KR20030010963A - Crankshaft of compressor for refrigerating machine - Google Patents

Abstract

PURPOSE: A crankshaft of compressor for a refrigerating machine is provided to have an oil pump smoothly supplying refrigerator oil even during low speed operation. CONSTITUTION: A crankshaft(30) includes a cylindrical axis part(33) having an oil hole(35) formed on a middle part thereof to be fluidically connected with an inside thereof and an oil groove(36) formed on a periphery thereof from the oil hole to one end thereof; a hollow eccentric part(31) placed on one end of the axis part so that the center thereof is eccentric to the center of the axis part and fluidically connected with the oil groove; and a positive-displacement oil pump comprising a case systematically placed on the other end of the axis part to rotate together with the axis part and having a drill hole(34) fluidically connected with the oil hole, a movable member, a piston(40), circumscribed to the case and submerged under refrigerator oil, a movement converting device, a piston guide(60), converting rotary movement of the case into vertical reciprocation of the movable member and an opening and closing device, a valve(50), controlling inflow of refrigerator oil into a hermetic space between the case and the movable member so as to supply refrigerator oil by change of the hermetic space.

Description

Crankshaft of compressor for refrigerating machine

The present invention relates to a compressor for a cold container, and more particularly, to a crankshaft of a compressor for a cold container having a volumetric oil pump capable of supplying sufficient refrigeration oil even at low speed operation.

In general, a compressor for a cold container serves to compress a working fluid passing through an evaporative heat exchanger and supply it to a condensation heat exchanger in a refrigeration air conditioner such as a refrigerator or an air conditioner.

Hereinafter, with reference to the accompanying drawings, in particular the configuration of a reciprocating compressor, in particular a compressor for cold applications in detail as follows.

First, Figure 1 is a cross-sectional view showing the structure of a conventional cold container compressor, Figure 2 is a front view showing a crankshaft of a typical cold container compressor, Figures 3a and 3b shows an oil pump of the crankshaft according to FIG. It is sectional drawing which showed a piece, and the front view which showed a propeller, respectively.

As shown in FIG. 1, the reciprocating compressor includes a transmission unit generating a rotational force by applying current in a closed space 1 including a lower shell 2 and an upper shell 3, and a rotational force of the transmission unit. It is largely composed of a compression section for compressing the working fluid.

The transmission part is composed of a stator 4 for generating an electromagnetic force by applying a current, and a rotor 5 for generating a rotational force by the electromagnetic force of the stator.

The crank shaft 20 is press-fitted into the rotor 5 to rotate together with the rotor, a connecting rod 13 for converting a rotational movement of the crank shaft into linear reciprocating motion, and the connecting rod. It consists of a piston 12 for compressing the working fluid in the interior of the cylinder block (11).

One end of the connecting rod 13 is pin-coupled to an eccentric portion 21 formed at the upper end of the crankshaft 20 and the other end is pin-coupled to the piston 12, thereby rotating the crankshaft 20. Can be converted into linear reciprocating motion.

And, the lower portion of the lower shell (2) is frozen in the refrigerator oil (L) to a suitable depth to prevent wear of various mechanical parts, the lower end of the crankshaft 20 is locked in the refrigerator oil (L). The refrigeration oil (L) is supplied to the eccentric portion (21) along the circumferential surface and the inside of the crankshaft while the crankshaft (20) rotates, thereby lubricating the frictional movement of the various mechanical parts and at the same time the internal heat Will be released.

On the other hand, one side of the lower shell 2 is provided with a hermetic terminal (hermetic terminal) 15 and the cluster 14 to connect the state 4 to an external power source. A plurality of lead wires 16 branched from the stator 4 are fixed to the cluster 14 by terminals, and a plurality of pins penetrating through the hermetic terminal 15 are coupled to the terminals.

Hereinafter, the structure of the crankshaft will be described in detail with reference to the accompanying drawings.

As shown in FIG. 2, the crankshaft 20 has an eccentric portion 21 eccentrically provided with an axial center at an upper end thereof, and a balance weight 22 provided at a lower end of the eccentric portion to prevent vibration during rotation. The lower end of the balance weight is immersed in the refrigeration oil and rotates the oil pump 27 for pumping the refrigeration oil and the shaft portion 23 is provided with a rising flow path of the refrigeration oil.

