JP2007032562A - Enclosed compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an enclosed compressor having improved lubrication structure of a thrust bearing in rolling-contact with a rotary shaft so as to support a load in the axial direction of the rotary shaft, thus improving reliability of a product. <P>SOLUTION: This enclosed compressor is provided with a sealed vessel forming an oil sump on a bottom face, a frame arranged in the sealed vessel and having a hollow part, the rotary shaft provided rotatably in the frame to pass through the hollow part and having an oil flow passage array for leading oil in the oil sump into an upper part, and the thrust bearing provided in a bearing installation channel at an upper end of the hollow part and coming into rolling-contact with the rotary shaft to support load in the axial direction of the rotary shaft. The oil flow passage array is constituted to supply at least a part of oil into the thrust bearing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hermetic compressor, and more particularly to a hermetic compressor in which a thrust bearing is in rolling contact with a rotating shaft so as to support an axial load of the rotating shaft.

  Generally, a hermetic compressor is a device that is employed in a refrigeration cycle such as an air conditioner or a refrigerator and has a function of compressing and supplying a fluid such as a refrigerant. And a drive unit that provides the compression power of the refrigerant. Here, the compression unit and the drive unit are installed in a sealed container.

  However, such a conventional hermetic compressor can supply oil between a hollow portion on the lower side of the thrust bearing and the rotating shaft or to a specific portion such as a friction portion of the compression portion by using an oil supply structure. On the other hand, the oil supply to the thrust bearing where the load on the rotating shaft is substantially applied was insufficient. As a result, when the compressor is used for a long time, the upper and lower thrust washers and the balls constituting the thrust bearing are worn, and the smooth rotation of the rotating shaft is obstructed, and dust generated mainly by this wear is applied to the thrust bearing. There is a problem in that the effect of reducing friction by the thrust bearing is reduced, resulting in a decrease in the reliability of the compressor.

  The present invention is to solve the above-mentioned problems, and its purpose is to improve the lubrication structure for a thrust bearing that is in rolling contact with the rotating shaft so as to support the axial load of the rotating shaft. It is an object of the present invention to provide a hermetic compressor that can improve reliability.

  In order to achieve the above object, the present invention provides a sealed container having an oil sump formed on a bottom surface, a frame disposed in the sealed container and having a hollow part, and a frame penetrating the hollow part. A rotary shaft that is rotatably installed and has an oil passage array that guides oil in the oil sump to the upper part, and is installed in a bearing installation groove at the upper end of the hollow portion so as to support the axial load of the rotary shaft. A hermetic compressor, wherein the oil flow path array is configured to supply at least part of the oil to the thrust bearing. To do.

  According to the hermetic compressor according to the present invention, the oil guided upward along the oil passage array formed on the rotating shaft is in rolling contact with the rotating shaft so as to support the axial load of the rotating shaft. Since it is transmitted directly to the thrust bearing side, lubrication to the thrust bearing is greatly improved, and as a result, smooth rotation of the rotating shaft through the thrust bearing can be sustained for a long period of time, improving product reliability. An effect is obtained.

  Hereinafter, preferred embodiments of a hermetic compressor according to the present invention will be described in detail with reference to the accompanying drawings.

  First, for convenience of explanation, it is assumed that in the hermetic compressor, the compression unit and the drive unit are arranged on the upper and lower sides of the frame 11, respectively. The compression section includes a cylinder provided on the upper side of the frame 11 so that the internal space forms a compression chamber, and a piston 15 that linearly reciprocates in the compression chamber to compress the refrigerant. The drive unit includes a stator 12 connected to a lower portion of the frame 11 and a rotor 13 provided inside the stator 12 and electrically interacting with the stator 12.

  A rotating shaft 20 is installed in the frame so as to transmit the driving force of the driving unit to the compressing unit, and the rotating shaft 20 is rotatably inserted into the hollow portion 11 a of the frame 11.

  Here, the lower end of the rotating shaft 20 extends to the lower part of the hollow portion of the frame, is press-fitted and fixed to the rotor 13, and rotates together with the rotor 13. The eccentric shaft portion 22 of the rotating shaft 20 is connected to the piston via the connecting rod 18 to convert the rotating motion of the rotating shaft 20 into the linear reciprocating motion of the piston 15.

  Further, around the rotating shaft 20 between the eccentric shaft portion 22 of the rotating shaft 20 and the frame 11, ring-shaped upper and lower thrust washers 31 that are in rolling contact with the rotating shaft so as to support the axial load of the rotating shaft. , 32 and a ball 33 supported between upper and lower thrust washers, and the frame 11 is ring-shaped at the upper end of the hollow portion 11a so that the thrust bearing 30 is installed. The bearing installation groove 11b is provided.

