WO2022219761A1

WO2022219761A1 - Hermetic compressor

Info

Publication number: WO2022219761A1
Application number: PCT/JP2021/015523
Authority: WO
Inventors: 貴也木本; 貴彦村上
Original assignee: 三菱電機株式会社
Priority date: 2021-04-15
Filing date: 2021-04-15
Publication date: 2022-10-20

Abstract

This hermetic compressor comprises: a sealed container in which an oil reservoir space for storing refrigerating machine oil is formed on a bottom part thereof; a compression mechanism unit which is disposed in the sealed container and compresses a refrigerant; an electric motor unit which is disposed in the sealed container and drives the compression mechanism unit; a main shaft which extends in the vertical direction and is fixed to and rotationally driven by the electric motor unit, and in which a cavity section from a lower end of the main shaft to a position above the compression mechanism unit is formed; and a disk part which is fixed to the lower end and inner peripheral side of the main shaft, and in which an opening is formed, wherein the refrigerating machine oil is suctioned up from the oil reservoir space via the opening of the disk part by means of the centrifugal force occurring in the cavity section due to the rotation of the main shaft, the compression mechanism unit has a lower bearing which rotatably supports the main shaft and covers the outer peripheral surface of the lower end of the main shaft, and the disk part is provided such that the lower surface of the disk part is positioned at the same height as the lower end of the lower bearing or above the lower end of the lower bearing.

Description

hermetic compressor

The present disclosure relates to a hermetic compressor with a main shaft.

In some hermetic compressors, an oil supply passage is provided in the center of the main shaft, and as the main shaft rotates, a centrifugal pump draws up refrigerating machine oil from the oil reservoir space at the bottom of the closed container. The refrigerating machine oil sucked up by the centrifugal pump flows through the oil supply passage of the main shaft and is supplied to each part of the compression mechanism through a branch passage provided on the wall surface of the oil supply passage to lubricate. In such a hermetic compressor, an oil supply pipe having an inner diameter narrower than that of the oil supply passage is generally arranged below the main shaft, and refrigerating machine oil is sucked into the oil supply passage through the oil supply pipe. In a configuration in which the oil supply pipe is fixed to the rotating main shaft, the rotation of the oil supply pipe agitates the refrigerating machine oil in the oil sump space during high-speed operation of the compressor, lowering the oil level in the center, which is necessary for lubrication of the compression mechanism. In some cases, the refrigerator oil could not be sucked up. Therefore, a technique has been disclosed in which an oil supply pipe is arranged below the main shaft or partially protrudes from the lower end of the main shaft, and the oil supply pipe is fixed to a lower bearing that supports the main shaft (see, for example, Patent Document 1). . In Patent Document 1, an oil supply pipe and a throttle plate are provided below the lower end of the spindle, and a lower bearing that covers the outer peripheral surface of the lower end of the spindle has an oil supply pipe and the throttle plate below the portion that covers the spindle. is fixed, rotating parts such as the main shaft are not exposed to the oil reservoir space.

JP-A-3-33493

As in Patent Document 1, in the structure in which the oil supply pipe is fixed to the lower bearing, although the lowering of the oil level can be suppressed by not exposing the rotating part to the oil reservoir space, the oil supply pipe having an inner diameter smaller than that of the oil supply passage is used. The lack of rotation reduces the radial pressure gradient in the oil supply passage. As a result, the amount of refrigerating machine oil flowing on the wall side in the oil supply passage and the height of the oil surface are lower than when the oil supply pipe rotates. In some cases, the refrigerating machine oil could not be supplied to the upper portion of the compression mechanism.

The present disclosure has been made to solve the above problems, and aims to provide a hermetic compressor with improved lubrication performance during low-speed operation.

A hermetic compressor according to the present disclosure includes a hermetic container having an oil reservoir space formed at the bottom for storing refrigerator oil, a compression mechanism disposed in the hermetic container for compressing a refrigerant, and a an electric motor portion arranged to drive the compression mechanism portion; and an electric motor portion extending vertically, fixed to the electric motor portion to be rotationally driven, and hollow inside from a lower end to a position above the compression mechanism portion. and a disk portion fixed to the lower end and inner peripheral side of the main shaft and having an opening formed therein. In a hermetic compressor that sucks up the refrigerating machine oil from the oil sump space through the opening of the disk portion, the compression mechanism portion rotatably supports the main shaft, and the outer peripheral surface of the lower end portion of the main shaft. and the disk portion is provided so that the lower surface of the disk portion is positioned at the same height as the lower end of the lower bearing or above the lower end of the lower bearing.

According to the present disclosure, the disc portion is fixed to the lower end and inner peripheral side of the main shaft and has an opening formed therein, and the lower surface of the disc portion is at the same height as the lower end of the lower bearing or at the lower end of the lower bearing. A disc portion is provided so as to be positioned above the . Therefore, since the lower surface of the disk portion fixed to the main shaft and rotating together with the main shaft does not protrude from the lower end of the lower bearing, the lowering of the oil level due to agitation of the refrigerating machine oil is suppressed. In addition, the disk portion fixed to the lower end and the inner peripheral side of the spindle forms an inlet narrower than the hollow portion of the spindle, and the disk portion that constitutes the inlet rotates together with the spindle, so even during low-speed operation. , the pressure gradient in the radial direction in the oil supply passage increases, and the height of the oil surface on the wall surface side becomes higher than before. As a result, it is possible to improve the lubrication efficiency during low-speed operation of the hermetic compressor.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1. FIG. 2 is a partially enlarged view around a compression mechanism in the hermetic compressor of FIG. 1; FIG. FIG. 3 is a cross-sectional view of the main shaft of FIG. 2 taken along the line AA; FIG. 7 is a partially enlarged view of the periphery of a compression mechanism portion of a hermetic compressor according to Embodiment 2; FIG. 11 is a partially enlarged view of the periphery of a compression mechanism of a hermetic compressor according to Embodiment 3; FIG. 11 is a partially enlarged view of the periphery of a compression mechanism of a hermetic compressor according to Embodiment 4; FIG. 11 is a partially enlarged view of the periphery of a compression mechanism of a hermetic compressor according to Embodiment 5; FIG. 8 is a BB cross-sectional view of the main shaft of FIG. 7;

Hereinafter, embodiments of the present disclosure will be described based on the drawings. It should be noted that the present disclosure is not limited by the embodiments described below. In each embodiment, the hermetic compressor is described as a rotary compressor, but each embodiment is not limited to a rotary compressor, and can be applied to a compressor having an oil supply form using a centrifugal pump. . Further, in each embodiment, a case where one cylinder is provided in the rotary compressor will be described as an example, but a plurality of cylinders can be provided. Also, in each figure, the same reference numerals denote the same or corresponding parts, which are common throughout the specification.