At this time, the oil pump 27 is inserted into the shaft portion 23, the drill hole (24) for the pumped refrigeration oil is moved upwards, and the circumferential surface of the shaft portion 23 at the end of the drill hole An oil groove 25 extending up to and an oil groove 26 are formed along the circumferential surface of the shaft portion 23 from the oil hole to the eccentric portion 21. At this time, the inner diameter of the drill hole 25 is approximately 50% of the outer diameter of the shaft portion 23, and is formed to be deflected with respect to the axis center of the shaft portion.

In addition, a gas hole for discharging gas is formed in one side surface of the drill hole 24 by extending a distance from the circumferential surface of the shaft portion 23 to a far side.

Meanwhile, as shown in FIG. 3, the oil pump 27 is a kind of centrifugal pump that pumps refrigeration oil using centrifugal force, a cylindrical piece 27a inserted into the lower end of the shaft portion of the crankshaft, and in the piece. It is composed of a propeller 27b inserted at an angle to form a rising flow path of the refrigeration oil.

The crankshaft 20 configured as described above rotates with the rotor 5 when power is applied to the transmission unit, and the oil pump 27 provided at the lower end of the crankshaft also rotates together. At this time, the refrigeration oil (L) is pumped into the drill hole (24) while moving upward through the propeller (27b) of the oil pump by centrifugal force, and the oil groove (26) through the oil hole (25) Will be moved to. Subsequently, the coolant oil L moves along the oil groove 26 to the eccentric portion 21 while lubricating the journal bearing (not shown) and is scattered to each part in the case. At this time, the gas of the refrigeration oil pumped into the drill hole 24 is discharged to the outside through a separate gas hole.

However, in recent years, a pole conversion motor or a BLDC motor capable of performing both a low speed operation and a high speed operation in order to reduce power consumption of a cold container product has been widely applied as a motor of a compressor.

However, the above-mentioned crankshaft is for high speed operation (approximately 3600 rpm), and there is a problem in that refrigeration oil is not smoothly supplied at low speed operation (approximately 1800 rpm). When the crankshaft is rotated at a low speed, the centrifugal force decreases rapidly, and thus refrigeration oil cannot be properly supplied. This results in a fatal effect on the life of the compressor by lowering the lubrication performance to prevent wear of various components and the ability to dissipate internal heat to the outside.

The present invention has been made to solve the above problems, an object of the present invention is a compressor for a cold container in parallel with a low speed operation and a high speed operation, the cold equipped with an oil pump that can smoothly supply the refrigeration oil at low speed operation It is to provide a crankshaft of a compressor for an application machine.

1 is a cross-sectional view showing the structure of a compressor for a typical cold application

Figure 2 is a front view showing a crankshaft of a typical cold container compressor

3a and 3b show an oil pump of the crankshaft according to FIG. 2, a cross-sectional view of the piece and a front view of the propeller, respectively.

4 is a partial cross-sectional view showing a crankshaft of a compressor for a cold container according to an embodiment of the present invention.

Figure 5 is a front view showing the shaft portion of the crankshaft according to an embodiment of the present invention

6a and 6b are a cross-sectional view and a plan view showing a piston of the oil pump of the crankshaft according to an embodiment of the present invention

7a and 7b is a cross-sectional view and a plan view showing a valve of the oil pump of the crankshaft according to an embodiment of the present invention

8a and 8b are a cross-sectional view and a plan view showing a piston guide of the oil pump of the crankshaft according to an embodiment of the present invention

9a and 9b are cross-sectional views showing the operation of the crankshaft of the compressor for a cold container according to another embodiment of the present invention.

