WO2017043471A1

WO2017043471A1 - Scroll fluid machine and refrigerating device in which same is used

Info

Publication number: WO2017043471A1
Application number: PCT/JP2016/076111
Authority: WO
Inventors: 橋本　俊一
Original assignee: サンデンホールディングス株式会社
Priority date: 2015-09-09
Filing date: 2016-09-06
Publication date: 2017-03-16
Also published as: JP2017053266A

Abstract

[Problem] To make it possible for a scroll fluid machine that is a single-plate compressor-integrated expander to start easily and reliably and operate stably. [Solution] Coolant compressed in a compressing unit of a scroll fluid machine 1 is suctioned into a compressor on the high-pressure side, and high-pressure coolant compressed by the compressor on the high-pressure side is suctioned into the expander. The invention is provided with: a back pressure chamber 52 formed on a back surface 7c side of a moveable scroll 7, which is the opposite side from a substrate surface 7b; an oil-supply hole 28 and a relief hole 33 by which the back pressure chamber and the discharge side of the compressing unit communicate; a check valve device 66 provided in the supply hole 28, the direction from a compression-side discharge chamber 22 on the discharge side of the compressing unit to a lubricating oil chamber 26 on the rear pressure chamber side is the forward direction; and a relief valve 67 provided in the relief hole 33.

Description

Scroll type fluid machine and refrigeration apparatus using the same

The present invention relates to a scroll type fluid machine that forms an expansion chamber and a compression chamber of a working fluid between wraps of fixed and movable scrolls, and a refrigeration apparatus using the scroll type fluid machine.

This type of scroll type fluid machine includes a scroll unit including a movable scroll provided with a lap on the base surface and a fixed scroll provided with a wrap meshing with the lap of the movable scroll on the base surface. There is known a single plate type compressor-integrated expander in which a working chamber of a unit is divided into an expansion chamber and a compression chamber by a partition wall to form a central expansion portion and an outer compression portion (for example, Patent Document 1).

In this case, a back pressure chamber is formed on the back surface opposite to the base surface of the movable scroll, and the working fluid maintained at the discharge pressure of the compression unit is supplied to the back pressure chamber via the communication path. Therefore, a configuration has been adopted in which the movable scroll is urged to be pressed against the fixed scroll by the pressure on the discharge side of the compression unit.

Such a scroll type fluid machine is used, for example, in a heat pump for heating a hot water heater or the like, and constitutes a refrigeration cycle of a refrigeration apparatus together with a high-stage compressor, a radiator, and a heat absorber (evaporator). In this case, the working fluid compressed by the high-stage compressor flows into the radiator and radiates heat there. This working fluid is sucked into the expansion portion from the center portion of the fixed scroll of the scroll type fluid machine while being kept at a high pressure, and is expanded in an expansion chamber formed between the wraps of the expansion portion, whereby the movable scroll is revolved. Power is recovered.

The working fluid (refrigerant) that has exited the expansion part of the scroll type fluid machine flows into the heat absorber and evaporates. After exerting the endothermic action, the working fluid is sucked into the compression part from the outer peripheral part of the fixed scroll of the scroll type fluid machine. The working fluid sucked into the compression unit is compressed in the compression chamber formed between the wraps of the compression unit by the power recovered by the expansion unit. That is, the compression unit of the scroll type fluid machine is on the lower stage side, and the working fluid compressed by the lower stage compression unit is repeatedly circulated by being sucked into the higher stage compressor (for example, Patent Documents). 2).

In this case, as shown in FIG. 4 of Patent Document 2, the conventional refrigeration apparatus is provided with a bypass pipe that bypasses the suction side and the discharge side of the compression unit of the scroll type fluid machine. The bypass pipe is provided with an opening / closing valve. By opening the opening / closing valve only when the high-stage compressor is started, the low-stage compression section is bypassed. The purpose is to increase the discharge pressure of the high-stage compressor quickly and increase the power applied to the expansion part early by making the high-stage compressor easily suck the working fluid. It was intended to start the scroll fluid machine quickly.

Japanese Patent No. 5209964 Japanese Patent No. 3953871

As described above, in the conventional refrigeration system, when the high-stage compressor is started, the suction side and the discharge side of the compression unit (low-stage compression unit) of the scroll type fluid machine are bypassed by the bypass pipe. It is considered that it is easier to start the scroll type fluid machine if the working fluid is sucked from the compression part of the scroll type fluid machine than when the high stage compressor is started without providing such a bypass pipe.

This is because when the working fluid is sucked in from the discharge side of the compression unit of the scroll type fluid machine by the high-stage compressor, the pressure on the discharge side of the compression unit of the scroll type fluid machine causes the suction of the compression unit. This is because the pressure difference is lower than the pressure side, and a starting torque is generated in the scroll type fluid machine in the direction of compressing the working fluid in the compression part of the scroll type fluid machine. That is, in addition to the power recovered in the expansion part, power is also generated in the compression part, and the scroll fluid machine is easily started.

However, since the scroll type fluid machine has a structure in which the pressure on the discharge side of the compression unit is supplied as the back pressure of the movable scroll as described above, and the movable scroll is pressed against the fixed scroll by this back pressure, the high-stage compressor If the pressure on the discharge side of the compression part of the scroll type fluid machine becomes lower than the suction side of the compression part at the time of starting, the back pressure of the movable scroll is surely insufficient. For this reason, the movable scroll is separated from the fixed scroll, and the expansion chamber and the compression chamber cannot be formed between the wraps, and the scroll type fluid machine cannot be started.

Therefore, at the time of starting the scroll type fluid machine, there is a method of blocking the communication path connecting the discharge side of the compression unit and the back pressure chamber with a check valve so that pressure does not escape from the back pressure chamber to the discharge side of the compression unit. Conceivable. However, if the difference between the back pressure chamber at the time of startup and the pressure on the discharge side of the compression section becomes too large, the force that presses the movable scroll against the fixed scroll becomes excessive, resulting in increased mechanical loss and inability to start up. There is.

In addition, the pressure in the back pressure chamber must be set to the pressure on the discharge side of the compression unit when it is stable after startup. If the pressure in the back pressure chamber remains high, the force to press the movable scroll against the fixed scroll will be excessive. Loss increases and in the worst case, driving becomes impossible. For this reason, when the check valve is constituted by, for example, a reed valve, it is necessary to make a fine work such as making a minute hole in the reed valve, but if this hole is clogged with foreign matter mixed in the working fluid No longer function as a hole. Furthermore, when this foreign matter is caught between the reed valve and the valve seat (biting), there is a problem that it becomes difficult to remove the foreign matter and it cannot be activated.

