KR20090047443A - Scroll compressor - Google Patents

Abstract

A scroll compressor according to the present invention. According to the present invention, the oil can be injected directly into the compression chamber while reducing the oil being scattered with the balance weight, thereby uniformly supplying the oil to the compression chamber regardless of the rotational speed of the drive motor. In addition, the gas can be easily discharged in the middle of the oil flow path of the drive shaft, and at the same time, by adopting a trocoid gear pump, the oil can be smoothly pumped and sucked up. In addition, by adopting a synchronous reluctance motor, the performance and operating range of the compressor can be expanded even if the oil supply amount is reduced.

Scroll Compressor, Oil Injection, Oil Block, Synchronous Reluctance

Description

Scroll Compressor {SCROLL COMPRESSOR}

The present invention relates to a compressor, and more particularly, to a scroll compressor capable of smoothly supplying oil to a compression chamber in a low pressure scroll compressor.

Compressors are devices that convert mechanical energy into compressive energy of a compressive fluid. The compressor may be classified into a reciprocating type, a rotary type, a vane type, and a scroll type according to the compression method for the fluid.

The scroll compressor is provided with a drive motor for generating power in an inner space of the sealed casing and a compressor mechanism for compressing a refrigerant that is a compressive fluid by receiving power of the drive motor.

The compression mechanism is a fixed scroll and the swing scroll is engaged with each other to form a pair of compression chamber while the swing scroll is pivoting with respect to the fixed scroll, and the compression chamber is moved inward to continuously compress the refrigerant discharged Done.

A certain amount of oil is filled in the inner space of the casing, and the oil is sucked up by the centrifugal force as the driving motor rotates, thereby cooling the driving motor and the compression mechanism, and some oil is introduced into the compression chamber together with the refrigerant. The sliding surface between the fixed scroll and the swing scroll is lubricated.

However, in the conventional scroll compressor as described above, when the drive motor is an inverter motor capable of variable speed, the amount of oil supplied to the compression chamber is greatly changed according to the rotational speed of the drive motor, which causes unstable performance of the compressor. There was a problem.

That is, when rotating at a low speed, the pumping force for the oil is weak and at the same time the amount of oil supplied to the compression chamber is reduced while the air bubbles block the oil flow path to increase the friction loss between the fixed scroll and the swing scroll, In the case of rotating at a high speed, the amount of oil scattering increases, so that a large amount of oil is mixed with the refrigerant and supplied to the compression chamber, thereby causing an excessive increase in the amount of leakage of oil discharged from the compressor.

The present invention solves the problems of the conventional scroll compressor as described above, it is an object of the present invention to provide a scroll compressor that can always be supplied to the compression chamber of the appropriate amount irrespective of the rotational speed of the drive motor.

In order to achieve the object of the present invention, a closed inner space is provided, the casing is provided with a suction pipe and a discharge pipe; A stator fixedly installed in the inner space of the casing, a rotor rotating inside the stator, coupled to the rotor to transmit rotational force, and an oil channel penetrates axially therein, and a lower end of the oil channel It includes a drive motor having a drive shaft provided with an oil pump; A frame fixedly installed in the inner space of the casing, the bearing hole being formed to support the drive shaft, and the oil pocket being formed so that a predetermined amount of oil is accumulated in the bearing hole; A fixed scroll having a hard plate formed to be fixed to the frame and having a fixed wrap spirally formed on one side of the hard plate; Sliding plate is formed to make a pivoting movement between the frame and the fixed scroll, spiral wrap is formed on one side of the hard plate portion, the pivoting wrap is engaged with the fixed wrap of the fixed scroll to form a compression chamber Turning scroll; A balance weight coupled to the drive shaft to have an eccentric load, the balance weight offsetting the eccentricity while rotating with the drive shaft; And an oil blocking plate fixed to the frame to accommodate the balance weight, to block the scattering of oil, wherein the oil supply hole is formed in the frame so as to communicate with the bearing surface between the frame and the turning scroll. And an oil injection hole communicating with the bearing surface between the frame and the swing scroll and before the starting point of compression of the swing wrap is formed at the hard plate portion of the swing scroll, and the oil supply hole and the oil injection hole communicate with each other. There is provided a scroll compressor characterized in that it is formed.