10 is a front view showing a body of the oil pump of the crankshaft according to another embodiment of the present invention

Explanation of symbols on the main parts of the drawings

40: piston 41: protrusion

43: valve stopper 47: inlet

49: wedge 50: valve

51: suction hole 60: piston guide

61: groove 70: insertion member

71: protrusion groove 73: drill hole

75: Lip 100: Shaft

110: indentation hole

In order to achieve the above object, the crankshaft of the compressor for a cold container according to the present invention is a cylindrical cylindrical oil hole is formed in communication with the inside in the middle portion and the oil groove is formed along the outer periphery from the oil hole to one end A shaft portion, a hollow eccentric portion eccentrically at the center of the shaft portion and in communication with the oil groove, and organically provided at the other end of the shaft portion are rotated together with the shaft portion and communicated with the oil hole at the same time. In the case in which the drill hole is formed and circumscribed to the case and at the same time the movable member submerged in the refrigerator oil and the movement switching means for converting the rotational movement of the case into the vertical reciprocating motion of the movable member and the sealed space between the case and the movable member It consists of opening and closing means for controlling the inflow of the refrigeration oil, by changing the sealed space It includes a volumetric oil pump to supply.

At this time, the case is made of a portion of the shaft portion in which the drill hole is formed to the height in communication with the oil hole in the other end.

Alternatively, the shaft portion is formed with a press-in hole from the other end to the height of the oil hole is formed, the case is one end is pressed into the other end of the shaft portion through the press-hole and the other end is exposed to the outside and at the same time a drill hole is formed therein It consists of a hollow cylindrical insert.

The movable member includes a hollow cylindrical piston having one end inserted into an outer circumference of the other end of the case and an inlet formed at the other end with suction of the refrigerant oil.

The movement switching means includes a protrusion groove formed as a single closed curve inclined obliquely on a horizontal line perpendicular to the axial direction at the outer circumference of the other end of the case, and a protrusion which protrudes inside one end of the piston and is inserted into the protrusion groove.

The opening and closing means is provided in the piston is formed of a disk-shaped valve for opening and closing the inlet port when the piston moves, the valve is a plurality of parts in which the refrigeration oil is sucked when opening the inlet port located in the outer portion than the inlet port of the piston Suction holes are formed.

On the other hand, the movement switching means further includes a hollow cylindrical piston guide which is open on both sides coupled to the outer periphery of the piston to limit the rotational movement of the piston.

In this case, at least one groove is formed in the inner circumference of the piston guide along the axial direction, and at least one wedge is formed in the outer circumference of the piston.

On the other hand, the inner wall of the piston is provided with a valve stopper for limiting the rising height of the valve when the inlet opening, the valve stopper is formed of a separate ring installed on the inner wall of the piston.

Finally, an inner circumference forming a drill hole at one end of the insertion member is extended to a predetermined length to form a circular lip to prevent backflow of the refrigeration oil.

Hereinafter, a crankshaft of a compressor for a cold container according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, Figure 4 is a partial cross-sectional view showing a crankshaft of the compressor for a cold container according to an embodiment of the present invention, Figure 5 is a front view showing the shaft portion of the crankshaft according to an embodiment of the present invention, Figure 6a and 6b Is a cross-sectional view and a plan view showing a piston of the oil pump of the crankshaft according to an embodiment of the present invention. 7A and 7B are cross-sectional views and a plan view showing a valve of an oil pump of a crankshaft according to an embodiment of the present invention, and FIGS. 8A and 8B are piston guides of an oil pump of a crankshaft according to an embodiment of the present invention. Is a cross-sectional view and a plan view.

On the other hand, the volumetric oil pump according to the present invention is to pump the liquid by the movement or change of the sealed space formed between the case forming a certain space and the movable member externally or inscribed in the case. The pump is a pump for changing the closed space while the movable member reciprocates.

At this time, the case forming a closed space with the movable member is divided into a case formed integrally with the crankshaft, and a case formed of a separate insert member pressed into the crankshaft, each embodiment Explained by dividing.

First, as shown in Figure 4, the crankshaft 30 of the compressor for a cold container according to an embodiment of the present invention is pressed into a rotor (not shown) of the electric motor portion of a cylindrical shaft that rotates with the rotor ( 33) and a hollow eccentric portion 31 whose center is eccentric with the center of the shaft portion and a connecting rod (not shown) is coupled to the outer circumference thereof, and at the lower end of the shaft portion 33 with a refrigeration oil. It is largely composed of a volumetric oil pump that is locked and pumps the refrigeration oil when the shaft portion rotates, and a balance weight 32 that reduces vibration generated during rotation between the shaft portion 33 and the eccentric portion 31.