The present invention has been made to solve various conventional technical problems, and is a single plate type compressor integrated type that constitutes a low-stage compression section of a refrigeration apparatus together with a high-stage compressor. In a scroll type fluid machine that is an expander, an object is to easily and surely start it up and to operate stably.

In order to solve the above-mentioned problems, a scroll type fluid machine according to the present invention is composed of a fixed scroll and a movable scroll each having a spiral wrap formed on each base surface of each substrate so as to face each other. Formed between each lap of both scrolls by expanding the working fluid in the expansion chamber formed between them, revolving the revolving motion of the movable scroll to recover the power, and the power recovered by this expansion section And a low-stage compression section that compresses the working fluid in the compressed chamber, and the working fluid compressed by the compression section is sucked into the high-stage compressor and compressed by the high-stage compressor. The high pressure working fluid is sucked into the expansion part, and the back pressure chamber formed on the back side opposite to the base surface of the movable scroll, the discharge side and the back pressure chamber of the compression part, respectively Communication for communication And a relief part, and a check valve device provided in the communication part, in which the direction from the discharge side to the back pressure chamber side of the compression part is the forward direction, and provided in the relief part. The relief part is always closed. And a relief valve device that opens the relief part when the pressure on the discharge side of the compression part is lower than the pressure in the back pressure chamber and the difference is larger than the first predetermined value D1. And

In the scroll type fluid machine according to the second aspect of the present invention, in the above invention, the check valve device always closes the communication portion, and the pressure in the back pressure chamber becomes lower than the pressure on the discharge side of the compression portion. Is characterized in that the communication portion is opened when the value is larger than the second predetermined value D2.

In the scroll type fluid machine of the invention of claim 3, in each of the above inventions, the check valve device and the relief valve device are each constituted by a ball plug and a spring for pressing the ball plug against the valve seat. It is characterized in that it is in line contact.

The scroll type fluid machine of the invention of claim 4 is characterized in that, in the above invention, the check valve device and the relief valve device are located in a lubricating oil chamber in which lubricating oil is stored.

A scroll type fluid machine according to a fifth aspect of the present invention is characterized in that, in the above invention, the communicating portion and the relief portion are formed on a fixed shaft constituting a support mechanism of the movable scroll.

A scroll type fluid machine according to a sixth aspect of the present invention is characterized in that, in the above invention, the communicating portion is formed through the center of the fixed shaft.

A refrigeration apparatus according to a seventh aspect of the invention comprises the scroll type fluid machine according to any one of the first to sixth aspects and a high-stage compressor, and the compression of the scroll type fluid machine. The working fluid is sucked into the higher stage compressor than the discharge side of the part, the high pressure working fluid compressed by the higher stage compressor is sucked into the expansion part of the scroll type fluid machine, and the higher stage side The working fluid is sucked from the compression portion of the scroll type fluid machine from the start of the compressor.

The refrigeration apparatus of the invention of claim 8 is characterized in that carbon dioxide is used as a working fluid in the above invention.

According to the present invention, a fixed scroll and a movable scroll each having a spiral wrap formed on each base surface of each substrate are opposed to each other, and the working fluid is supplied in an expansion chamber formed between the wraps of both scrolls. By expanding, the expanding part that revolves the movable scroll to recover the power, and the power recovered by the expanding part, the working fluid is compressed in the compression chamber formed between the laps of both scrolls. And a working fluid compressed by the compressor is sucked into the high-stage compressor, and a high-pressure working fluid compressed by the high-stage compressor is sucked into the expansion portion. In the scroll type fluid machine, a back pressure chamber formed on the back side opposite to the base surface of the movable scroll, a communication portion for communicating the discharge side of the compression portion and the back pressure chamber, and the communication portion Provided in the pressure Since the check valve device in which the direction from the discharge side to the back pressure chamber side is the forward direction is provided, the higher-stage side than the discharge side of the compression part of the scroll type fluid machine as in the invention of claim 7 is provided. The scroll type fluid machine of the present invention is used in a refrigeration apparatus that sucks a working fluid into a compressor and sucks the high pressure working fluid compressed by the high-stage side compressor into the expansion part of the scroll type fluid machine, and Even when the working fluid is sucked from the compression unit of the scroll type fluid machine from the time of starting the high stage side compressor, the scroll type fluid is also generated when the high stage side compressor is started by the check valve device. The inconvenience that the pressure in the back pressure chamber of the machine rapidly decreases is prevented.

As a result, the movable scroll is fixed even if the working fluid is sucked from the compression unit of the scroll type fluid machine from the start of the high-stage compressor without bypassing the compression unit of the scroll type fluid machine as in the prior art. The scroll type fluid machine can be activated without being peeled off from the scroll and pressed against the fixed scroll. Then, by sucking the working fluid from the discharge side of the compression unit with the high-stage compressor, the pressure on the discharge side of the compression unit becomes lower than the pressure on the suction side of the compression unit. Thereby, since a starting torque is generated in the scroll type fluid machine, it is possible to start up more easily than in the prior art.

In particular, in the present invention, the relief part for communicating the discharge side of the compression part and the back pressure chamber is always closed, and the relief part is always closed, and the pressure on the discharge side of the compression part is lower than the pressure of the back pressure chamber. Since the relief valve device is provided in the relief portion for opening the relief portion when the difference is larger than the first predetermined value D1, the discharge side of the compression portion and the back pressure chamber are connected when the scroll fluid machine is started. The communicating part is closed by a check valve device so that pressure does not escape from the back pressure chamber to the discharge side of the compression part, so that the pressure on the discharge side of the compression part decreases, and the pressure difference from the back pressure chamber When the difference increases and the difference exceeds the first predetermined value D1, the relief valve device opens and the pressure in the back pressure chamber can be released to the discharge side of the compression unit.

As a result, the difference between the back pressure chamber and the pressure on the discharge side of the compression part at the time of starting the scroll type fluid machine becomes too large, and the force that presses the movable scroll against the fixed scroll becomes excessive, increasing the mechanical loss and starting. The inconvenience of being impossible can be avoided in advance.

In this case, for example, as in the invention of claim 2, the check valve device always closes the communication portion, the pressure in the back pressure chamber becomes lower than the pressure on the discharge side of the compression portion, and the difference is the second difference. By opening the communication portion when the pressure is larger than the predetermined value D2, the pressure in the back pressure chamber is compressed by the pressure on the discharge side of the compression portion minus the second predetermined value D2 or more in cooperation with the relief valve device. It is possible to control within the range of the pressure on the discharge side of the section + the first predetermined value D1 or less, so that the scroll-type fluid machine can be started easily and reliably as a whole, and a stable operation can be realized. Become.

