and the lubricating oil) into the space H4 formed in the space H4. Therefore, due to the depression of the outer edge of the swinging member 23, the refrigerant introduction passage is sufficiently secured, and the pressure loss of the refrigerant introduction passage can be easily reduced. The swivel bearing 22 is mounted between the hole wall surface of the swivel bearing mounting hole 23a of the swing member 23 and the outer peripheral surface of the eccentric shaft 21b. The slewing bearing 22 is press-fitted along, for example, either the outer peripheral surface of the eccentric shaft 21b or the hole wall surface of the slewing bearing mounting hole 23a, and the outer peripheral surface of the eccentric shaft 21b and the slewing bearing mounting hole 23a. Is slidably fitted along the other surface of the hole wall surface. As a result, the swing member 23 is rotatably attached to the eccentric shaft 21b via the swivel bearing 22 about the axis of the eccentric shaft 21b (that is, the axis eccentric to the rotation axis X of the drive shaft 21a). It is installed. The slewing bearing 22 may be slidably fitted to both the outer peripheral surface of the eccentric shaft 21b and the hole wall surface of the slewing bearing mounting hole 23a.

As shown in FIG. 1, the thrust receiving portion 24 is provided between the second bottom plate 3 a of the movable scroll 3 and the swing member 23, faces the rear surface 3 a 1 of the second bottom plate 3 a of the movable scroll 3, and is movable. It has a thrust receiving surface 24c for receiving the thrust force from. In the present embodiment, the thrust receiving surface 24c is formed in a flat planar shape like the back surface 3a1 of the second bottom plate 3a.

In the present embodiment, the thrust receiving portion 24 is formed separately from the housing 10. Specifically, the thrust receiving portion 24 is appropriately made of, for example, a steel material having better wear resistance than a material (for example, an aluminum alloy) used for the movable scroll 3, the swing member 23, the housing 10, and the like. It consists of members. The thrust receiving portion 24 is formed in a substantially disc shape having an outer diameter that matches the inner diameter of the opening on the one end side (the upper side in FIG. 1) of the center housing 11. An end surface of the thrust receiving portion 24 on the rocking member side (that is, an end surface opposite to the thrust receiving surface 24c) is in contact with an end surface 11b1 of the projecting portion 11b of the center housing 11. The thrust receiving portion 24 is fixed in the center housing 11 by, for example, the outer edge portion being sandwiched between the tip end surface of the cylindrical portion 2c of the fixed scroll 2 and the end surface 11b1 of the protruding portion 11b. The angular position of the thrust receiving portion 24 with respect to the fixed scroll 2 in the circumferential direction is determined by appropriate positioning means such as pins and pin holes (not shown).

In the present embodiment, the space within the center housing 11 is accommodated by the thrust receiving portion 24 in the accommodating region of the scroll unit 1 (upper space in FIG. 1) and the main components of the drive mechanism 20 including the crankshaft 21. It is divided into a region (a lower space in FIG. 1). Further, the play amount of the crankshaft 21 in the rotation axis X direction is restricted by the thrust receiving portion 24 and the front bearing 16.

As shown in FIG. 1 and FIG. 5, a plurality of through holes 24 a penetrating the outer edge portion are formed in the outer edge portion of the thrust receiving portion 24. In the present embodiment, the through holes 24a are opened in a circular shape, and are opened in a plurality of (six in FIG. 5) portions at equal intervals in the circumferential direction in the outer edge portion of the thrust receiving portion 24.

In the present embodiment, a cylindrical convex portion 24b is provided so as to project at the central portion of the end surface of the thrust receiving portion 24 on the rocking member side. The convex portion 24 b has an outer diameter that matches the inner diameter of the rear bearing 26. The protruding height of the convex portion 24b is approximately matched with the height of the slewing bearing 22. A rear bearing 26 is fitted on the outer peripheral surface of the convex portion 24b.

Further, as described above, the through hole 24a of the thrust receiving portion 24 functions as a refrigerant introduction passage for introducing the refrigerant into the space H4. Since the through hole 24a communicates between the space H4 and the suction chamber H1, the pressure in the space H4 is equal to the pressure in the suction chamber H1 (pressure in the suction chamber).

As shown in FIGS. 1 and 6, a plurality of holes 3c are opened in the outer edge portion of the second bottom plate 3a of the movable scroll 3. The hole 3c of the movable scroll 3 is opened at the same position as the opening position of the insertion hole 23b opened in the swing member 23.

7 and 8 are conceptual diagrams for explaining the meshing state of the orbiting scroll 3 at a predetermined revolving orbiting angle position (hereinafter referred to as a phase angle). FIG. FIG. 8 is a sectional view taken along the line BB shown in FIG. 7. The shapes of the main parts shown in FIGS. 7 and 8 do not completely match those of FIG. In FIG. 1, the number of the first wraps 2b and the second wraps 3b is reduced for the sake of simplicity. Further, the phase angle of the movable scroll 3 shown in FIG. 1 is different from the phase angle of the movable scroll 3 shown in FIGS. 7 and 8. In FIGS. 7 and 8, the hole 3c of the movable scroll 3 is not shown for simplification of the drawings.

As shown in FIG. 7, the scroll fluid machine 100 includes a back pressure chamber H3 formed on the second bottom plate 3a of the movable scroll 3 on the side opposite to the fixed scroll 2 (that is, on the back surface 3a1 side). The scroll fluid machine 100 rotates the scroll unit 1 while pressing the movable scroll 3 toward the fixed scroll 2 side by the pressure in the back pressure chamber H3 (back pressure chamber pressure).

A plurality of back pressure chambers H3 are arranged in a ring shape between the back surface 3a1 of the second bottom plate 3a of the movable scroll 3, the thrust receiving surface 24c of the thrust receiving portion 24, and the back surface 3a1 and the thrust receiving surface 24c. It is divided into a plurality of regions (three regions in the drawing) by the three annular sealing members 19 in the drawing. The back pressure chamber H3 is cut off from communication with a region having a lower pressure than the pressure inside the back pressure chamber H3. That is, in the scroll type fluid machine 100, the back pressure chamber H3 and the suction chamber H1 are not directly communicated with each other, and a relief passage (pressure release passage) for releasing the pressure in the back pressure chamber H3 is positively provided. Not provided.

As shown in FIGS. 7 and 8, through holes 3d penetrating the second bottom plate 3a of the orbiting scroll 3 in the plate thickness direction are opened corresponding to the respective regions of the plurality of regions. In addition, each region of the plurality of regions of the back pressure chamber H3 is a closed space S in which the through hole 3d is opened (connected) among the plurality of closed spaces S via the through hole 3d corresponding to the region. It is in communication.

In the present embodiment, the plurality of annular seal members 19 include an annular inner seal member 19a, an outer seal member 19c annularly arranged outside the inner seal member 19a, an inner seal member 19a and an outer seal member 19c. It is composed of an intermediate seal member 19b arranged annularly between them. The respective seal members 19a, 19b, 19c are fitted into corresponding groove portions 3e formed on the back surface 3a1 of the second bottom plate 3a of the movable scroll 3, and are arranged concentrically around the axis of the movable scroll 3.

