JP5709544B2 - Compressor - Google Patents

Description

  The present invention relates to a compressor driven by an electric motor provided in a sealed housing.

As an example of a multi-stage compressor provided with a low-stage compression mechanism and a high-stage compression mechanism driven by an electric motor in a hermetic housing, an electric motor is installed at a substantially central portion in the hermetic housing. A low-stage rotary compression mechanism is installed on the lower side and a high-stage scroll compression mechanism is installed on the upper side. The low-stage rotary compression mechanism and the high-stage scroll compression mechanism are driven by an electric motor through a rotating shaft. A multistage compressor configured as described above is disclosed in Patent Document 1.
The multistage compressor of Patent Document 1 sucks low-pressure refrigerant gas from the refrigeration cycle side through a suction pipe into a low-stage rotary compression mechanism and compresses the intermediate-pressure refrigerant gas into a sealed housing. Exhale. This multi-stage compressor is configured to suck intermediate pressure refrigerant gas by a high-stage side scroll compression mechanism, compress it into a high-temperature and high-pressure state in two stages, and discharge it to the outside through a discharge pipe. Thus, the inside of the sealed housing is an intermediate pressure refrigerant gas atmosphere.

In this multistage compressor, the intermediate pressure refrigerant gas discharged into the hermetic housing is supplied with lubricating oil discharged into the hermetic housing together with the refrigerant gas after being used for lubrication of the low-stage rotary compression mechanism. After the side scroll compression mechanism is lubricated, a large amount of lubricating oil is dropped from the high stage scroll compression mechanism along the sealed housing. That is, this intermediate pressure refrigerant gas is in an oil-rich state. This intermediate-pressure refrigerant gas flows through the internal passage of the electric motor and flows into the upper space, and is then guided to the suction port of the high-stage scroll compression mechanism. The lubricating oil is separated.
However, a large amount of lubricating oil is dissolved in the intermediate pressure refrigerant gas in the hermetic housing, and the lubricating oil is sucked into the high-stage scroll compression mechanism together with the intermediate pressure refrigerant gas without being sufficiently separated. This lubricating oil is discharged from the high-stage scroll compression mechanism along with the compressed refrigerant gas, and is circulated to the refrigeration cycle side. As a result, the oil circulation rate (OCR) [ratio of the lubricating oil mass flow rate to the total mass flow rate (refrigerant flow rate + lubricating oil flow rate)] of the lubricating oil circulated to the refrigeration cycle side increases, and heat on the refrigeration cycle side increases. Inhibiting the replacement reduces system efficiency and may cause the compressor to run out of lubricating oil.

  Therefore, in the patent document 2, the present inventor reduced the oil circulation rate by reducing the amount of lubricating oil sucked into the high-stage compression mechanism accompanying the intermediate pressure refrigerant gas, improving the system efficiency and lacking lubricating oil. A multi-stage compressor that can solve the problem is proposed. As shown in FIG. 4, this multistage compressor has a low-stage compression mechanism (not shown) in the lower part of the electric motor 200 and a high-stage compression mechanism 201 in the upper part. The intermediate-pressure refrigerant gas compressed by the stage-side compression mechanism is discharged into the hermetic housing 203, and this intermediate-pressure refrigerant gas is sucked by the high-stage compression mechanism 201 to be compressed in two stages. In this multistage compressor, an oil separation plate 202 that centrifuges the lubricating oil contained in the intermediate pressure refrigerant gas sucked into the high stage side compression mechanism 201 is provided through the rotary shaft 205. The oil separation plate 202 is a disk-like member fixed and installed on a balance weight 206 provided at the upper end of the rotor 204.

  The effect | action of the lubricating oil separation by patent document 2 is as follows. When the intermediate pressure refrigerant gas in which the lubricating oil is dissolved flows through the gas passage 204A of the rotor 204 and flows into the upper space of the electric motor 200, the intermediate pressure refrigerant gas collides with the oil separation plate 202 rotating together with the rotor 204, and is centrifuged. By the action, the lubricating oil having a large specific gravity is separated from the intermediate pressure refrigerant gas. The centrifugally separated lubricant oil is guided to the outer peripheral side after colliding with the stator coil end 207 of the electric motor 200 or directly through the gap, and flows to the bottom along the inner peripheral surface of the sealed housing 203.

