WO2015059833A1

WO2015059833A1 - Scroll fluid machine

Info

Publication number: WO2015059833A1
Application number: PCT/JP2013/079033
Authority: WO
Inventors: 祐司 ▲高▼村
Original assignee: 三菱電機株式会社
Priority date: 2013-10-25
Filing date: 2013-10-25
Publication date: 2015-04-30
Also published as: JPWO2015059833A1; JP6120982B2

Abstract

A scroll fluid machine is characterized by having: a stationary scroll (4) and an orbiting scroll (5), which are provided within a hermetic container (60); a frame (6) for supporting the orbiting scroll (5) so that the orbiting scroll can orbit; a space (6c) within the frame, the space (6c) being formed between the frame (6) and the orbiting scroll (5); a main shaft (14) for transmitting drive power to the orbiting scroll (5); an oil discharge hole (6b) formed extending through the frame (6) and discharging excessive oil present inside the space (6c) within the frame to the outside of the frame (6); and an oil discharge valve (28) provided to the oil discharge hole (6b) and opening and closing the oil discharge hole (6b) according to oil pressure (P) within the space (6c) within the frame.

Description

Scroll fluid machinery

The present invention relates to a scroll fluid machine such as a scroll compressor and a scroll pump.

The scroll compressor is provided with an oil pump that is operated by the rotation of the main shaft and pumps up the oil stored in the oil sump at the bottom of the shell. The oil pumped up by the oil pump is supplied to sliding parts such as a rocking bearing, a main bearing, and a sub-bearing through an oil supply vertical hole penetrating the main shaft in the longitudinal direction. The oil that has finished lubricating the rocking bearing is stored inside the frame and used for lubrication of the Oldham coupling and the thrust surface of the rocking scroll, cooling the rocking bearing, and the main bearing.

¡An oil drain pipe is connected inside the frame. Excess oil inside the frame is returned to the sump at the bottom of the shell through the oil drain pipe. During high-speed operation, the amount of oil supplied to the inside of the frame increases, resulting in insufficient oil drainage due to pressure loss due to throttling at the oil drain pipe inlet and wall friction inside the oil drain pipe. Rises. When the hydraulic pressure inside the frame rises, the drive input of the oil pump rises, and the amount of oil that hangs down on the shell bottom without passing through the oil drain pipe is increased. When the amount of oil dripping at the bottom of the shell increases, a large amount of oil is wound up by the refrigerant, sucked into the compression chamber together with the refrigerant and discharged to the outside, and the oil rise of the scroll compressor increases.

Patent Document 1 discloses a scroll compressor provided with a bypass hole that branches from an oil supply hole of a main shaft and opens to the outside of the main shaft, and a valve that opens and closes the bypass hole with a predetermined hydraulic pressure. In this scroll compressor, when the rotational speed of the main shaft increases and the centrifugal force increases, the valve is opened with a hydraulic pressure exceeding a predetermined pressure, and excess oil is discharged from the bypass hole and returned to the oil sump. .

Japanese Patent Laid-Open No. 2-5787

In the conventional scroll compressor, the fluid taken into the shell from the suction pipe is taken into the frame through the suction port. The space in the frame is provided with fixed vortex and oscillating vortex that are alternately combined, and the oscillating vortex oscillates with respect to the fixed vortex. The fluid taken into the frame is compressed in a compression chamber formed by a fixed vortex and an oscillating vortex, and is discharged to the outside of the scroll compressor through a discharge chamber, a muffler, and a discharge pipe.

The driving force for compressing the fluid is applied to the oscillating spiral by the rotation of the main shaft integrated with the rotor of the electric motor. The main shaft and the oscillating vortex are connected via an oscillating bearing, and the rotation of the oscillating vortex is regulated by an Oldham coupling. Thereby, the rotational motion of the main shaft is converted into the swing motion of the swing spiral. The main shaft is supported by a main bearing and a sub bearing. The frame is a housing for storing a fixed spiral and a swing spiral, and has a thrust bearing and a main bearing that support an axial load acting on the swing spiral. The main bearing, the rocking bearing, the auxiliary bearing, the thrust bearing, and the Oldham coupling are lubricated with oil. The oil is pumped from the bottom of the shell by an oil pump that uses the rotation of the main shaft as a driving force. The oil pump is connected to the lower end of the main shaft, and supplies the oil pumped up from the bottom of the shell to each sliding portion through an oil supply vertical hole formed in the main shaft. The amount of oil pumped up by the oil pump increases as the rotational speed of the compressor increases.

Here, the oil flow path will be described. Oil supply to the rocking bearing is performed by an oil supply vertical hole in the main shaft. Oil supply to the main bearing and the sub-bearing is performed by an oil supply vertical hole and an oil supply horizontal hole branched in an orthogonal direction from the oil supply vertical hole in the main shaft. The oil that has lubricated the main and sub bearings drips down and returns to the sump at the bottom of the shell. The oil that has lubricated the rocking bearing is stored in the space in the frame. The oil accumulated in the space in the frame is lubricated to the thrust bearing, lubricated to the Oldham coupling, lubricated to the spiral sliding part (sliding part of the fixed spiral and swinging spiral), lubricated to the main bearing, It plays a role of cooling the dynamic bearing and the main bearing. An oil drain pipe is connected to the space in the frame. Excess oil in the space in the frame is returned from the space in the frame to the oil sump at the bottom of the shell through the oil drain pipe.