Specifically, as shown in FIG. 6, the groove portion 3e for the inner seal member 19a and the groove portion 3e for the intermediate seal member 19b are each formed in a circular ring shape. The groove portion 3e for the outer seal member 19c is formed so as not to overlap the region of the plurality of through holes 24a in the thrust receiving portion 24 when the movable scroll 3 revolves around the axis X'of the fixed scroll 2. ing. That is, the groove portion 3e for the outer seal member 19c is formed so as to be curved inward, avoiding a portion corresponding to the moving region of the through hole 24a in the back surface 3a1 of the second bottom plate 3a of the movable scroll 3. Each of the sealing members 19a, 19b, 19c is formed in a shape matching the corresponding groove 3e.

In the present embodiment, as shown in FIG. 7, the back pressure chamber H3 includes a central region H3a inside the inner seal member 19a, an intermediate region H3b between the inner seal member 19a and the intermediate seal member 19b, and an intermediate seal. It is partitioned into an outer region H3c between the member 19b and the outer seal member 19c. That is, the plurality of regions are the central region H3a, the intermediate region H3b, and the outer region H3c.

Further, the respective seal members (19a, 19b, 19c) fitted in the respective groove portions 3e of the back surface 3a1 protrude from the back surface 3a1 by a predetermined protrusion height. The respective seal members (19a, 19b, 19c) fitted in the groove 3e are pressed by the rear surface 3a1 and deformed by the amount of the crushing margin, and in this state, they slightly protrude from the rear surface 3a1. Therefore, the back pressure chamber H3 has a slight gap height corresponding to the crushing allowance of each seal member (19a, 19b, 19c). The gap height is set to be, for example, about 1 to 200 μm.

In the state (phase angle) shown in FIGS. 7 and 8, between the fixed scroll 2 and the movable scroll 3, a plurality of closed spaces S are provided, which are opposed to each other with the central space Sa interposed therebetween. A pair of crescent-shaped intermediate spaces Sb1 and Sb2, and a pair of crescent-shaped outer spaces Sc1 and Sc2 that are opposed to each other with the central space Sa and the pair of crescent-shaped intermediate spaces Sb1 and Sb2 interposed therebetween are formed. ing. The through hole 3d is opened corresponding to each of the central region H3a, the intermediate region H3b, and the outer region H3c (H3a, H3b, H3c) as the plurality of regions. The through-holes 3d are arranged, for example, so as to form a line as a whole. In the state shown in FIG. 7 and FIG. 8, the through hole 3d opened in the inner portion of the groove 3e for the inner seal member 19a in the second bottom plate 3a communicates between the central region H3a and the central space Sa. .. The through hole 3d opened at a portion of the second bottom plate 3a between the groove portion 3e for the inner seal member 19a and the groove portion 3e for the intermediate seal member 19b is one of the intermediate region H3b and the pair of intermediate spaces Sb1 and Sb2. (The intermediate space Sb2 on the lower side in FIG. 8) communicates. The through hole 3d opened at a portion of the second bottom plate 3a between the groove portion 3e for the intermediate seal member 19b and the groove portion 3e for the outer seal member 19c is one of the outer region H3c and the pair of outer spaces Sc1, Sc2. (In FIG. 8, the outer space Sc1 on the upper side) is in communication.

The rotation prevention mechanism unit 25 is a mechanism for preventing rotation of the movable scroll 3. In the present embodiment, the rotation preventing mechanism portion 25 includes the above-described plurality of through holes 24a penetrating the outer edge portion of the thrust receiving portion 24 and the outer edge portion of the rocking member 23 and the movable scroll 3 while penetrating the through hole 24a. The second bottom plate 3a is configured by a connecting pin 25a that connects the outer edge of the second bottom plate 3a. The intermediate portion of the connecting pin 25a slides on the hole wall surface of the through hole 24a to prevent the movable scroll 3 from rotating and to transmit the revolution driving force of the movable scroll 3 to the movable scroll 3. That is, in this embodiment, the connecting pin 25a has both the function of transmitting the revolution driving force and the function of preventing rotation of the movable scroll 3. The insertion hole 23b in the swing member 23 and the hole 3c in the movable scroll 3 are formed at positions corresponding to the through holes 24a. The inner diameter of the through hole 24a is larger than the inner diameters of the insertion hole 23b and the hole 3c, and is determined, for example, according to the revolution radius of revolution required by the movable scroll 3. The connecting pin 25a is made of, for example, a steel material like the thrust receiving portion 24, and is formed in a cylindrical shape having a diameter smaller than that of the through hole 24a. In this way, the rotation blocking mechanism section 25 for blocking the rotation of the movable scroll 3 is configured by slidingly contacting the intermediate portion of the connecting pin 25a with the hole wall surface of the through hole 24a. The drive mechanism 20 including the rotation prevention mechanism portion 25 has a connecting pin 25a, and transmits the revolution driving force to the movable scroll 3 via the connecting pin 25a.

In the present embodiment, one end of the connecting pin 25a is press-fitted into the insertion hole 23b which is a hole formed in the outer edge of the swing member 23, and the other end of the connecting pin 25a is attached to the outer edge of the movable scroll 3. It is loosely fitted in the formed hole 3c. The movable scroll 3 is connected to the swinging member 23 by a connecting pin 25a, and is thus integrally joined to the swinging member 23.

The rear bearing 26 is fitted between the outer peripheral surface of the convex portion 24b of the thrust receiving portion 24 and the inner peripheral surface of the circular hole 21b1 of the eccentric shaft 21b, and the eccentric shaft 21b, which is one end of the crankshaft 21, is attached to the rotary shaft center. It is a bearing that rotatably supports around X. In the rear bearing 26, for example, the outer peripheral surface of the rear bearing 26 slides on the inner peripheral surface of the circular hole 21b1, and the inner peripheral surface of the rear bearing 26 slides on the outer peripheral surface of the convex portion 24b. It is fitted between the outer peripheral surface of the convex portion 24b and the inner peripheral surface of the circular hole 21b1. The rear bearing 26 is formed of, for example, a cylindrical slide bearing like the orbiting bearing 22. As a result, the one end portion (the eccentric shaft side end portion) of the crankshaft 21 is rotatably supported by the rear bearing 26, and the other end portion (the inverter side end portion) of the crankshaft 21 is fitted to the supporting portion 12a1. The front bearing 16 is rotatably supported, and both ends of the crankshaft 21 are rotatably supported in the housing 10. Further, the one end of the crankshaft 21 is rotatably supported via the convex portion 24 b of the thrust receiving portion 24. That is, in the present embodiment, the eccentric shaft 21b that is the one end of the crankshaft 21 is rotatably supported by the thrust receiving portion 24 about the rotation axis X. The total radial clearance (that is, radial clearance) of the rear bearing 26 with respect to the circular hole 21b1 and the convex portion 24b is smaller than the total radial clearance of the swing bearing 22 with respect to the swing member 23 and the eccentric shaft 21b. It is set to be small. In this way, whirling of the crankshaft 21 is suppressed, and an assembling error can be absorbed.