JP-A-5-87074 JP 2009-47039 A

However, even in the technique described in Patent Document 2, it cannot be said that the separation performance of the lubricating oil is sufficient, and further improvement is required.
Such a problem is not limited to a multistage compressor, but is common to a rotary compressor including a rotary compression mechanism below an electric motor.

  The present invention has been made based on such a technical problem, and further improves the separation performance of the lubricating oil, and improves the system efficiency by suppressing the oil circulation rate of the lubricating oil circulated to the refrigeration cycle side, It is an object of the present invention to provide a compressor that can reliably prevent the compressor from falling short of lubricating oil.

The compressor of the present invention made for this purpose is driven via a hermetically sealed housing, an electric motor provided in the hermetically sealed housing and provided with a rotor and a stator, and a rotating shaft that rotates together with the rotor of the electric motor. The compressor is installed at least in the lower part of the electric motor, and compresses the refrigerant gas containing the lubricating oil, and is provided in the lower part of the rotor so as to surround the discharge port that discharges the refrigerant gas compressed by the compressor. And a first oil that is located above the rotor and that centrifuges the lubricating oil contained in the refrigerant gas discharged upward after flowing through the gas passage formed in the rotor of the electric motor comprising a separator plate and a second oil separation plate, a first oil separation plate, and rotates with the rotor, below the upper end of the stator of the stator coil end, inside near the stator coil end A predetermined gap is formed between the outer peripheral portion of the first oil separation plate and the inner peripheral portion of the stator coil end, and the second oil separation plate is an annular shape provided along the inner peripheral surface of the hermetic housing. Thus, it is located above the upper end of the stator coil end, and the inner peripheral part of the second oil separation plate is located on the inner peripheral side of the outer peripheral part of the stator coil end .
As described above , the cylindrical member is provided in the lower part of the rotor, and the flow of the refrigerant gas discharged from the discharge port is set upward by surrounding the discharge port that discharges the refrigerant gas compressed by the compression mechanism. It can be rectified to head toward.
In addition, the refrigerant gas containing the lubricating oil collides with the lower surface of the rotor, and the lubricating oil adhering to the lower surface of the rotor flows to the outer peripheral side due to the centrifugal force caused by the rotation of the rotor. And can flow downward.

A compressor provided with such a cylindrical member and an oil separation plate may be any compressor provided with a compression mechanism at least at the lower part of the electric motor, but is installed at the lower part and the upper part of the electric motor as a compression mechanism. A low-stage compression mechanism and a high-stage compression mechanism can also be provided.
Here, the compression method of the compression mechanism may be either a rotary type or a scroll type as long as it is driven by an electric motor.

According to the present invention, by providing the cylindrical member at the lower part of the rotor, the flow of the refrigerant gas discharged from the discharge port of the compression mechanism is rectified so as to be directed upward, and the lubricating oil in the refrigerant gas is recovered. Can do.
Furthermore, oil separation performance is further enhanced by providing an oil separation plate above the rotor.
In this way, the separation performance of the lubricating oil is further improved, the oil circulation rate of the lubricating oil circulated to the refrigeration cycle side is suppressed, the system efficiency is improved, and the compressor is reliably prevented from falling short of the lubricating oil. It becomes possible.

It is sectional drawing of the compressor in this Embodiment. (A) is sectional drawing of the compressor of the part which provided the baffle member, (b) is sectional drawing of the compressor of the part which provided the 2nd oil separation board. It is a figure which shows the modification of a 2nd oil separation board. It is sectional drawing which shows the principal part of the conventional compressor.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
As shown in FIG. 1, the multistage compressor (compressor) 1 includes a sealed housing 10.
An electric motor 4 including a stator 5 and a rotor 6 is fixedly installed at a substantially central portion in the hermetic housing 10. A rotating shaft (crankshaft) 7 is integrally coupled to the rotor 6.
A low-stage rotary compression mechanism (low-stage compression mechanism, compression mechanism) 2 is installed at the lower part of the electric motor 4, and a high-stage scroll compression mechanism (high-stage compression mechanism, compression mechanism) 3 is installed at the upper part. Is set.