At this time, an oil hole 35 communicating with the inside is formed at the intermediate outer circumference of the shaft portion 33, and a flow path of the refrigeration oil flows from the oil hole 35 to one end of the eccentric portion 31. The oil groove 36 to be formed is formed in a spiral shape along the outer circumference. At this time, the end of the oil groove 36 should be in communication with the eccentric portion (31).

And, in order to configure the volumetric oil pump, the lower end of the shaft portion 33 to form a drill hole (drill hole, 34) therein from the end to the height of the oil hole 35 is formed in the case, One end is inserted into the outer periphery of the lower end of the shaft portion 33 so as to be movable upward and downward, and the other end is provided with a piston 40 which is immersed in the refrigerator oil. A protrusion groove 37 is formed at the outer circumference of the lower end of the shaft 33, and a protrusion 41 is inserted into the protrusion groove 37 at one end of the piston 40. To achieve the exercise conversion means. In addition, the opening and closing means is provided with a valve 50 which is provided inside the piston 40 to move up and down.

On the other hand, as a part of the movement switching means, the piston guide 60 is coupled to the outside of the piston 40 to limit the rotation of the piston when rotating the shaft portion 33 is provided. And, the inner wall of the piston 40 is provided with a valve stopper 43 for limiting the rising height of the valve (50).

Hereinafter, each element constituting the volumetric oil pump will be described in detail.

First, as shown in FIG. 5, at the lower end of the shaft portion 33, a drill hole 34 having a predetermined diameter therein is straightened along the axial direction, and the drill hole 34 must communicate with an oil hole. do. The protrusion groove 37 is formed as a single closed curve which is inclined at an angle with respect to the horizontal line perpendicular to the axial direction. That is, the protrusion groove 37 is an elliptical groove formed on the outer circumference of the shaft portion 33. Therefore, the height of the protrusion groove 37 is formed differently according to the position, the height difference between the highest point (37a) and the lowest point (37b) occurs, the height difference is equal to the stroke distance of the piston.

6A and 6B, the piston 40 is a hollow cylinder having both sides open for insertion into the outer periphery of the lower end of the shaft, and one end inserted into the shaft is completely open and the other end 45. The portion is bent inward to form a suction opening 47 of a predetermined diameter.

On the other hand, one end of the inner wall of the piston 40 is formed with a projection 41 inserted into the projection groove formed on the outer periphery of the shaft portion. The protrusions 41 relatively move along the protrusion grooves when the shaft is rotated, and the protrusions are not rotated but rotated in a state in which the protrusion grooves are joined to the protrusions. In this case, the piston 40 itself must be constrained against rotational movement so that the protrusion 41 does not rotate with the protrusion groove.

Therefore, as the protrusion 41 is repeatedly positioned at the highest point and the lowest point of the protrusion groove, the piston 40 also reciprocates up and down by the height difference between the highest point and the lowest point.

As shown in Figure 7a and 7b, the valve 50 is a disc inserted into the interior of the piston, the end 53 in contact with the inner wall is bent by a predetermined length so as to be able to move up and down on the inner wall of the piston. have. At this time, the disc area of the valve 50 should be larger than the inlet area of the piston, which is to form a sealed space with the piston by completely closing the inlet when the valve is in contact with the inlet.

In addition, a plurality of suction holes 51 are formed at the outer portion of the valve 50. The suction hole 51 is intended to allow the coolant oil introduced through the suction port to flow into the drill hole through the valve when the valve 50 is spaced apart from the suction port of the piston. To this end, the suction holes 51 are preferably formed at equal intervals in the outer portion of the valve 50, for example, eight suction holes are formed at equal intervals.

6A and 6B, on the inner wall of the piston 40, strictly speaking, at a position between the lower end of the shaft portion inserted into the piston 40 and the valve, the jaw is prevented from passing. A valve stopper 43 is provided to serve as.