The scroll compressor according to the present invention is capable of injecting oil directly into the compression chamber while reducing oil from being scattered with the balance weight, thereby uniformly supplying the oil to the compression chamber regardless of the rotational speed of the drive motor. Can be. In addition, by employing a trocoid gear pump that allows gas to be easily discharged from the middle of the oil passage of the drive shaft, the oil can be smoothly pumped and sucked up. In addition, by adopting a synchronous reluctance motor, the performance and operating range of the compressor can be expanded even if the oil supply amount is reduced.

Hereinafter, the scroll compressor according to the present invention will be described in detail with reference to the embodiment shown in the accompanying drawings.

As shown in FIG. 1, the low-pressure scroll compressor according to the present invention includes a casing 10 in which a seal is formed to fill a predetermined amount of oil, and a refrigerant suction pipe SP and a refrigerant discharge pipe DP are in communication with each other. A driving motor 20 installed above the casing 10 to generate a rotational force, and a compression mechanism unit configured to compress the refrigerant by receiving a rotational force generated from the casing 10 and generated from the driving motor 20 ( 30).

The casing 10 is formed in a cylindrical shape and is sealed by covering the main body 11 and the upper and lower sides of the main body 11 and the main body 11 on which the drive motor 20 and the compression mechanism part 30 are fixedly installed on both upper and lower sides of the inner circumferential surface thereof. The upper cap 12 and the lower cap 13 is made up.

The main frame 14 and the subframe 15 having fixed holes 14a and 15a are respectively fixed to upper and lower sides of the main body 11 so as to support the driving shaft 23 of the driving motor 20. In addition, the lower half of the main body 11 is in communication with the oil level pipe 16 and the oil recovery pipe 17 connected to the refrigeration cycle system so as to maintain the appropriate amount of oil. The oil return pipe 17 communicates lower than the oil level pipe 16.

The drive motor 20 is fixed to the inside of the casing 10 and the power is applied from the outside and the stator 21 is disposed with a predetermined gap inside the stator 21 is mutually Rotor 22 that rotates while acting, and the drive shaft 23 is coupled to the rotor 22 in a shrink fit to transmit the rotational force of the drive motor 20 to the compression mechanism (30). An oil passage 23a penetrates through the drive shaft 23 in the axial direction. And the upper end of the drive shaft 23, that is, the upper side of the rotor 22, the balance weight 24 for offsetting the eccentric amount is fixedly coupled to the rotation with the drive shaft 23.

The main compression mechanism 30 is fixed to the fixed scroll 31 is installed on the upper surface of the main frame 14, as shown in Figure 1, and the fixed scroll 31 to engage the fixed scroll 31 to form a plurality of compression chamber (P) An all-damm ring that is pivotally mounted on an upper surface of the frame 14 and is provided between the pivoting scroll 32 and the main frame 14 to pivot while preventing rotation of the pivoting scroll 32. (Oldham's ring) 33 and the high and low pressure separating plate 34 is provided on the rear surface of the hard plate portion of the fixed scroll 31 to partition the inside of the casing 10 into the suction space (S1) and the discharge space (S2). And a check valve 35 for opening and closing the discharge port 31c of the fixed scroll 31 to block the reverse flow of the discharge gas.

The fixed scroll 31 has a fixed wrap 31a constituting two pairs of compression chambers P on the bottom surface of the hard plate portion in an involute shape, and a suction space of the casing 10 on the side of the hard plate portion. A suction port 31b communicating with S1 is formed, and a discharge port 31c for discharging the compressed refrigerant into the discharge space S2 of the casing 10 is formed at the center of the upper surface of the hard plate portion.

The turning scroll 32 is formed on the upper surface of the hard plate portion of the rotating wrap (32a) forming a pair of compression chamber (P) together with the fixed wrap (31a) of the fixed scroll 31 is formed in the involute shape The boss 32b is coupled to the driving shaft 23 to receive the power of the driving motor 20 at the center of the bottom surface of the hard plate part.

The scroll compressor of the present invention operates as follows.

