KR19980025985A - Hollow shaft of hermetic compressor - Google Patents

Abstract

The present invention relates to a hollow shaft of a hermetic compressor for improving the structure of a rotating shaft connecting the high pressure generating unit and the motor unit in the hermetic compressor of the refrigerator.

The suction groove A, the spiral groove, and the discharge groove C form a flow path while going from the lower part of the shaft to the upper part of the present invention, and as the shaft 22 rotates, through the bushing part of the frame through the bushing part of the frame, 18. A compressor for sending hydraulic oil to a side, comprising: a hollow cylinder (25) in which a plurality of lubrication holes (25a) are regularly formed over a range in contact with the bushing portion (17a); An upper shaft 28 having a discharge groove C and an eccentric cam 18 penetrating up and down and fixed to an upper end of the cylinder 25; A lower cap 24 having upper and lower suction grooves A and fixed to a lower end of the cylinder 25; The upper and lower ends of the cylinder 25 are connected to the discharge groove C of the eccentric cam 18 and the suction groove A of the lower cap 24, respectively, and a plurality of micropores ( 26a) includes a feed tube 26 formed regularly.

Accordingly, the present invention has the effect of improving the performance and whiskers of the compressor by reducing the inertial energy of the shaft and maintaining high lubrication by installing a feed pipe having a hollow portion on a part of the rotating shaft.

Description

Hollow shaft of hermetic compressor

The present invention relates to a compressor, and more particularly, in a hermetic compressor of a refrigerator having a means for sucking and discharging a refrigerant in a hermetic case so as to maintain high lubrication while reducing the weight of the rotating shaft connecting the high pressure generating part and the motor part. A hollow shaft of a hermetic compressor that improves.

In a refrigerator, a compressor is a means for converting rotational force due to electrical energy into mechanical energy of reciprocating motion, and a refrigerant having a low boiling point is brought to a high pressure (about 12 atm) while passing through the compressor. Again the high pressure refrigerant is cooled to the condenser and becomes liquid, and once this liquid refrigerant is gasified in the cooler, one refrigeration cycle is completed.

1 is a front view showing a partially cut away to reveal the inside of the hermetic compressor.

The hermetic compressor 10 has a structure in which a suction pipe (not shown) and a discharge pipe (not shown) of a refrigerant are bonded to the outside of the sealed case 11 and a high pressure generating part and a motor part are mounted therein.

The high pressure generating part can be roughly classified into a cylinder 13, a piston 14, a valve 15, and the like, and the motor 19 can be roughly classified into a stator and a rotor. The high-pressure generating unit 12 is connected to the motor 19 installed in the lower shaft 12 is formed integrally with the eccentric cam 18 for generating a crank motion from the top.

The cylinder 13, the piston 14, the valve 15, the discharge muffler 16 and the like are formed as an integral assembly and supported on the frame 17. As shown in FIG. The frame 17 also has a bushing portion 17a to rotatably support the rotor-mounted shaft 12 and to act as a sliding bearing.

In operation, the shaft 12 rotated by the motor 19 induces the cam motion of the eccentric cam 18 on its upper part, which in turn moves the piston 14 in the cylinder 13 through the connecting rod. Reciprocating motion, the valve 15 is passively opened and closed by the pressure difference between both sides formed at this time to move the refrigerant in one direction.

Accordingly, the refrigerant introduced through the suction pipe is filled in the sealed case 11 and then introduced into the cylinder 13 through the suction muffler, and the refrigerant compressed in the cylinder 13 passes through the discharge muffler 16 and discharges the discharge pipe. Via condenser (not shown).

In the compressor 10 having such a configuration, the mechanical frictional loss is closely related to the compressor efficiency, and therefore requires proper lubrication on the rotating contact. In particular, the bushing part of the shaft 12 and the frame 17 having the largest friction area ( There is a need for a highly lubricating structure between 17a).

In a sliding bearing such as a bushing portion 17a supporting a shaft 12 rotating about a vertical axis, various oil supply methods such as drop oiling, screw oiling, and forced lubrication are applied. Can be.