In this embodiment, the rear bearing 26 and the front bearing 16 as bearings that rotatably support both ends of the crankshaft 21 are housed inside the housing 10 (specifically, the center housing 11) together with the crankshaft 21. ing. The space inside the housing 10 is partitioned by the thrust receiving portion 24 into the accommodation area of the scroll unit 1 and the accommodation area of the crankshaft 21, as described above, and rotatably supports the crankshaft 21. The bearings (rear bearing 26 and front bearing 16) are arranged in the accommodation area of the crankshaft 21.

In the present embodiment, the outermost annular seal member (that is, the outer seal member 19c) of the plurality of annular seal members 19 (the inner seal member 19a, the intermediate seal member 19b, and the outer seal member 19c) is the crankshaft 21. The communication between the accommodation area and the inside of the back pressure chamber H3 is blocked.

The electric motor 30 is a drive source of the scroll unit 1 and generates a rotational drive force of the drive shaft 21a. The electric motor 30 is provided inside the housing 10 (specifically, the center housing 11) together with the drive shaft 21a. The electric motor 30 is configured to include a rotor 31 and a stator core unit 32 arranged outside the rotor 31 in the radial direction. As the electric motor 30, for example, a three-phase AC motor is applied. For example, a DC current from a vehicle battery (not shown) is converted into an AC current by the inverter 40 and is supplied to the electric motor 30.

The rotor 31 is rotatably supported inside the stator core unit 32 in the radial direction via a drive shaft 21a that is fitted (for example, press-fitted) into a shaft hole formed in the radial center of the rotor 31. When a magnetic field is generated in the stator core unit 32 by the power supply from the inverter 40, rotational power acts on the rotor 31 and the drive shaft 21a is rotationally driven.

In the scroll fluid machine 100 configured as described above, when the drive shaft 21a is rotationally driven by the electric motor 30, the eccentric shaft 21b moves along with the orbiting bearing 22 and the swing member 23, and the axial center X of the fixed scroll 2 is provided. ′ Revolves around and the revolution driving force is transmitted to the movable scroll 3 via the connecting pin 25a. At this time, the movable scroll 3 is integrally coupled to the swing member 23 via the connecting pin 25a, and revolves around the swing member 23 integrally. The scroll type fluid machine 100 compresses the refrigerant flowing into the closed space S between the fixed scroll 2 and the movable scroll 3 by this orbiting motion.

Next, the flow of the refrigerant in the scroll fluid machine 100 will be described.
Refrigerant from the low pressure side of the refrigerant circuit is introduced into the suction chamber H1 via the low pressure side port C1 and flows toward the swinging member 23 side while cooling the electric motor 30. The refrigerant guided to the rocking member 23 side is then guided to the space H4 near the spiral outer end of the scroll unit 1 through the through hole 24a as a refrigerant introducing passage and the recess of the outer edge of the rocking member 23. .. Then, the refrigerant in the space H4 is taken into the closed space S between the first wrap 2b and the second wrap 3b and is compressed in the closed space S. The compressed refrigerant is discharged to the discharge chamber H2 via the discharge hole 2a1 and the one-way valve 18, and then discharged from the discharge chamber H2 to the high pressure side of the refrigerant circuit via a discharge port (not shown). That is, in this embodiment, the refrigerant flowing from the low-pressure side port C1 into the periphery of the electric motor 30 in the housing 10 passes through the through hole 24a and then passes through the first hole 2a of the fixed scroll 2 and the second scroll of the movable scroll 3. It is guided to a space H4 formed near the outer end of the spiral of the wrap 3b. Further, for example, in the state (phase angle) shown in FIG. 7 and FIG. 8, a part of the refrigerant in the outer space Sc1 in the plurality of closed spaces S passes through the corresponding through hole 3d and the outer region H3c in the back pressure chamber H3. Similarly, a part of the refrigerant in the intermediate space Sb2 flows into the intermediate region H3b through the corresponding through hole 3d, and a part of the refrigerant in the central space Sa passes through the corresponding through hole 3d. It flows into the central region H3a.

FIG. 9 is a conceptual diagram for explaining the load in the thrust direction that acts on the movable scroll 3. Further, Table 1 below shows the pressure in each of the closed spaces Sa, Sb1, Sb2, Sc1, Sc2 in the state shown in FIGS. 7 and 8, the area of the second bottom plate 3a on which this pressure acts, and the compression reaction. Load due to force (that is, downward load in the figure), back pressure in each region H3a, H3b, H3c of the back pressure chamber H3, area of the second bottom plate 3a on which this back pressure acts, and back pressure load (that is, , An upward load in the figure) is shown.

As shown in FIG. 9, since the scroll fluid machine 100 is a compressor, the overall pressure distribution of the plurality of closed spaces S generally rises from the outer peripheral portion of the second bottom plate 3a of the movable scroll 3 toward the central portion. Shows the distribution of Therefore, the compression reaction force acting on the movable scroll 3 in the thrust direction (direction of the rotation axis X) generally increases from the outer peripheral portion of the second bottom plate 3a of the movable scroll 3 toward the central portion. Further, due to the communication effect of the through holes 3d, the overall pressure distribution of the back pressure chamber H3 substantially matches the overall pressure distribution of the plurality of closed spaces S.

Then, a load in the thrust direction, which substantially satisfies the following formula 1, acts on the movable scroll 3 from above and below. However, F is the minimum seal holding force required to ensure the airtightness of the closed space S.

[Formula 1]
Pd×A3+P2×A2+P1×A1+F=Pd×B3+P2×B2+P1×B1

Therefore, in the orbiting scroll 3, the downward compression reaction force, the downward minimum seal holding force F, and the upward back pressure load are substantially balanced. In addition, when it is considered that P1 is substantially equal to the suction pressure Ps, or when the three chambers at the center of the spiral (that is, the three chambers of the central space Sa and the pair of intermediate spaces Sb1 and Sb2) are combined (phase angle), the following formula 2 Is generally satisfied. Therefore, the back pressure chamber H3 is not limited to three chambers, but even if it is two chambers, the load imbalance in the thrust direction of the movable scroll 3 is effectively reduced.

[Formula 2]
Pd×A3+P2×A2+F=Pd×B3+P2×B2

In the scroll-type fluid machine 100 according to the present embodiment, the back pressure chamber H3 is not in communication with a region of a pressure lower than the pressure inside the back pressure chamber H3 (the suction chamber H1 in the case of the present embodiment, which is a compressor). .. That is, a relief passage (pressure release passage) such as the refrigerant discharge passage of Patent Document 1 and the throttle passage of Patent Document 2 for releasing the pressure in the back pressure chamber H3 is positive in the scroll fluid machine 100. Not provided. Therefore, in the scroll fluid machine 100, even if a part of the high-pressure refrigerant (fluid) obtained by the compression operation is supplied to the back pressure chamber H3 through the through hole 3d to form the back pressure, the refrigerant (fluid) ) Does not flow down to a region (intake chamber H1) having a pressure lower than the pressure in the back pressure chamber H3. As a result, energy loss can be reduced.

