JP2010121583A - Hermetic electric compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an increase in an oil delivery amount in a simple structure, and to improve cycle efficiency and reliability in a hermetic electric compressor. <P>SOLUTION: The hermetic electric compressor 50 includes an electric motor 7 and a compression mechanism 2 connected to the electric motor 7 through a crankshaft 6 in a sealed vessel 1, and a disk shaped sub bearing member 15 supporting a sub bearing 26 journaled to the crankshaft 6 and covering an oil reservoir 9 in the upper space of the oil reservoir 9 in a bottom of the sealed vessel 1. A communication port 15a is provided for communicating the oil reservoir side of the sub bearing member 15 and the opposite oil reservoir side. The communication port 15a has an opening surface opened to a peripheral direction on the opposite oil reservoir side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hermetic electric compressor, and is particularly suitable for a hermetic electric compressor used in a refrigeration air conditioner or the like.

  As a conventional hermetic electric compressor, one described in JP-A-5-209593 (Patent Document 1) is known.

  In this hermetic type electric compressor, a compression mechanism is provided in the upper part of the hermetic container. The compression mechanism includes a fixed scroll and a movable scroll that orbits with respect to the fixed scroll. In addition, an electric motor including a rotor attached to the crankshaft and a stator attached to the airtight container is provided below the airtight container. Furthermore, a sub-bearing of the crankshaft and a sub-bearing support part that supports the sub-bearing and is fixed to the sealed container are provided below the rotor, and lubricating oil is stored at the bottom of the sealed container. An oil sump is provided.

  The auxiliary bearing support component is arranged to have a plurality of substantially circular openings having a disk shape and a size of 1/4 to 1/20 of the inner diameter of the sealed container. As a result, the lubricating oil can be returned to the oil sump without impairing the foaming suppression effect of the bearing support component.

Japanese Patent Laid-Open No. 5-209593

  However, in the hermetic electric compressor of Patent Document 1 described above, the opening that communicates the oil sump and the upper space with the auxiliary bearing support component is merely open on the upper surface. There has been a problem that the lubricating oil in the oil reservoir is lifted into the upper space through the opening of the auxiliary bearing part and easily flows out together with the refrigerant gas, leading to an increase in the oil discharge amount (oil rate). In particular, when the crankshaft rotates at a high speed, the behavior of the lubricating oil in the oil reservoir is greatly disturbed and is lifted to the upper space through the opening of the auxiliary bearing support component, and there is a high risk of increasing the oil discharge amount. When the oil discharge amount is increased, the cycle efficiency is lowered and the oil level is cut and the reliability is lowered.

  An object of the present invention is to provide a hermetic electric compressor that has a simple configuration, prevents an increase in oil discharge amount, and can improve cycle efficiency and reliability.

  In a first aspect of the present invention for achieving the above-mentioned object, an electric motor and a compression mechanism connected to the electric motor via a crankshaft are provided in the hermetic container, and above the oil sump at the bottom of the hermetic container. The space has a disc-shaped sub-bearing member that supports the sub-bearing that supports the crankshaft and covers the oil reservoir, and communicates the oil reservoir side and the anti-oil reservoir side of the sub-bearing member. In the hermetic electric compressor in which the port is provided in the auxiliary bearing member, the communication port of the auxiliary bearing member is provided so as to have an opening surface in the circumferential direction on the anti-oil reservoir side.

A more preferable specific configuration example in the first aspect of the present invention is as follows.
(1) The electric motor is installed above the auxiliary bearing member, a lower balance weight is installed at the lower end of the rotor of the electric motor, and the swirl flow generated by the rotation of the balance weight is provided at the communication port of the auxiliary bearing member Opened in the direction opposite to.
(2) An upper balance weight is installed at the upper end of the rotor of the electric motor, and the balance weight on the side near the discharge pipe is made smaller than the balance weight on the side far from the discharge pipe.
(3) The weight of the balance weight far from the discharge pipe is made lighter by using a member or a hollow member having a density lower than that of the balance weight near the discharge pipe.