During high-speed operation, the amount of oil pumped up by the oil pump becomes very large, and the amount of oil supplied into the frame increases accordingly. In that case, the flow rate of oil discharged through the oil discharge pipe also increases. However, when the flow rate of oil drained increases, pressure loss occurs in the oil drain pipe due to the effect of throttle at the oil drain pipe inlet and the effect of pipe friction inside the oil drain pipe, and the hydraulic pressure in the frame increases. To do. If the oil pressure in the frame rises excessively, the oil pumped up by the oil pump tends to come out of the oil supply side hole with a relatively low flow resistance, so the amount of oil that drips from the main bearing or the sub-bearing to the shell bottom is reduced. Increase. When the oil dripping from the main bearing or the sub-bearing is wound up by the refrigerant, the increase in oil as described above occurs. Moreover, since the downstream pressure in the oil supply passage is increased, the drive input of the oil pump is increased.

In the scroll compressor of Patent Document 1, since the valve of the bypass hole is opened when the hydraulic pressure rises, excess oil is discharged from the bypass hole. This prevents excessive lubrication of the bearings and the space in the frame during high-speed operation. However, since the valve in the scroll compressor of patent document 1 is attached to the outer peripheral surface of the rotating main shaft, centrifugal force acts on the valve. For this reason, it becomes difficult to ensure the strength and reliability of the valve. Further, since the centrifugal force acting on the valve itself and the fluid affects the opening characteristic of the valve, it is difficult to adjust the opening characteristic of the valve. Therefore, there is a problem that it is difficult to discharge the excess oil in the frame appropriately.

Furthermore, in the scroll compressor of Patent Document 1, when oil is discharged from the bypass hole, the oil is sprinkled like a sprinkler from the outer peripheral surface of the rotating main shaft to the space in the shell. For this reason, there is a problem that the oil is likely to be wound up by the refrigerant, which may cause an increase in the amount of oil.

The present invention has been made to solve the above-described problems, and provides a scroll fluid machine capable of appropriately discharging excess oil in a frame and suppressing an increase in oil rising. With the goal.

A scroll fluid machine according to the present invention is formed between a fixed scroll and a swing scroll provided in a container, a frame that supports the swing scroll in a swingable manner, and the frame and the swing scroll. A frame inner space, a main shaft for transmitting a driving force to the orbiting scroll, an oil drain hole provided through the frame and discharging excess oil in the frame inner space to the outside of the frame, and the drain And an oil discharge valve that opens and closes the oil discharge hole based on the oil pressure in the space in the frame.

According to the present invention, since the oil drain valve opens when the hydraulic pressure in the space in the frame rises, excess oil in the frame can be discharged out of the frame from the oil drain hole. Therefore, even if the rotation speed of the main shaft increases and the amount of oil pumped up increases, it is possible to prevent an excessive increase in the hydraulic pressure in the space in the frame.

Since the oil drain valve is provided in the oil drain hole of the frame, the centrifugal force does not act on the oil drain valve unlike the configuration in which the oil drain valve is provided on the rotating parts such as the main shaft. Thereby, since it is not necessary to consider a centrifugal force as a load which acts on a drain valve, the opening degree characteristic of a drain valve can be adjusted easily. Further, since centrifugal force does not act on the oil discharge valve, the strength and reliability of the oil discharge valve can be ensured. Therefore, according to the present invention, surplus oil in the frame can be appropriately discharged out of the frame.

In addition, since the oil drain hole is fixed to the container, it is possible to prevent the oil from being scattered as compared with a configuration in which oil is discharged from the outer peripheral surface of the rotating main shaft. Therefore, it is possible to suppress the oil from being wound up by the refrigerant, and it is possible to suppress an increase in the oil.

1 is a schematic cross-sectional view showing an overall configuration of a scroll compressor according to Embodiment 1 of the present invention. It is sectional drawing which expands and shows a part of scroll compressor which concerns on Embodiment 1 of this invention. It is a figure which shows the flow of the oil in the scroll compressor which concerns on Embodiment 1 of this invention. It is a figure which shows the flow of the oil in space 6c vicinity in the frame in the scroll compressor which concerns on Embodiment 1 of this invention. It is sectional drawing which expands and shows a part of scroll compressor which concerns on Embodiment 2 of this invention. It is sectional drawing which expands and shows a part of scroll compressor which concerns on the modification of Embodiment 2 of this invention. It is sectional drawing which expands and shows a part of scroll compressor which concerns on Embodiment 3 of this invention. It is sectional drawing which expands and shows a part of scroll compressor which concerns on Embodiment 4 of this invention. It is sectional drawing which expands and shows a part of scroll compressor which concerns on Embodiment 5 of this invention.

