Abstract:
An oil supply apparatus for a linear compressor reduces the number of valves which control oil suction and discharge, thereby enabling fabrication and assembly of an apparatus and supplying an oil of an adequate amount to friction areas of driving elements, and increases a compression force of a mass, thereby increasing circulation volume of an oil. The oil supply apparatus for the linear compressor, includes: a compressor unit in which an oil discharge outlet is formed; an oil supply pipe disposed at an outer side of the compressor unit, an end of which communicates with an end of the oil discharge outlet; an oil valve an end of which is fixedly engaged with a side portion of the compressor unit and the other end of which is selectively in contact with the other end of the oil discharge outlet; and a discharge cover positioned at an outer side of the oil valve and engaged with the compressor unit, so that an oil path is formed between the discharge cover and the compressor unit.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an oil supply apparatus for a linear compressor, and more particularly to an oil supply apparatus for a linear compressor which reduces the number of valves which control suction and discharge of an oil, thereby enabling fabrication and assembly thereof, and supplying an oil of an adequate amount to friction areas of driving elements. 
     2. Description of the Conventional Art 
     As generally well known, a linear compressor compresses a refrigerant by reciprocating a piston in a cylinder using a magnet and a coil, instead of a crank shaft. 
     FIG. 1 illustrates a conventional linear compressor. As shown therein, the conventional linear compressor includes a compressor unit  10  horizontally provided in a hermetic vessel C having a predetermined shape and sucking, compressing, and discharging a refrigerant, and an oil supply unit  20  disposed at an outer side of the compressor unit  10  and supplying an oil to friction areas of driving elements of the compressor. 
     More particularly, in the compressor unit  10  there are provided a cylinder  12  connected with a stator  11   a  (inner and outer laminations) as a single body and a piston  13  which is connected with a rotor (including a magnet)  11   b  of a linear motor  11  and reciprocates into the cylinder  12 . 
     The oil supply unit  20 , as shown in FIG. 2, consists of an oil supply pipe  21  disposed at an outer side of the compressor unit  10 , a suction cover  22  engaged with an end of the oil supply pipe  21  at an oil suction side and having a suction inlet  22   a  at a bottom thereof, and a discharge cover  23  engaged with the other end of the oil supply pipe  21  at an oil discharge side and connected to one side of the compressor unit  10 . 
     Further, in the oil supply pipe  21 , there are provided a mass  24  in which there is formed a first oil path  24   a  communicating with the suction cover  22  and the discharge cover  23 , respectively, the mass sucking and discharging the oil which is moved by the reciprocation of compressor unit  10  and placed at a bottom of the hermetic vessel C, first and second compression coil springs  25 A,  25 B, respectively connected between both ends of the mass  24  and ends of inner surfaces of both sides of the oil supply pipe  21 , a suction valve  26  which is connected with an end of the first compression coil spring  25   a  and in contact with an inner surface of the suction cover  22 , thereby allowing or blocking the flow of the oil which flows thereinto through the suction opening  22   a  formed at the bottom of the suction cover  22 , and a discharge valve  27  which is connected with an end of the second compression coil spring  25   b  and in contact with an end portion of an oil discharge side of the mass  24 , thereby allowing or blocking the flow of the oil which has passed through the first oil path  24   a.    
     As shown in FIG. 3, the suction valve  26  and the discharge valve  27  are respectively formed in a scroll type, in which opening/closing units  26   a ,  27   a  are provided in each center thereof. 
     Now, the operation of the conventional linear compressor will be described with reference to the accompanying drawings. 
     When an electric current is applied to the linear motor  11 , the rotor  11   b  linearly reciprocates and accordingly the piston  13  reciprocates in the cylinder  12 . As the piston  13  reciprocates in the cylinder  12 , the refrigerant gas flowing into the hermetic vessel C is sucked into a compression chamber (not shown) of the cylinder  12 , passing through a refrigerant oil path  13   a  provided in a center of the piston  13 . 
     Being supported to move in the hermetic vessel C, the compressor unit  10  regularly vibrates by the driving of the linear motor  11  and accordingly the oil supply pipe  21  of the oil supply unit  20  reciprocates from side to side by the vibration of the compressor unit  10 . Here, the mass  24  located in the oil supply pipe  21  moves due to inertial force produced by the reciprocation of the oil supply pipe  21 , so that the oil O located in the bottom of the hermetic vessel C is sucked into the oil supply pipe  21  by pressure difference between the portions formed at both sides of the mass  24 . Thus, the oil flowing into the oil supply pipe  21  passes through the first oil path  24   a  provided in the mass  24  and then a second oil path  23   a  in the discharge cover  23 , and is discharged into an oil pocket P, thereby being supplied to a slide portion formed between the cylinder  12  and the piston  13 . Numerals  14  and  15  are a head cover and a valve, respectively.  16  and  17  respectively indicate a coil spring, and  18  and  19  are an external refrigerant suction pipe and a mounting spring, respectively. 