In the scroll fluid machine 100 according to the present embodiment, the pressure distribution of the entire back pressure acting on the back surface 3a1 of the second bottom plate 3a of the movable scroll 3 is determined by the plurality of closed spaces S acting on the end surface of the second bottom plate 3a on the closed chamber side. Can be roughly matched to the overall pressure distribution of Further, since the through hole 3d simply penetrates the second bottom plate 3a in the plate thickness direction, the flow path length is shorter than the conventional flow path and the flow path is simple. Therefore, the pressure loss in the process of circulation of the refrigerant as the fluid through the through holes 3d becomes lower than that in the conventional case. Accordingly, in the scroll fluid machine 100, the load imbalance between the thrust-direction load acting on the movable scroll 3 and the back pressure load can be effectively reduced.

In this way, it is possible to provide the scroll fluid machine 100 that can reduce energy loss and can effectively reduce the load imbalance in the thrust direction of the movable scroll 3 in the scroll unit 1. Further, it is possible to apply a stable back pressure load with a simple structure without requiring a special control valve or the like for adjusting the pressure of the back pressure chamber H3. Then, due to the appropriate back pressure, the sliding resistance between the back surface 3a1 of the second bottom plate 3a of the movable scroll 3 and the thrust receiving surface 24c is reduced, the power loss is reduced, and the efficiency is improved.

In the present embodiment, the back surface 3a1 of the second bottom plate 3a and the thrust receiving surface 24c are each formed in a flat planar shape. Therefore, the back pressure chamber H3 is easily formed by the gap having the height corresponding to the crushing margin of the annular seal member 19. The back pressure chamber H3 is formed with a slight gap. Therefore, for example, when the pressure in the closed space (compression chamber) S rapidly rises during liquid compression or the like, the pressure in the back pressure chamber H3 rapidly increases in the closed space S via the through hole 3d. Immediately follow the increase in pressure. As a result, even when the liquid is compressed, the pressure in the closed space S is made uniform (approximate) immediately, and an appropriate back pressure can be maintained.

In the present embodiment, the plurality of annular seal members 19 include an inner seal member 19a, an outer seal member 19c outside the inner seal member 19a, and an intermediate seal member 19b between the inner seal member 19a and the outer seal member 19c. Consists of. The back pressure chamber H3 includes a central region H3a inside the inner seal member 19a, an intermediate region H3b between the inner seal member 19a and the intermediate seal member 19b, and an intermediate seal member 19b and the outer seal member 19c. And an outer region H3c. Therefore, the plurality of closed spaces S are divided into low pressure (P1:Sc1, Sc2), intermediate pressure (P2:Sb1, Sb2), and high pressure (Pd:Sa) spaces, and the fluid (refrigerant) having these pressures is divided into a plurality of spaces. It is supplied to the regions (H3a, H3b, H3c) close to each other in the thickness direction. In this embodiment, the closed space S has a lap shape that can be divided into three pressure regions of low pressure, intermediate pressure, and high pressure, and the back pressure chamber H3 is divided into three chambers correspondingly. However, not limited to this, the closed space S has a lap shape that can be divided into two pressure regions, and the back pressure chamber H3 is divided into two chambers corresponding to this, or there are four or more closed spaces S. The back pressure chamber H3 may be divided into four or more chambers so that the back pressure chamber H3 can be divided into four pressure regions.

In the present embodiment, the scroll unit 1, the crankshaft 21, and the bearings (rear bearing 26 and front bearing 16) that rotatably support the crankshaft 21 are housed inside the housing 10. The space is partitioned by the thrust receiving portion 24 into a housing area for the scroll unit 1 and a housing area for the crankshaft 21. The bearing that rotatably supports the crankshaft 21 is arranged in the accommodation area of the crankshaft 21. That is, the bearing for the crankshaft 21 is arranged outside the back pressure chamber H3. Therefore, it is not necessary to consider the supply of the lubricating oil for sliding the bearing in the structure itself of the back pressure chamber H3. Further, in order to ensure the airtightness of the back pressure chamber H3, a shaft seal between the crankshaft 21 and the bearing of this shaft is unnecessary, so that power loss due to the shaft seal is eliminated.

In the present embodiment, specifically, the outermost annular seal member (that is, the outer seal member 19c) of the plurality of annular seal members 19 is the housing area of the crankshaft 21 in the housing 10 and the back pressure chamber H3. The communication with the inside of is cut off. As a result, the central region H3a of the back pressure chamber H3, which is the high pressure region (region of the discharge pressure Pd in this embodiment), is the accommodation region of the crankshaft 21, which is the low pressure region (region of the suction pressure Ps in this embodiment). On the other hand, at least double (triple in the present embodiment) annular seal member 19 is used for sealing. Therefore, the airtightness of the back pressure chamber H3 is simply and reliably ensured.

In the present embodiment, the drive mechanism 20 includes a plurality of through holes 24a penetrating the outer edge portion of the thrust receiving portion 24, the outer edge portion of the rocking member 23 and the second bottom plate 3a of the movable scroll 3 while penetrating the through hole 24a. Has a connecting pin 25a for connecting with the outer edge of the. Therefore, when the drive shaft 21a is rotationally driven, the eccentric shaft 21b revolves around the shaft center X'of the fixed scroll 2 together with the orbiting bearing 22 and the swing member 23, and this revolving driving force causes the connecting pin 25a to move. It is transmitted to the movable scroll 3 via. As described above, since the revolution drive force for revolving the orbiting scroll 3 around the axis X'of the fixed scroll 2 is transmitted by the connecting pin 25a, the second bottom plate of the orbiting scroll 3 caused by the orbital drive force transmitting structure. The distortion of 3a is suppressed or prevented.

Further, in the scroll fluid machine 100, the connecting pin 25a of the rotation preventing mechanism portion 25 has its intermediate portion slidably contacting the hole wall surface of the through hole 24a, thereby preventing the movable scroll 3 from rotating and generating the revolution driving force. It is transmitted to the movable scroll 3. Therefore, the hole wall surface is effective as a surface for sliding contact of the connecting pin 25a over the entire wall surface of the through hole 24a in the hole depth direction (that is, the entire thickness of the thrust receiving portion 24 in the present embodiment). Can be used for. Therefore, there is no dead space in the hole depth direction, and the housing 10 can be downsized accordingly.