  Further, in the second aspect of the present invention, an electric motor and a compression mechanism connected to the electric motor via a crankshaft are provided in the hermetic container, and the crankshaft is disposed in the space above the oil sump at the bottom of the hermetic container. A disk-shaped sub-bearing member that supports the sub-bearing that supports the oil reservoir and covers the oil reservoir, and the motor is installed above the sub-bearing member, and the compression mechanism is installed above the motor A discharge pipe that communicates with a space between the electric motor and the compression mechanism and discharges a working fluid from the space to the outside, and an upper balance weight is installed at an upper end portion of the rotor of the electric motor, and the electric motor In the hermetic electric compressor in which the lower balance weight is installed at the lower end of the rotor, the upper balance weight on the side close to the discharge pipe is made smaller than the lower balance weight. That.

  According to the hermetic electric compressor of the present invention having such a configuration, an increase in oil discharge amount can be prevented with a simple configuration, and cycle efficiency and reliability can be improved.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. The same reference numerals in the drawings of the respective embodiments indicate the same or equivalent.

(First embodiment)
A scroll compressor according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a longitudinal sectional view of a scroll compressor according to a first embodiment of the present invention, and FIG. 2 is a perspective view of the vicinity of an auxiliary bearing member in FIG. The scroll compressor 50 of this embodiment is an example of a hermetic electric compressor of the present invention. The scroll compressor 50 is used as a constituent element of a refrigeration cycle of a refrigeration air conditioner.

  The scroll compressor 50 is configured by connecting the compression mechanism 2 and the electric motor 7 with the crankshaft 6 and storing them in the sealed container 1.

  The sealed container 1 includes a vertically long cylindrical portion 1a and lid portions 1b and 1c that close the upper and lower surfaces of the cylindrical portion 1a. An oil sump 9 for storing the lubricating oil 23 is formed at the bottom of the sealed container 1. The compression mechanism 2 is arranged at the upper part in the sealed container 1, and the electric motor 7 is arranged at the lower part in the sealed container 1. The crankshaft 6 is disposed perpendicularly to the central portion of the sealed container 1.

  The compression mechanism 2 includes a fixed scroll 3, a turning scroll 4, a frame 5, and an Oldham ring 10, and compresses a refrigerant gas that is a working fluid.

  The fixed scroll 3 includes a base plate 3a and a scroll wrap 3b provided upright on the base plate 3a. A suction port 12 is provided at the peripheral edge of the fixed scroll 3, and a discharge port 14 is provided at the center of the fixed scroll 3. The fixed scroll 3 is fixed to the frame 5 with fixing bolts 22. A suction pipe 11 is connected to the suction port 12. The low-pressure refrigerant gas of the external refrigeration cycle is sucked into the compression mechanism 2 through the suction pipe 11.

  The orbiting scroll 4 includes a base plate 4a, a scroll wrap 4b erected on the base plate 4a, and a boss portion 4c. The fixed scroll 3 and the orbiting scroll 4 are engaged with the respective scroll wraps 3 b and 4 b to form a compression chamber 17. The boss portion 4c has the swivel bearing 21 installed therein. The pin portion 6 b of the crankshaft 6 is inserted into the slewing bearing 21.

  The frame 5 is positioned below the fixed scroll 3 and is fixed to the sealed container 1. A turning scroll 4 is disposed between the frame 5 and the fixed scroll 3 so as to be turnable. A main bearing 24 and a shaft seal 25 are installed in the central hole of the frame 5.

  The fixed scroll 3 is provided with a back pressure hole 8 for communicating the back pressure chamber 13 and the compression chamber 17 on the back surface of the orbiting scroll 4, and a back pressure control valve 28 is provided in the back pressure hole 8. The back pressure control valve 28 holds the pressure in the back pressure chamber 13 at an intermediate pressure (intermediate pressure) between the suction pressure and the discharge pressure. The back pressure chamber 13 configured on the back surface of the orbiting scroll 4 is a space formed by being surrounded by the orbiting scroll 4, the frame 5, and the fixed scroll 3.