     However, the oil supply apparatus for the conventional linear compressor has several problems. 
     First, since the size of the suction valve and the discharge valve that control the suction and the discharge, respectively, of the oil is small, the fabrication and assembly are not easily achieved, thereby decreasing the productivity. 
     Second, since the suction and discharge valves are compressed and fixed by the compression coil springs supporting the mass, the opening/closing units of the suction and discharge valves are controlled by the compression coil springs, so that the valves can not properly control the suction and discharge of the oil. 
     Third, since the oil path is provided in the mass, the weight of the mass is reduced as the volume of the oil path so that the compressing force of the mass is reduced and thus the circulation volume of the oil is reduced. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to an oil supply apparatus for a linear compressor which obviates the problems and disadvantages in the conventional art. 
     An object of the present invention is to provide an oil supply apparatus for a linear compressor that reduces the number of valves which control oil suction and discharge, thereby enabling more efficient fabrication and assembly thereof. 
     Another object of the present invention is to provide an oil supply apparatus for a linear compressor that supplies an oil of an adequate amount to friction areas of driving elements by having free ends of a valve not contacting with other constituent elements, thereby improving reliability of the compressor. 
     Still another object of the present invention is to provide an oil supply apparatus for a linear compressor that reduces dead volume of a space formed between a mass and an oil supply pipe to increase a compression force of the mass, thereby increasing circulation volume of an oil. 
     To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an oil supply apparatus for a linear compressor which includes: a compressor unit in which an oil discharge outlet is formed; an oil supply pipe disposed at an outer side of the compressor unit, an end of which communicates with an end of the oil discharge outlet; an oil valve an end of which is fixedly engaged with a side portion of the compressor unit and the other end of which is selectively in contact with the other end of the oil discharge outlet; and a discharge cover positioned at an outer side of the oil valve and engaged with the compressor unit, so that an oil path is formed between the discharge cover and the compressor unit. 
     Also, to achieve the above objects of the present invention, there is provided an oil supply apparatus for a linear compressor which includes: a compressor unit; a discharge cover engaged with the compressor unit, in which there is formed an oil path communicating with an oil pocket of the compressor unit; an oil supply tube an upper semicircle of an open end of which is compressively inserted into an end of the discharge cover; and an oil valve disposed at a connection area of the oil supply tube and the discharge cover. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. 
     In the drawings: 
     FIG. 1 a vertical cross-sectional view of a conventional linear compressor; 
     FIG. 2 is a vertical cross-sectional view illustrating an oil supply apparatus of a conventional linear compressor; 
     FIG. 3 is a front view illustrating a suction valve and a discharge valve of an oil supply apparatus of a conventional linear compressor; 
     FIG. 4 is a vertical cross-sectional view of an oil supply apparatus for a linear compressor according to a first embodiment of the present invention; 
     FIG. 5 is a perspective view illustrating a suction cover of an oil supply apparatus for a linear compressor according to a first embodiment of the present invention; 
     FIG. 6 is a perspective view illustrating a discharge cover of an oil supply apparatus for a linear compressor according to a first embodiment of the present invention; 
     FIG. 7 is a front view illustrating an oil valve of an oil supply apparatus for a linear compressor according to a first embodiment of the present invention; 
     FIG. 8A is a vertical cross-sectional view illustrating an open condition of an oil valve in an oil supply apparatus for a linear compressor according to a first embodiment of the present invention; 
     FIG. 8B is a vertical cross-sectional view illustrating a closed condition of an oil valve in an oil supply apparatus for a linear compressor according to a first embodiment of the present invention; 
     FIG. 9 is a vertical cross-sectional view of an oil supply apparatus for a linear compressor according to a second embodiment of the present invention; 
     FIG. 10A is a vertical cross-sectional view illustrating a location of an oil valve when sucking an oil according to a second embodiment of the present invention; 
     FIG. 10B is a vertical cross-sectional view illustrating a location of an oil valve when discharging an oil according to a second embodiment of the present invention; 
     FIG. 11 is a vertical cross-sectional view illustrating a modification of an oil supply apparatus for a linear compressor according to a second embodiment of the present invention; 
     FIG. 12 is a vertical cross-sectional view of an oil supply apparatus for a linear compressor according to a third embodiment of the present invention; 
     FIG. 13 is a front view illustrating an oil valve of an oil supply apparatus for a linear compressor according to a third embodiment of the present invention; 
     FIG. 14A is a vertical cross-sectional view illustrating a location of an oil valve when sucking an oil according to a third embodiment of the present invention; and 
     FIG. 14B is a vertical cross-sectional view illustrating a location of an oil valve when discharging an oil according to a third embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
     In the present invention, those which are identical to the elements in the conventional art will have the same numerals. 