  With such a structure, when the rotating shaft 20 rotates due to the electrical interaction between the stator 12 and the rotor 13, the piston 15 connected to the eccentric portion of the rotating shaft 20 via the connecting rod 18 becomes the compression chamber 14a of the cylinder. The refrigerant is compressed by reciprocating linearly inside, and the axial load of the rotating shaft 20 is supported by the use of the thrust bearing 30 that is in rolling contact with the rotating shaft during the compressing operation of the refrigerant.

  Further, the compressor is provided with an oil supply structure for supplying oil to the frictional portions of the rotary shaft 20 and the compression unit to perform lubrication and cooling during the refrigerant compression operation as described above. In this oil supply structure, an oil sump 19 for storing predetermined oil is formed on the bottom surface of the sealed container 10, and an oil pickup means 40 for sucking up the oil in the oil sump 19 upward at the lower end of the rotating shaft 20. And an oil flow path array for guiding the oil sucked up by the oil pickup means 40 between the rotary shaft 20 and the hollow portion 11a and to the compression portion is formed on the rotary shaft.

  The oil passage array communicates with the first oil passage so as to lubricate between the first oil passage formed inside the rotary shaft at the lower portion of the hollow portion and between the rotary shaft and the hollow portion, and the thrust bearing lower portion. A second oil passage formed in the shape of a spiral groove on the outer surface of the rotary shaft on the hollow portion side, a second oil passage communicating with the second oil passage, and extending again through the inside of the rotary shaft to the upper end of the rotary shaft. And 3 oil flow paths.

  Therefore, when the rotary shaft rotates during the refrigerant compression operation, first, oil in the oil sump is lubricated between the rotary shaft and the hollow portion of the frame while passing through the second oil passage through the first oil passage by the oil pickup means. The oil that has been cooled and passed through the second oil passage is subsequently injected through the third oil passage to the upper end of the rotating shaft and transmitted to the compression portion side, thereby connecting the piston 15 and the connecting rod 18 to each other. The oil is finally collected in the oil sump 19. The recovered oil is repeatedly used to lubricate and cool the friction parts of the rotary shaft 20 and the compression unit while passing through the plurality of oil flow paths.

  As shown in FIG. 1, the hermetic compressor according to the present invention includes a hermetic container 10 in which an upper container 10a and a lower container 10b are coupled to each other.

  On one side and the other side of the sealed container 10, a suction pipe 10c for inflow of an external refrigerant and a discharge pipe 10d for discharging the refrigerant compressed in the sealed container 10 to the outside are installed. In addition, a frame 11 is installed inside the hermetic container 10, and an upper part and a lower part of the frame 11 are respectively provided with a compression unit that performs a refrigerant compression operation and a drive unit that provides the compression power of the refrigerant.

  Here, the driving unit is arranged on the inner side of the stator 12 so as to rotate by electrical interaction between the stator 12 fixed to the outside and the stator 12 so as to generate a predetermined electromagnetic force by applying a current. A compression block is formed integrally with the frame 11 on the upper side of the frame 11, and the compression block 14a is formed inside the compression block 14a. A cylinder head that is coupled to one side of the cylinder block 14 so as to seal the compression chamber 14a and a piston 15 that compresses the refrigerant while reciprocating linearly, and is provided with a refrigerant discharge chamber 16a and a refrigerant suction chamber 16b. 16 and between the cylinder block 14 and the cylinder head 16 and is sucked into the compression chamber 14a from the refrigerant suction chamber 16b or from the compression chamber 14a to the refrigerant discharge chamber. A valve device 17 intermittently the flow of the refrigerant discharged to 6a, configured with a. The frame 11 has a hollow portion 11a at the center, and the rotary shaft 20 is rotatably inserted into the hollow portion 11a to transmit the driving force of the drive portion to the compression portion.

  Referring to FIG. 2, the rotating shaft 20 is rotatably supported at the upper portion by the hollow portion 11 a of the frame 11, and the lower portion is press-fitted into the center of the rotor 13 of the driving unit so that the rotating shaft 20 can rotate together with the rotor 13. Side main shaft portion 21, an eccentric shaft portion 22 provided eccentric to the main shaft portion 21 at the upper portion of the main shaft portion 21 so as to form the upper end of the rotating shaft 20, and rotation by the eccentric shaft portion 22 A weight balance portion 23 provided between the eccentric shaft portion 22 and the main shaft portion 21 is configured to compensate for the unbalance. Here, the eccentric shaft portion 22 forms an eccentric portion together with the weight balance portion 23, and the rotational motion of the rotary shaft 20 is converted into the linear reciprocating motion of the piston 15 between the eccentric shaft portion 22 and the piston 15 of the compression portion. The connecting rod 18 to be converted is connected, so that the piston 15 can linearly reciprocate inside the compression chamber 14a.