That is, the valve stopper 43 is to maintain the amount of the refrigeration oil flowing between the valve and the lower end of the shaft by limiting the rising height of the valve that rises relatively when the piston descends. If the valve stopper 43 is not provided, as the valve 40 rises to the lower end of the shaft when the piston 40 descends, the refrigerant oil flows to the outside through the suction port 47 when the piston rises. You will not be able to pump.

To this end, the valve stopper 43 may be a part of the piston protruding by a predetermined length along the inner wall of the piston 40, or a separate member is pressed into the inner wall of the piston by a circular ring and fixed at an appropriate position It may be made of.

8A and 8B, the piston guide 60 is a part of the movement switching means for further ensuring the up and down reciprocation of the piston. To a stator (not shown).

To this end, the piston guide 60 is a hollow cylinder of which both sides are open, and at least one groove groove 61 for restricting the rotational movement of the piston at its inner circumference is formed along the axial direction. A total of two are formed, one each. At this time, the length of the wedge 61 should be long enough not to interfere with the movement of the piston having a certain stroke. In addition, both ends 63 of the piston guide are bent inward by a predetermined length to prevent separation of the piston.

On the other hand, as shown in Figure 6a and 6b, a wedge (49) is inserted into the groove of the piston guide on the outer peripheral edge of the lower side of the piston (40). At this time, the wedge 49 should be formed equal to the number of grooves, for example, a total of two are formed, one each on the left and right.

As a result, as the wedge 49 is inserted into the groove of the piston guide, even if a rotational force is generated by the rotation of the shaft portion in the piston 40, the piston moves only up and down linearly.

The crankshaft 40 of the compressor for a cold container configured as described above has the piston 40 reciprocating up and down as the shaft portion 33 rotates together with the rotor, and the shaft portion 33 and the piston 40. And the refrigeration oil introduced into the closed space formed by the valve 50 rises along the oil hole 35 and the oil groove 36 through the drill hole 34 and finally each part in the compressor through the eccentric portion 31. To be scattered. The above-described operation will be described later in detail.

On the other hand, with reference to the accompanying drawings, an embodiment consisting of a separate insert member that is pressed into the shaft portion of the case constituting the volumetric oil pump of the crankshaft according to the present invention will be described in detail.

First, Figures 9a and 9b is a cross-sectional view showing the operation of the crankshaft of the compressor for a cold container according to another embodiment of the present invention, Figure 10 is a front view showing a case of the oil pump of the crankshaft according to another embodiment of the present invention to be.

9A and 9B, the crankshaft of the compressor for a cold container according to another embodiment of the present invention is a volumetric oil from the end to the height of the oil hole (not shown) is formed at the lower end of the cylindrical shaft portion (100) The indentation hole 110 is installed is a pump is formed. At this time, although not shown, the press-in hole 110 should be in communication with the oil hole, of course.

In addition, the volumetric oil pump includes a separate insertion member 70 press-fitted into the press-in hole 110, a movable member 40 inserted into one outside of the insertion member and reciprocating up and down, and the movable member. It is provided with an opening and closing means (50) for controlling the inflow of the refrigeration oil provided in the sealed space formed by the insertion member 70 and the movable member (40). Then, the movement switching means for converting the rotational movement of the insertion member 70 to the vertical reciprocating movement of the movable member 40 is provided.

Hereinafter, each element constituting the volumetric oil pump will be described in detail.

First, as shown in FIG. 10, the insertion member 70 is a hollow cylinder installed in the lower end of the shaft portion 100 through a press-in hole 110 to rotate together with the shaft portion, and has a predetermined diameter therein. The drill hole 73 is formed. At this time, one end of the insertion member 70 is press-fitted to the lower end of the shaft portion through the press-in hole 110 and the other end is exposed to the outside of the shaft portion 70 and the piston which is a movable member is inserted in the outer circumference thereof. .

Then, at the outer circumference of the other end of the insertion member 70, a protrusion groove 71 for converting the rotational movement of the insertion member into the vertical reciprocating motion of the movable member is formed. At this time, the protrusion groove 71 is a single closed curve inclined obliquely with respect to the horizontal line perpendicular to the axial direction as in the above-described embodiment, and the piston is moved up and down by the height difference between the highest point 71a and the lowest point 71b. Go to.