  A known positive displacement oil pump 11 is incorporated at the lowermost end of the rotating shaft 7. The oil pump 11 pumps up the lubricating oil 12 filled in the bottom of the hermetic housing 10, and the low-stage rotary compression mechanism 2 and the high-stage scroll compression through an oil supply hole 13 provided in the rotary shaft 7. The lubricating oil 12 can be forcibly supplied to a required lubricating portion such as a bearing portion of the mechanism 3.

  The low-stage rotary compression mechanism 2 includes a cylinder chamber 20, a cylinder body 21 fixedly installed in the sealed housing 10, and an upper bearing fixedly installed above and below the cylinder body 21 and sealing the upper and lower portions of the cylinder chamber 20. 22 and the lower bearing 23, a rotor 24 that is held by the crank portion 7A of the rotary shaft 7 and rotates on the inner peripheral surface of the cylinder chamber 20, and a blade (not shown) that partitions the cylinder chamber 20 into a suction side and a discharge side. And a known rotary compression mechanism including a blade pressing spring and the like.

  As shown in FIG. 2A, the upper bearing 22 is provided with a discharge chamber (discharge port) 26 for discharging the refrigerant gas compressed from the low-stage rotary compression mechanism 2. The discharge chamber 26 is fixed to the upper bearing 22 and is provided so as to have a gap with the outer peripheral surface 22 a of the upper bearing 22. The discharge chamber 26 is formed to be constricted so that a gap formed between the discharge chamber 26 and the outer peripheral surface 22a of the upper bearing 22 gradually decreases as it goes upward.

  A cylindrical rectifying member (tubular member) 50 extending toward the lower discharge chamber 26 is provided on the lower surface of the rotor 6 of the electric motor 4 positioned above the discharge chamber 26. The rectifying member 50 is formed to have an inner diameter larger than the outer diameter of the upper portion 26 a so as not to interfere with the upper portion 26 a of the discharge chamber 26.

  The low-stage rotary compression mechanism 2 sucks low-pressure refrigerant gas (working gas) from the accumulator 15 provided outside the hermetic housing 10 into the cylinder chamber 20 through the suction pipe 25, and this refrigerant gas is supplied to the rotor. After being compressed to an intermediate pressure by the rotation of 24, the air is discharged into the sealed housing 10 through the discharge chamber 26.

  At this time, the intermediate pressure refrigerant gas discharged from the discharge chamber 26 diffuses into the hermetic housing 10 through a gap between the upper portion 26a of the discharge chamber 26 and the outer peripheral surface 22a of the upper bearing 22, but the outer peripheral side has a cylindrical shape. Accordingly, the flow of the intermediate pressure refrigerant gas is rectified so as to be directed upward.

  The intermediate pressure refrigerant gas discharged from the discharge chamber 26 flows through the gas passage 6 </ b> A provided in the rotor 6 of the electric motor 4 and flows into the upper space of the electric motor 4, and further, the high-stage scroll compression mechanism 3. It is inhaled and compressed in two stages.

The high-stage scroll compression mechanism 3 includes a support member 31 including a bearing 30 that supports the rotating shaft 7, a fixed scroll member 32, and a turning scroll member 33.
The fixed scroll member 32 and the orbiting scroll member 33 are provided with spiral wraps 32B and 33B standing on the end plates 32A and 33A. A pair of compression chambers 34 is configured by meshing the spiral wraps 32B and 33B with each other.

  In addition, the high-stage scroll compression mechanism 3 connects the orbiting scroll member 33 and an eccentric pin 7B provided at the shaft end of the rotating shaft 7, and the orbiting boss portion 35 for driving the orbiting scroll member 33 to revolve and rotate, and the orbiting scroll member A rotation prevention mechanism 36 such as an Oldham ring, which is provided between the support member 31 and revolves while preventing the rotation of the orbiting scroll member 33; and a discharge valve 40 provided on the back surface of the fixed scroll member 32. A fixed scroll member 32 is provided on the back surface of the fixed scroll member 32, and includes a discharge cover 42 that forms a discharge chamber 41 between the fixed scroll member 32 and a known scroll compression mechanism.