  The Oldham ring 10 is disposed between the orbiting scroll 4 and the frame 5 and prevents the orbiting scroll 4 from rotating.

  The electric motor 7 includes a rotor 7a and a stator 7b, and drives the compression mechanism 2. The electric motor 7 is located between the frame 5 of the compression mechanism 2 and the auxiliary bearing member 15.

  The rotor 7a is fixed to the crankshaft 6 by press-fitting the central portion of the crankshaft 6. A semi-arc-shaped upper balance weight 16a is fixed to the upper end surface of the rotor 7a with a pin, and a semi-arc-shaped lower balance weight 16b is fixed to the lower end surface of the rotor 7a with a pin. Yes. Thereby, the rotor 7a and the crankshaft 6 rotate stably, and the orbiting scroll 4 can be stably orbited. The upper balance weight 16a is larger and heavier than the lower balance weight 16b.

  The stator 7 b is disposed around the rotor 7 a and is fixed to the sealed container 1.

  A discharge pipe 18 is provided through the sealed container 1 so as to communicate with the central portion of the space between the frame 5 and the electric motor 7. The refrigerant gas compressed by the compression mechanism 2 is discharged to the external refrigeration cycle through the discharge pipe 18.

  The crankshaft 6 includes a main shaft portion 6a, a pin portion 6b, and an oil supply piece 6c. The crankshaft 6 connects the compression mechanism 2 and the electric motor 7 and supplies lubricating oil 23 to each sliding portion.

  The main shaft portion 6a extends vertically through the electric motor 7 and the frame 5, is supported by the main bearing 24 and the shaft seal 25, and fixes the rotor 7a. An oil supply hole 6d is provided at the center of the main shaft portion 6a and the pin portion 6b so as to penetrate vertically.

  The pin portion 6 b is provided so as to extend upward from the upper end portion of the main shaft portion 6 a that protrudes upward from the frame 5. The pin portion 6b is inserted into the orbiting bearing 21 and drives the orbiting scroll 4 to orbit.

  The lower portion of the main shaft portion 6 a that protrudes downward from the electric motor 7 is formed with a smaller diameter than the portion above the main shaft portion 6 a, and is supported by the auxiliary bearing 26. Accordingly, the upper portion of the main shaft portion 6a is pivotally supported by the main bearing 24 and the shaft seal 25, and the lower portion of the main shaft portion 6a is pivotally supported by the auxiliary bearing 26, so that it can rotate stably.

  The oil supply piece 6c is formed of a cylindrical member and is attached to the lower end portion of the main shaft portion 6a. The oil supply piece 6c extends to the lower part of the oil reservoir 9, and an oil supply port 19 is provided at the lower end of the oil supply piece 6c. The central hole of the oil supply piece 6 c and the oil supply hole 6 d of the main shaft portion 6 a are in communication with each other and constitute an oil supply passage of the crankshaft 6.

  The auxiliary bearing 26 is fixed to the lower surface of the central portion of the auxiliary bearing member 15 with fixing bolts 27. The auxiliary bearing member 15 is formed in a disk shape, is disposed in the space above the oil reservoir 9 so as to cover the oil reservoir 9, and is fixed to the sealed container 1. The auxiliary bearing member 15 is formed of a metal plate such as a steel plate, and divides the upper space of the oil sump 9 vertically, and has a communication port 15 a that communicates the oil sump side and the anti-oil sump side of the auxiliary bearing member 15. Provided.

  When the electric motor 7 is energized and the rotor 7a is rotated, the crankshaft 6 is rotated accordingly, and the main shaft portion 6a is eccentrically rotated. As a result, the orbiting scroll 4 is orbited, and the compression chamber 17 formed by the orbiting scroll 4 and the fixed scroll 3 is gradually reduced. The refrigerant gas sucked through the suction pipe 11 and the suction port 12 is retained in the compression chamber 17. It is compressed and discharged into the sealed container 1 from the discharge port 14 at the center of the fixed scroll 3. This discharged refrigerant gas contains lubricating oil.