On the other hand, one end of the insertion member 70 is formed with a circular lip (lip, 75) extending the inner circumference forming the drill hole 73 by a predetermined length. The lip 75 is for preventing the refrigerant oil from escaping through the drill hole 73 when the piston descends. That is, the coolant oil introduced into the press-in hole 110 through the drill hole 73 rises through the inner wall by centrifugal force, and at this time, the lip forms a predetermined partition between the press-in hole and the drill hole. Oil can be prevented from flowing back into the drill hole.

Next, the piston applied as the movable member inserted into the outer circumference of the other end of the insertion member is the same as the above-described embodiment, and is well illustrated in FIGS. 6A and 6B.

In addition, the opening and closing means provided in the piston is a valve as in the above-described embodiment, and is well illustrated in FIGS. 7A and 7B.

In addition, the piston guide coupled to the outer periphery of the piston is also the same as the above-described embodiment, it is well shown in Figures 8a and 8b.

The operation of the crankshaft of the compressor for a cold container configured as described above will be described in detail with reference to the accompanying drawings.

9A and 9B, first, power is applied to the transmission unit so that the rotor 100 rotates as the rotor rotates. At the same time, the insertion member 70 press-fitted to the lower end of the shaft portion 100 is rotated at the same speed as the shaft portion. Therefore, the piston 40 is moved up and down by the relative movement of the projection 41 and the projection groove 71 into which the projection is inserted. At this time, the rotational force of the piston 40 generated by the rotating insertion member 70 is completely constrained by the piston guide 60. In other words, as the wedge 49 of the piston is inserted into the Ｖ groove 61 of the piston guide and performs only a linear motion up and down, the piston 40 also performs only a vertical motion.

Here, FIG. 9A illustrates that the protrusion 41 is located at the highest point of the protrusion groove 71. At this time, the piston 40 also moves upward and reaches the highest point. In this case, the valve 50 provided inside the piston 40 comes into contact with the surface on which the inlet port 47 of the piston is formed and the inlet port is closed. At this time, the refrigeration oil (L) of the sealed space formed between the insertion member 70, the piston 40, the valve 50 is introduced into the drill hole 73 of the insertion member.

Subsequently, as the insertion member 70 continues to rotate by the shaft portion 100, the protrusion 41 descends on the protrusion groove 71, thereby moving the piston 40 downward.

9b shows that the protrusion 41 is located at the lowest point of the protrusion groove 71. At this time, the piston 40 also moves downward and reaches the lowest point. In this case, as the piston 40 descends, a vacuum is temporarily formed in the piston, and the valve 50 rises to a height at which the valve stopper 43 is provided by the pressure of the refrigeration oil (L). At the same time, the inlet 47 of the piston is opened while the refrigeration oil (L) is introduced. Thereafter, the refrigerator oil (L) is introduced into the space between the valve 50 and the insertion member 70 through the suction hole 51 of the valve, and subsequently drill hole ( 73).

Therefore, in the above-described volumetric oil pump, each time the shaft portion 100 rotates once, the protrusion 41 passes once the highest point and the lowest point of the protrusion groove 71, and thus the piston 40 reciprocates once. .

Next, the coolant oil introduced into the drill hole 73 flows through the oil hole and the oil groove to the eccentric part by the centrifugal force generated by the rotation of the shaft part 100 after being introduced into the indentation hole 110 of the shaft part. do. At this time, the refrigeration oil located at the upper end of the insertion member of the press-in hole 110 forms a parabolic shape convex downward by the centrifugal force. Therefore, even if the piston 40 is lowered, the refrigeration oil is positioned between the lip 75 and the press-in hole 110 at the upper end of the insertion member, and thus does not flow back into the drill hole 73.

As described above, the crankshaft according to another embodiment of the present invention uses the centrifugal force together with the lifting force by the volumetric oil pump to supply the refrigeration oil to the oil hole.

On the other hand, the operation of the crankshaft according to an embodiment of the present invention, which has not been described above, is also as described above.