  The high-stage scroll compression mechanism 3 sucks the intermediate-pressure refrigerant gas compressed by the low-stage rotary compression mechanism 2 and discharged into the hermetic housing 10 into the compression chamber 34, and the intermediate-pressure refrigerant gas is swung into the orbiting scroll member 33. It is configured to discharge to the discharge chamber 41 through the discharge valve 40 after being compressed into a high-temperature and high-pressure state by the revolving turning drive. This high-temperature and high-pressure refrigerant gas is led out from the discharge chamber 41 through the discharge pipe 43 to the outside of the compressor, that is, to the refrigeration cycle side.

  In the multistage compressor 1, a balance weight 46 is installed on one side of the upper surface of the rotor 6 constituting the electric motor 4.

As shown in FIG. 2B, a first oil separation plate (oil separation plate) 45 that rotates together with the rotor 6 is provided at the upper end of the balance weight 46.
The first oil separation plate 45 has a disk shape and is provided below the upper end of the stator coil end 5A. The outer diameter of the first oil separation plate 45 is set to a size that maintains a slight gap from the inner periphery of the stator coil end 5 </ b> A of the electric motor 4.

  An annular plate-like second oil separation plate (oil separation plate) 60 is provided on the inner peripheral surface 10a of the sealed housing 10 so as to be positioned above the stator coil end 5A. The second oil separation plate 60 is provided such that the outer peripheral portion 60a is in contact with the inner peripheral surface 10a of the sealed housing 10 and the inner peripheral portion 60b is located on the inner peripheral side with respect to the outer peripheral portion 5b of the stator coil end 5A. Yes.

According to the multistage compressor 1 having the configuration described above, the following operational effects are obtained.
The low-temperature and low-pressure refrigerant gas sucked into the cylinder chamber 20 of the low-stage-side rotary compression mechanism 2 through the suction pipe 25 is compressed to the intermediate pressure by the rotation of the rotor 24 and then discharged to the discharge chamber 26. The intermediate pressure refrigerant gas is discharged from the discharge chamber 26 into the lower space of the electric motor 4 and then flows through the gas passage 6 </ b> A provided in the rotor 6 of the electric motor 4 to reach the upper space of the electric motor 4. .

  The intermediate-pressure refrigerant gas that has reached the upper space of the electric motor 4 passes through the gap between the support member 31 constituting the high-stage scroll compression mechanism 3 and the hermetic housing 10, and is provided in the fixed scroll member 32. It is guided to the suction port of the stage side scroll compression mechanism 3 and sucked into the compression chamber 34. This intermediate-pressure refrigerant gas is compressed into a high-temperature and high-pressure state by the high-stage side scroll compression mechanism 3 and then discharged into the discharge chamber 41 from the discharge valve 40 and led out to the refrigeration cycle side through the discharge pipe 43. The

In the above-described two-stage compression process, part of the lubricating oil 12 used for the lubrication of the low-stage rotary compression mechanism 2 is dissolved in the refrigerant gas and discharged into the sealed housing 10 together with the intermediate pressure refrigerant gas. Further, the intermediate pressure refrigerant gas is supplied to the high-stage scroll compression mechanism 3 through the oil supply hole 13, lubricates the high-stage scroll compression mechanism 3, and then flows down to the bottom in the hermetic housing 10. Part of the oil 12 is caught and melted.
When the intermediate pressure refrigerant gas in which the lubricating oil 12 is dissolved is discharged from the discharge chamber 26, a part of the intermediate pressure refrigerant gas collides with the lower surface of the rotor 6 of the electric motor 4. Then, due to the centrifugal force, the lubricating oil 12 in the refrigerant gas is separated to the outer peripheral side, the flow direction is changed downward by the rectifying member 50, and flows down to the bottom of the sealed housing 10.

Further, the intermediate-pressure refrigerant gas in which the lubricating oil 12 has melted collides with the first oil separation plate 45 rotating together with the rotor 6 when flowing in the gas passage 6A of the rotor 6 and reaching the upper space of the electric motor 4. Then, the lubricating oil 12 is separated from the intermediate pressure refrigerant gas by the centrifugal separation action.
The intermediate-pressure refrigerant gas that has flowed into the upper space through the gap between the first oil separation plate 45 and the inner peripheral surface of the stator coil end 5A flows toward the outer peripheral side by centrifugal force. And if the one part collides with the 2nd oil separation plate 60 located in the upper direction, the lubricating oil 12 will be isolate | separated from the intermediate pressure refrigerant gas by the centrifugal separation action.
The lubricating oil 12 centrifuged by the first oil separating plate 45 and the second oil separating plate 60 is guided to the outer peripheral side while interfering with the stator coil end 5 </ b> A of the electric motor 4. It flows along the surface to the bottom.