In the present embodiment, a cylindrical convex portion 24b is projectingly provided at the central portion of the end surface of the thrust receiving portion 24 on the rocking member side, and the eccentric shaft 21b is formed with a circular hole 21b1 concentric with the rotational axis X. It has a configuration. Then, the drive mechanism 20 is fitted between the outer peripheral surface of the convex portion 24b and the inner peripheral surface of the circular hole 21b1 and rotatably supports the one end portion (the eccentric shaft side end portion) of the crankshaft 21. 26 is further included. That is, the bearing structure for the one end of the crankshaft 21 is integrated in the region inside the slewing bearing 22 that rotatably supports the swing member 23. As a result, the bearing position of the one end portion of the crankshaft 21 (in other words, the end portion on the movable scroll side) can be set in the vicinity of the movable scroll 3, so that the crank reaction is caused by the compression reaction force generated when the refrigerant is compressed. The rotational moment load that acts on the bearing that engages with the shaft 21 can be reduced, and the durability of the bearing is improved. Further, the main parts of the drive mechanism 20 (the swinging member 23, the swing bearing 22, the eccentric shaft 21b, and the rear bearing 26) are gathered in a region corresponding to the outer shape of the swinging member 23, so that the housing 10 of the housing 10 is covered. It is possible to reduce the size and effectively use the space in the housing 10. Further, the bearing structure on the movable scroll side of the crankshaft 21 is configured by using a part of the thrust receiving portion 24 (convex portion 24b) and a part of the crankshaft 21 (eccentric shaft 21b). Therefore, it is not necessary to form a bearing support portion on the housing 10 to support the movable scroll side bearing of the crankshaft 21, and as a result, the structure of the housing 10 is simplified.

In the present embodiment, the electric motor 30 is provided in the housing 10 integrally with the drive shaft 21a, the scroll unit 1 compresses and discharges the refrigerant in the closed space S, and the housing 10 receives the low pressure side port C1 into which the refrigerant flows. Are formed. Then, the refrigerant that has flowed from the low-pressure side port C1 to the periphery of the electric motor 30 in the housing 10 passes through the through hole 24a and is formed in the space near the spiral outer ends of the first wrap 2b and the second wrap 3b. Guided to H4. That is, the through hole 24a has not only the function as the rotation preventing mechanism portion 25 but also the function as a refrigerant introducing passage for introducing the refrigerant from the suction chamber H1 to the space H4. Therefore, it is not necessary to separately form the refrigerant introduction passage in the housing 10 or the like, and the productivity of the scroll fluid machine 100 can be improved. Further, the recess on the outer edge of the swinging member 23 also has a function as a refrigerant introduction passage, and has the same effect as the through hole 24a.

In the present embodiment, one end of the connecting pin 25a is press-fitted into the insertion hole 23b formed in the outer edge of the swing member 23, and the other end of the connecting pin 25a is formed in the outer edge of the orbiting scroll 3c. Is loosely fitted to. That is, play (a gap between the outer surface of the pin and the hole wall surface of the hole 3c) is eliminated on the drive side (the swinging member 23 side) of the connecting pin 25a, and the idle side (the movable scroll 3 side) of the connecting pin 25a is free. It is provided. As a result, manufacturing tolerances of the first wrap 2b, the second wrap 3b, etc. are absorbed by the play of the connecting pin 25a on the driven side.

In the present embodiment, the eccentric shaft 21b is formed separately from the drive shaft 21a. As a result, the crankshaft 21 can be manufactured more easily than when the eccentric shaft 21b is formed integrally with the drive shaft 21a. That is, in the case of integral formation, for example, where the eccentric shaft 21b must be formed by a machine such as a forming machine having a high time charge, it can be formed by a separate machine and can be formed by a general-purpose machine. As a result, the manufacturing cost can be reduced.

In the present embodiment, the thrust receiving portion 24 is formed separately from the housing 10. As a result, the thrust receiving portion 24, which has a high demand for wear resistance, can be made of a material in consideration of wear resistance or subjected to surface treatment or the like, and the housing 10 can be made of a material in which weight reduction or the like is prioritized.

In the present embodiment, the counterweight 27 is formed separately from the crankshaft 21. Thereby, the manufacturing cost of the counterweight 27 can be reduced. Further, in the conventional scroll type fluid machine described in Patent Document 1, the counterweight is arranged in a narrow space in the radial direction of the housing 10 between the movable scroll and the bearing of the crankshaft on the movable scroll side. Therefore, it is necessary to shorten the size of the counterweight in the radial direction. Therefore, the position of the center of gravity of the counterweight is close to the center of rotation of the drive shaft, and as a result, the weight of the counterweight has to be increased in order to secure the necessary weight balance. On the other hand, in the present embodiment, the counterweight 27 is provided so that the swivel bearing 22 is located between the counterweight 27 and the thrust receiving portion 24 at the one end of the drive shaft 21a. Therefore, the counterweight 27 can be arranged in a wide space between the outer peripheral portion of the one end of the drive shaft 21a and the inner peripheral surface of the housing 10 (center housing 11), so that the position of the center of gravity of the counterweight 27 can be adjusted. The drive shaft 21a can be moved away from the rotation axis X of the drive shaft 21a as compared with the related art. Therefore, the counterweight 27 can be made lighter than the conventional counterweight.

In the present embodiment, the bearing structure on the one end side (eccentric shaft side) of the crankshaft 21 is integrated in an area inside the slewing bearing 22 that rotatably supports the swing member 23. However, the present invention is not limited to this, and for example, instead of the rear bearing 26, a bearing that supports the movable scroll side end of the crankshaft 21 is provided in the region between the flange portion 21a1 and the electric motor 30, and this bearing is used. A bearing support portion for supporting the above may be provided so as to project from the inner peripheral surface of the housing 10 (center housing 11). Further, one end of the connecting pin 25a is press-fitted into the insertion hole 23b of the swinging member 23, and the other end of the connecting pin 25a is loosely fitted in the hole 3c of the movable scroll 3, but not limited to this. Both ends of the connecting pin 25a may be press-fitted into the corresponding holes (insertion hole 23b, hole 3c), or may be appropriately loosely fitted. Further, the eccentric shaft 21b may be formed integrally with the drive shaft 21a, and the thrust receiving portion 24 may be formed integrally with the housing 10. Further, in order to accommodate the rear bearing 26, the circular hole 21b1 penetrating the eccentric shaft 21b is provided, but the present invention is not limited to this. In addition to the through hole 24a, a hole that communicates between the suction chamber H1 and the space H4 may be formed through the thrust receiving portion 24. As a result, the number of refrigerant introduction passages is increased, pressure loss is further reduced, and as a result, power consumption is further reduced.

Further, in the present embodiment, the scroll type fluid machine 100 has been described by taking the so-called inverter integrated type as an example, but the present invention is not limited to this, and may be a separate body from the inverter 40. Further, although the electric motor 30 is incorporated, the electric motor 30 may be provided outside the housing 10. Although the electric motor 30 is used as the drive source, the present invention is not limited to this, and the rotational power may be transmitted from the engine of the vehicle to the drive shaft 21a. Further, in each of the embodiments, the fluid is the refrigerant, but the fluid is not limited to this, and an appropriate fluid can be applied.