Embodiment 1 FIG.
A scroll compressor (an example of a scroll fluid machine) according to Embodiment 1 of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing the overall configuration of the scroll compressor according to the present embodiment. FIG. 2 is an enlarged cross-sectional view of a part of the scroll compressor according to the present embodiment. The scroll compressor sucks a fluid (for example, a refrigerant), compresses the fluid, and discharges it as a high-temperature and high-pressure state. A scroll compressor becomes one of the components of the refrigerating cycle apparatus used for various industrial machines, such as a refrigerator, a freezer, a vending machine, an air conditioning apparatus, a freezing apparatus, or a water heater. In the following drawings including FIG. 1 and FIG. 2, the dimensional relationship and shape of each component may differ from the actual ones.

As shown in FIGS. 1 and 2, the scroll compressor has a configuration in which a compression mechanism portion 40 that compresses a fluid and an electric motor portion 50 that drives the compression mechanism portion 40 are accommodated in an airtight container 60 (shell). have. The sealed container 60 has a configuration in which the upper shell 24, the middle shell 25, and the lower shell 26 are airtightly joined by welding or the like. An oil sump 18 is formed at the bottom of the lower shell 26. The oil sump 18 stores oil (refrigeration machine oil) that lubricates each sliding part in the scroll compressor. A suction pipe 7 is connected to the middle shell 25 as a suction port for sucking low-pressure refrigerant into the sealed container 60. Further, the frame 6 is fixedly supported at the upper part of the middle shell 25, the stator 11 of the electric motor unit 50 is fixedly supported at the lower part thereof, and the subframe 15 is fixedly supported at the lower part thereof. Yes. A discharge pipe 1 is connected to the upper shell 24 as a discharge port for discharging the compressed refrigerant to the outside of the sealed container 60.

The electric motor unit 50 drives the rocking scroll 5 of the compression mechanism unit 40 via the main shaft 14 in order to compress the refrigerant gas by the compression mechanism unit 40. The electric motor unit 50 includes a stator 11 fixed to the inner peripheral surface of the sealed container 60 and a rotor 12 fixed to the main shaft 14. The rotor 12 is rotationally driven by energizing the stator 11 and rotates the main shaft 14 that transmits the driving force to the orbiting scroll 5. As a power source for supplying power to the stator 11, for example, an inverter power source is used that can change the driving rotational speed within a predetermined range in order to make the refrigerant circulation amount variable. At the upper end portion of the main shaft 14, an eccentric shaft portion 29 that is rotatably fitted to the rocking bearing 21 of the rocking scroll 5 is formed. Inside the main shaft 14, an oil supply vertical hole 14 a serving as a supply channel for oil stored in the oil sump 18 is provided so as to penetrate from the lower end to the upper end along the longitudinal direction (axial direction) of the main shaft 14. Yes. In addition, oil supply lateral holes 14 b and 14 c that branch in an orthogonal direction from the oil supply vertical hole 14 a and extend to the outer peripheral surface of the main shaft 14 along the radial direction of the main shaft 14 are provided in the main shaft 14. The oil supply lateral hole 14b is provided near or above a main bearing 19 described later, and the oil supply horizontal hole 14c is provided near or above a ball bearing 16 (sub bearing) described later.

An oil pump 17 is provided at the lower end of the main shaft 14. The oil pump 17 pumps up the oil in the oil sump 18 using the rotation of the main shaft 14 as a driving force. The amount of oil pumped up by the oil pump 17 increases as the rotational speed of the main shaft 14 increases. The pumped-up oil is supplied to each sliding portion in the scroll compressor and a frame inner space 6c described later through the oil supply vertical holes 14a and the oil supply

horizontal holes

14b and 14c.

A first balancer 10 is provided above the main shaft 14. A second balancer 13 is provided below the rotor 12. The first balancer 10 and the second balancer 13 rotate together with the main shaft 14 and the rotor 12, and have a function of balancing the rocking scroll 5 with respect to the rotation center of the main shaft 14. The first balancer 10 is covered with a balancer cover 9 attached to the lower part of the frame 6.

The compression mechanism unit 40 has a fixed scroll 4 and a swing scroll 5. The fixed scroll 4 is fixed to the frame 6 fixedly supported by the middle shell 25. The fixed scroll 4 includes an end plate 4a and a spiral portion 4b that is an involute curved projection provided on the lower surface of the end plate 4a. A discharge port 30 is formed at the center of the fixed scroll 4 to discharge the refrigerant gas that has been compressed to a high pressure. A discharge chamber 3 and a muffler 2 are provided on the outlet side of the discharge port 30.