That is, when power is applied to the drive motor 20, the drive shaft 23 rotates together with the rotor 22 to transmit a rotational force to the pivoting scroll 32, and the rotational scroll receives the rotational force. The reference numeral 32 is a turning wrap of the fixed scroll 31a of the fixed scroll 31 and the turning scroll 32 while pivoting by an eccentric distance from the upper surface of the main frame 14 by the old dam ring 33 ( A pair of compression chambers P which are continuously moved between 32a) is formed, and the compression chambers P are moved to the center by the continuous rotational movement of the turning scroll 32 and the volume is reduced and the refrigerant is sucked in. Will be compressed. The compressed refrigerant is continuously discharged to the discharge space S2 of the casing 10 through the discharge port 31c of the fixed scroll 31 and then moved to the refrigeration cycle system through the refrigerant discharge pipe DP. The refrigerant circulating in the refrigeration cycle system is again sucked into the suction space S1 of the casing 10 through the refrigerant suction pipe and then supplied to the compression chamber P to repeat the series of processes.

At this time, the oil accommodated in the lower cap 13 of the casing 10 is sucked through the oil flow path 23a of the drive shaft 23 while the lady between the drive shaft 23 and the frames 14, 15. The bearing surface and the thrust bearing surface between the main frame 14 and the turning scroll 32 are lubricated.

Here, the oil drawn up through the oil flow path of the drive shaft is scattered by the balance weight in the process of being recovered to the lower cap through the oil return hole of the main frame, which will be described later, and mixed with the refrigerant along the suction path of the refrigerant. It can be refueled into the compression chamber. However, in this case, since the amount of oil scattered largely varies according to the rotational speed of the drive motor, the amount of oil lubricated into the compression chamber is not constant, which may cause a large performance deviation of the compressor.

Accordingly, in the present invention, while the oil blocking plate is installed between the oil recovery hole and the balance weight, the oil recovered is prevented from being scattered by the balance weight, but before the oil is recovered through the oil recovery hole. By injecting a portion of the into the compression chamber it can be so that the oil can be uniformly supplied to the compression chamber.

Hereinafter, a specific embodiment in which the oil may be directly injected into the compression chamber instead of being mixed with the refrigerant and refueled into the compression chamber while the oil is stirred and scattered by the balance weight is prevented.

That is, the main frame 14 is formed through the bearing hole (14a) in the center, the oil pocket (14b) so that the oil sucked through the drive shaft 13 to be described later is collected at the upper end of the bearing hole (14a) The oil return hole 14c penetrates to an outer circumferential surface of the main surface of one side of the oil pocket 14b so that oil collected in the oil pocket 14a can be recovered to the casing 10.

In addition, the bottom surface of the main frame 14 accommodates the bearing hole 14a and blocks oil from being scattered by the balance weight 24 so that the oil is mixed with the refrigerant, and the compression chamber P is along the suction path of the refrigerant. An oil barrier plate 18 is installed to prevent oil supply.

The oil blocking plate 18 may be formed in a cylindrical shape as shown in FIG. 2 or may be formed in a truncated cone shape so as to extend downward as shown in FIG. 3, but the oil blocking plate 18 may have a balance weight as described above. It is preferable to be positioned between the oil recovery hole 14c and the balance weight 24 in a position where it can be prevented from being scattered by (24). To this end, the oil barrier plate 18 is preferably formed in a width that can accommodate the balance weight 24 in both the cylindrical and truncated cone shape can prevent the oil from being scattered by the balance weight 24. .

The oil blocking plate 18 is cylindrical or truncated cone-shaped, but both the area capable of accommodating the coil 21a of the stator 21 to be described later, or the oil recovered in contact with the oil blocking plate 18 is returned to the coil 21a. It is preferable to be formed in an area overlapping with the coil (21a) at least in the vertical direction so that it can be supplied dropwise. In this case, the truncated cone-shaped oil barrier plate may be more advantageous in installation than the cylindrical oil barrier plate.

In this case, when the oil blocking plate 18 is a truncated cone as shown in FIG. 3, the oil blocking plate 18 may collect oil scattered while the balance weight 24 rotates from the inside thereof and supply the oil to the coil 21a. At least one oil guide protrusion 18a may be formed in a circular shape on the bottom of 18.

As shown in FIG. 6, the main frame 14 has an oil supply hole 14d for uniformly injecting a part of oil collected in the oil pocket 14b into the compression chamber P regardless of an operation state of a compressor. Is formed, and the hard disk portion of the turning scroll 32 communicates with the oil supply hole 14e to supply oil supplied from the oil pocket 14b through the oil supply hole 14e to the compression chamber P. More precisely, an oil injection hole 32c is formed for guiding before the start of compression, which is a position before the compression chamber is formed.