Here, in the first embodiment, the crankshaft 21 is uniaxial, but the invention is not limited to this, and it may be biaxial as shown in FIGS. 10 and 11. FIG. 10 is a schematic sectional view of a scroll type fluid machine 100′ showing a second embodiment of the present invention, and FIG. 11 is a schematic sectional view of a scroll type fluid machine 100″ showing a third embodiment of the present invention. First, in the scroll type fluid machine 100' of the second embodiment, the same elements as those in the first embodiment are designated by the same reference numerals, and the parts different from the first embodiment will be briefly described respectively.

The scroll type fluid machine 100' according to the second embodiment shown in FIG. 10 is an expander. In the scroll type fluid machine 100', both scrolls of one of the first scroll and the second scroll (the scroll on the left side in the figure) and the other scroll (the scroll on the right side in the figure) that are meshed with each other can revolve. It is configured. That is, the one scroll revolves with respect to the other scroll, and the other scroll revolves with respect to the one scroll. In addition, below, the said one scroll is called the left scroll 2', and the said other scroll is called the right scroll 3'.

In the scroll-type fluid machine 100′, the scroll unit 1 is configured to rotate between the left scroll 2′ and the right scroll 3′ by revolving the left scroll 2′ and the right scroll 3′. A plurality of closed spaces S whose volumes change with movement are formed. The closed space S is moved from the central portion of the first wrap 2'b of the left scroll 2'and the second wrap 3'b of the right scroll 3'to the outer end of the spiral, so that the volume of the closed space S is increased. The fluid changes in the increasing direction, and the fluid taken into the closed space S from the central portion side of the first wrap 2'b and the second wrap 3'b is expanded. In the scroll-type fluid machine 100′, the left scroll 2′ and the right scroll 3′ are supported by a biaxial crankshaft 21 so as to be capable of revolving orbital movement by the expansion energy of the fluid, and this revolving orbital movement is converted into rotational movement and externally It is configured to be output to.

In the scroll fluid machine 100′, the back pressure chamber H3 is different from the side opposite to the right scroll 3′ in the bottom plate 2′a of the left scroll 2′ and the left scroll 2′ in the bottom plate 3′a of the right scroll 3′. It is formed on the opposite side. The back pressure chamber H3 for the left scroll 2'includes a back surface 2'a1 of the bottom plate 2'a of the left scroll 2'and a thrust receiving surface 24c facing the back surface 2'a1 and receiving thrust force from the left scroll 2'. ', and a plurality of annular seal members 19 arranged in multiple annular shapes between the back surface 2'a1 and the thrust receiving surface 24c' are divided into a plurality of regions. The back pressure chamber H3 for the right scroll 3'includes a back surface 3'a1 of the bottom plate 3'a of the right scroll 3'and a thrust receiving surface 24c facing the back surface 3'a1 and receiving thrust force from the left scroll 2'. ', and a plurality of annular seal members 19 arranged in multiple annular shapes between the back surface 3'a1 and the thrust receiving surface 24c'. The back pressure chamber H3 is cut off from communication with a region having a lower pressure than the pressure inside the back pressure chamber H3. That is, in the scroll type fluid machine 100′, the back pressure chamber H3 and the discharge region of the expanded low-pressure fluid are not in direct communication with each other, and the relief passage (release pressure) for releasing the pressure in the back pressure chamber H3 is released. Passages) are not actively provided.

The back surface 2'a1, the back surface 3'a1, and each thrust receiving surface 24c' are formed in a flat plane shape. Each thrust receiving surface 24 c ′ is formed by the inner surface of the housing 10.

In the second embodiment, two annular seal members 19 for the left scroll 2'are concentrically provided, and the back pressure chamber H3 for the left scroll 2'is divided into two regions. The through hole 3d for the bottom plate 2'a of the left scroll 2'penetrates in the plate thickness direction and is opened corresponding to each of the two regions. In the left scroll 2′, each of the two regions communicates with the closed space S of the plurality of closed spaces S where the through hole 3d opens, through the through hole 3d corresponding to the region. ..

Further, two annular seal members 19 for the right scroll 3'are also provided concentrically. At the central portion of the bottom plate 3'a of the right scroll 3'and the portion where the thrust receiving surface 24c' of the housing 10 is formed, an introduction port C1' for high pressure gas as a fluid is opened. The inner annular seal member 19 of the two annular seal members 19 for the right scroll 3'is arranged so as to surround the introduction port C1'. The back pressure chamber H3 for the right scroll 3'is defined as a region between the inner annular seal member 19 and the outer annular seal member 19. The through hole 3d for the bottom plate 3'a of the right scroll 3'penetrates in the plate thickness direction and is opened corresponding to the one area. In the right scroll 3', the one region communicates with the sealed space S at the outer peripheral portion of the plurality of sealed spaces S where the through hole 3d opens, through the through hole 3d.

The crankshaft 21 is composed of two axes, a main shaft 21' and a sub-shaft 21", which are arranged in parallel with each other. The crankshaft 21 outputs the expansion energy of fluid to the outside, that is, the power from the scroll unit 1 is output. The main shaft 21′ and the sub-shaft 21″ are arranged so as to penetrate the outer peripheral portion of the scroll unit 1, respectively. The main shaft 21 ′ is rotatably supported in the housing 10 by two first bearings 51. The sub-shaft 21 ″ is rotatably supported in the housing 10 by two second bearings 52. One ends of the main shaft 21 ′ and the sub-shaft 21 ″ penetrate the housing 10. Shaft seals 53 are provided respectively at the penetrating portions of the main shaft 21' and the sub-shaft 21" in the housing 10. A pulley 60 is attached to one end of the main shaft 21'. The power from the scroll unit is output (transmitted) to the outside.On the outside of the housing 10, one end side of the main shaft 21' and one end side of the sub shaft 21" are connected by a timing belt 61 for behavior correction of both shafts. Has been done. In the figure, rolling bearings are shown as the first bearing 51 and the second bearing 52, but the present invention is not limited to this, and sliding bearings may be used.

A columnar first eccentric portion 54, which is eccentric with respect to the rotation axis of the main shaft 21′, is provided between the two first bearings 51 at a penetrating portion of the left scroll 2′ and the right scroll 3′ of the main shaft 21′. Are provided respectively. In addition, between the two second bearings 52, a second eccentric columnar shape eccentric with respect to the rotation axis of the sub-shaft 21″ is provided in a penetrating portion of the left scroll 2′ and the right scroll 3′ of the sub-shaft 21″. Each part 55 is provided. The two first eccentric portions 54 are eccentric with a phase difference of 180, and the two second eccentric portions 55 are also eccentric with a phase difference of 180. Further, the phases of the two first eccentric portions 54 and the phases of the two second eccentric portions 55 are matched with each other by the timing belt 61.