The oscillating scroll 5 performs an oscillating motion (revolving orbiting motion) without rotating with respect to the fixed scroll 4. The orbiting scroll 5 includes an end plate 5a and a spiral portion 5b that is an involute curved projection provided on the upper surface of the end plate 5a. A thrust bearing 31 is provided on the surface of the orbiting scroll 5 opposite to the surface where the spiral portion 5b is formed (on the side opposite to the compression chamber). The orbiting scroll 5 is supported in the axial direction by the thrust surface of the frame 6 via the thrust bearing 31. A bottomed cylindrical rocking bearing 21 is formed at a substantially central portion of the surface of the rocking scroll 5 on the side opposite to the compression chamber. The rocking bearing 21 accommodates a slider 22 that supports the rocking scroll 5 so that the rocking scroll 5 can revolve. An eccentric shaft portion 29 provided at the upper end of the main shaft 14 is inserted into the slider 22.

The fixed scroll 4 and the orbiting scroll 5 are mounted in the sealed container 60 in a state in which the spiral part 4b and the spiral part 5b whose winding directions are opposite to each other are meshed with each other. By combining the spiral portion 4b of the fixed scroll 4 and the spiral portion 5b of the swing scroll 5, the volume changes between the spiral portion 4b and the spiral portion 5b as the swing scroll 5 swings. A compression chamber is formed. An Oldham joint 23 is disposed between the orbiting scroll 5 and the frame 6 for preventing the rotation of the orbiting scroll 5 during the orbiting movement. The key portion formed on the upper surface of the Oldham joint 23 is slidably received in the Oldham groove provided in the swing scroll 5, and the key portion formed on the lower surface is provided by the Oldham provided in the frame 6. It is slidably received in the groove.

The frame 6 is fixed to the inner peripheral surface of the sealed container 60. The frame 6 fixedly supports the fixed scroll 4 and supports the swing scroll 5 through a thrust bearing 31 so as to be swingable. Between the frame 6 and the orbiting scroll 5, an in-frame space 6c is formed. A predetermined amount of the oil supplied through the oil supply vertical hole 14a can be stored in the frame internal space 6c.

In the thrust surface of the frame 6, an oil drain hole 6a for discharging excess oil in the frame internal space 6c is formed. One end of an oil drain pipe 8a for returning the oil to the oil sump 18 is connected to the oil drain hole 6a. The other end of the oil drain pipe 8 a extends through the stator 11 and above the oil sump 18. Unlike the oil discharge hole 6b described later, the oil discharge hole 6a and the oil discharge pipe 8a are not provided with an oil discharge valve. That is, the oil drain hole 6a and the oil drain pipe 8a constitute an oil drain passage that is always open.

The oil receiver 27 is attached to the outside of the frame 6. The space 6c in the frame and the space in the oil receiver 27 communicate with each other via an oil drain hole 6b formed through the frame 6 at a different location from the oil drain hole 6a. The oil drain hole 6 b is configured to discharge excess oil in the frame inner space 6 c to the oil receiver 27 outside the frame 6. The oil receiver 27 is configured to temporarily receive the oil discharged from the oil discharge hole 6 b without being exposed to the flow of the fluid (refrigerant) in the sealed container 60. An outlet on the oil receiver 27 side of the oil drain hole 6 b is formed on a vertical surface outside the frame 6. An oil discharge valve 28 having a reed valve structure in which one end of a rigid leaf spring portion is fixed is provided at the oil receiver 27 side outlet of the oil discharge hole 6b. The oil drain hole 6b is closed from the oil receiver 27 side by a drain valve 28 having a reed valve structure. The oil discharge valve 28 is adjusted so as to start to open when the hydraulic pressure P in the frame internal space 6c increases to reach a predetermined pressure P ′ by deforming the leaf spring portion with a predetermined deformation amount, for example. ing. One end of an oil drain pipe 8 b for returning oil to the oil sump 18 is connected to the bottom of the oil receiver 27. The oil drain pipe 8 b is provided between the oil receiver 27 and the oil reservoir 18, and the other end of the oil drain pipe 8 b extends through the stator 11 and above the oil reservoir 18. The oil drain hole 6b and the oil drain pipe 8b constitute an oil drain passage that is opened only when the hydraulic pressure P in the frame inner space 6c rises above the pressure P '.

Further, the frame 6 rotatably supports an upper portion of the main shaft 14 in the vicinity of the eccentric shaft portion 29 via a main bearing 19 provided in a through hole in the center portion. A sleeve 20 for smoothly rotating the main shaft 14 penetrating the main bearing 19 is rotatably accommodated in the main bearing 19.

The subframe 15 is provided below the frame 6 and is fixed to the inner peripheral surface of the sealed container 60. The sub-frame 15 rotatably supports the lower part of the main shaft 14 through a through hole formed in the center. An outer ring of a ball bearing 16 for rotatably supporting the main shaft 14 is press-fitted and fixed in the through hole of the sub frame 15.