Here, the inlet end of the oil supply hole (14d) is formed on the inner circumferential surface of the oil pocket (14b), the outlet end of the oil supply hole (14d) between the main frame 14 and the turning scroll (32) It is formed on the thrust bearing surface. At the outlet end of the oil supply hole 14d, an oil storage groove 14e having an area that can be stored in a predetermined amount of oil and included in the turning trajectory of the oil injection hole 32c to be described later is formed.

The oil injection hole 32c is formed in the axial direction, and is at least smaller than the diameter of the oil storage groove 14e, that is, the oil storage groove 14e is rotated along the swing trajectory of the swing scroll 32. It is desirable to be formed in an area that can be included.

In the scroll compressor as described above, the oil drawn up to the upper end of the drive shaft (23) is stored in the oil pocket (14b) of the main frame 14, and part of the casing (10) through the oil return hole (14c) While some of the oil is transferred to the thrust bearing surface between the main frame 14 and the turning scroll 32 through the oil supply hole 14d, the oil injection hole of the turning scroll 32 32c) is supplied to the compression chamber P before the start of compression, that is, through the suction chamber.

In this way, the oil recovered through the oil recovery hole 14c in the oil pocket 14b is prevented from being scattered while being stirred by the balance weight 24 by being blocked by the oil blocking plate 18, and thus oil The oil of the oil pocket 14b can be directly injected into the compression chamber P through the suction chamber through the oil supply hole 14e and the oil injection hole 32c while preventing mixing with the refrigerant to be introduced into the compression chamber. Will be. The oil separated from the refrigerant by being buried in the oil blocking plate 18 is transferred to the coil 21a of the stator 21 by the oil guide protrusion 18a of the oil blocking plate 18 or the oil blocking plate 18. ) To cool the coil 21a.

Meanwhile, as shown in FIGS. 1 and 4, the driving motor 20 has a high efficiency and a low heat generation, and thus will be described later, such as a synchronous reluctance motor. It is preferable to apply a motor configured such that the electron 22 is synchronously rotated in the direction in which the magnetoresistance is minimized by the reluctance torque. have.

That is, the stator 21 of the drive motor 20 has a cylindrical laminated body formed in a cylindrical shape such that the rotor 22 is rotatably positioned at the center thereof, and a coil 21a connected to an external power source at the tooth portion thereof. This is done by winding. The rotor 22 has a shaft hole 22a formed at the center of the rotary laminated body in which a plurality of thin steel sheets are laminated in the axial direction so as to be fixed in shrinkage, and the shaft hole 22a is formed. A circular arc-shaped magnetic flux barrier 22b is formed through a plurality of radially penetrating radially along the circumferential direction of the rotary laminated body.

At least one oil recovery groove 22c is formed in the main surface of the shaft hole 22a to increase the heat dissipation effect while the recovered oil passes through the rotor 22. The oil recovery groove 22c may be formed in a direction coinciding with an axial direction, and may be formed in an axial direction inclined at a predetermined angle. When the oil recovery groove 22c is inclined, the oil recovery groove 22c may be formed in the rotational direction of the drive shaft 23 when the upper side is lower than the lower side.

On the other hand, in order to smoothly suck up the oil drawn through the oil flow path of the drive shaft it may be desirable to quickly remove the blockage of the oil flow path by the gas.

That is, as shown in FIG. 4, the drive shaft 23 has the oil passage 23a penetrated therein in the axial direction, and oil sucked in the middle of the oil passage 23a is formed in the subframe 15. The oil through holes 23b and 23b are radially penetrated in both the upper and lower sides so as to be supplied to the bearing holes 15a and 14a of the main frame 14. At least one gas draining hole 23c and 23d is disposed between the oil through holes 23b and 23b so that the gas drawn together with the oil through the oil flow passage 23a can be discharged out of the oil flow passage 23a. It may be preferable that more than two pieces are formed because the oil flow path 23a is blocked by gas during low-speed operation, thereby preventing the oil supply from being poor.