Embodiment 1.
1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1. FIG. FIG. 2 is a partial enlarged view of the periphery of the compression mechanism in the hermetic compressor of FIG. The hermetic compressor is composed of, for example, a rotary compressor. Hereinafter, the hermetic compressor may be simply referred to as compressor 100 .

The compressor 100 is one of the components of a refrigeration cycle used in air conditioners, for example. The compressor 100 has a function of taking in a gaseous fluid, compressing it, and discharging it in a state of high temperature and high pressure. A case where this fluid is a coolant will be described below as an example.

The compressor 100 has a closed container 1. The compressor 100 also includes a compression mechanism section 10 that compresses refrigerant, a main shaft 11 , and an electric motor section 20 that drives the compression mechanism section 10 via the main shaft 11 , inside the sealed container 1 .

The closed container 1 has, for example, a cylindrical shape with both ends closed. In the following description, the direction in which the main shaft 11 extends which is the longitudinal direction of the sealed container 1 (vertical direction in the drawing; arrow Z direction) is the axial direction, and the direction perpendicular to the axial direction is the radial direction. is called the circumferential direction.

One end of a suction pipe 40 for sucking refrigerant is connected to the side surface of the sealed container 1 . The other end of the suction pipe 40 is connected to the suction muffler 41 . In order to prevent the liquid refrigerant from flowing into the compression mechanism 10 and causing a failure, the intake muffler 41 separates the liquid refrigerant and the refrigerant gas that have flowed in from the outside (for example, the evaporator of the refrigerant circuit). Only the refrigerant gas is sucked into the sealed container 1 from the suction muffler 41 through the suction pipe 40 . A discharge pipe 2 for discharging the compressed refrigerant gas from the internal space of the closed container 1 to the outside (for example, the condenser of the refrigerant circuit) is provided on the upper surface of the closed container 1 . The bottom of the closed container 1 forms an oil reservoir space 50 in which refrigerating machine oil for lubricating the compression mechanism 10 is stored.

The electric motor unit 20 has a variable number of revolutions, for example, by inverter control or the like, and includes a stator 22 and a rotor 21 . The stator 22 is formed in a substantially cylindrical shape, and its outer peripheral portion is fixed to the sealed container 1 by shrink fitting or the like. Although not shown, the stator 22 is wound with a coil to which power is supplied from an external power supply. The rotor 21 has a substantially cylindrical shape and is arranged inside the stator 22 so as to form a predetermined gap from the inner peripheral surface of the stator 22 . A main shaft 11 is fixed to the rotor 21 , and the electric motor section 20 and the compression mechanism section 10 are connected via the main shaft 11 . That is, by rotating the electric motor portion 20 , rotational power is transmitted to the compression mechanism portion 10 via the main shaft 11 .

As shown in FIG. 2, the compression mechanism portion 10 includes an upper bearing 14, a lower bearing 15, a cylinder 13, an eccentric shaft portion 12 that rotates together with the main shaft 11, a piston 16, and vanes (not shown). have Further, in the example shown in FIG. 2, the upper bearing 14 is provided with a discharge muffler 19 . As shown in FIG. 1 , the compression mechanism section 10 is arranged below the electric motor section 20 . In the compression mechanism portion 10, an upper bearing 14, a cylinder 13, and a lower bearing 15 are sequentially stacked from top to bottom.

As shown in FIG. 2, a shaft hole 14a is formed in the center of the upper bearing 14, and the main shaft 11 is arranged in this shaft hole 14a. A cylindrical boss portion 14b extending upward is formed on the edge of the upper bearing 14 on the side of the shaft hole 14a. Although not shown, the upper bearing 14 is formed with a refrigerant discharge port (not shown). A shaft hole 15a is formed in the center of the lower bearing 15, and the main shaft 11 is arranged in this shaft hole 15a. A cylindrical boss portion 15b extending downward is formed at the edge of the lower bearing 15 on the side of the shaft hole 15a. The upper and

lower bearings

14 and 15 support the main shaft 11 at upper and lower portions of the compression mechanism portion 10 .

The lower bearing 15 is configured to cover the outer peripheral surface of the lower end of the main shaft 11 . Specifically, the lower bearing 15 is positioned such that the lower end 15e of the lower bearing 15 is at the same height as or lower than the lower end 11e of the main shaft 11 in the axial direction (arrow Z direction). It is configured such that the boss portion 15b extends.

The cylinder 13 is made of a flat plate member, and has a substantially cylindrical through hole that is substantially concentric with the main shaft 11 and penetrates in the vertical direction, and the cylinder 13 has a cylindrical shape. A part of the main shaft 11 supported by an upper bearing 14 and a lower bearing 15 is arranged in the through hole of the cylinder 13 . An upper bearing 14 closes the upper end of the through hole of the cylinder 13 , a lower bearing 15 closes the lower end of the through hole of the cylinder 13 , and a compression chamber 30 is formed between the upper bearing 14 and the lower bearing 15 . An eccentric shaft portion 12 provided on the main shaft 11 and a piston 16 are arranged in the compression chamber 30 .

Although not shown, the cylinder 13 is formed with radial vane grooves, and vanes are slidably held in the vane grooves. The rear side of the vane, which is the outer peripheral side of the cylinder 13, is open to the space of the airtight atmosphere of the airtight container 1. As shown in FIG. The vane is pressed against the piston 16 by the high-pressure refrigerant discharged into the closed container 1, and slides horizontally in the vane groove in conjunction with the movement of the piston 16, and the low-pressure space of the compression chamber 30 and the high-pressure space of the compression chamber 30 are compressed. play a role in partitioning the space.