Next, the operation of the scroll compressor according to this embodiment will be described. First, the basic operation of the scroll compressor will be described. When electric power is supplied to the stator 11 by an inverter power source or the like, the main shaft 14 is rotationally driven by the rotor 12. When the main shaft 14 is rotationally driven, the eccentric shaft portion 29 provided at the upper end of the main shaft 14 rotates in the rocking bearing 21 via the slider 22, and the driving force is transmitted to the rocking scroll 5. At this time, each key portion of the Oldham joint 23 reciprocates in the Oldham groove of the swing scroll 5 and in the Oldham groove of the frame 6. As a result, the orbiting scroll 5 is restricted from rotating and performs an orbiting motion (revolving orbiting motion). That is, only the swing motion is transmitted from the eccentric shaft portion 29 to the swing scroll 5.

The low-pressure gas refrigerant in the refrigerant circuit is sucked into the sealed container 60 through the suction pipe 7 and flows into the compression chamber through a suction port (not shown) provided in the frame 6. The refrigerant that has flowed into the compression chamber is compressed along with the swing of the swing scroll 5 to be in a high temperature and high pressure state, flows out of the compression chamber through the discharge port 30, and flows into the discharge chamber 3. The high-pressure gas refrigerant that has flowed into the discharge chamber 3 pushes open a discharge valve provided in the discharge chamber 3 due to a pressure difference, passes through the muffler 2 and the discharge space in the sealed container 60, and passes from the discharge pipe 1 to the sealed container 60. It is discharged outside. The discharged refrigerant circulates in the refrigerant circuit of the refrigeration cycle apparatus and returns to the suction pipe 7 of the scroll compressor as a low-pressure gas refrigerant.

Next, the flow of oil in the scroll compressor will be described with reference to FIGS. FIG. 3 is a diagram illustrating the flow of oil in the scroll compressor. FIG. 4 is a diagram showing the flow of oil in the vicinity of the space 6c in the frame. The arrow in FIG.3 and FIG.4 represents the example of the flow of oil. As shown in FIGS. 3 and 4, the oil in the oil sump 18 is pumped up by the oil pump 17 using the rotation of the main shaft 14 as a driving force. The pumped oil flows upward through the oil supply vertical hole 14a. Part of the oil flowing through the oil supply vertical hole 14a lubricates the main bearing 19 through the oil supply lateral hole 14b, and the other part lubricates the ball bearing 16 through the oil supply horizontal hole 14c. The oil after lubricating the main bearing 19 and the ball bearing 16 hangs downward and returns to the oil sump 18. The remaining oil that has not flowed into the oil supply

horizontal holes

14b and 14c rises to the upper end in the oil supply vertical hole 14a and lubricates the rocking bearing 21. The ratio between the flow rate of oil flowing into the feed oil

horizontal holes

14b and 14c in the middle of the feed oil vertical hole 14a and the flow rate of oil rising to the upper end of the feed oil vertical hole 14a is affected by the pressure state on the downstream side, The flow rate flowing toward the lower pressure side on the downstream side is relatively large. The oil after lubricating the rocking bearing 21 is stored in the space 6c in the frame. The oil stored in the frame inner space 6c plays a role of lubrication of the Oldham joint 23 and the thrust bearing 31, cooling of the rocking bearing 21 and the main bearing 19, and the like. Of the oil stored in the frame inner space 6c, the surplus is discharged to the outside of the frame inner space 6c (outside the frame 6) via the oil discharge hole 6a and the oil discharge pipe 8a that are always open, and the oil reservoir 18 Return to.

The amount of oil supplied to the frame inner space 6c through the oil supply vertical hole 14a increases as the rotational speed of the main shaft 14 increases. Further, as the amount of oil supplied increases, the flow rate of the oil discharged through the oil drain hole 6a and the oil drain pipe 8a also increases. When the flow rate of the oil discharged through the oil drain hole 6a and the oil drain pipe 8a increases, the pressure due to the throttle near the inlet of the oil drain hole 6a and the oil drain pipe 8a, the wall friction inside the oil drain pipe 8a, etc. Due to the loss, the hydraulic pressure P in the frame internal space 6c increases. That is, during the high speed operation of the scroll compressor, the rotational speed of the main shaft 14 increases, so that the hydraulic pressure P in the frame inner space 6c increases. When the oil pressure P rises and reaches the pressure P ′, the oil discharge valve 28 of the oil discharge hole 6 b is pushed open by the oil pressure P. Thereby, the oil in the frame inner space 6c starts to be discharged out of the frame 6 through the oil drain hole 6b in addition to the oil drain hole 6a (oil drain pipe 8a). The oil discharged to the outside of the frame 6 through the oil drain hole 6b is received by the oil receiver 27, and then returns to the oil reservoir 18 at the bottom of the sealed container 60 through the oil drain pipe 8b. When the hydraulic pressure P in the frame inner space 6c further increases, the opening degree of the oil discharge valve 28 becomes larger, and more oil is discharged from the oil discharge hole 6b. Accordingly, it is possible to prevent the oil pressure in the frame internal space 6c from increasing while maintaining a state where oil is stored in the frame internal space 6c.