First eccentric bearings 56 are provided between the outer peripheral surfaces of the two first eccentric portions 54 and the inner wall surfaces of the holes at the penetrating portions of the left scroll 2'and the right scroll 3', respectively. Second eccentric bearings 57 are also provided between the outer peripheral surfaces of the two second eccentric portions 55 and the inner wall surfaces of the holes at the penetrating portions of the left scroll 2'and the right scroll 3', respectively. In the figure, rolling bearings are shown as the first eccentric bearing 56 and the second eccentric bearing 57, but the present invention is not limited to this, and sliding bearings may be used. The two first bearings 51 and the two first eccentric bearings 56 rotatably support the left scroll 2'with respect to the right scroll 3'with an orbiting radius r0 so as to be able to orbit. The second eccentric bearing 57 supports the right scroll 3'with respect to the left scroll 2'in such a manner that it can revolve around a revolution radius r0. That is, one scroll (the left scroll 2'or the right scroll 3') revolves around the other scroll (the right scroll 3'or the left scroll 2') with the revolution radius r0. Here, the diameter d1 of the portion of the main shaft 21′ other than the first eccentric portion 54 and the diameter d2 of the first eccentric portion 54 satisfy the relationship of d2=d1+r0, and other than the second eccentric portion 55 of the sub-shaft 21″. The diameter d3 of the portion and the diameter d4 of the second eccentric portion 55 satisfy the relationship of d4=d3+r0. In other words, the left scroll 2'has a half of r0 with respect to the rotation axis of the main shaft 21'. The orbiting orbiting motion is performed at the orbiting orbiting radius, and the right scroll 3'orbits at the orbiting radius of r0 with respect to the rotation axis of the sub-shaft 21". Therefore, assuming that the total volume of the plurality of closed spaces S is the same as in the case of the uniaxial structure, the respective scrolls 2', 3'for the shafts 21', 21" are half the revolution radius of the uniaxial structure. Therefore, the centrifugal force generated by the orbiting motion of each scroll 2', 3'is half the centrifugal force of the uniaxial structure, and the load on the bearing structure of the scroll unit 1 is lower than that of the uniaxial structure. A bearing structure having a smaller allowable load than that of the uniaxial structure can be adopted, and deformation of each scroll 2′, 3′ due to a centrifugal force can be reduced, and a scroll that can endure high-speed orbiting motion. Unit 1 can be provided.

Further, the left scroll 2'and the right scroll 3'are connected to the main shaft 21' through two first eccentric parts 54 with 180° different phases, and the sub-shaft 21" has two second eccentric parts. The left scroll 2′ and the right scroll 3′ themselves serve as counterweights, and there is no need to provide a separate counterweight. Since the sub-shaft 21″ itself serves as a rotation preventing mechanism for the left scroll 2′ and the right scroll 3′, it is not necessary to separately provide a rotation preventing mechanism. The left scroll 2'and the right scroll 3'are arranged between the main shaft 21' and the sub-shaft 21", and as a rotation preventing mechanism, compared with a conventional so-called pin & hole type rotation preventing mechanism. The scroll unit is located far away from the central portion of the scroll unit, and therefore, even if the radial clearances of the bearings 51, 52, 56, and 57 are taken into consideration, the angular deviation (phase deviation) of the wraps in the scroll unit 1 is large. Less than the angle deviation in the conventional pin-and-hole method.

Further, in the second embodiment, as in the first embodiment, the scroll unit 1, the crankshaft 21 for outputting the power from the scroll unit 1, and the crankshaft 21 can be rotated inside the housing 10. Bearings (51, 52, 56, 57) that are supported by are housed. The bearings (51, 52, 56, 57) are arranged outside the back pressure chamber H3. Therefore, since it is not necessary to consider the supply of the lubricating oil for sliding the bearing in the structure of the back pressure chamber H3 itself, it is possible to provide the scroll fluid machine 100' which is particularly suitable as an expander. Further, in order to ensure the airtightness of the back pressure chamber H3, a shaft seal between the crankshaft 21 and the bearing of this shaft becomes unnecessary, so that power loss due to this shaft seal is eliminated. The outermost annular seal member (outer seal member 19c) of the plurality of annular seal members 19 blocks communication between the housing region of the crankshaft 21 in the housing 10 and the inside of the back pressure chamber H3. There is. This ensures the airtightness of the back pressure chamber H3 simply and reliably.

Next, the flow of the refrigerant in the scroll fluid machine 100' will be described.
The high-pressure gas is introduced into the closed space S at the center of the spiral through the introduction port C1′ and expands in the closed space S. The gas in the closed space S further expands and moves toward the outer end of the spiral due to the revolving movement of the left scroll 2'and the right scroll 3'by the expansion energy. The gas that has expanded to a low pressure is discharged or recovered to the outside through, for example, the discharge port C2′ that communicates with the storage area of the sub-shaft 21″. In addition, a part of the gas in the plurality of closed spaces S is It flows into the back pressure chamber H3 which is adjacent in the plate thickness direction via the corresponding through hole 3d.

In the scroll type fluid machine 100′ according to the second embodiment, energy loss can be reduced and at least the load in the thrust direction and the back pressure load acting on the left scroll 2′ can be achieved as in the first embodiment. The load imbalance of can be effectively reduced.

A scroll type fluid machine 100 ″ according to the third embodiment shown in FIG. 11 is a compressor that compresses and discharges a refrigerant as a fluid similarly to the first embodiment, but the crankshaft 21 is the same as that of the second embodiment. Similarly, in the scroll type fluid machine 100″ of the second embodiment, the same elements as those of the second embodiment are designated by the same reference numerals, and mainly different from the second embodiment. Each of these will be briefly described.

In the scroll type fluid machine 100″, the closed space S is moved from the central portion of the first wrap 2′b of the left scroll 2′ and the second wrap 3′b of the right scroll 3′ toward the outer end of the spiral. As a result, the volume of the closed space S changes in a decreasing direction, and the fluid taken into the closed space S from the central side of the first wrap 2'b and the second wrap 3'b is compressed. In the machine 100 ′, the left scroll 2 ′ and the right scroll 3 ′ are supported by the biaxial crankshaft 21 so as to be able to revolve by the expansion energy of the fluid, and the housing 10 has a main drive shaft 70 and a main bearing 71. The main drive shaft 70 is rotatably supported via an external drive source such as an electric motor or an engine (not shown), which is connected to one end of the main drive shaft 70 protruding outside the housing 10. A main gear 80 is attached to the other end of the.

In the scroll type fluid machine 100″, the crankshaft 21 functions as a drive shaft (input shaft) for driving the scroll unit 1 as in the first embodiment. The main shaft 21′ and the sub shaft 21″ are It is arranged in the housing 10. The space inside the housing 10 is divided by the thrust receiving portion 24 into two regions in the rotational axis direction of the crankshaft 21 and the main drive shaft 70. One ends of the main shaft 21 ′ and the sub-shaft 21 ″ respectively penetrate the thrust receiving portion 24 and are located in a region of the two regions on the side of the main drive shaft 70. The main shaft in the thrust receiving portion 24. One of the first bearing 51 and one of the second bearing 52 are provided at the penetrating portions of the sub shaft 21' and the sub shaft 21''. A sub gear 81 that meshes with the main gear 80 is attached to one end of each of the main shaft 21′ and the sub shaft 21″. The phase of the two first eccentric portions 54 and the phase of the two second eccentric portions 55 are the same. They are aligned with each other by a sub gear 81. Accordingly, when the main drive shaft 70 is rotationally driven by the external drive source, this rotational force is transmitted via the main gear 80 and the sub gear 81 to the main shaft 21' and the sub shaft. 21". Then, the transmitted rotational force becomes the revolution revolving force of the left scroll 2′ and the right scroll 3′ via the first eccentric portion 54 and the first eccentric bearing 56 and the second eccentric portion 55 and the second eccentric bearing 57. To be converted. Further, the speed can be increased according to the ratio of the number of teeth of the main gear 80 and the number of teeth of the sub gear 81, and the size can be reduced.