Further, as shown in FIG. 1, the inner peripheral surface of the cylinder 13 is formed with a horizontal suction port 13a that communicates with the low-pressure space of the compression chamber 30 . A suction port 13a of the cylinder 13 is connected to a suction muffler 41 by a suction pipe 40, and refrigerant from the suction muffler 41 is introduced into the compression chamber 30 through the suction port 13a.

The eccentric shaft portion 12 is attached to the main shaft 11 and rotates eccentrically from the center O of the main shaft 11 as the main shaft 11 rotates. The eccentric shaft portion 12 transmits the rotational force transmitted from the electric motor portion 20 to the main shaft 11 to the piston 16 to rotate the piston 16 eccentrically from the center O of the main shaft 11 . The eccentric shaft portion 12 is configured by, for example, a separate member from the main shaft 11 and attached to the main shaft 11 . Note that the eccentric shaft portion 12 and the main shaft 11 may be integrally formed of the same member. The piston 16 has an annular shape and is slidably fitted to the eccentric shaft portion 12 . As the main shaft 11 rotates, the piston 16 rotates eccentrically together with the eccentric shaft portion 12 to compress the refrigerant.

As shown in FIG. 1, the main shaft 11 extends in the axial direction (direction of arrow Z) of the sealed container 1, one end is fixed to the rotor 21 of the electric motor section 20, and the other end is above the compression mechanism section 10. It is supported by bearing 14 and lower bearing 15 . The main shaft 11 is rotationally driven by the electric motor section 20 and transmits rotational power to the compression mechanism section 10 . In the example shown in FIG. 1, the main shaft 11 extends vertically along the axial direction of the closed container 1, and the rotational power of the electric motor section 20 is transferred to the compression mechanism section 10 arranged below the electric motor section 20. introduce.

A cylindrical cavity 17 extending in the axial direction is formed at the center O of the main shaft 11 . The hollow portion 17 extends from the lower end 11e of the main shaft 11 to a position above the compression mechanism portion 10 in the axial direction, and serves as a passage for refrigerating machine oil for lubricating the compression mechanism portion 10 . The wall surface 17a of the hollow portion 17 in the main shaft 11 functions not only as an oil supply passage but also as part of a centrifugal pump that generates centrifugal force and sucks up the refrigerating machine oil by the centrifugal force.

In addition, as shown in FIG. 2, the main shaft 11 is formed with a plurality of

branch paths

18a, 18b and 18c penetrating from the cavity 17 to the outer peripheral surface of the main shaft 11 in the radial direction. The plurality of

branch paths

18a, 18b, and 18c are provided at different height positions in the axial direction (the direction of the arrow Z) so that the refrigerating machine oil is supplied to the parts of the compression mechanism 10 that come into contact with particularly the rotating parts. It is configured.

In the example shown in FIG. 2, the branch path 18a is provided at the height of the upper bearing 14, specifically, at a position higher than the lower end of the upper bearing 14 in the axial direction (the direction of the arrow Z), and the branch path 18c is provided at the lower end of the upper bearing 14. It is provided at a height of the bearing 15 , specifically, at a position equal to or lower than the upper end of the lower bearing 15 . With this configuration, the friction between the main shaft 11 and the upper and

lower bearings

14 and 15 is reduced by the refrigerating machine oil supplied through the

branch passages

18a and 18c. The fluid lubrication of the oil film allows the main shaft 11 to be rotatably supported.

In addition, in the example shown in FIG. 2, the branch passage 18b is provided between the upper end and the lower end of the piston 16 in the axial direction (direction of arrow Z). With such a configuration, the friction between the piston 16, the main shaft 11, the upper bearing 14, and the lower bearing 15 is reduced by the refrigerating machine oil supplied through the branch passage 18b, and the piston 16 is lubricated by the fluid lubrication of the oil film. It can rotate between the bearing 14 and the lower bearing 15 .

Further, the compressor 100 of the present disclosure includes a disc portion 60 provided on the main shaft 11, and an opening portion 61 is formed in the disc portion 60. The opening 61 is provided in the center of the disk portion 60 , and the opening diameter D2 of the opening 61 is smaller than the opening diameter D1 of the hollow portion 17 of the main shaft 11 . The disk portion 60 is fixed to the lower end 11e of the main shaft 11 and to the inner peripheral side. In the example shown in FIG. 2, the disc portion 60 is fixed to the main shaft 11 so that the lower surface 60e of the disc portion 60 and the lower end surface of the main shaft 11 are flush with each other. Further, in the example shown in FIG. 2, the outer peripheral surface of the disk portion 60 is in contact with the wall surface 17a of the hollow portion 17, and the main shaft 11 is circularly mounted so that the center O of the main shaft 11 and the center of the opening 61 are aligned. A plate portion 60 is attached. The disc portion 60 may be press-fitted into the hollow portion 17 of the main shaft 11, or alternatively, the wall surface 17a of the hollow portion 17 of the main shaft 11 and the outer peripheral surface of the disc portion 60 are threaded, and the main shaft 11 is threaded. A fixed configuration may also be used.

As described above, the disk portion 60 is fixed to the lower end 11e of the main shaft 11 and on the inner peripheral side, so that it constitutes the entrance of the hollow portion 17 of the main shaft 11 and rotates as the main shaft 11 rotates. That is, the disc portion 60 constitutes a centrifugal pump that sucks up the refrigerating machine oil together with the wall surface 17a of the hollow portion 17 of the main shaft 11. As shown in FIG. Since the disk portion 60 is provided at the lower end 11e of the main shaft 11 and on the inner peripheral side, the hollow portion 17 has a narrow entrance.

The lower surface 60e of the disc portion 60 is positioned at the same height as the lower end 15e of the lower bearing 15 or above the lower end 15e of the lower bearing 15. As described above, the lower bearing 15 is configured to cover the outer peripheral surface of the lower end portion of the main shaft 11, and the lower end 15e of the lower bearing 15 is at the same height as or lower than the lower end 11e of the main shaft 11. is also located below. In other words, the rotating parts such as the main shaft 11 and the disk part 60 do not protrude from the lower end 15 e of the lower bearing 15 .