As shown in FIG. 1, the suction groove A, the spiral groove B, and the discharge groove C communicate with the shaft 12 of the compressor 10 to which the screw oil supply method is applied. The spiral groove B is formed over the length of the bushing portion 17a of the frame 17 on the outer circumferential surface of the shaft 12, and the suction groove A and the discharge groove C are moved from the center of the shaft 12 to the outside. While being guided, each end is formed to be connected to the bottom and top of the spiral groove (B).

In the compressor 10, when the hydraulic oil is filled to perform a lubricating function to a predetermined height in the sealed case 11 and one end of the suction groove A is immersed in the hydraulic oil, the hydraulic oil rises by the rotation of the shaft 12. After lubricating the bushing portion 17a and sprayed onto the eccentric cam 18 of the shaft 12 through the discharge groove C, it goes through a circulation system that falls back to the sealed case 11.

This serves to reduce the sliding friction resistance and to cool the heat generated from the high pressure generating portion.

However, since the spiral groove B of the shaft 12 is intermittently lubricating the bushing portion 17a in accordance with the rotation of the shaft 12, there is a drawback that a stable lubrication cannot be achieved and an unstable lubrication state close to gun friction can be obtained. have.

Accordingly, the present invention provides a hollow shaft of a hermetic compressor which improves the rotational shaft connecting the high-pressure generator and the motor to maintain high lubrication in the hermetic compressor of the refrigerator having a means for injecting and discharging the refrigerant into the hermetic case. For that purpose.

In addition, the weight reduction structure in which the hollow part is provided on the shaft 12 reduces the inertial energy, thereby obtaining the advantage of improving the compressor efficiency.

1 is a front view showing a partially cut to expose the inside of the hermetic compressor,

2 is a front view showing an exploded shaft according to the present invention;

3 is a front view showing the assembled state of FIG.

Explanation of symbols on main parts of drawing

10 compressor 11 sealed case

12 shaft (conventional) 13: cylinder

14 Piston 15 Valve

16 discharge muffler 17 frame

17a: bushing 18: eccentric cam

19: motor 22: shaft (invention)

24: lower cap 24a: end

25 cylinder 25a lubricator

26: transfer pipe 26a: fine hole

28: upper axis 28a: spline

A: Suction groove B: Spiral groove

C: discharge groove

In order to achieve the object of the present invention, the suction groove (A), the spiral groove (B), the discharge groove (C) forms a flow path while going from the bottom of the shaft to the top, and the screw pump action according to the rotation of the shaft 22 In the compressor for sending the hydraulic oil to the eccentric cam (18) side through the bushing portion of the frame: a hollow cylinder in which a plurality of lubrication holes (25a) is formed regularly over the range in contact with the bushing portion (17a) 25; An upper shaft 28 having a discharge groove C and an eccentric cam 18 penetrating up and down and fixed to an upper end of the cylinder 25; A lower cap 24 having upper and lower suction grooves A and fixed to a lower end of the cylinder 25; The upper and lower ends of the cylinder 25 are connected to the discharge groove C of the eccentric cap 18 and the suction groove A of the lower cap 24, respectively, and a plurality of micropores ( Provided is a hollow shaft of a hermetic compressor, characterized in that 26a) comprises a feed tube 26 which is formed regularly.

At this time, the upper shaft 28 is fixed to form a spline (28a) and the lower cap 24 is formed by fixing the end (24a).

In addition, the transfer pipe 26 is formed in the spiral portion over the same length as the length of the lubrication hole 25a of the cylinder 25 is formed, the fine hole 26a is formed on the outer peripheral surface of the spiral portion.

EXAMPLE

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.

2 is a front view showing an exploded view of a shaft according to the present invention.

According to the present invention, the suction groove (A), the spiral groove (B), the discharge groove (C) forms a flow path while going from the lower portion of the shaft (12) to the upper portion, and the screw pump acts according to the rotation of the shaft (22). It is applied to a compressor for sending hydraulic oil to the eccentric cam 18 side through the bushing part.