Further, as in the invention of claim 3, the check valve device and the relief valve device are respectively constituted by a ball stopper and a spring for pressing the ball stopper against the valve seat, and the ball stopper is in line contact with the valve seat. After the high-stage compressor is started, pressure gradually leaks from between the ball plug and the valve seat of the check valve device or relief valve device to the discharge side of the compression unit. That is, the pressure in the back pressure chamber that has risen to an equilibrium pressure higher than the pressure on the discharge side of the compressor during the stop is gradually reduced after the high-stage compressor is started.

As a result, the pressure in the back pressure chamber can be lowered to the pressure on the discharge side of the compression unit early after the scroll type fluid machine is started, and the back pressure applied to the movable scroll can be quickly set to an appropriate value. It becomes like this.

Also, foreign matter is hard to be caught between the ball stopper and the valve seat, and even if it is caught, it will be removed by the movement of the ball stopper due to pressure change. In particular, the communication portion and the relief portion are formed on the fixed shaft constituting the movable scroll support mechanism as in the invention of claim 5, and the check valve device and the relief valve device are stored in the lubricating oil as in the invention of claim 4. By being positioned in the lubricating oil chamber, the sealing function and the foreign substance removal function can be effectively exhibited.

In addition, although the boss | hub part which comprises the support mechanism of the said movable scroll is normally protrudingly provided in the back of the movable scroll, if a communicating part is penetrated and formed in the center of a fixed axis like invention of Claim 6, it will be related Lubricating oil can be supplied to the inside of the boss part without any problem.

Each of the above inventions is particularly effective for a refrigeration apparatus using carbon dioxide as a working fluid as in the invention of claim 8.

It is a vertical side view of the scroll type fluid machine of one example to which the present invention is applied. It is the top view which looked at the fixed scroll of FIG. 1 from the base surface side. FIG. 3 is a sectional view taken along line AA in FIG. 2. It is an expanded sectional view of the check valve device part of the scroll type fluid machine of FIG. It is a figure which shows the refrigerating cycle of the freezing apparatus of one Example using the scroll type fluid machine of FIG. It is a figure explaining the change of the pressure of each part of the scroll type fluid machine of FIG. It is a vertical side view of the scroll type fluid machine of other examples to which the present invention is applied.

Hereinafter, embodiments of the present invention will be described in detail.

(1) Basic Structure of Scroll Type Fluid Machine 1 FIG. 1 shows a vertical side view of a scroll type fluid machine 1 according to an embodiment of the present invention. The scroll type fluid machine 1 of the embodiment is, for example, a vertically installed single-plate type compressor-integrated expander, and refrigeration of a refrigeration apparatus RC that uses carbon dioxide whose high pressure side is a supercritical pressure as a refrigerant (working fluid). Used in the cycle (FIG. 5). Although the configuration of the refrigeration apparatus RC will be described in detail later, the refrigeration apparatus RC is incorporated as a heat pump in an air conditioner or a heat pump type hot water heater (not shown). The scroll fluid machine 1 according to the embodiment includes an expansion unit 2 that performs an expansion operation by the pressure of the refrigerant, and a compression unit 3 (low stage side) that performs a compression operation by the expansion operation of the expansion unit 2 ( FIG. 1, FIG. 2).

The scroll fluid machine 1 includes a housing 4. In the housing 4, a scroll unit 8 mainly composed of a fixed scroll 6 and a movable scroll 7 that revolves with respect to the fixed scroll 6, and a frame that supports the movable scroll 7 so that it can revolve. A main frame 9, and a lower flange portion 11 a are fixed to the bottom surface of the main frame 9, and a fixed shaft 11 provided with a central shaft portion 11 b protruding from the bottom surface of the main frame 9.

The outer peripheral portion of the main frame 9 is fixed to the inside of the housing 4, and the refrigerant (carbon dioxide) taken in from the refrigeration cycle of the refrigeration apparatus RC as the working fluid of the scroll fluid machine 1 is enclosed in the sealed housing 4. ) Is compressed by the compression unit 3.

Connected to the housing 4 is an expansion side suction pipe 16 that sucks into the expansion section 2 the refrigerant taken from the refrigeration cycle of the refrigeration apparatus RC. Further, the housing 4 has an expansion side discharge pipe 17 (FIG. 3) for discharging the refrigerant expanded in the expansion unit 2 toward the refrigeration cycle of the refrigeration apparatus RC, and the refrigerant compressed in the compression unit 3 is frozen. A compression-side discharge pipe 18 (FIG. 5) that discharges toward the refrigeration cycle of the device RC is connected. The ends of the expansion side suction pipe 16 and the expansion side discharge pipe 17 are opened and communicated with an expansion side suction chamber 19 and an expansion side discharge chamber 21 formed in the substrate 6 a of the fixed scroll 6, respectively. An end portion of the pipe 18 opens into the housing 4 and communicates with a compression side discharge chamber 22 as a discharge side of the compression portion 3 formed inside the upper portion of the housing 4.

Further, the housing 4 is connected with a compression side suction pipe 23 (FIG. 3) for sucking refrigerant taken from the refrigeration cycle of the refrigeration apparatus RC into the compression section 3, and an end portion of the compression side suction pipe 23 is fixed scroll. 6 is communicated with a compression side suction chamber 24 as a suction side of a compression portion formed in the substrate 6a.

On the other hand, a lubricating oil chamber 26 is formed inside the bottom of the housing 4, and lubricating oil for lubricating the scroll unit 8 is stored in the lubricating oil chamber 26. The compression side suction chamber 23 is provided with an oil feed hole 27 (FIG. 2) penetrating the substrate 6 a and the main frame 9 of the fixed scroll 6, and the lubricating oil chamber 26 is formed through the oil feed hole 27. Lubricating oil is sent to the compression side suction chamber 24.

The fixed scroll 6 is fixed to the upper surface portion 9a of the main frame 9, and a compression side discharge hole (not shown) is slightly located in the radial direction of the fixed scroll 6 with respect to the compression side suction chamber 24 of the substrate 6a of the fixed scroll 6 in the radial direction. Z). An oil separator (not shown) for separating the lubricating oil in the refrigerant is attached to the opening of the compression side discharge hole with respect to the compression side discharge chamber 22.

The movable scroll 7 is connected to a pedestal portion 9b of the main frame 9 through a rotation prevention mechanism (not shown) such as an Oldham ring at the outer peripheral portion of the back surface 7c which is the surface opposite to the base surface 7b of the substrate 7a. It is supported so that it can revolve without rotating. Further, a cylindrical boss portion (concave portion) 31 into which the eccentric bush 36 is slidably and rotatably fitted is projected on the back surface 7c of the movable scroll 7.