In the example shown in FIG. 2, both the lower end 11e of the main shaft 11 and the lower surface 60e of the disk portion 60 are positioned at the same height as the lower end 15e of the lower bearing 15. The lower end 11 e of the main shaft 11 and the lower surface 60 e of the disk portion 60 may be positioned above the lower end 15 e of the lower bearing 15 . However, when the lower surface 60e of the disc portion 60, which is the inlet of the hollow portion 17, is higher than the lower end 15e of the lower bearing 15, compared to the case where the lower surface 60e of the disc portion 60 is at the same height as the lower end 15e of the lower bearing 15, , the lower end of the centrifugal pump is far from the bottom of the closed container 1 (see FIG. 1), and the lubricating property is slightly inferior. Therefore, it is preferable that the lower surface 60e of the disc portion 60 and the lower end 15e of the lower bearing 15 are positioned at the same height in the axial direction (the direction of the arrow Z). Further, the lower surface 60e of the disc portion 60 may be positioned below the lower end 11e of the main shaft 11 as long as the disc portion 60 is fixed to the inner peripheral side of the lower end 11e of the main shaft 11 . That is, if the disk portion 60 has an opening 61 narrower than the hollow portion 17 and does not protrude from the lower end 15e of the lower bearing 15, a part of the disk portion 60 may protrude from the lower end 11e of the main shaft 11. good.

Next, operation of the compressor 100 will be described with reference to FIGS. When electric power is supplied to a coil (not shown) of the electric motor section 20 , the electric motor section 20 is driven, and the main shaft 11 is rotationally driven by the electric motor section 20 . When the main shaft 11 rotates, the eccentric shaft portion 12 and the piston 16 attached to the main shaft 11 rotate eccentrically within the compression chamber 30 . When the piston 16 rotates eccentrically within the compression chamber 30 , low-pressure refrigerant is supplied from the suction muffler 41 into the compression chamber 30 via the suction pipe 40 . Further, the rotation of the piston 16 reduces the volume of the compression chamber 30, compressing the low-pressure refrigerant. The compressed refrigerant is discharged into the discharge muffler 19 from a discharge port (not shown) formed in the upper bearing 14, and then discharged into the sealed container 1 from a discharge port (not shown) of the discharge muffler 19. be. The high-pressure refrigerant discharged into the internal space of the sealed container 1 is discharged from the discharge pipe 2 to the outside of the sealed container 1 .

Further, when the main shaft 11 is rotationally driven by the electric motor portion 20 , the centrifugal force generated in the hollow portion 17 by the rotation of the main shaft 11 draws up the refrigerating machine oil in the oil reservoir space 50 through the opening 61 of the disk portion 60 . be done.

Here, the outer peripheral surface of the lower end of the rotating main shaft 11 is covered with the lower bearing 15 and is not exposed to the oil reservoir space 50. Therefore, compared to the structure in which the main shaft 11 is exposed, even if the main shaft 11 rotates, Agitation of the refrigerating machine oil stored in the bottom of the sealed container 1 is suppressed. Further, the disk portion 60 that rotates together with the main shaft 11 is accommodated in the lower bearing 15 and is configured so as not to protrude from the lower end 15e of the lower bearing 15. Agitation of the refrigerating machine oil is suppressed as compared with a configuration in which a portion is provided. Therefore, a decrease in the oil level near the rotating portion caused by the stirring of the refrigerating machine oil stored in the bottom portion of the closed container 1 by the rotating portion is suppressed.

A disk portion 60 is fixed to the inner peripheral side of the lower end 11e of the main shaft 11, and the disk portion 60 constitutes the hollow portion 17, that is, the inlet of the oil supply passage. As a result, when the main shaft 11 rotates, the wall surface 17a of the hollow portion 17 becomes a so-called cylindrical container, and the flow of the refrigerating machine oil sucked up from the oil reservoir space 50 easily develops into a forced vortex within the hollow portion 17.

FIG. 3 is a cross-sectional view of the spindle 11 of FIG. 2 taken along the line AA. In FIG. 3, an arrow R indicates the direction of rotation of the main shaft 11. As shown in FIG. In FIG. 3, four points (point P1, point P2, point P3 and point P4) represent positions in the cavity 17 at different distances from the center O of the main shaft 11, and each point is a starting point. The length of the arrow represents the magnitude of the circumferential velocity of the refrigerating machine oil at that point. A point P1, a point P2, a point P3, and a point P4 are set in this order from the center O toward the outside in the radial direction.

As shown in FIG. 3, when the disk portion 60 rotates together with the main shaft 11, a pressure distribution is generated in the hollow portion 17 such that the pressure increases with increasing distance from the center O of the main shaft 11 (for example, the position of point P4). Then, the refrigerating machine oil becomes a forced vortex. At this time, the speed in the axial direction (direction of arrow Z) of the refrigerating machine oil sucked through the opening 61 of the disk portion 60 is less susceptible to the rotation. A pressure gradient in the hollow portion 17 is generated between the edge 60 a of the opening 61 of the disk portion 60 and the wall surface 17 a of the hollow portion 17 . As shown in FIG. 3, between the end 60a of the opening 61 of the disk portion 60 and the wall surface 17a of the hollow portion 17, the velocity of the refrigerating machine oil in the circumferential direction increases at radially outer positions. In addition, the pressure generated in the refrigerating machine oil also increases with increasing position radially outward. That is, the pressure of the refrigerating machine oil increases in the order of point P1, point P2, point P3, and point P4. The height of the oil level inside the cavity 17 is proportional to the pressure. In the present disclosure, provision of the disk portion 60 increases the pressure gradient in the radial direction, and the oil level on the wall surface 17a side of the hollow portion 17 is higher than in the conventional art.