The opening characteristic of the oil discharge valve 28 including the pressure P ′ at which the oil discharge valve 28 starts to open and the opening degree change of the oil discharge valve 28 with respect to the increase in the hydraulic pressure in the frame internal space 6c, It can be arbitrarily adjusted depending on the rigidity and the initial deformation amount. At this time, since only the oil pressure P needs to be considered as the load acting on the oil discharge valve 28, the opening degree of the oil discharge valve 28 is compared with a configuration in which the oil discharge valve is attached to the main shaft 14 or the like that is a rotating part. The characteristics can be easily adjusted. The mounting position and mounting direction of the oil drain hole 6a and the oil drain valve 28 can be freely selected.

As described above, the scroll fluid machine according to the present embodiment includes the fixed scroll 4 and the swing scroll 5 provided in the hermetic container 60, the frame 6 that supports the swing scroll 5 so as to be swingable, A frame inner space 6c formed between the frame 6 and the orbiting scroll 5, a main shaft 14 for transmitting a driving force to the orbiting scroll 5, and the oil in the oil reservoir 18 by the rotation of the main shaft 14 causes the oil in the oil sump 18 to flow. An oil pump 17 that is pumped up, an oil drain hole 6b that passes through the frame 6 and discharges excess oil in the frame inner space 6c to the outside of the frame 6, and an oil drain hole based on the hydraulic pressure P of the frame inner space 6c. And an oil discharge valve 28 that opens and closes 6b.

According to this configuration, the oil discharge valve 28 opens when the hydraulic pressure P in the frame internal space 6c increases, so that excess oil in the frame internal space 6c can be discharged out of the frame 6 through the oil discharge holes 6b. Therefore, even if the rotation speed of the main shaft 14 increases and the amount of oil pumped up by the oil pump 17 increases, it is possible to prevent an excessive increase in the hydraulic pressure in the frame inner space 6c.

The opening characteristic of the oil discharge valve 28 can be arbitrarily adjusted by the rigidity of the leaf spring portion of the oil discharge valve 28 and the initial deformation amount. Since the oil drain valve 28 is provided in the oil drain hole 6b of the frame 6 fixed to the sealed container 60, the oil drain valve 28 is different from the configuration in which the oil drain valve is provided in a rotating part such as a main shaft. Centrifugal force does not act on. Thereby, it is not necessary to consider the centrifugal force as a load acting on the oil discharge valve 28, and for example, only the oil pressure P needs to be considered. Therefore, the opening characteristic of the oil discharge valve 28 can be easily adjusted. Further, it is possible to prevent the opening characteristic of the oil discharge valve 28 from changing depending on the rotation speed of the main shaft 14. Furthermore, since centrifugal force does not act on the oil discharge valve 28, the strength and reliability of the oil discharge valve 28 can be ensured. Therefore, according to the present embodiment, excess oil in the frame inner space 6c can be discharged out of the frame 6 appropriately.

Further, since the oil drain hole 6b is provided fixed to the sealed container 60, it is possible to prevent the oil from being scattered as compared with the configuration in which the oil is discharged from the outer peripheral surface of the rotating main shaft. Therefore, it is possible to suppress the oil from being wound up by the refrigerant, and it is possible to suppress an increase in the oil.

Further, the scroll fluid machine according to the present embodiment is characterized in that the oil discharge valve 28 has a reed valve structure that is opened and closed by the hydraulic pressure P. According to this configuration, the configuration of the oil discharge valve 28 can be simplified.

Further, the scroll fluid machine according to the present embodiment is attached to the outside of the frame 6 and receives an oil receiver 27 that receives oil discharged from the oil drain hole 6b, an oil receiver 27, and an oil sump 18 at the bottom of the sealed container 60. And an oil drain pipe 8b for returning the oil received by the oil receiver 27 to the oil sump 18 at the bottom of the sealed container 60.

According to this configuration, the oil discharged from the oil discharge hole 6b can be returned to the oil sump 18 without being exposed to the flow of the fluid (refrigerant) in the sealed container 60, thereby further suppressing an increase in oil rise. Can do.

Embodiment 2. FIG.
A scroll compressor according to Embodiment 2 of the present invention will be described. FIG. 5 is an enlarged sectional view showing a part of the scroll compressor according to the present embodiment. In addition, about the component which has the same function and effect | action as the scroll compressor of Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 5, the oil drain valve 28 of the present embodiment includes a valve body 28a and a coil spring 28b that biases the valve body 28a. The oil drain hole 6b is provided on the frame inner space 6c side (upstream side) and extends in the horizontal direction, and is provided on the oil receiver 27 side (downstream side). And a downstream portion 6e. The valve body 28a is provided between the upstream portion 6d and the downstream portion 6e of the oil discharge hole 6b. The valve body 28a is provided so as to be slidable in the horizontal direction coaxial with the upstream portion 6d. The valve body 28a takes at least a closed position for closing the oil drain hole 6b and an open position for opening the oil drain hole 6b. The opening degree of the oil drain hole 6b depends on the position of the valve body 28a. Is changing. The upstream portion 6d is provided with a stopper 32 that regulates the closed position (initial position) of the valve body 28a. The coil spring 28b biases the valve body 28a in the direction from the open position to the closed position. The coil spring 28b is contracted and deformed by a predetermined contraction amount when the valve element 28a is in the closed position. A hydraulic pressure P of the frame inner space 6c acts on the valve body 28a in a direction from the closed position toward the open position (counter biasing direction). The biasing force of the coil spring 28b is adjusted so that the valve element 28a starts to slide in the counter-biasing direction when the hydraulic pressure P in the frame inner space 6c increases to reach a predetermined pressure P ′. .