  Further, on the outer side of the upper end of the main shaft portion 21 between the eccentric portion of the rotating shaft 20 and the frame 11, ring-shaped upper and lower thrust washers that are in rolling contact with the rotating shaft 20 to support the axial load of the rotating shaft 20. 31 and 32, and a thrust bearing 30 comprising a ball 33 supported between the upper and lower thrust washers 31 and 32 is installed, and the frame 11 at the upper end of the hollow portion 11a is provided for the installation of the thrust bearing 30. A ring-shaped bearing installation groove 11b is formed.

  With such a configuration, when the rotating shaft 20 rotates together with the rotor 13 by the electrical interaction between the stator 12 and the rotor 13 due to the application of power, the eccentric shaft portion 22 of the rotating shaft 20 and the connecting rod 18 are interposed. The piston 15 connected in this manner reciprocates linearly inside the compression chamber 14a, whereby the refrigerant flows into the compression chamber 14a through the suction pipe 10c and the refrigerant suction chamber 16b. The refrigerant that has flowed in is compressed in the compression chamber 14a and then discharged to the outside of the sealed container 10 through the refrigerant discharge chamber 16a and the discharge pipe 10d. When the rotary shaft 20 rotates, the axial direction of the rotary shaft 20 The load is supported by the use of a thrust bearing 30 that is in rolling contact with the rotating shaft 20.

  On the other hand, the hermetic compressor according to the present invention supplies oil to the friction part of the rotating shaft 20 and the compression portion and the thrust bearing 30 side during the refrigerant compression operation as described above, and to supply and lubricate the oil. Is provided. This oil supply structure is formed on the bottom surface of the hermetic container 10 and includes an oil sump 19 in which predetermined oil is stored, and an oil pickup means 40 that is coupled to the lower end of the rotary shaft 20 and sucks up the oil in the oil sump 19 upward. It is equipped with.

  The oil pickup means 40 has a cylindrical oil pickup member 41 formed so that the upper and lower ends are opened and the lower end is immersed in the oil sump 19, and is installed inside the oil pickup member 41. An oil pick-up blade 42 for pumping up the oil in the sump 19 upward, and the rotary shaft 20 receives oil sucked up by the oil pick-up means 40 from the rotary shaft 20 and the compression portion. In addition to the friction part, an oil flow path array 50 is also formed for guiding to the thrust bearing 30 side.

  The oil passage array 50 includes a first oil passage 51 formed inside the main shaft portion 21 below the hollow portion 11a, and a first oil passage so as to lubricate between the main shaft portion 21 and the hollow portion 11a. 51, a second oil passage 52 formed by a spiral groove on the outer surface of the main shaft portion 21 on the hollow portion 11a side below the thrust bearing 30, and a second oil passage 52, and the rotary shaft 20 again. The third oil passage 53 extending from the main shaft portion 21 on the upper end side of the second oil passage 52 to the upper end of the eccentric shaft portion 22 and the outside of the main shaft portion 21 on the thrust bearing 30 side. As described above, the third oil flow path 53 is configured to include a branch flow path 54 including a straight hole branched radially from the outer surface of the main shaft portion 21.

  Further, there is a gap between the upper end of the first oil passage 51 and the lower end of the second oil passage 52 and between the upper end of the second oil passage 52 and the lower end of the third oil passage 53. The first oil passage 51 is formed with a first communication hole 55a and a second communication hole 55b, respectively, for increasing the oil more effectively by receiving a centrifugal force when the rotary shaft 20 rotates. As the upper side deviates from the axial center C of the main shaft portion 21, it is formed to be gradually inclined toward the eccentric portion side toward the upper side, and the third oil passage 53 is also eccentric from the axial center C of the main shaft portion 21. It is formed to be biased toward the part side.

  Here, since the third oil passage 53 is close to the outer surface of the main shaft portion 21, the branch passage 54 that branches from the third oil passage 53 that is eccentric with respect to the axis of the main shaft portion 21, It can also be formed by a simple punching process from the outer surface side of the main shaft portion 21.