As shown in FIG. 2, the refrigerating machine oil that is sucked up from the opening 61 of the disk portion 60 and flows along the wall surface 17a of the hollow portion 17 due to the forced vortex motion flows through

branch paths

18a, 18b and 18c provided on the wall surface 17a. is supplied to each part of the compression mechanism section 10 via the . Specifically, the refrigerating machine oil is supplied to the lower bearing 15 through the branch passage 18c, to the piston 16 through the branch passage 18b, and to the upper bearing 14 through the branch passage 18a.

Generally, during low-speed operation of the compressor 100, the speed of the refrigerating machine oil on the wall surface 17a side of the cavity 17 is lower than that during high-speed operation, so the oil level on the wall surface 17a side cannot be sufficiently high. , it becomes difficult to supply oil to the upper portion of the compression mechanism 10 (for example, the upper bearing 14). In the present disclosure, by providing the disk portion 60, a certain distance is secured between the end 60a of the opening 61 of the disk portion 60 and the wall surface 17a in the horizontal direction. Therefore, the refrigerating machine oil that has flowed in from the inlet of the hollow portion 17 can generate a forced vortex between the end 60a of the opening 61 and the wall surface 17a, and the pressure gradient in the radial direction becomes larger than before. Therefore, even when the compressor 100 is operating at a low speed, the oil can be supplied to the upper portion of the compression mechanism portion 10 .

The smaller the opening diameter D2 of the opening 61 of the disc portion 60, the greater the pressure gradient in the hollow portion 17, and the more the compressor 100 operates at low speed. Since it becomes smaller, the amount of oil supplied may be insufficient during high-speed operation. The opening diameter D2 of the opening 61 of the disc portion 60 is about 0.3D1 to 0.7D1 with respect to the opening diameter D1 of the hollow portion 17 of the main shaft 11, taking into account the balance between the lubricating property and the amount of lubricating oil. is preferred.

As described above, the hermetic compressor (compressor 100) of Embodiment 1 includes the hermetically sealed container 1 in which the oil reservoir space 50 for storing the refrigerating machine oil is formed at the bottom. The hermetic compressor includes a compression mechanism portion 10 arranged in the closed container 1 for compressing the refrigerant, an electric motor portion 20 arranged in the closed container 1 for driving the compression mechanism portion 10, and a vertical direction (arrow and a main shaft 11 that extends in the Z direction) and that is fixed to the electric motor section 20 and driven to rotate. A hollow portion 17 is formed inside the main shaft 11 from the lower end 11 e to a position above the compression mechanism portion 10 . The hermetic compressor also includes a disk portion 60 having an opening 61 formed therein. The hermetic compressor sucks up the refrigerating machine oil from the oil reservoir space 50 through the opening 61 of the disc portion 60 by the centrifugal force generated in the hollow portion 17 by the rotation of the main shaft 11 . The compression mechanism section 10 has a lower bearing 15 covering the outer peripheral surface of the lower end 11e of the main shaft 11, and the lower bearing 15 supports the main shaft 11 so as to be rotatable. The disc portion 60 is provided so that the lower surface 60 e of the disc portion 60 is at the same height as the lower end 15 e of the lower bearing 15 or above the lower end 15 e of the lower bearing 15 .

As a result, the lower surface 60e of the disk portion 60, which is fixed to the main shaft 11 and rotates together with the main shaft 11, does not protrude from the lower end 15e of the lower bearing 15, thereby suppressing a decrease in the oil level due to agitation of the refrigerating machine oil. The disc portion 60 fixed to the lower end 11 e of the main shaft 11 and the inner peripheral side constitutes an inlet narrower than the hollow portion 17 of the main shaft 11 . As a result, the pressure on the radially outer wall surface 17a side in the hollow portion 17 increases. Since the oil level in the cavity 17 is proportional to the pressure, the oil level on the wall surface 17a of the refrigerating machine oil in the cavity 17 is higher than in the conventional case. Therefore, the lowering of the oil level due to agitation of the refrigerating machine oil stored in the bottom of the closed container 1 is suppressed, and the height of the oil level on the side of the wall surface 17a in the hollow portion 17 becomes higher than before, so that the compression Refueling is improved when the machine 100 is operated at low speed.

Further, the disc portion 60 is provided so that the lower surface 60e of the disc portion 60 is at the same height as the lower end 11e of the main shaft 11 or above the lower end 11e of the main shaft 11. As a result, the disk portion 60 is entirely accommodated in the main shaft 11 and does not protrude from the lower end 11e of the main shaft 11, so that the exposed surface area of the disk portion 60 can be reduced, and the lower bearing 15 and the disk portion can be arranged in the radial direction. 60, the decrease in the oil level is suppressed.

Embodiment 2.
FIG. 4 is a partially enlarged view around the compression mechanism section 10 of the hermetic compressor according to the second embodiment. The compressor 100 of the second embodiment differs from the first embodiment in that a discharge muffler 62 is provided below the lower bearing 15, and the rest of the configuration is the same as that of the first embodiment. be.

Although FIG. 4 shows the compression mechanism 10 having one cylinder 13, the compression mechanism 10 may have a plurality of cylinders 13 in the axial direction (direction of arrow Z). In this case, the lower bearing 15 is provided with a discharge port for the refrigerant from the lower cylinder, and a discharge muffler 62 provided below the lower bearing 15 discharges the refrigerant from the lower cylinder into the container. A coolant outlet is provided for cooling.

The discharge muffler 62 is provided so as to cover the entire boss portion 15b of the lower bearing 15, and has a convex shape protruding downward in the example shown in FIG. A muffler hole 62 a is formed in the discharge muffler 62 at a position below the shaft hole 15 a of the lower bearing 15 . The muffler hole 62a has a circular shape, for example, and has an opening diameter D3 that is larger than the opening diameter D2 of the opening 61 of the disc portion 60. As shown in FIG. In plan view, the center of the muffler hole 62a coincides with the center O of the main shaft 11 and the center of the opening 61 of the disk portion 60. As shown in FIG.