The fixed shaft 11 described above constitutes a support mechanism 54 that supports the movable scroll 7 together with the main frame 9 so as to be capable of revolving and turning at the center of the back surface 7c. In this case, the upper end portion of the shaft portion 11b of the fixed shaft 11 is inserted inside the slide bush 56 so as to be slidable and rotatable by the bearing 49. The slide bush 56 is inserted into the eccentric bush 36 in the eccentric direction. It is stored movably. That is, the upper end portion of the shaft portion 11 b of the fixed shaft 11 is inserted into the eccentric bush 36 through the slide bush 56. A spring (not shown) is interposed between the slide bush 56 and the eccentric bush 36. By this spring, the slide bush 56 is always urged in the eccentric direction, and thereby the misalignment of the

scrolls

6 and 7 is adjusted.

The eccentric bush 36 is slidably inserted into the boss 31 via a bearing 48. The bearing 48 receives a radial load that acts on the eccentric bush 36 as the orbiting scroll 7 revolves. Further, a bearing 51 is disposed between the lower end of the eccentric bush 36 and the main frame 9. As described above, the fixed shaft 11 supports the movable scroll 7 through the bearing 49, the slide bush 56, the eccentric bush 36, the bearing 48, and the bearing 51 so as to be capable of revolving, and the support mechanism 54 includes the boss portion 31. The eccentric bush 36, the slide bush 56, the fixed shaft 11, and the spring described above.

Here, the scroll unit 8 of the embodiment is a compressor-integrated expander, and includes a compression chamber of the compression unit 3 and an expansion chamber of the expansion unit 2 as a refrigerant working chamber by a pair of fixed scroll 6 and movable scroll 7. The fixed shaft 11 only supports the movable scroll 7 together with the main frame 9 so as to be capable of revolving, and the fixed shaft 11 itself is driven to rotate. There is no.

In detail, as shown in FIG. 2, an annular intermediate partition wall (annular wall) 38 and an annular outer partition wall 39 are erected on the base surface 6 b of the fixed scroll 6. A spiral outer fixed scroll wrap (wrap) 40 is provided between the partition wall (annular wall) 39 and a spiral inner fixed scroll wrap (wrap) 41 is provided on the center side of the intermediate partition wall 38. ing. Further, an annular groove 42 into which a seal ring (not shown) is inserted is recessed in the end surface of the intermediate partition wall 38 on the base surface 6b. By the seal ring of the annular groove 42, the inside of the scroll unit 8 is partitioned into an inner expansion portion 2 side and an outer compression portion 3 side.

On the substrate 6 a of the fixed scroll 6, the above-described compression side suction chamber 24 is formed at the outer peripheral end of the compression portion 3 slightly inside the outer partition wall 39, and the inner peripheral end of the compression portion 3 slightly outside the intermediate partition wall 38. A compression-side discharge hole 32 is formed in the upper part. In addition, the expansion side discharge chamber 21 described above is formed on the outer peripheral end of the expansion portion 2 slightly inside the intermediate partition wall 38 on the substrate 6a, and the expansion side suction chamber 19 described above is the inner peripheral end of the expansion portion 2. It is formed at the center. Furthermore, an annular oil groove 43 is formed on the substrate 6a slightly outside the outer partition wall 39, and is countersunk at a predetermined depth with a diameter larger than the groove width provided on the oil groove 43. The oil feed hole 27 described above is formed on the bottom surface of the formed recess.

On the other hand, on the base surface 7 b of the movable scroll 7, a spiral outer movable scroll wrap (wrap) 44 that meshes with the outer fixed scroll wrap 40 and a spiral inner movable scroll wrap (wrap) that meshes with the inner fixed scroll wrap 41. ) 46 is erected in the direction of the opposite spiral.

According to the scroll unit 8 described above, the expansion part 2 is formed inside the intermediate partition wall 38, and the compression part 3 is formed between the intermediate partition wall 38 and the outer partition wall 39. Specifically, as indicated by solid line arrows in FIG. 1, the refrigerant sucked from the expansion side suction pipe 16 is taken into the central portion of the expansion portion 2 through the expansion side suction chamber 19, and the

scrolls

6, 7 are mutually connected. By cooperating, it is expanded in an expansion chamber (working chamber) formed between the

laps

41 and 46. The volume of the expansion chamber is increased while moving toward the outer peripheral side of each of the

scrolls

6, 7, and accordingly, the movable scroll 7 is revolved around the axis of the fixed scroll 6. The refrigerant used for the revolving orbiting motion of the movable scroll 7 is discharged toward the refrigeration cycle of the refrigeration apparatus RC outside the housing 4 through the expansion side discharge chamber 21 via the expansion side discharge chamber 21.

On the other hand, the refrigerant sucked from the compression side suction pipe 23 is taken into the compression section 3 through the compression side suction chamber 24 as shown by the arrow marked as low stage suction in FIG. As the movable scroll 7 revolves around the axis of the fixed scroll 6 as it expands, the

scrolls

6 and 7 cooperate with each other to form a compression chamber (working chamber) formed between the

wraps

40 and 44. It is compressed with. The volume of the compression chamber is reduced while moving toward the center of each of the

scrolls

6 and 7 as the orbiting scroll 7 revolves. As the volume of the compression chamber decreases, the high-pressure refrigerant passes through the compression-side discharge hole 32 and the compression-side discharge chamber 22 and then passes through the compression-side discharge pipe 18 toward the refrigeration cycle of the refrigeration apparatus RC outside the housing 4. (Indicated by an arrow labeled low-stage discharge in FIG. 1).

(2) Communication part (oil supply hole 28)
Further, in this process, the refrigerant discharged from the compression side discharge hole 32 to the compression side discharge chamber 22 is separated from the lubricating oil in the refrigerant when passing through the oil separator described above. The lubricating oil separated from the refrigerant flows down to the lubricating oil chamber 26 through an oil return passage 47 formed between the main frame 9 and the housing 4 and is stored, as indicated by the white arrow in FIG. Further, in the shaft portion 11b located at the center of the fixed shaft 11, an oil supply hole 28 constituting the communication portion of the present invention is formed. The oil supply hole 28 penetrates the shaft portion 11 b in the axial direction of the shaft portion 11 b, and the lower end thereof is opened in the lubricating oil chamber 26, and the upper end opening is a back pressure inside the boss portion 31. It communicates with the chamber 52. Thereby, the oil supply hole (communication part) 28 functions as a hole which connects the discharge side (compression side discharge chamber 22) and the back pressure chamber 52 of the compression part 3 in this invention.

The lubricating oil stored in the lubricating oil chamber 26 rises in the oil supply hole 28 due to a differential pressure between a lubricating oil chamber 26 and a back pressure chamber 52, which will be described later, and the pedestal 9b of the main frame 9 and the back surface 7c of the movable scroll 7 The bearing 49, the bearing 48, and the bearing 51 are lubricated by being discharged into the back pressure chamber 52 formed between them. A check valve device 66 (described later) is attached in the oil supply hole 28.