In the scroll type fluid machine 100″, the centrifugal force generated by the revolving orbiting motion of each scroll 2′, 3′ is half the centrifugal force of the uniaxial structure like the scroll type fluid machine 100′, and the counterweight and rotation prevention are separately provided. There is no need to provide a mechanism, the angle deviation (phase deviation) of the wrap in the scroll unit 1 is smaller than the angle deviation in the conventional pin and hole method, and the airtightness of the back pressure chamber H3 is simple due to the plurality of annular seal members 19. And surely secured.

Next, the flow of the refrigerant in the scroll fluid machine 100″ will be described.
Refrigerant from the low pressure side of the refrigerant circuit is introduced into the suction chamber H1 via the low pressure side port C1″ that is opened at a predetermined circumferential position in the region of the housing 10 where the second eccentric bearing 57 and the like are provided, and the scroll unit The refrigerant in the space H4 is introduced into the closed space S between the first wrap 2′b and the second wrap 3′b, and is closed. It is compressed in the space S. The compressed refrigerant is discharged to the high pressure side of the refrigerant circuit through the high pressure side port C2″ that penetrates the central portion of the bottom plate 3′a of the right scroll 3′ and the housing 10. Further, a part of the gas in the plurality of closed spaces S flows into the back pressure chamber H3 which is adjacent in the plate thickness direction via the corresponding through hole 3d.

Also in the scroll type fluid machine 100″ according to the third embodiment, similarly to the first embodiment, it is possible to effectively reduce the load imbalance between the load in the thrust direction and the back pressure load acting on at least the left scroll 2′. You can

Further, in the scroll type fluid machine 100″, in order to ensure the airtightness of the back pressure chamber H3, a shaft seal between the crankshaft 21 and the bearing of this shaft is not required, and the entire crankshaft 21 is provided in the housing 10. Since it is disposed inside, the shaft seal 53 as in the second embodiment is not necessary, and therefore power loss can be reduced more effectively. By housing the electric motor for rotating 21 in the housing 10, the shaft seal 53 becomes unnecessary, and the power loss is effectively reduced as in the third embodiment.

Further, the scroll type fluid machine 100' of the second embodiment is an expander, but the invention is not limited to this and may be a compressor. In this case, for example, instead of the structure on the output side of the scroll unit 1 (the pulley 60, the timing belt 61, etc.), the structure on the input side of the scroll type fluid machine 100 ″ of the third embodiment (main drive shaft 70, main The structure of the gear 80, the sub gear 81, etc. may be applied. Further, although the scroll type fluid machine 100″ of the third embodiment is a compressor, the present invention is not limited to this and may be an expander. In this case, for example, instead of the structure of the input side of the scroll type fluid machine 100″ (main drive shaft 70, main gear 80, sub gear 81, etc.), the output side of the scroll unit 1 of the second embodiment is replaced. A structure (pulley 60, timing belt 61, etc.) may be applied.

Further, in the second embodiment and the third embodiment, both scrolls of the left scroll 2′ and the right scroll 3″ are supposed to orbit each other, but the present invention is not limited to this, and the left scroll 2′ or the right scroll 3″. Only the orbiting orbiting motion may be performed.

Although some preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and modified examples, and various modifications and changes can be made based on the technical idea of the present invention. is there.

2... Fixed scroll (other scroll), 2a... First bottom plate (bottom plate), 2'... Left scroll (one scroll), 2'a... Bottom plate, 3... Movable scroll (one scroll), 3a... Second Bottom plate (bottom plate), 3a1... Rear surface, 3d... Through hole, 3'... Right scroll (other scroll), 3'a... Bottom plate, 10... Housing, 16... Front bearing (bearing), 19... Annular seal member, 19a ... inner seal member, 19b... intermediate seal member, 19c... outer seal member, 21... crankshaft, 21'... main shaft (crankshaft), 21"... sub-shaft (crankshaft), 24c... thrust receiving surface, 24c' ... Thrust receiving surface, 26... Rear bearing (bearing), 51... First bearing (bearing), 52... Second bearing (bearing), 100... Scroll type fluid machine, 100'... Scroll type fluid machine, 100"... Scroll Type fluid machine, H3... back pressure chamber, H3a... central region, H3b... intermediate region, H3c... outer region, S... closed space

Claims (5)

It has a first scroll and a second scroll which are meshed with each other, and at least one scroll of the first scroll and the second scroll revolves revolvingly with respect to the other scroll, so that A scroll unit that forms a plurality of sealed spaces that change in volume with the orbiting orbiting motion between the scroll unit and the second scroll;
A back pressure chamber formed on the opposite side of the other scroll in the bottom plate of the one scroll,
Comprising, while pressing the one scroll toward the other scroll side by the back pressure chamber pressure, to compress or expand the fluid by the scroll unit, scroll-type fluid machine,
The back pressure chamber includes a back surface of the bottom plate of the one scroll, a thrust receiving surface that faces the back surface and receives a thrust force from the one scroll, and a plurality of back surface and the thrust receiving surface. While being divided into a plurality of regions by a plurality of annular seal members arranged in an annular shape, communication with a region of a lower pressure than the pressure in the back pressure chamber is blocked.
Through holes penetrating the bottom plate of the one scroll in the plate thickness direction are opened corresponding to respective regions of the plurality of regions,
The scroll-type fluid machine, wherein each region of the plurality of regions communicates with the sealed space in which the through hole opens among the plurality of sealed spaces via the through hole corresponding to the region. The scroll type fluid machine according to claim 1, wherein the back surface and the thrust receiving surface are each formed in a flat plane shape. The plurality of annular seal members are annularly arranged between the inner seal member, the outer seal member annularly arranged outside the inner seal member, and the inner seal member and the outer seal member. Consisting of an intermediate seal member,
The back pressure chamber has a center region inside the inner seal member, an intermediate region between the inner seal member and the intermediate seal member, and an outer region between the intermediate seal member and the outer seal member. The scroll type fluid machine according to claim 1 or 2, which is partitioned into. At least a housing for accommodating the scroll unit, a crankshaft for driving the scroll unit or for outputting power from the scroll unit, and a bearing for rotatably supporting the crankshaft. ,
The scroll type fluid machine according to claim 1, wherein a bearing that rotatably supports the crankshaft is arranged outside the back pressure chamber. The outermost annular seal member of the plurality of annular seal members blocks communication between the housing region of the crankshaft in the housing and the inside of the back pressure chamber. Scroll type fluid machine.