  With such an oil supply structure, when the rotating shaft 20 rotates during the refrigerant compression operation, first, the oil in the oil sump 19 is sucked up by the pumping force of the oil pickup means 40, and the oil thus sucked up is First, while passing through the first oil passage 51 and the second oil passage 52, the space between the main shaft portion 21 on the lower side of the thrust bearing 30 and the hollow portion 11a of the frame 11 is lubricated and cooled. Part of the oil passing therethrough is transmitted to the compression part side while being injected to the upper end of the eccentric shaft part 22 through the third oil flow path 53, and lubricates and cools the connection part between the piston 15 and the connecting rod 18 and the like. The remaining oil that passes through the third oil passage 53 is directly transmitted to the thrust bearing 30 side through the branch passage 54 to moisten the thrust bearing 30. And cooling.

  As described above, when the oil guided to the upper portion along the oil flow path array 50 is directly transmitted to the thrust bearing 30, the upper and lower thrust washers constituting the thrust bearing 30 even if the compressor is used for a long time. Since wear of the balls 31 and 32 and the ball 33 is minimized, smooth rotation of the rotary shaft 20 by the thrust bearing 30 can be sustained. Even if the upper and lower thrust washers 31, 32 and the ball 33 are slightly worn and a small amount of dust is generated, the dust is removed without being accumulated on the thrust bearing 30 by the oil directly transmitted to the thrust bearing 30. Therefore, the reduction of the rotational force of the thrust bearing 30 due to wear dust can be suppressed.

  Thereafter, the oil flowing out from the upper ends of the branch flow path 54 and the third oil flow path 53 is collected in the oil sump 19 by its own weight. The recovered oil is supplied again to the rotary shaft 20, the compression unit, and the thrust bearing 30 along the oil passage array 50, and the lubrication and cooling operations are repeated.

  On the other hand, in order to increase the amount of oil supplied to the thrust bearing 30 through the branch flow path 54, the branch flow path 54 is formed in a direction in which the centrifugal force is maximized when the rotary shaft 20 rotates. The branch channel 54 must be branched from the third oil channel 53 in a direction opposite to the direction of the axis C of the main shaft portion 21.

  However, when the amount of oil supplied through the branch passage 54 becomes excessive, most of the oil guided from the second oil passage 52 to the third oil passage 53 passes through the branch passage 54 to the thrust bearing 30. In some cases, the oil may not be smoothly supplied from the upper end of the third oil passage 53 to the compression section and compressed. Lubrication and cooling on the part side may be difficult. Accordingly, the branch flow path 54 is branched in a direction intersecting with a straight line connecting the axis C of the main shaft portion 21 and the third oil flow path 53 without adversely affecting the oil supply to the compression section. It is preferable to transmit oil directly to the thrust bearing 30.

  Even if the branch flow path 54 branches in a direction intersecting with a straight line connecting the axis C of the main shaft portion 21 and the third oil flow path 53, the branch direction of the branch flow path 54 is the main shaft portion. 21 is slightly close to the direction opposite to the axis C of the shaft 21, the phenomenon that the oil supply concentrates on the branch channel 54 cannot be effectively prevented. On the contrary, the branch direction of the branch channel 54 is the main shaft portion. In the case of being formed in the direction of the axial center C of the oil 21, oil supply itself through the branch flow path 54 becomes difficult. Therefore, as shown in FIGS. 3 and 4, the branch direction of the branch flow path 54 branched from the third flow path is the direction opposite to the axis C direction of the main shaft portion 21 and the axis center of the main shaft portion 21. More preferably, the direction is approximately in the middle of the C direction.

  Of course, the oil once transmitted to the branch flow path 54 is effectively transmitted to the thrust bearing 30 even if the oil supply is prevented from concentrating on the branch flow path 54. Improved lubrication is advantageous.

  Therefore, as shown in FIG. 5 showing another embodiment, the branch flow path 54 ′ may be formed in a tapered shape so that the Bernoulli principle that the speed of fluid increases when passing through a narrow passage is applied. . That is, if the branch flow path 54 ′ is formed such that the diameter decreases from the inlet on the third oil flow path 53 side to the outlet on the outer surface side of the main shaft portion 21, the flow rate of the oil on the outlet side of the branch flow path 54 ′ increases. In addition, oil supply to the thrust bearing 30 side becomes smoother.

  In addition, as shown in FIG. 6 showing still another embodiment, when the branch flow path 54 ″ is formed so as to be inclined such that the height of the outlet is higher than the height of the inlet, The oil that has been guided to the upper portion is not suddenly changed in the course of flowing into the branch flow path 54 ", and thus the flow resistance of the oil that flows along the branch flow path 54" is reduced.