(3) Relief part (Relief hole 33)
A relief hole 33 constituting a relief portion in the present invention is further bored in the flange portion 11a at the lower portion of the fixed shaft 11. The lower end of the relief hole 33 is also opened in the lubricating oil chamber 26, and the upper end opening communicates with the back pressure chamber 52 (constitutes a second communicating portion). A relief valve device 67 described later is attached in the relief hole 33 and is always closed.

(4) Back pressure of the movable scroll 7 As described above, in the back pressure chamber 52 of the scroll type fluid machine 1, the sliding portion between the rotation prevention mechanism described above and the base portion 9b and the back surface 7c of the movable scroll 7 by the lubricating oil, and the like. Is lubricated. Further, since the inside of the housing 4 is maintained at the discharge pressure of the compression unit 3 discharged from the compression side discharge hole 32 to the compression side discharge chamber 22, it passes through the oil return path 47, the lubricating oil chamber 26, and the oil supply hole 28. The back pressure chamber 52 is supplied with a refrigerant (working fluid) maintained at the discharge pressure of the compression unit 3 together with the lubricating oil. Accordingly, the movable scroll 7 from the back pressure chamber 52 is pressed and urged against the fixed scroll 6 by the discharge pressure of the compression unit 3.

Due to the pressure (back pressure) from the back pressure chamber 52, the tips of the

wraps

44 and 46 of the movable scroll 7 abut against the base surface 6 b of the fixed scroll 6, and the tips of the

wraps

40 and 41 of the fixed scroll 6 are the movable scroll 7. The base surface 7b of each other (both contact with the lubricating oil). As a result, an expansion chamber is formed in the expansion portion 2 between the laps, and a smooth revolving motion of the movable scroll 7 with respect to the fixed scroll 6 is possible while forming a compression chamber in the compression portion 3. In the scroll type fluid machine 1, the scroll unit 8 is driven by the expansion energy of the refrigerant in the expansion unit 2, and the refrigerant is compressed in the compression unit 3 by the driving force of the scroll unit 8.

(5) Check valve device 66
A check valve device 66 is mounted in the oil supply hole 28 formed through the center of the shaft portion 11b of the fixed shaft 11 as described above. The check valve device 66 of this embodiment includes a ball plug 68, a valve seat 69 having a passage formed therein, and a spring (which presses the ball plug 68 from the back pressure chamber 52 side (upper side) to the upper surface of the valve seat 69. Coil spring) 71. In this case, the upper surface of the valve seat 69 with which the ball stopper 68 abuts is a funnel-shaped inverted conical surface that is inclined inwardly as shown in FIG. 4, and the ball stopper 68 is in line contact (contact) with the valve seat 69. The part is configured to be circular).

Further, at least the ball stopper 68 and the valve seat 69 of the check valve device 66 are configured to be located in the lubricating oil of the lubricating oil chamber 26 (located below the oil level of the lubricating oil chamber 26). Further, the urging force of the spring 71 is set to, for example, 0.05 MPa, so that the ball plug 68 is always in contact with the valve seat 69 to close the oil supply hole 28.

On the other hand, the space between the back surface 7c of the movable scroll 7 and the base portion 9b of the main frame 9 is sealed with an O-ring 61 shown in FIG. At this time (in the compression section suction process), the pressure P4 in the back pressure chamber 52 is instantaneously reduced due to the low pressure. In this way, the pressure P4 in the back pressure chamber 52 becomes lower than the pressure P3 on the discharge side of the compression section 3 (pressure in the lubricating oil chamber 26), and the difference (P3−P4) is the second predetermined value D2 (0. 05 MPa + self-weight of the ball stopper 68. When the pressure is larger than a later-described first predetermined value D1, the ball stopper 68 is spaced upward from the valve seat 69 to open the oil supply hole 28, and the back pressure from the lubricating oil chamber 26 is increased. The lubricating oil is allowed to move to the chamber 52 and is supplied to the sliding portion as described above (indicated by a white arrow in FIG. 1).

That is, in the check valve device 66, the direction from the discharge side (lubricating oil chamber 26 side) to the back pressure chamber 52 side of the compression unit 3 is the forward direction, and the movement of the lubricating oil in the opposite direction is the ball plug 68. Is configured to be blocked by abutting the valve seat 69 and closing the oil supply hole 28. In particular, since the ball stopper 68 and the valve seat 69 are in the lubricating oil, the sealability between them is good. However, since the contact between the ball stopper 68 and the valve seat 69 is a line contact, even when the ball stopper 68 is in contact with the valve seat 69, the lubricating oil chamber 26 (compressing portion) is compressed from the back pressure chamber 52 side when stable. 3), a very small amount of lubricating oil (pressure) leaks.

(6) Relief valve device 67
Further, as described above, the relief valve device 67 is mounted in the relief hole 33 formed in the flange portion 11a below the fixed shaft 11. The check valve device 67 of this embodiment also includes a ball plug 72, a valve seat 73 having a passage formed therein, and a spring that presses the ball plug 72 from the lubricating oil chamber 26 side (lower side) to the lower surface of the valve seat 73. (Coil spring) 74. The structure of the relief valve device 67 is an upside down structure of the check valve device 66 shown in FIG. 4. In this case as well, the lower surface of the valve seat 73 with which the ball stopper 72 abuts is highly inclined inward. The conical surface has a reverse funnel shape, and the ball stopper 72 is configured to be in line contact with the valve seat 73 (the contact portion is circular).

Further, at least the ball stopper 72 and the lower surface of the valve seat 73 of the relief valve device 67 are configured to be located in the lubricating oil of the lubricating oil chamber 26 (located below the oil level of the lubricating oil chamber 26). Further, the urging force of the spring 74 is set to, for example, 0.3 to 0.5 MPa (0.5 MPa in the embodiment), whereby the ball stopper 72 always contacts the valve seat 73 and closes the relief hole 33. Yes. Then, the pressure P3 (pressure in the lubricating oil chamber 26) on the discharge side of the compression unit 3 becomes lower than the pressure P4 in the back pressure chamber 52, and the difference (P4−P3) is a first predetermined value D1 (0.5 MPa− When the ball plug 72 is larger than the dead weight of the ball plug 72, the ball plug 72 is spaced downward from the valve seat 73 to open the relief hole 33, and the pressure is released from the back pressure chamber 52 to the lubricating oil chamber 26 (the hatched arrow in FIG. 1). ).