In particular, in such a compressor, the present invention is characterized by a shaft 22 composed of a cylinder 25, an upper shaft 28, a lower cap 24, a conveying pipe 26, and the like.

The cylinder 25 has a hollow structure in which a plurality of lubrication holes 25a are regularly formed over the range in contact with the bushing portion 17a.

The lubrication hole 25a formed through the inside and outside of the cylinder 25 is preferably formed large so as to allow the oil to flow in and out freely, but the motor 19 (Fig. 1) a and the eccentric cam 18 (Fig. 1) are provided. In consideration of the weakening of the strength of the cylinder 25 subjected to the torsion stress by the reaction force of the), it is appropriately sized.

The lubrication hole 25a is formed over a range in contact with the bushing portion 17a because the lubrication hole 25a is for lubricating the bushing portion 17a (FIG. 1) of the frame 17. In order to maximize the total area of the lubrication hole 25a under the conditions of holding, it is preferable to arrange | position the lubrication hole 25a by a zigzag material.

In the present invention, the upper shaft 28 having the discharge groove C and the eccentric cam 18 penetrating up and down is fixed to the upper end of the cylinder 25.

Since the upper shaft 28 is the place where the eccentric cam 18 and the rotation balance weight (not shown) are formed, it is made of a casting as in the prior art, and the discharge groove C is drilled.

At this time, the upper shaft 28 is fixed by forming a spline (28a). The structure indented using the spline 28a can sufficiently support the torsion stress, and the problem of heat deformation due to welding does not occur.

In addition, in the present invention, the lower cap 24 having the suction groove A penetrating up and down is fixed to the lower end of the cylinder 25.

Suction groove (A) is formed to be inclined as in the prior art to perform a screw pump action by the rotation of the shaft (22).

At this time, the lower cap 24 is fixed to form an end (24a). Unlike the cylinder 25 and the upper shaft 28, the lower end of the shaft 22 is hardly subjected to torsional stress, bending stress, or the like, and thus the spline 28a may be fixed without a simple interference fit.

In addition, in the present invention, a transfer pipe 26 in which a plurality of micropores 26a are regularly formed over a predetermined length is used, and upper and lower ends of the transfer pipe 26 are eccentric in the cylinder 25, respectively. It is connected to the discharge groove (C) of the cam 18 and the suction groove (A) of the lower cap (24).

The cylinder 25 of the shaft 22 is rotatably mounted to the bushing portion 17a (FIG. 1), and a flow path for supplying hydraulic oil is required. As shown in the related art, the spiral groove B (FIG. 1) is formed on the outer circumferential surface thereof. It is difficult to form because of the strength of the shaft 22 having a hollow portion, so a separate feed pipe 26 is used.

At this time, the transfer pipe 26 is formed of a spiral over the same length as the length of the lubrication hole (25a) of the cylinder 25 is formed, the fine hole (26a) is formed on the outer peripheral surface of the spiral portion.

The upper part of the conveying pipe 26 is press-fitted to the lower end of the discharge groove C of the upper shaft 28, and the lower part of the conveying pipe 26 is selected to be loosely fitted to the lower cap 24. do. The loose fitting structure allows the hydraulic fluid collected in the shaft 22 to escape downward and circulate.

The purpose of forming the middle of the conveying pipe 26 in a spiral is to make it easy for the hydraulic oil coming up to the suction groove A to be scattered into the fine holes 26a by receiving the centrifugal force due to the rotation of the shaft 22. The scattering hydraulic oil not only cools the bushing portion 17a (FIG. 1) indirectly, but also directly cools and lubricates the bushing portion 17a through the lubrication hole 25a of the adjacent cylinder 25.