However, the crankshaft according to another embodiment of the present invention has an advantage over the crankshaft according to the embodiment in terms of supply efficiency of the refrigeration oil, as a separate insertion member 70 is provided. In other words, the lift force by the volumetric oil pump is advantageous as the inner diameter of the flow path is smaller, while the lift force by the centrifugal force is advantageous as the inner diameter of the flow path is larger. However, the crankshaft according to another embodiment may satisfy the above conditions because the flow path of the refrigeration oil may be formed by the drill hole 73 having a small inner diameter and the press-hole 110 having a large inner diameter on the drill hole. .

The crankshaft of the compressor for a cold container according to the present invention is provided with a volumetric oil pump for pumping the refrigeration oil in the vertical reciprocating motion of the piston at the lower end of the shaft, so that a sufficient amount of the freezer is independent of centrifugal force even during low speed operation of the compressor. Oil can be fed to the eccentric at the top of the shaft.

Therefore, wear of various components provided in the compressor can be prevented, and heat dissipation of internal parts can be easily released, thereby improving reliability.

Claims (12)

A shaft having a cylindrical shape in which an oil hole communicating with the inside is formed, and an oil groove formed along an outer circumference from the oil hole to one end thereof; A hollow eccentric portion whose center is eccentric to the shaft center at one end of the shaft portion and in communication with the oil groove; A case which is organically provided at the other end of the shaft portion and rotates like the shaft portion and is formed with a drill hole communicating with the oil hole, a movable member external to the case and immersed in the refrigerator oil, and rotation of the case Movement switching means for converting the movement to the vertical reciprocating motion of the movable member, and opening and closing means for controlling the inflow of the refrigeration oil into the sealed space between the case and the movable member, the volume for supplying the refrigeration oil by the change of the sealed space Crankshaft of compressor for cold container containing oil pump. The method of claim 1, The case is a crankshaft of the compressor for a cold container consisting of a portion of the shaft portion in which the drill hole is formed to the height in communication with the oil hole in the other end. The method of claim 1, The shaft portion has a press-in hole formed from the other end to the height of the oil hole is formed, the case is one end is pressed into the other end of the shaft portion through the press-hole and the other end is exposed to the outside and at the same time a hollow cylindrical hole is formed therein Crankshaft of the compressor for cold applications consisting of an upper insertion member. The method of claim 2 or 3, The movable member is a crankshaft of the compressor for a cold container consisting of a hollow cylindrical piston, one end of which is inserted into the outer circumference of the other end of the case and the other end of which is formed a suction port through which the refrigerant oil is sucked. The method of claim 4, wherein The movement switching means includes a protrusion groove formed as a single closed curve inclined obliquely with respect to a horizontal line perpendicular to the axial direction at the outer circumference of the other end of the case, and a protrusion which protrudes inside one end of the piston and is inserted into the protrusion groove. Crankshaft for compressors for cold applications. The method of claim 4, wherein The opening and closing means of the crankshaft of the compressor for a cold container consisting of a disk-shaped valve which is provided inside the piston to open and close the suction port when the piston moves. The method of claim 6, The valve is a crankshaft of the compressor for a cold container, wherein a plurality of suction holes through which the refrigerant oil is sucked when opening the suction port is formed at a portion located outside the suction port of the piston. The method of claim 5, The crankshaft of the compressor for a cold container, the movement switching means further comprises a hollow cylindrical piston guide which is coupled to the outer periphery of the piston to limit the rotational movement of the piston. The method of claim 8, The crankshaft of the compressor for a cold container, the inner circumference of the piston guide is formed with at least one groove in the axial direction, the outer circumference of the piston is formed with at least one wedge is inserted into the groove. The method of claim 6, The crankshaft of the compressor for a cold container, the inner wall of the piston is provided with a valve stopper for limiting the rising height of the valve when the inlet opening. The method of claim 10, The valve stopper is a crankshaft of the compressor for cold applications consisting of a separate ring installed on the inner wall of the piston. The method of claim 3, wherein The crankshaft of the compressor for a cold container, the inner circumference forming a drill hole in one end of the insertion member is extended to a predetermined length to form a circular lip to prevent the back flow of the refrigeration oil.