Further, since the bottom surfaces of the ball plug 72 and the valve seat 73 are also in the lubricating oil, the sealing performance of the both is similarly good. However, as in the case of the check valve device 66, the ball plug 72 and the valve seat 73 are Since the contact is a line contact, even when the ball stopper 72 is in contact with the valve seat 73, a very small amount of pressure is applied from the back pressure chamber 52 side to the lubricating oil chamber 26 (the discharge side of the compression unit 3) when stable. It will leak.

(7) Refrigeration equipment RC
Next, FIG. 5 shows a refrigeration cycle of the refrigeration apparatus RC of one embodiment using the scroll type fluid machine 1 of the present invention. In this figure, for the sake of explanation, the expansion portion 2 and the compression portion 3 of the scroll type fluid machine 1 are shown separately. The compression unit 3 driven by the power recovered by the expansion unit 2 of the scroll type fluid machine 1 constitutes a low-stage compressor (low-stage compression unit) in the refrigeration cycle of the refrigeration apparatus RC. The above-described compression-side discharge pipe 18 of the compression unit 3 is connected to a high-stage side compression unit 70 a that is driven by an electric motor 70 b of a high-stage side compressor 70 that is located downstream of the compression unit 3.

A gas cooler 76 for cooling the refrigerant is connected to the subsequent stage of the compression unit 70 a, and the expansion unit 2 of the scroll fluid machine 1 is connected between the outlet of the gas cooler 76 and the inlet of the evaporator (heat absorber) 77. ing. The refrigerant from the gas cooler 76 is sucked into the expansion side suction chamber 19 of the expansion portion 2 from the expansion side suction pipe 16 described above. Further, the refrigerant is sent from the expansion section 2 of the scroll type fluid machine 1 to the evaporator 77 via the expansion side discharge pipe 17. The low-pressure refrigerant discharged from the evaporator 77 is sucked into the compression unit 3 of the scroll type fluid machine 1 from the compression side suction pipe 23.

(8) Operation of Refrigeration Apparatus RC Next, the operation of the refrigeration apparatus RC including the scroll fluid machine 1 will be described. In addition, operation | movement at the time of starting of freezing apparatus RC is mentioned later. The intermediate pressure refrigerant (carbon dioxide refrigerant) boosted by the low-stage compression section 3 driven by the expansion section 2 of the scroll type fluid machine 1 is sent from the compression-side discharge pipe 18 to the high-stage compressor 70. Further, the pressure is further increased by the compression unit 70a driven by the electric motor 70b, and becomes high pressure (supercritical). The high-pressure refrigerant is cooled by the gas cooler 76 in the supercritical state, and then taken into the expansion portion 2 of the scroll type fluid machine 1 from the expansion side suction pipe 16 and decompressed.

When the refrigerant expands isentropically in the expansion section 2, the movable scroll 7 revolves and the power is recovered. The revolving orbiting motion of the movable scroll 7 causes the compressor 3 to operate as a low-stage compressor. The refrigerant expanded in the expansion unit 2 is heated by the evaporator 77 (or the object is thereby cooled), and is again sucked into the compression unit 3 of the scroll type fluid machine 1 through the compression side suction pipe 23.

In this way, the compression unit 3 of the scroll fluid machine 1 takes part of the compression process of the refrigeration cycle of the refrigeration apparatus RC (low stage side), and the compression part 70a of the compressor 70 on the high stage side remains the compression process ( Take the higher stage). The compression power in the compression unit 3 is covered by the recovery power in the expansion unit 2.

(8-1) State of Check Valve Device 66 and Relief Valve Device 67 During Operation of Refrigeration Device RC As described above, the housing 4 including the back pressure chamber 52 is compressed on the compression side during the operation of the scroll fluid machine 1. The discharge pressure (P3) of the compression unit 3 discharged from the discharge hole 32 to the compression side discharge chamber 22 is maintained. Further, as described above, when the refrigerant is sucked in the compression section 3 of the scroll unit 8 (compression section suction process), the low pressure (pressure P2 on the suction side of the compression section 3 to be described later) is attracted to the back pressure chamber 52. The pressure P4 drops instantaneously, the pressure P4 in the back pressure chamber 52 becomes lower than the pressure P3 on the discharge side of the compression section 3 (pressure in the lubricating oil chamber 26), and the difference (P3−P4) is the second mentioned above. When the ball plug 68 is spaced apart from the valve seat 69 and the oil supply hole 28 is opened to allow the lubricating oil to pass from the lubricating oil chamber 26 to the back pressure chamber 52. The pressure (back pressure) is the same as the pressure in the compression side discharge chamber 22 (pressure P3 on the discharge side of the compression unit 3).

As a result, the lubricating oil maintained at the discharge pressure of the compression unit 3 is supplied to the back pressure chamber 52 via the oil return path 47, the lubricating oil chamber 26, and the oil supply hole 28. 7 is urged against the fixed scroll 6 by the discharge pressure of the compression unit 3, and the expansion and compression (low stage) of the refrigerant is stably performed in the expansion unit 2 and the compression unit 3 of the scroll type fluid machine 1. .

Further, since the pressure P4 in the back pressure chamber 52 is set to the pressure P3 on the discharge side of the compression unit 3 in this way, the difference (P4−P3) is smaller than the first predetermined value D1 described above. The ball stopper 72 of the valve device 67 is pressed against the valve seat 73 by a spring 74, and the relief hole 33 is closed.

(8-2) Operation at the time of starting the refrigeration apparatus RC (action of the check valve device 66 and the relief valve device 67)
Next, the operation at the time of starting the refrigeration apparatus RC will be described with reference to FIG. Assuming that the high-stage compressor 70 and the scroll type fluid machine 1 are stopped before t1 in FIG. 6, the freezing of the refrigeration apparatus RC including the housing 4 and the scroll unit 8 of the scroll type fluid machine 1 is performed. The entire cycle has an equilibrium pressure of about 6 MPa.

When the high-stage compressor 70 is started at time t1 in FIG. 6 from this equilibrium pressure state, the discharge pressure P1 of the compressor 70 (pressure at the inlet sucked into the expansion section 2 from the expansion-side suction pipe 16) is It rises from the equilibrium pressure and reaches about 10 MPa during operation. Further, the pressure P2 of the refrigerant that expands in the expansion section 2 and exits from the expansion side outlet pipe 17 (pressure at the outlet of the expansion section 2 = pressure on the suction side of the compression section 3) decreases from the equilibrium pressure.

On the other hand, since the refrigerant is sucked into the compressor 70 from the compression side discharge chamber 22 through the compression side discharge pipe 18 from the time when the high stage side compressor 70 is started up, the pressure P3 ( The pressure in the lubricating oil chamber 26 and the compression-side discharge chamber 22) decreases rapidly and becomes lower than the pressure P2 on the suction side of the compression unit 3. Due to this sudden pressure drop in the compression side discharge chamber 22, the pressure in the compression side discharge chamber 22 (the pressure in the lubricating oil chamber 26 which is the same as the pressure P3 on the discharge side of the compression unit 3) is lower than the pressure P4 in the back pressure chamber 52. Therefore, the ball stopper 68 of the check valve device 66 contacts the valve seat 69 and closes the oil supply hole 28.