Since the spiral portion of the transfer pipe 26 is a factor that increases the flow resistance of the working oil, it is wound about one to two times over the length of the bushing portion 17a. That is, the pitch of the spiral is equal to or about 1/2 the length of the bushing 17a,

The micropores 26a of the transfer pipe 26 are formed to have a small size (for example, 1 mm or less) so that the working oil is easily scattered.

On the other hand, if the hydraulic fluid collected in the shaft 22 after scattering stays in the cylinder 25 for a long time, the deterioration of the hydraulic oil due to high temperature may be promoted to be quickly discharged downward. To this end, it is necessary to put a separate through hole (not shown) in the lower cap 24 or to form a suction groove (A) in a relaxed size.

Conventionally, while the spiral groove B intermittently lubricates the bushing portion 17a as the shaft 12 rotates, the lubrication hole 25a of the present invention can continuously supply hydraulic oil to the entire range of the bushing portion 17a. So that stable lubrication is achieved.

3 is a front view showing the assembled state of FIG.

The order of assembling the shaft 22 includes the steps of pressing the transfer pipe 26 into the discharge groove C of the upper shaft 28 and pressing the cylinder 25 into the spline 28a of the upper shaft 28. Step, inserting the lower end of the transfer pipe 26 into the suction groove (A) of the lower cap 24, and the step of pressing the lower cap 24 to the lower end of the cylinder 25 is sequentially made.

In particular, the step of pressing the cylinder 25 into the spline 28a of the upper shaft 28 is the most important part, and it is preferable to use a fixture so that the eccentric cam 18 and the cylinder 25 maintain a predetermined parallelism. .

1 and 2, the operation of the present invention, in the compressor 10 employing the screw lubrication method is filled with the hydraulic oil for performing a lubrication function to a predetermined height in the interior of the sealed case 11 and of the suction groove (A) When one end is immersed in the hydraulic oil, the hydraulic oil rises due to the rotation of the shaft 22, and part of it is scattered to lubricate the bushing portion 17a.

Thereafter, the remaining hydraulic fluid is discharged from the eccentric cam 18 of the shaft 22 to the discharge groove C, and is also dispersed between the eccentric cam 18 and the piston 14, the piston 14 and the cylinder 13. do.

As described above, the hollow shaft of the hermetic compressor of the present invention is provided with a conveying pipe having a hollow part on a part of the rotating shaft connecting the high pressure generating part and the motor in the hermetic compressor of the refrigerator, thereby reducing the inertial energy of the shaft and Maintaining lubricity has the effect of improving the performance and life of the compressor can be expected.

While the invention has been shown and described with respect to certain preferred embodiments, it will be understood that the invention can be variously modified and modified without departing from the spirit or scope of the invention as set forth in the following claims. Those skilled in the art can easily know that.

Claims (3)

The suction groove A, the spiral groove B, and the discharge groove C form a flow path while going from the lower part of the shaft to the upper part, and the eccentric cam passes through the bushing part of the frame by a screw pump action according to the rotation of the shaft 22. 18) In the compressor sending hydraulic oil to the side: A hollow cylinder 25 in which a plurality of lubrication holes 25a are regularly formed over a range in contact with the bushing portion 17a; An upper shaft 28 having discharge grooves C and a core cam 18 penetrating upward and downward, and fixed to an upper end of the cylinder 25; A lower cap 24 having upper and lower suction grooves A and fixed to a lower end of the cylinder 25; The upper and lower ends of the cylinder 25 are connected to the discharge groove C of the eccentric cam 18 and the suction groove A of the lower cap 24, respectively, and a plurality of micropores ( Hollow shaft of the hermetic compressor, characterized in that it comprises a feed pipe (26) is formed regularly (26a). The method of claim 1, The hollow shaft of the hermetic compressor, characterized in that the upper shaft (28) forms and fixes the spline (28a) and the lower cap (24) forms the end (24a). The method of claim 1, The conveying pipe 26 is formed of a spiral over the same length as the length of the lubrication hole (25a) of the cylinder 25 is formed, the fine hole (26a) is formed on the outer peripheral surface of the spiral portion Hollow shaft of hermetic compressor.