  The discharged refrigerant gas passes through a plurality of grooves provided around the fixed scroll 3 and the frame 5 to reach a space between the frame 5 and the electric motor 7, and further, a plurality of refrigerant gas provided around the stator 7b. The lower space of the electric motor 7 through the groove (in other words, the upper space of the auxiliary bearing member 15, and further the space between the electric motor 7 and the frame 5 through the gap between the rotor 7 a and the stator 7 b, It is discharged to the outside through the discharge pipe 18.

  On the other hand, the lubricating oil 23 in the oil reservoir 9 is slewing bearing 21 through the central hole and the oil supply hole 6d of the oil supply piece 6c due to the differential pressure between the discharge pressure in the sealed container 1 and the back pressure chamber 13 on the back of the orbiting scroll 4. After the slewing bearing 21 is lubricated, it is supplied to the back pressure chamber 13. The back pressure chamber 13 is maintained at a predetermined intermediate pressure by the back pressure control valve 28 as described above.

  The lubricating oil supplied to the oil supply hole 6d is supplied to the main bearing 24, the shaft seal 25, and the auxiliary bearing 26 through a lateral hole provided in the main shaft portion 6a.

  In the present embodiment, the communication port 15a of the auxiliary bearing member 15 is provided such that the opening surface on the anti-oil reservoir side opens in the circumferential direction, and the opening surface on the oil reservoir side opens downward. . For this reason, when viewed from vertically below, the oil reservoir side space and the anti-oil reservoir side space are closed, and the lubricating oil 23 is hardly lifted through the communication port 15a with a simple configuration. In other words, since the oil sump 9 and the anti-oil sump side space are not directly opened in the axial direction, the lubricating oil 23 is hardly lifted through the communication port 15a with a simple configuration.

  Moreover, the opening surface of the communication port 15a on the side opposite to the oil reservoir is opened in a direction opposite to the swirling flow generated by the rotation of the lower balance weight 16, as shown in FIG. As a result, the lubricating oil about to come out from the opening surface on the side opposite to the oil reservoir of the communication port 15a is suppressed by the swirling flow, and the lubricating oil 23 is more difficult to be lifted through the communication port 15a. Lubricating oil floating together with the refrigerant gas in the pool side space can be recovered, and the oil level can be prevented from running out. The communication portion 15a can be easily formed by press molding a metal plate.

  According to the present embodiment, it is possible to reduce the lubricating oil 23 of the oil reservoir 9 from being taken out to the space above the auxiliary bearing member 15, reduce the oil rate, and improve the cycle efficiency. Moreover, since the oil level of the lubricating oil 23 of the oil sump 9 can be prevented from dropping below the oil supply port 19 of the oil supply piece 6c, the reliability of the compressor can be improved.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a cross-sectional view of main parts of a scroll compressor of a comparative example, and FIG. 4 is a cross-sectional view of main parts of a scroll compressor according to a second embodiment of the present invention. The second embodiment is different from the first embodiment in the points described below, and the other points are basically the same as those in the first embodiment, and thus redundant description is omitted.

  In the scroll compressor 50, when the balance weights 16a and 16b are provided on the upper and lower sides of the rotor 7a to correct the balance of the rotating system, if the same density material is used on the upper and lower sides, as shown in the comparative example of FIG. The upper balance weight 16a on the side close to 2 needs to be increased. At this time, since the upper balance weight 16a on the larger side has a larger amount of stirring the surrounding refrigerant gas, a flow of refrigerant gas that flows greatly upward is generated between the rotor 7a and the stator 7b as shown in FIG. Will be. The flow of the refrigerant gas is a direction in which the refrigerant gas and the lubricating oil are lifted from the central portion of the lower space of the electric motor 7 and flows toward the discharge pipe 18, so that the oil rate is likely to increase.