Further, in Embodiment 2, an annular sealing member 151 is installed on the lower end surface of the boss portion 15b of the lower bearing 15 so as to surround the muffler hole 62a. The sealing material 151 is provided between the lower end surface of the boss portion 15b of the lower bearing 15 and the upper surface of the discharge muffler 62 facing the lower end surface so as to be in contact with both of them. It is configured to separate the space. In addition, in the configuration in which the discharge muffler 62 is provided below the lower bearing 15, the seal member 151 may not be provided, and the lower end surface of the boss portion 15b and the upper surface of the discharge muffler 62 may be in direct contact. In this case, an upward convex portion is formed in a portion of the discharge muffler 62 facing the lower end surface of the boss portion 15b, and the convex portion is brought into contact with the lower end surface of the boss portion 15b. It may be configured to partition the space inside the discharge muffler 62 .

The operation of compressing the refrigerant in the compressor 100 of the second embodiment is the same as that of the first embodiment. A part of the refrigerant compressed in the compression chamber 30 is discharged into the discharge muffler 19 from the discharge port (not shown) of the upper bearing 14, and then discharged from the discharge port (not shown) of the discharge muffler 19 to the sealed container 1. discharged inside. The rest of the refrigerant compressed in the compression chamber 30 is discharged from the discharge port (not shown) of the lower bearing 15 into the discharge muffler 62, and then from the discharge port (not shown) of the discharge muffler 62. It is discharged into the closed container 1 . Then, the high-pressure gaseous refrigerant discharged into the internal space of the sealed container 1 is discharged from the discharge pipe 2 to the outside of the sealed container 1 .

Further, when the main shaft 11 is rotationally driven, the centrifugal force generated in the hollow portion 17 sucks up the refrigerating machine oil in the oil reservoir space 50 through the opening 61 of the disk portion 60 . Also in the second embodiment, as in the case of the first embodiment, a disk portion 60 fixed to the inner peripheral side of the lower end 11e of the main shaft 11 is provided. The disc portion 60 is provided so that the lower surface 60 e of the disc portion 60 is at the same height as the lower end 15 e of the lower bearing 15 or above the lower end 15 e of the lower bearing 15 . Therefore, a drop in the oil level due to agitation of the refrigerating machine oil is suppressed, and the height of the oil level on the radially outer wall surface 17a of the hollow portion 17 is higher than in the conventional art, thereby improving the oil supply performance. can get.

Further, the compressor 100 of Embodiment 2 includes the discharge muffler 62 provided below the lower bearing 15 . 62a is formed. An opening diameter D3 of the muffler hole 62a is larger than an opening diameter D2 of the opening 61 of the disc portion 60. As shown in FIG. As a result, even if the discharge muffler 62 is provided in the lower bearing 15 in the compressor 100, the action of the centrifugal pump by the main shaft 11 and the disk portion 60 described above is not hindered, as in the case of the first embodiment. , the effect of improving lubrication is obtained.

By the way, in the first embodiment described above, the discharge muffler 62 is not provided below the lower bearing 15 in the compressor 100 . Therefore, the lower end 11e of the main shaft 11 and the lower surface 60e of the disc portion 60 are exposed to the oil sump space 50, and the main shaft 11 and the disc portion 60 rotate, so that the refrigerating machine oil in the oil sump space 50 is slightly agitated. and the oil surface is disturbed. In contrast, in Embodiment 2, the discharge muffler 62 is provided below the lower bearing 15, and the opening diameter D3 of the muffler hole 62a is smaller than the opening diameter D4 of the shaft hole 15a of the lower bearing 15. there is As a result, at least a portion of the lower surface of the rotating portion such as the lower end 11 e of the main shaft 11 and the lower surface 60 e of the disk portion 60 is covered with the discharge muffler 62 . Therefore, as compared with the case of the first embodiment, disturbance of the liquid surface of the stored refrigerating machine oil can be suppressed, and the oil supply performance is further improved.

Embodiment 3.
FIG. 5 is a partial enlarged view of the periphery of the compression mechanism of the hermetic compressor according to Embodiment 3. FIG. The compressor 100 of the third embodiment differs from the first embodiment in that the lower bearing 15 is provided with the fixed pipe 63, and the rest of the configuration is the same as that of the first embodiment.

The main shaft 11 and the disc portion 60 rotate, but the fixed pipe 63 is independent of them and does not rotate. The fixed pipe 63 has a pipe portion 63a extending in the axial direction (the direction of the arrow Z) and a disk-shaped mounting portion 63b provided on the outer periphery of the upper end of the pipe portion 63a. is fixed to Specifically, the fixed pipe 63 is fixed to the lower bearing 15 so that the lower end surface of the boss portion 15b of the lower bearing 15 and the upper surface of the mounting portion 63b of the fixed pipe 63 are in contact with each other. A gap is provided between the tip of the pipe portion 63a of the fixed pipe 63 and the bottom surface of the sealed container 1 so that the refrigerating machine oil can flow.

A fixed pipe 63 is fixed to the lower bearing 15 so that the hole 63c of the pipe portion 63a is positioned below the opening 61 of the disk portion 60. More specifically, the center of the hole 63c of the pipe portion 63a coincides with the center O of the main shaft 11 and the center of the opening 61 of the disk portion 60 in plan view. Further, the opening diameter D4 of the hole 63c of the fixed pipe 63, that is, the inner diameter of the pipe portion 63a is larger than the opening diameter D2 of the opening portion 61 of the disk portion 60. As shown in FIG.

In the compressor 100 of the third embodiment, the operation of compressing the refrigerant and discharging it from the discharge pipe 2 to the outside of the sealed container 1 is the same as in the case of the first embodiment. Note that the fixed pipe 63 of Embodiment 3 can also be applied to the compressor 100 of Embodiment 2 described above. In this case, the fixed pipe 63 is fixed to the lower bearing 15 by sandwiching the mounting portion 63b of the fixed pipe 63 between the discharge muffler 62 (see FIG. 4) of Embodiment 2 and the lower end face of the boss portion 15b of the lower bearing 15. may be configured.

Further, when the main shaft 11 is rotationally driven, the centrifugal force generated in the hollow portion 17 sucks up the refrigerating machine oil in the oil reservoir space 50 through the opening 61 of the disk portion 60 . Also in the third embodiment, as in the case of the first embodiment, a disk portion 60 fixed to the inner peripheral side of the lower end 11e of the main shaft 11 is provided. The disc portion 60 is provided so that the lower surface 60 e of the disc portion 60 is at the same height as the lower end 15 e of the lower bearing 15 or above the lower end 15 e of the lower bearing 15 . Therefore, a drop in the oil level due to agitation of the refrigerating machine oil is suppressed, and the height of the oil level on the radially outer wall surface 17a of the hollow portion 17 is higher than in the conventional art, thereby improving the oil supply performance. can get.