1 is a side sectional view showing an overall structure of a hermetic compressor according to the present invention. It is a fragmentary sectional side view which shows the rotating shaft in the hermetic compressor by this invention. 1 is an enlarged perspective view showing a rotating shaft of a hermetic compressor according to the present invention, and a part thereof is shown in a sectional view. It is a plane sectional view which shows the branch flow path of the rotating shaft in the hermetic compressor by this invention. It is a sectional side view which shows the other Example of the branch flow path of the rotating shaft in the hermetic compressor by this invention. It is a sectional side view which shows the further another Example of the branch flow path of the rotating shaft in the hermetic compressor by this invention.

Explanation of symbols

11 Frame 11a Hollow portion 11b Bearing installation groove 20 Rotating shaft 21 Main shaft portion 22 Eccentric shaft portion 23 Weight balance portion 30 Thrust bearing 31 Upper thrust washer 32 Lower thrust washer 33 Ball 50 Oil passage array 51 First oil passage 52 First 2 oil passage 53 third oil passage 54, 54 ', 54 "branch passage

Claims (10)

An airtight container with an oil sump on the bottom;
A frame disposed in the sealed container and having a hollow portion;
A rotary shaft that is rotatably installed in the frame so as to penetrate the hollow portion, and has an oil passage array that guides the oil in the oil reservoir to the upper part;
A thrust bearing that is installed in a bearing installation groove at the upper end of the hollow portion and that is in rolling contact with the rotary shaft so as to support an axial load of the rotary shaft;
The hermetic compressor, wherein the oil passage array is configured to supply at least a part of oil to the thrust bearing. The rotation axis is
A lower main shaft portion extending through the hollow portion and extending downward,
An eccentric shaft portion formed at an upper end so as to be eccentric with respect to the main shaft portion, and a weight balance provided between the eccentric shaft portion and the main shaft portion so as to compensate for rotational unbalance due to the eccentric shaft portion With an eccentric part consisting of parts,
The oil flow path array is
A first oil passage formed inside the main shaft at the lower part of the hollow part;
A second oil passage formed on the outer surface of the main shaft portion on the hollow portion side of the thrust bearing lower portion so as to communicate with the first oil passage;
A third oil passage formed inside the main shaft portion and the eccentric portion on the thrust bearing side;
A branch formed so as to branch from the third oil flow path and communicate with the outside of the main shaft portion on the thrust bearing side so that a part of the oil guided to the third oil flow path is transmitted to the thrust bearing. The hermetic compressor according to claim 1, further comprising a flow path. The branch channel is formed in the form of a straight hole,
The third oil flow path is formed offset from an axis of the main shaft portion;
3. The hermetic compressor according to claim 2, wherein the branch flow path is branched in a direction intersecting with a straight line connecting the axis of the main shaft portion and the third oil flow path.   4. The hermetic seal according to claim 3, wherein the branch passage is formed to be inclined so that the height of the outlet on the outer surface side of the main shaft portion is higher than the inlet on the side of the third oil passage. Mold compressor.   4. The hermetic type according to claim 3, wherein the branch flow path is formed in a tapered shape such that a diameter thereof decreases from an inlet on the third oil flow path side to an outlet on the outer surface side of the main shaft portion. Compressor. The branch channel is formed in the form of a straight hole,
The third oil flow path is formed offset from an axis of the main shaft portion;
The hermetic compressor according to claim 2, wherein the branch channel is formed by punching from the outer surface side of the main shaft portion. An airtight container with an oil sump inside,
A frame disposed in the sealed container and having a hollow portion;
A rotating shaft configured to be inserted into the frame;
At least one oil passage configured to direct oil from the oil sump;
A thrust bearing configured to contact the rotating shaft so as to support a load of the rotating shaft;
The hermetic compressor, wherein the at least one oil passage is configured to supply at least a part of oil to the thrust bearing.   The hermetic compressor according to claim 7, wherein the rotation shaft is configured to penetrate at least a part of the hollow portion.   The hermetic compressor according to claim 7, wherein the at least one oil passage includes a plurality of oil passages forming an oil passage array. The rotation axis is
A main shaft portion configured to penetrate at least a part of the hollow portion;
An eccentric shaft portion disposed eccentrically with respect to the main shaft portion on the upper side of the main shaft portion;
The hermetic compressor according to claim 7, further comprising: a weight balance unit configured to compensate for an unbalance in the rotational operation of the rotating shaft.

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