When the valve body 28a is in the closed position, the upstream portion 6d and the downstream portion 6e are closed by the valve body 28a, and the oil drain valve 28 is in a closed state. When the hydraulic pressure P in the frame inner space 6c increases to reach the pressure P ′, the hydraulic pressure P acting on the valve body 28a overcomes the urging force of the coil spring 28b, and the valve body 28a slides in the direction from the closed position toward the open position. Start moving. As a result, the upstream portion 6d and the downstream portion 6e communicate with each other, and the oil drain valve 28 is opened. As the hydraulic pressure P increases, the amount of contraction of the coil spring 28b increases, and the opening degree of the oil discharge valve 28 increases.

FIG. 6 is an enlarged cross-sectional view showing a part of a scroll compressor according to a modification of the present embodiment. In the above-described configuration shown in FIG. 5, the moving direction of the valve element 28a of the oil discharge valve 28 is horizontal, but the moving direction of the valve element 28a may be vertical as in the configuration shown in FIG. . In the configuration shown in FIG. 6, the upper surface of the valve body 28a is inclined toward the frame internal space 6c so that the hydraulic pressure P is likely to act on the valve body 28a from the closed position toward the open position. Also good.

As described above, in the scroll fluid machine according to the present embodiment, the oil discharge valve 28 has the valve body 28a and the coil spring 28b, and the valve body 28a is closed to close the oil discharge hole 6b. The coil spring 28b urges the valve body 28a in the direction from the open position to the closed position, and takes the valve body 28a. Is characterized in that the hydraulic pressure P acts in the direction from the closed position toward the open position.

According to this configuration, the same effects as those of the first embodiment can be obtained, and the configuration of the oil discharge valve 28 can be simplified.

Embodiment 3 FIG.
A scroll compressor according to Embodiment 3 of the present invention will be described. FIG. 7 is an enlarged cross-sectional view of a part of the scroll compressor according to the present embodiment. In addition, about the component which has the same function and effect | action as the scroll compressor of Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 7, the oil drain valve 28 of the present embodiment has a valve body 28a that is slidable in the vertical direction. The oil drain hole 6b extends in the horizontal direction as a whole, and has an upstream portion 6d provided on the frame internal space 6c side and a downstream portion 6e provided on the oil receiver 27 side. The valve body 28a is provided between the upstream portion 6d and the downstream portion 6e of the oil discharge hole 6b. A vertical hole 28c is formed above the valve body 28a so that the valve body 28a can be slid in the vertical direction (for example, the vertical vertical direction). The valve body 28a has at least a lower closed position for closing the oil drain hole 6b and an upper open position for opening the oil drain hole 6b. The oil drain hole depends on the position of the valve body 28a. The opening degree of 6b changes. The space in the vertical hole 28 c and the outside of the frame 6 (in this example, the space in the oil receiver 27) communicate with each other through a pressure equalizing hole 33. As a result, the pressure P ₀ in the space in the vertical hole 28 c is equalized with the pressure outside the frame 6 (for example, the suction space in the sealed container 60).

Assuming that the sectional area of the valve body 28a is A, a downward force (F + P ₀ × A) from the open position to the closed position is applied to the valve body 28a by its own weight F and the pressure P ₀ acting on the upper surface. Further, an upward force (P × A) from the closed position to the open position is applied to the valve body 28a by the hydraulic pressure P of the frame internal space 6c acting on the lower surface. When the hydraulic pressure P in the frame inner space 6c is low, the downward force is greater than the upward force, and thus the valve body 28a is located at the lower closed position. In this state, the upstream portion 6d and the downstream portion 6e are closed by the valve body 28a, and the oil drain valve 28 is closed. When the hydraulic pressure P in the frame inner space 6c rises and reaches the pressure (P ₀ + F / A), the upward force becomes larger than the downward force, so that the valve element 28a slides and moves above the vertical hole 28c. As a result, the upstream portion 6d and the downstream portion 6e communicate with each other, and the oil drain valve 28 is opened. Since the valve body 28a slides upward as the oil pressure P increases, the opening degree of the oil discharge valve 28 increases as the oil pressure P increases.

As described above, in the scroll fluid machine according to the present embodiment, the oil drain valve 28 has the valve body 28a, and the valve body 28a has a closed position in which the oil drain hole 6b is closed, and a closed position. And at least an open position that opens the oil drain hole 6b. Gravity acts on the valve body 28a in a direction from the open position toward the closed position, and from the closed position. The hydraulic pressure P acts in the direction toward the open position.