As a result, the pressure P4 in the back pressure chamber 52 does not drop abruptly like the pressure P3 on the discharge side of the compression section 3, and the back pressure of the movable scroll 7 is secured, so that the scroll fluid machine 1 can be started. Become. However, since the contact between the ball stopper 68 and the valve seat 69 is a line contact, the pressure P4 in the back pressure chamber 52 gradually leaks to the lubricating oil chamber 26 side and decreases.

Note that the pressure (P3) of the lubricating oil chamber 26 and the pressure P4 of the back pressure chamber 52, which are the same pressure, due to a sudden pressure drop in the compression side discharge chamber 22 (pressure P3 on the discharge side of the compression unit 3). When the difference (P4−P3) is larger than the first predetermined value D1, the ball stopper 72 of the relief valve device 67 is separated from the valve seat 73 and opens the relief hole 33. As a result, the pressure escapes from the back pressure chamber 52 to the lubricating oil chamber 26 side, and further expansion of the pressure difference is prevented.

As described above, the pressure P3 on the discharge side of the compression unit 3 (pressure on the compression side discharge chamber 22) is lower than the pressure on the suction side of the compression unit 3, so that the scroll unit 8 of the scroll type fluid machine 1 has Generates a starting torque. Thereby, the scroll type fluid machine 1 becomes easy to start and starts at time t2.

When the scroll fluid machine 1 is activated, the refrigerant starts to be compressed in the compression chamber of the compression unit 3, so that the pressure in the compression side discharge chamber 22 which is the pressure P3 on the discharge side of the compression unit 3 also rises, and eventually the compression unit 3 and the pressure P2 in the back pressure chamber 52 becomes the same as about 5 MPa. Thereafter, as described above, the ball plug 68 of the check valve device 66 opens the oil supply hole 28 in the suction process of the compression unit 3 so that the pressure P3 on the discharge side of the compression unit 3 is supplied as the back pressure P4. become.

As described above, the back pressure chamber 52 formed on the back surface 7c side opposite to the base surface 7b of the movable scroll 7 of the scroll type fluid machine 1, and the discharge side (compression side discharge chamber 22) of the compression unit 3 An oil supply hole 28 serving as a communication portion for communicating the pressure pressure chamber 52 and the back pressure chamber 52, and the oil supply hole 28 is provided in the oil supply hole 28. Therefore, the refrigerant is sucked into the compressor 70 on the higher stage side than the discharge side of the compressor 3 of the scroll type fluid machine 1, and the compressor 70 on the higher stage side. The scroll type fluid machine 1 of the present invention is used in the refrigeration apparatus RC that sucks the compressed high-pressure refrigerant into the expansion unit 2 of the scroll type fluid machine 1 and the scroll type is started from the start of the compressor 70 on the high stage side. The refrigerant is sucked from the compression unit 3 of the fluid machine 1. Even if, disadvantage that the pressure (back pressure) is rapidly reduced in the back pressure chamber 52 of the scroll type fluid machine 1 at the start of the compressor 70 of the high-stage side is prevented by the check valve device 66.

As a result, the refrigerant is sucked from the compressor 3 of the scroll type fluid machine 1 from the start of the high-stage compressor 70 without bypassing the compressor 3 of the scroll type fluid machine 1 as in the prior art. The movable scroll 7 is pressed against the fixed scroll 6 without being peeled off from the fixed scroll 6, and the scroll fluid machine 1 can be activated. Then, by sucking the refrigerant from the discharge side of the compression unit 3 with the high-stage compressor 70, the pressure on the discharge side of the compression unit 3 becomes lower than the pressure on the suction side of the compression unit 3. Thereby, since the starting torque is generated in the scroll type fluid machine 1, it is possible to start up more easily than in the prior art.

In particular, a relief hole 33 as a relief part that communicates the discharge side of the compression part 3 and the back pressure chamber 52 and the relief hole 33 are always closed, and the pressure P3 on the discharge side of the compression part 3 is the back pressure chamber. The relief valve device 67 that opens the relief hole 33 when the difference (P4−P3) is larger than the first predetermined value D1 is provided in the relief hole 33. When the machine 1 is started, the oil supply hole 28 that connects the discharge side of the compression unit 3 and the back pressure chamber 52 is closed by the check valve device 66 so that pressure does not escape from the back pressure chamber 52 to the discharge side of the compression unit 3. As a result, the pressure P3 on the discharge side of the compression section 3 decreases, the pressure difference with the back pressure chamber 52 increases, and the difference (P4-P3) exceeds the first predetermined value D1. Then, the relief valve device 67 is opened and the pressure in the back pressure chamber 52 is reduced to the compression unit 3. It is possible to escape to the discharge side (the lubricant chamber 26).

As a result, the difference (P4-P3) between the back pressure chamber 52 and the pressure on the discharge side of the compression unit 3 at the time of starting the scroll fluid machine 1 becomes too large, and the force pressing the movable scroll 7 against the fixed scroll 6 is excessive. As a result, the mechanical loss increases and the inconvenience of being unable to start can be avoided.

In this case, the check valve device 66 always closes the oil supply hole 28, the pressure P4 in the back pressure chamber 52 becomes lower than the pressure P3 on the discharge side of the compression section 3, and the difference (P3-P4) is the first. Since the oil supply hole 28 is opened when it is larger than the predetermined value D2 of 2, the pressure P4 in the back pressure chamber 52 is increased by the pressure P3 on the discharge side of the compression unit 3 in cooperation with the relief valve device 67. It is possible to control within the range of the predetermined value D2 of 2 or more and the pressure P3 on the discharge side of the compression unit 3 + the first predetermined value D1 or less, and generally the scroll type fluid machine 1 can be started easily and reliably and stably. Can be realized.

Further, the check valve device 66 and the relief valve device 67 are constituted by ball plugs 68 and 72 and springs 71 and 74 that press the ball plugs 68 and 72 against the valve seats 69 and 73, respectively. Since the

seats

69 and 73 are in line contact, after the high-stage compressor 70 is started, the ball plugs 68 and 72 of the check valve device 66 and the relief valve device 67 are inserted between the valve seats 69 and 73. The pressure gradually leaks to the discharge side (lubricant chamber 26 side) of the compression unit 3. That is, the pressure in the back pressure chamber 52 that has risen to an equilibrium pressure higher than the pressure on the discharge side of the compression unit 3 during the stop is gradually reduced after the high-stage compressor 70 is started. Become.