  Therefore, in the second embodiment, as shown in FIG. 4, the discharge pipe 18 is formed by making the density of the lower balance weight 16b smaller than the density of the upper balance weight 16a or by making the lower balance weight 16b have a hollow structure. The lower balance weight 16b far from the upper balance weight 16a is lighter and larger than the upper balance weight 16a, and the flow between the rotor 7a and the stator 7b is directed downward. Thereby, the discharge amount of the lubricating oil 23 can be further reduced.

(Other embodiments)
In the above-described embodiment, the scroll compressor is described as an example, but the present invention can also be applied to a rotary compressor.

It is a longitudinal cross-sectional view of the scroll compressor of 1st Embodiment of this invention. It is a perspective view of the sub bearing member vicinity of FIG. It is principal part sectional drawing of the scroll compressor of a comparative example. It is principal part sectional drawing of the scroll compressor of 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Airtight container, 2 ... Compression mechanism, 3 ... Fixed scroll, 3a ... Base plate, 3b ... Scroll wrap, 4 ... Revolving scroll, 4a ... Base plate, 4b ... Scroll wrap, 4c ... Boss part, 5 ... Frame, 5a DESCRIPTION OF SYMBOLS ... Bearing part, 6 ... Crankshaft, 6a ... Main shaft part, 6b ... Pin part, 6c ... Oil supply piece, 6d ... Oil supply hole, 7 ... Electric motor, 7a ... Rotor, 7b ... Stator, 8 ... Back pressure hole, 9 ... Oil Pool, 10 ... Oldham ring, 11 ... Suction pipe, 12 ... Suction port, 13 ... Back pressure chamber, 14 ... Discharge port, 15 ... Sub-bearing member, 15a ... Communication port, 16a ... Upper balance weight, 16b ... Lower balance weight , 17 ... Compression chamber, 18 ... Discharge pipe, 19 ... Oil supply port, 21 ... Swivel bearing, 22 ... Fixing bolt, 23 ... Lubricating oil, 24 ... Main bearing, 25 ... Shaft seal, 26 ... Sub-bearing, 27 ... Fixing bolt , 28 ... Back pressure Valve.

Claims (5)

An electric motor and a compression mechanism connected to the electric motor via a crankshaft in a sealed container;
In the space above the oil sump at the bottom of the sealed container, there is a disc-shaped sub-bearing member that supports the sub-bearing that supports the crankshaft and covers the oil sump.
In the hermetic electric compressor in which a communication port for communicating the oil reservoir side and the anti-oil reservoir side of the auxiliary bearing member is provided in the auxiliary bearing member,
A hermetic electric compressor characterized in that the communication port of the auxiliary bearing member is provided with an opening surface in the circumferential direction on the anti-oil reservoir side.   2. The motor according to claim 1, wherein the electric motor is installed above the auxiliary bearing member, a lower balance weight is installed at a lower end portion of the rotor of the electric motor, and a communication port of the auxiliary bearing member is generated by the rotation of the lower balance weight. A hermetic electric compressor having an opening in a direction opposite to the swirling flow.   3. The sealed type according to claim 2, wherein an upper balance weight is installed at the upper end of the rotor of the electric motor, and the balance weight on the side near the discharge pipe is made smaller than the balance weight on the side far from the discharge pipe. Electric compressor.   4. The hermetic electric compression according to claim 3, wherein the weight of the balance weight on the side far from the discharge pipe is made lighter by using a member having a lower density or a hollow member than the balance weight on the side near the discharge pipe. Machine. An electric motor and a compression mechanism connected to the electric motor via a crankshaft in a sealed container;
In the space above the oil sump at the bottom of the sealed container, there is a disc-shaped sub-bearing member that supports the sub-bearing that supports the crankshaft and covers the oil sump.
While installing the electric motor above the auxiliary bearing member, installing the compression mechanism above the electric motor,
A discharge pipe that communicates with a space between the electric motor and the compression mechanism and discharges the working fluid from the space;
In the hermetic electric compressor in which the upper balance weight is installed at the upper end of the rotor of the electric motor and the lower balance weight is installed at the lower end of the rotor of the electric motor,
A hermetic electric compressor characterized in that an upper balance weight closer to the discharge pipe is smaller than the lower balance weight.

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