Embodiment 4 FIG.
A scroll compressor according to Embodiment 4 of the present invention will be described. FIG. 8 is an enlarged cross-sectional view of a part of the scroll compressor according to the present embodiment. In addition, about the component which has the same function and effect | action as the scroll compressor of Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 8, this embodiment is characterized in that the oil drain hole 6a (and the oil drain pipe 8a) that is always open is not provided. In other words, in the present embodiment, the surplus portion of the oil stored in the frame internal space 6c is discharged out of the frame 6 only from the oil drain hole 6b provided with the oil drain valve 28. . The oil discharged from the oil drain hole 6b is received by the oil receiver 27 and returns to the oil sump 18 through the oil drain pipe 8b. The oil discharge valve 28 of this example has a reed valve structure similar to that of the first embodiment, but may have a configuration similar to that of the second or third embodiment. Further, a plurality of oil drain holes 6b may be provided, and the oil drain valve 28 may be provided in all of the plurality of oil drain holes 6b.

Embodiment 5 FIG.
A scroll compressor according to Embodiment 5 of the present invention will be described. FIG. 9 is an enlarged cross-sectional view of a part of the scroll compressor according to the present embodiment. In addition, about the component which has the same function and effect | action as the scroll compressor of Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 9, in the present embodiment, an oil drain hole 6b provided with an oil drain valve 28 and an oil drain hole 6a that is always open are provided and discharged from the oil drain hole 6b. The oil receiver 27 receives not only the oil but also the oil discharged from the oil drain hole 6a. The oil received by the oil receiver 27 returns to the oil sump 18 through the oil drain pipe 8b. A plurality of oil drain holes 6a that are always open may be provided.

Other embodiments.
The present invention is not limited to the above embodiment, and various modifications can be made.
For example, in the above embodiment, the scroll compressor is taken as an example of the scroll fluid machine, but the present invention can also be applied to other scroll fluid machines such as a scroll pump.

The above embodiments and modifications can be implemented in combination with each other.

1 discharge pipe, 2 muffler, 3 discharge chamber, 4 fixed scroll, 4a, 5a end plate, 4b, 5b spiral part, 5 swing scroll, 6 frame, 6a, 6b oil drain hole, 6c space in frame, 6d upstream part, 6e downstream part, 7 suction pipe, 8a, 8b oil drain pipe, 9 balancer cover, 10 1st balancer, 11 stator, 12 rotor, 13 2nd balancer, 14 spindle, 14a oil supply vertical hole, 14b, 14c oil supply horizontal hole, 15 sub-frame, 16 ball bearing, 17 oil pump, 18 oil sump, 19 main bearing, 20 sleeve, 21 rocking bearing, 22 slider, 23 Oldham joint, 24 upper shell, 25 middle shell, 26 lower shell, 27 oil receiver, 28 Oil drain valve, 28a valve body, 28b carp Spring, 28c vertical hole, 29 eccentric shaft, 30 a discharge port, 31 a thrust bearing, 32 a stopper, 33 equalizing hole, 40 compression mechanism 50 electric motor unit, 60 closed container (container).

Claims

A fixed scroll and an orbiting scroll provided in the container;
A frame for swingably supporting the swing scroll;
A space in the frame formed between the frame and the orbiting scroll;
A main shaft for transmitting driving force to the orbiting scroll;
An oil drain hole provided through the frame, for discharging excess oil in the space in the frame to the outside of the frame;
A scroll fluid machine comprising: an oil discharge valve provided in the oil discharge hole and opening and closing the oil discharge hole based on a hydraulic pressure of the space in the frame.
The scroll fluid machine according to claim 1, wherein the oil discharge valve has a reed valve structure that is opened and closed by the hydraulic pressure.
The oil discharge valve has a valve body and a coil spring,
The valve body takes at least a closed position for closing the oil drainage hole and an open position for opening the oil drainage hole,
The coil spring biases the valve body in a direction from the open position toward the closed position,
The scroll fluid machine according to claim 1, wherein the hydraulic pressure acts on the valve body in a direction from the closed position toward the open position.
The oil drain valve has a valve body,
The valve body takes at least a closed position for closing the oil drain hole and an open position for positioning the oil drain hole above the closed position.
The gravity acts on the valve body in a direction from the open position toward the closed position, and the hydraulic pressure acts in a direction from the closed position toward the open position. A scroll fluid machine according to claim 1.
An oil pan attached to the outside of the frame and receiving oil discharged from the oil drain hole;
5. The oil drain pipe provided between the oil receiver and the bottom of the container and returning oil received by the oil receiver to the bottom of the container. The scroll fluid machine according to any one of the above.
In addition to the oil drainage hole, it further has a second oil drainage hole for discharging excess oil in the space in the frame to the outside of the frame,
The scroll fluid machine according to any one of claims 1 to 5, wherein the second oil drain hole is always open.
The scroll fluid machine according to any one of claims 1 to 5, wherein the oil drain valve is provided in all of the oil drain holes.