Here, the gas bleed holes 23c and 23d are formed with a first gas bleed hole 23c between the subframe 15 and the rotor 22 and the rotor 22 and the main frame 14. A second gas vent hole 22d is formed therebetween. Here, the second gas bleed hole 22d may be formed below the balance weight 24 when the balance weight 24 is coupled to the driving shaft 23.

An oil pump 25 is installed at a lower end of the drive shaft 23 to pump oil of the casing 10 as shown in FIG. 1. The oil pump 25 has a trochoidal gear pump (Trochoidgear PumP) in which the inner gear 25a and the outer gear 25b form a volume so as to reduce the time of oil bleeding due to the change in suction pressure and vaporization of the liquid refrigerant. Can be applied. Here, the pump driving unit 23e is integrally formed at the lower end of the drive shaft 23 so as to be coupled to the inner gear 25a of the trocoid gear pump. A drive cutting surface 23f is formed on the outer circumferential surface of the pump driving unit 23e so as to be engaged with the inner gear 25a so that the inner gear 25a can rotate.

The trocoid gear pump is composed of an inner gear 25a, an outer gear 25b, a pump cover 25c, and a mesh cylinder 25d, as shown in FIG. 5, and between the drive shaft 23 and the oil pump 25. Thrust plate 25e may be installed. The thrust plate 25e may be fixedly coupled to the through hole 15b of the subframe 15.

In addition, the trocured gear pump may be formed with a plurality of suction ports having a height difference so that a certain amount of oil can be pumped at all times regardless of the degree of mixing of oil and refrigerant. For example, when the oil and the coolant are mixed considerably high, the oil and the coolant are pumped together through both inlets, while the mixing degree of the oil and the coolant decreases so that the high density of the coolant sinks downward. If it is formed in consideration of low, only the refrigerant can be pumped, but if the inlet is formed with a height difference, the upper oil can also be pumped together to prevent the extreme deterioration of lubrication performance.

As described above, the gas generated in the oil may be introduced into the oil flow path 23a to block the suction of the oil while the trocoid gear pump pumps the oil, but the gas is provided in the middle of the driving shaft 23. Since the oil is discharged from the oil passage 23a through the mining holes 23c and 23d, the oil can be sucked up smoothly through the oil passage 23a.

In this way, even when the drive shaft of the drive motor rotates at a low speed, the oil is supplied to the compression chamber through the oil supply hole and the oil injection hole so that the amount of oil supplied to the compression chamber is kept constant so that the fixed scroll It is possible to prevent abrasion and overturning scroll in advance and to improve the performance of the compressor by reducing the friction loss.

In addition, even when the drive shaft of the drive motor rotates at a high speed, the oil blocking plate prevents the oil from being scattered while being stirred by the balance weight, thereby preventing the oil from being mixed with the refrigerant and excessively flowing into the compression chamber. The amount of leakage to the refrigeration cycle system, together with the compressed refrigerant, can prevent damage and deterioration due to oil shortages in the compressor. On the contrary, a graph illustrating the change in the EER and the oil discharge rate OCR of the compressor according to whether the oil barrier plate is installed is attached to FIG. 7. As shown in FIG. 7, the grade coefficient is increased by 0.5 to 0.6, and the oil discharge rate is reduced by about 12 to 13 wt% compared to the case where the oil barrier plate is not. It can also be seen that the effect is greater when the compressor rotates at a high speed of 60 Hz or more.

In addition, as the drive motor is configured as a synchronous reluctance motor, the compressor performance is improved during low speed operation, and the amount of heat generated by the motor is lowered, thereby expanding the operation region of the compressor.

In addition, as the balance weight is coupled to the drive shaft, deformation caused by the eccentric load of the driving motor can be reduced, and the eccentric load can be effectively canceled even by reducing the weight of the balance weight.

In addition, as the oil pump uses a trocoid gear pump, it is possible to reduce the time of oil bleeding due to fluctuation of suction pressure and vaporization of liquid refrigerant, and to directly reduce the number of parts and reduce assembly time by directly connecting the trocoid gear to the drive shaft. Can be.

The present invention is applied to a scroll compressor widely used in air conditioners, etc., in particular, can be effectively applied to a low pressure scroll compressor in which the inner space of the casing is divided into a suction space and a discharge space.