Further, the compressor 100 of Embodiment 3 includes a fixed pipe 63 fixed to the lower end 15e of the lower bearing 15. The fixed pipe 63 extends downward from the lower end 15e of the lower bearing 15 to connect with the bottom surface of the sealed container 1. provided to form a gap between the The hole 63c of the fixed pipe 63 is positioned below the opening 61 of the disk portion 60, and the inner diameter (opening diameter D4) of the fixed pipe 63 is larger than the opening diameter D2 of the opening 61 of the disk portion 60. It has a large configuration.

In general, the compressor 100 may be operated under operating conditions such that, for example, the amount of refrigerating machine oil that flows out of the compressor 100 together with the refrigerant increases and the level of the oil level in the oil reservoir space 50 decreases. be. Since the compressor 100 of the present disclosure is provided with the fixed pipe 63 extending downward from the lower end 15e of the lower bearing 15, the amount of oil in the oil reservoir space 50 is reduced as described above, and the height of the oil level is lowered. Oil can be supplied from the bottom surface of the sealed container 1 through the fixed pipe 63 even under such operating conditions.

Here, since the fixed pipe 63 is fixed to the lower bearing 15, it does not rotate, and the effect of suppressing the oil level drop in the oil reservoir space 50 is maintained. In addition, since the inner diameter (opening diameter D4) of the fixed pipe 63 is larger than the opening diameter D2 of the opening 61 of the disk portion 60, the action of the centrifugal pump by the main shaft 11 and the disk portion 60 is not hindered. The effect of improving the refueling property is also maintained.

Embodiment 4.
FIG. 6 is a partial enlarged view of the periphery of a compression mechanism of a hermetic compressor according to Embodiment 4. FIG. The compressor 100 of the fourth embodiment is different from the first embodiment in that a cap 64 is provided in place of the disk portion 60, and the rest of the configuration is the same as that of the first embodiment. be.

The cap 64 has a disc portion 64a corresponding to the disc portion 60 of the first embodiment, and a cylindrical flange portion 64b extending upward from the outer peripheral edge of the disc portion 64a. It is fixed to the lower end 15e and the inner peripheral side. Specifically, the cap 64 is fixed to the main shaft 11 so that the outer peripheral surface of the flange portion 64b and the wall surface 17a of the hollow portion 17 of the main shaft 11 are in contact with each other. The disc portion 64a and the flange portion 64b are molded, for example, from sheet metal and are integrally formed.

An opening 61 is formed in the disc portion 64a. The opening 61 is provided in the center of the disc portion 64a, and the opening diameter D2 of the opening 61 is smaller than the opening diameter D1 of the hollow portion 17 of the main shaft 11. As shown in FIG. The disk portion 64a is provided on the main shaft 11 so that the center O of the main shaft 11 and the center of the opening 61 are aligned. The cap 64 may be press-fitted into the hollow portion 17 of the main shaft 11, or alternatively, the wall surface 17a of the hollow portion 17 of the main shaft 11 and the outer peripheral surface of the flange portion 64b of the cap 64 are threaded, and the main shaft 11 is screwed. A fixed configuration may also be used.

The positional relationship between the cap 64, the lower bearing 15 and the main shaft 11 in the fourth embodiment is the same as the positional relationship between the disc portion 60 (see FIG. 1), the lower bearing 15 and the main shaft 11 in the first embodiment. be. That is, the lower surface 64e of the disc portion 64a and the lower end 11e of the main shaft 11 are positioned at the same height as the lower end 15e of the lower bearing 15 or above the lower end 15e of the lower bearing 15. 11 and the cap 64 are configured so as not to protrude. Further, the lower surface 64e of the disk portion 64a may be positioned below the lower end 11e of the main shaft 11 as long as the cap 64 is fixed to the inner peripheral side of the lower end 11e of the main shaft 11 .

As described above, in the fourth embodiment, as in the case of the first embodiment, the disc portion 64a is provided, and the lower surface 64e of the disc portion 64a is at the same height as or below the lower end 15e of the lower bearing 15. A cap 64 is fixed to the main shaft 11 so as to be positioned above the lower end 15 e of the bearing 15 . Therefore, a drop in the oil level due to agitation of the refrigerating machine oil is suppressed, and the height of the oil level on the radially outer wall surface 17a of the hollow portion 17 is higher than in the conventional art, thereby improving the oil supply performance. can get.

Further, the compressor 100 of Embodiment 4 has a cylindrical flange portion 64b integrally formed with the disk portion 64a and extending upward from the outer peripheral edge of the disk portion 64a. As a result, the disc portion 64a and the flange portion 64b can be integrally molded as the cap 64 by using easily deformable sheet metal or the like. Therefore, compared to the case where a part composed only of the disc portion 60 without the flange portion 64b is press-fitted or screw-fixed into the hollow portion 17 of the main shaft 11, it is easier to insert into the main shaft 11 during assembly or processing. , deformation of the main shaft 11 can be suppressed because the load on the main shaft 11 can be reduced. Further, for example, the insertion into the main shaft 11 is facilitated compared to the structure in which the oil supply pipe is directly inserted into the main shaft 11 .

Embodiment 5.
FIG. 7 is a partial enlarged view of the periphery of the compression mechanism of the hermetic compressor according to Embodiment 5. FIG. FIG. 8 is a BB cross-sectional view of the spindle 11 of FIG. As shown in FIG. 7, the compressor 100 of the fifth embodiment differs from the first embodiment in that a partition plate 65 is provided in the hollow portion 17 of the main shaft 11. are the same as in the first embodiment.