As a result, the pressure in the back pressure chamber 52 can be lowered to the pressure on the discharge side of the compression unit 3 at an early stage after the scroll type fluid machine 1 is started, and the back pressure applied to the movable scroll 7 is quickly set to an appropriate value. Will be able to.

Here, it is difficult for foreign matter to get caught between the

ball stoppers

68 and 72 and the valve seats 69 and 73. Even if the ball plugs 68 and 72 are moved due to a change in pressure, they are removed. In particular, in the embodiment, the oil supply hole 28 and the relief hole 33 are formed in the fixed shaft 11 that constitutes the support mechanism 54 of the movable scroll 7, and the check valve device 66 and the relief valve device 67 are provided in the lubricating oil in which the lubricating oil is stored. Since it is located in the lubricating oil of the chamber 26, the sealing function is improved.

In particular, in this embodiment, the oil supply hole 28 is formed at the center of the shaft portion 11 b of the fixed shaft 11 and opens inside the boss portion 31, so that the bearing 49 and the like positioned inside the boss portion 31 can be smoothly smoothed. Can be supplied with lubricating oil.

In addition, since the foreign matter sandwiched between the ball plugs 68 and 72 and the valve seats 69 and 73 can be removed along with the movement of the lubricating oil, the foreign matter removing function can be effectively exhibited. The scroll fluid machine 1 of the present invention is particularly effective for the refrigeration apparatus RC that uses carbon dioxide as a working fluid.

FIG. 7 shows a scroll type fluid machine 1 according to another embodiment of the present invention. In this embodiment, an oil supply hole 28 constituting the communication portion of the present invention is formed in the flange portion 11a at the lower portion of the fixed shaft 11. Also in this case, the lower end of the oil supply hole 28 is located in the lubricating oil chamber 26 and is open, and the upper end opening communicates with the back pressure chamber 52, whereby the oil supply hole 28 is discharged from the compression section 3 in the present invention. It functions as a hole (communication portion) that communicates the side (compression side discharge chamber 22) and the back pressure chamber 52. The other configuration is basically the same as that of FIG. 1, and the check valve device 66 described above is attached to the oil supply hole 28 in this embodiment as well.

When the oil supply hole 28 is formed in the flange portion 11a of the fixed shaft 11 as shown in FIG. 7, the boss portion 31 protruding from the back surface 7c of the movable scroll 7 becomes a so-called pocket, and the lubricating oil is applied to the bearing 49 and the like inside thereof. It is difficult to turn around and there is a danger. By forming the oil supply hole 28 at the center of the shaft portion 11b as in the embodiment described above, such a problem is solved, but in the case of a configuration that does not hinder the supply of lubricating oil to the inside of the boss portion 31, As in this embodiment, the check valve device 66 may be arranged by forming the oil supply hole 28 in the flange portion 11a below the fixed shaft 11.

Here, in each of the above-described embodiments, the ball stopper 68 of the check valve device 66 is pressed against the valve seat 69 by the spring 71. However, the configuration is not limited thereto, and the configuration may be such that the weight of the ball stopper 68 contacts the valve seat 69. . In this case, the second predetermined value D2 is a value corresponding to the weight of the ball stopper 68.

Further, in the embodiment, the oil supply hole 28 and the relief hole 33 are formed in the fixed shaft 11. However, except for the inventions of claims 5 and 6, the check valve device 66 is formed in the main frame 9, for example. Alternatively, a relief valve device 67 may be attached. Furthermore, each numerical value shown in the embodiment is not limited to that.

DESCRIPTION OF SYMBOLS 1 Scroll type fluid machine 2 Expansion part 3 Compression part (low stage side)
6

Fixed scroll

6a,

7a Substrate

6b, 7b Base surface 7 Movable scroll 8 Scroll unit 9 Main frame 11 Fixed shaft 22 Compression side discharge chamber 26 Lubricating oil chamber 28 Oil supply hole (communication portion)
31 Boss part 33 Relief hole (Relief part)
47 Oil return path 52 Back pressure chamber 66 Check valve device 67

Relief valve device

68, 72

Ball stopper

69, 73

Valve seat

71, 74 Spring RC Refrigeration device

Claims

It is composed of a fixed scroll and a movable scroll each formed with a spiral wrap facing each base surface of each substrate, and by expanding the working fluid in an expansion chamber formed between the wraps of both scrolls, An expansion part that collects power by revolving orbiting the movable scroll, and a low stage that compresses the working fluid in a compression chamber formed between the laps of the scrolls by the power recovered by the expansion part. The working fluid compressed by the compression portion is sucked into a high-stage compressor, and the high-pressure working fluid compressed by the high-stage compressor is supplied to the expansion portion. In the scroll type fluid machine
A back pressure chamber formed on the back side opposite to the base surface of the movable scroll;
A communication part and a relief part for communicating the discharge side of the compression part and the back pressure chamber respectively;
A check valve device provided in the communication part, wherein the direction from the discharge side of the compression part toward the back pressure chamber side is a forward direction;
Provided in the relief part, the relief part is always closed, and the pressure on the discharge side of the compression part is lower than the pressure in the back pressure chamber, and the difference is larger than the first predetermined value D1 A relief valve device for opening the relief part to
A scroll type fluid machine characterized by comprising:
The check valve device always closes the communication portion, and the pressure in the back pressure chamber becomes lower than the pressure on the discharge side of the compression portion, and the difference is larger than a second predetermined value D2. The scroll type fluid machine according to claim 1, wherein the communication portion is opened at the same time.
The check valve device and the relief valve device are each configured by a ball stopper and a spring that presses the ball stopper against the valve seat, and the ball stopper is in line contact with the valve seat. The scroll type fluid machine according to claim 2.
The scroll type fluid machine according to claim 3, wherein the check valve device and the relief valve device are located in a lubricating oil chamber in which lubricating oil is stored.
5. The scroll fluid machine according to claim 4, wherein the communication part and the relief part are formed on a fixed shaft constituting a support mechanism of the movable scroll.
6. The scroll type fluid machine according to claim 5, wherein the communication portion is formed through the center of the fixed shaft.
A scroll-type fluid machine according to any one of claims 1 to 6 and the high-stage compressor, wherein the high-stage from a discharge side of a compression unit of the scroll-type fluid machine. The working fluid is sucked into the compressor on the side, the high-pressure working fluid compressed by the high-stage compressor is sucked into the expansion portion of the scroll type fluid machine, and
A refrigerating apparatus, wherein the working fluid is sucked from a compression section of the scroll type fluid machine from the time of starting the high stage compressor.
The refrigeration apparatus according to claim 7, wherein carbon dioxide is used as the working fluid.