1 is a longitudinal sectional view showing an example of a low pressure scroll compressor according to the present invention;

Figure 2 is a longitudinal sectional view showing an example of the oil barrier plate in Figure 1,

Figure 3 is a longitudinal sectional view showing another embodiment of the oil barrier plate in Figure 1,

4 is a perspective view showing the rotor and the drive shaft of the drive motor in FIG.

5 is an exploded perspective view illustrating an example of an oil pump in FIG. 1;

Figure 6 is a longitudinal cross-sectional view showing an oil supply structure for the compression chamber in Figure 1,

7 is a graph showing the coefficient of performance and the oil discharge rate of the compressor according to FIG.

** Description of symbols for the main parts of the drawing **

10: casing 14: mainframe

14b: oil pocket 14d: oil supply hole

14e: Oil storage groove 18: Oil barrier plate

18a: oil guide protrusion 20: drive motor

21: stator 22: rotor

22a: shaft hole 22b: magnetic flux barrier

22c: oil return groove 23: drive shaft

23a: oil passage 23b: oil passage

23c, 23d: Gas bleed hole 23e: Pump drive part

23f: driving cutting surface 24: balance weight

25: oil pump 30: compressor section

31: fixed scroll 32: turning scroll

32c: oil injection hole 33: Olddam ring

34: high and low pressure separator 35: check valve

Claims (12)

A casing provided with a sealed inner space and provided with a suction pipe and a discharge pipe; A stator fixedly installed in the inner space of the casing, a rotor rotating inside the stator, coupled to the rotor to transmit rotational force, and an oil channel penetrates axially therein, and a lower end of the oil channel It includes a drive motor having a drive shaft provided with an oil pump; A frame fixedly installed in the inner space of the casing, the bearing hole being formed to support the drive shaft, and the oil pocket being formed so that a predetermined amount of oil is accumulated in the bearing hole; A fixed scroll having a hard plate formed to be fixed to the frame and having a fixed wrap spirally formed on one side of the hard plate; Sliding plate is formed to make a pivoting movement between the frame and the fixed scroll, spiral wrap is formed on one side of the hard plate portion, the pivoting wrap is engaged with the fixed wrap of the fixed scroll to form a compression chamber Turning scroll; A balance weight coupled to the drive shaft to have an eccentric load, the balance weight offsetting the eccentricity while rotating with the drive shaft; And And an oil blocking plate fixed to the frame to accommodate the balance weight to block scattering of oil. The frame is provided with an oil supply hole so as to communicate from the oil pocket to the bearing surface between the frame and the swing scroll, An oil injection hole is formed in the hard plate portion of the swing scroll to communicate between the bearing surface between the frame and the swing scroll and before the compression start point of the swing wrap. And the oil supply hole and the oil injection hole communicate with each other. The method of claim 1, And an oil storage groove extending from an end of the oil supply hole on the bearing surface of the frame, wherein the oil storage groove is formed to include a turning trajectory of the oil injection hole. The method of claim 1, The oil blocking plate is a scroll compressor, characterized in that formed in a cylindrical shape of approximately the diameter of both ends. The method of claim 1, The oil blocking plate is a scroll compressor, characterized in that extending from the top to the bottom direction fixed to the frame is formed. The method of claim 4, wherein The oil blocking plate is a scroll compressor, characterized in that the oil guide protrusion is formed on the bottom surface. The method of claim 1, The oil passage of the drive shaft is formed so that at least two or more outgassing holes penetrate radially, The degassing hole is scroll compressor, characterized in that formed on both sides of the upper rotor. The method of claim 1, The oil pump is a scroll compressor, characterized in that consisting of a trocoid gear pump. The method of claim 7, wherein The trocoid gear pump is a scroll compressor, characterized in that the inlet is formed in plurality with a difference in height. The method of claim 1, And the drive motor is a synchronous reluctance motor configured to synchronously rotate the rotor in a direction in which the magnetic resistance is minimized by the reluctance torque. The method of claim 9, The rotor is a scroll compressor, characterized in that the magnetic flux barrier through which the magnetic resistance difference is formed in the axial direction. The method of claim 9, And a shaft hole to which the drive shaft is coupled is formed at the center of the rotor, and at least one oil guide groove is formed in the axial direction or the inclined axis direction on the main surface of the shaft hole. The method according to any one of claims 1 to 11, And an inner space of the casing is divided into a suction space through which the suction pipe communicates with a discharge space through which the discharge pipe communicates.

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