The partition plate 65 is composed of a plate-shaped member extending in the vertical direction (direction of arrow Z), and has a plate thickness t that is thinner than the opening diameter D2 of the opening 61 of the disc portion 60 . The partition plate 65 has a lower end 65e in contact with the disk portion 60 as shown in FIG. 7, and both edges in contact with the wall surface 17a of the hollow portion 17 as shown in FIG. It is fixed to the main shaft 11 at the same time, and is configured to partition the hollow portion 17 into two. That is, as shown in FIG. 7, inside the hollow portion 17, a semi-cylindrical first hollow portion S1 and a second hollow portion S2 extending in the vertical direction are formed on both sides of the partition plate 65. As shown in FIG. A lower end 65e of the partition plate 67 passes through the center of the opening 61 of the disc portion 60 in plan view as shown in FIG.

In the example shown in FIG. 7, the partition plate 65 has a flat plate shape, and the surface facing the first cavity S1 and the surface facing the second cavity S2 extend parallel to the center O of the main shaft 11. . The partition plate 65 may have a spiral shape twisted by 90° or more about the longitudinal direction of the plate-like member. In this case, the first cavity S1 and the second cavity S2 formed on both sides of the partition plate 65 have a spiral shape.

As described above, in the fifth embodiment, similarly to the first embodiment, the disk portion 60 fixed to the inner peripheral side of the lower end 11e of the main shaft 11 is provided. The disc portion 60 is provided so that the lower surface 60 e of the disc portion 60 is at the same height as the lower end 15 e of the lower bearing 15 or above the lower end 15 e of the lower bearing 15 . Therefore, a drop in the oil level due to agitation of the refrigerating machine oil is suppressed, and the height of the oil level on the radially outer wall surface 17a of the hollow portion 17 is higher than in the conventional art, thereby improving the oil supply performance. can get.

Further, the compressor 100 of Embodiment 5 includes a partition plate 65 arranged in the hollow portion 17 of the main shaft 11 and extending in the vertical direction. , divides the flow path of the refrigerating machine oil in the hollow portion 17 into two.

Thus, by disposing the partition plate 65 in the hollow portion 17 of the main shaft 11, the flow path of the refrigerating machine oil flowing into the hollow portion 17 from the opening 61 of the disc portion 60 can be divided into two. The pressure gradient in the radial direction within the hollow portion 17 is likely to increase as compared with the case where the is not provided. Further, since the lower end 65e of the partition plate 65 is in contact with the disk portion 60, the effect of increasing the pressure gradient by the partition plate 65 can be obtained immediately after the refrigerating machine oil flows into the hollow portion 17 from the opening 61. can be done. As a result, compared to the case where the partition plate 65 is not provided, the oil surface on the side of the wall surface 17a in the hollow portion 17 of the main shaft 11 is higher, and the oil supply is improved.

It should be noted that it is possible to combine each embodiment, and to modify or omit each embodiment as appropriate.

1 closed container, 2 discharge pipe, 10 compression mechanism, 11 main shaft, 11e lower end, 12 eccentric shaft, 13 cylinder, 13a inlet, 14 upper bearing, 14a shaft hole, 14b boss, 15 lower bearing, 15a shaft hole , 15b boss portion, 15e lower end, 16 piston, 17 cavity portion, 17a wall surface, 18a branch passage, 18b branch passage, 18c branch passage, 19 discharge muffler, 20 electric motor section, 21 rotor, 22 stator, 30 compression chamber, 40 suction pipe, 41 suction muffler, 50 oil reservoir space, 60 disc portion, 60a end, 60e lower surface, 61 opening, 62 discharge muffler, 62a muffler hole, 63 fixed pipe, 63a pipe portion, 63b mounting portion, 63c hole , 64 Cap, 64a Disc portion, 64b Flange portion, 64e Lower surface, 65 Partition plate, 65e Lower end, 67 Partition plate, 100 Compressor, 151 Seal material, D1, D2, D3, D4 Opening diameter, O center, S1 th 1 cavity, S2 second cavity, t plate thickness.

Claims

a closed container having an oil reservoir space formed at the bottom for storing refrigerating machine oil;
a compression mechanism section arranged in the sealed container for compressing a refrigerant;
an electric motor unit arranged in the closed container for driving the compression mechanism;
a main shaft extending in the vertical direction, fixed to the electric motor portion and driven to rotate, and having a hollow portion formed therein from a lower end to a position above the compression mechanism portion;
a disk portion fixed to the lower end and inner peripheral side of the main shaft and having an opening formed therein;
A hermetic compressor that sucks up the refrigerating machine oil from the oil reservoir space through the opening of the disc portion by centrifugal force generated in the hollow portion by the rotation of the main shaft,
The compression mechanism section is
a lower bearing that rotatably supports the main shaft and covers the outer peripheral surface of the lower end of the main shaft;
The disk portion is provided such that the lower surface of the disk portion is positioned at the same height as or above the lower end of the lower bearing.
2. The hermetic compression according to claim 1, wherein the disk portion is provided such that the lower surface of the disk portion is positioned at the same height as the lower end of the main shaft or above the lower end of the main shaft. machine.
A discharge muffler provided below the lower bearing,
3. The closed type compression according to claim 1, wherein a muffler hole having an opening diameter larger than that of said opening is formed in said discharge muffler at a position below said opening of said disc portion. machine.
The hermetic compressor according to claim 3, wherein the opening diameter of the muffler hole is larger than the opening diameter of the opening of the disk portion and smaller than the opening diameter of the shaft hole of the lower bearing.
A fixed pipe fixed to the lower end of the lower bearing, extending downward from the lower end, and provided to form a gap with the bottom surface of the closed container,
The hole of the fixed pipe is positioned below the opening of the disk portion, and the inner diameter of the fixed pipe is larger than the opening diameter of the opening of the disk portion. 1. The hermetic compressor according to claim 1.
The hermetic compressor according to any one of claims 1 to 5, further comprising a cylindrical flange portion integrally formed with the disk portion and extending upward from the outer peripheral edge of the disk portion.
a partition plate disposed in the hollow portion of the main shaft and extending in the vertical direction;
The hermetic compressor according to any one of claims 1 to 6, wherein the partition plate has a lower end in contact with the disk portion and bisects the flow path of the refrigerating machine oil in the hollow portion.