  On the other hand, the intermediate-pressure refrigerant gas from which the lubricating oil 12 has been separated flows further upward, is guided from there to the suction port of the high-stage scroll compression mechanism 3, and is sucked into the compression chamber 34 to be compressed in two stages. Is done.

  Thus, the intermediate pressure refrigerant gas from which the lubricating oil 12 has been separated by the rectifying member 50 (the bottom surface of the rotor 6 of the electric motor 4), the first oil separation plate 45, and the second oil separation plate 60 is converted into the high-stage scroll compression mechanism 3. Therefore, it is possible to reduce the amount of the lubricating oil 12 that is sucked into the high-stage scroll compression mechanism 3 along with the intermediate-pressure refrigerant gas and discharged together with the high-pressure compressed gas. This reduces the oil circulation rate (OCR) [ratio of the mass flow rate of the lubricating oil to the total mass flow rate (refrigerant flow rate + lubricating oil flow rate)] of the lubricating oil 12 circulated to the refrigeration cycle side, and improves the system efficiency. And the occurrence of a lack of lubricating oil in the compressor can be eliminated.

  In the above embodiment, the second oil separation plate 60 is in the shape of an annular plate. However, as shown in FIG. As shown in FIG. 3 (b), it is intended to include a modification of the shape including a tapered filed bowl shape or the like that falls downward as it goes to the inner periphery.

In the above-described embodiment, the multi-stage compressor 1 configured using the rotary compression mechanism as the low-stage compression mechanism and the scroll compression mechanism as the high-stage compression mechanism has been described as an example. However, the low-stage compression mechanism and the high-stage compression mechanism The side compression mechanism is not limited to the compression mechanism. Furthermore, the present invention can also be applied to a rotary compressor that does not include the high-stage scroll compression mechanism 3 and includes only the same rotary compression mechanism as the low-stage rotary compression mechanism 2.
In addition to this, as long as it does not depart from the gist of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.

  DESCRIPTION OF SYMBOLS 1 ... Multistage compressor (compressor), 2 ... Low stage side rotary compression mechanism (low stage side compression mechanism, compression mechanism), 3 ... High stage side scroll compression mechanism (high stage side compression mechanism, compression mechanism), 4 ... Electric motor, 5 ... stator, 5A ... stator coil end, 6 ... rotor, 6A ... gas passage, 7 ... rotating shaft, 10 ... sealed housing, 26 ... discharge chamber (discharge port), 46 ... balance weight, 45 ... first Oil separation plate (oil separation plate), 50 ... Rectifying member (tubular member), 60 ... Second oil separation plate (oil separation plate)

Claims (2)

A sealed housing;
An electric motor provided in the hermetic housing and including a rotor and a stator;
A compression mechanism that is driven through a rotating shaft that rotates together with the rotor of the electric motor, is installed at least in the lower portion of the electric motor, and compresses a refrigerant gas containing lubricating oil;
A cylindrical member provided at a lower portion of the rotor and provided so as to surround an upper side of a discharge port for discharging the refrigerant gas compressed by the compression mechanism;
A first oil separation plate and a second oil that are located above the rotor and centrifuge the lubricating oil contained in the refrigerant gas discharged upward after flowing through the gas passage formed in the rotor of the electric motor. A separation plate ,
The first oil separation plate rotates with the rotor, is below the upper end of the stator coil end of the stator, and is inside the stator coil end,
A predetermined gap is formed between the outer periphery of the first oil separation plate and the inner periphery of the stator coil end,
The second oil separation plate is an annular shape provided along the inner peripheral surface of the hermetic housing, and is located above the upper end of the stator coil end,
The inner peripheral part of the second oil separation plate is located on the inner peripheral side of the outer peripheral part of the stator coil end,
A compressor characterized by that. 2. The compressor according to claim 1, wherein the compression mechanism includes a low-stage compression mechanism and a high-stage compression mechanism that are installed below and above the electric motor.

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