     As shown in FIGS. 4 through 8B, in an oil supply apparatus for a linear compressor according to a first embodiment of the present invention, an oil supply pipe  110  which is an oil supply means is disposed at an outer side of a compressor unit  10 . A mass  120 , which sucks and discharges an oil to/from the oil supply pipe  110  by pressure difference which is produced by inertial force due to the reciprocation of the oil supply pipe  110 , is inserted in the oil supply pipe  110  and first and second compression coil springs  131 ,  132  are respectively connected with both ends of the mass  120 . 
     Further, at an oil suction side of the oil supply pipe  110 , a suction cover  140  supporting the other end of the first compression coil spring  131  is attachedly fixed to the compressor unit  10 , being compressively inserted in an end portion of the oil supply pipe  110  at the oil suction side. An oil discharge outlet  10   a  is provided in the compressor unit  10  supporting the other end of the second compression coil spring  132 , one side of the oil discharge outlet  10   a  communicating with the oil supply pipe  110  and the other side thereof selectively contacting with an end of an oil valve  160 , the other end of which is fixedly connected with the compressor unit  10 . The oil valve  160  controls the volume of the oil which is sucked and discharged to/from the oil supply pipe  110 . A discharge cover  150  is disposed at the outer side of the oil valve  160 , the discharge cover  150  being connected with the compressor unit  10  in order that an oil path  151  is formed between the compressor unit  10  and the discharge cover  150 . In other words, in the present invention, an oil valve is substituted for the suction valve and the discharge valve employed in the conventional oil supply apparatus, thereby reducing the number of the constituent elements of the oil supply apparatus. 
     To describe the suction cover  140  in more detail, as shown in FIG. 5, a ring-shaped groove  141  is formed on a center of a lower side of a side surface of the suction cover  140  facing the oil supply pipe  110 , the groove  141  compressively receiving an end of the oil suction portion of the oil supply pipe  110 , and an oil suction inlet  142  is formed in the center of the groove  141 , the oil suction inlet  142  becoming a path through which the oil placed in a bottom of the hermetic vessel C is flowed into the oil supply pipe  110  by the vibration of the oil supply pipe  110 . 
     Here, it is noted that, the oil suction inlet  142  is formed smaller than the oil discharge outlet  10   a.    
     Further, as shown in FIG. 6, a vertically longitudinal rectangular recess  150 ′ is formed on a center of a side surface of the discharge cover  150  facing the oil supply pipe  110 . Here, a width of the recess  150 ′ is formed larger than that of the oil valve  160 , for thereby receiving the oil valve  160  and a length thereof is formed longer than that of the oil valve  160  so that the oil valve  160  can move therein. 
     As shown in FIG. 7, the oil valve  160  consists of a body  163 , a mounting portion  161  which forms a ‘T’ shape with the body  163  and is attached to one side of the compressor unit  10 , and a ring-shaped opening/closing unit  162  formed at a bottom of the body  163  and extended to the end of the oil supply pipe  110  at the oil discharge side. 
     Now, an operation of the oil supply apparatus for the linear compressor according to the first embodiment of the present invention will be described with the reference to the accompanying drawings. 
     When the current is applied to the linear motor  11  of the compressor unit  10 , the piston  13  reciprocates in the cylinder  12  with the rotor  11   b  and accordingly the refrigerant gas sucked into the hermetic vessel C is flowed into the compression chamber (not shown) of the cylinder  12 , passing through the refrigerant path  13   a  provided in the center of the piston  13 , and then discharged therefrom, the above-mentioned process being repeatedly performed. 
     Here, as described above, the oil supply pipe  110  reciprocates from side to side as shown in FIG. 4 with the compressor unit  10  and the mass  120  located in the oil supply pipe  10  inertially moves due to the reciprocation of the oil supply pipe  10 . 
     The oil which is placed at the bottom of the hermetic vessel C by the inertial movement of the mass  120  is sucked into the oil supply pipe  110  due to the pressure difference between both ends of the mass  120  and then discharged to the oil pocket P through the oil path  151  formed by the discharge cover  150  and the compressor unit  10 . 
     Specifically, as shown in FIG. 8A, when the oil supply pipe  110  moves to a direction ‘A’, the mass  120  moves opposite to the direction ‘A’ due to the inertial force, so that a portion of the oil supply pipe  110  at the oil suction side has a lower pressure than a portion thereof at the oil discharge side. Accordingly, the oil placed at the bottom of the hermetic vessel C is flowed into the oil supply pipe  110  through the oil suction inlet  142  formed in the suction cover  140 . While, the oil placed in the oil supply pipe  110  and moving towards the oil discharge side in accordance with the movement of the mass  120  moves the oil valve  160  in the direction being distant from the oil discharge outlet  10   a , thereby opening the oil discharge outlet  10   a , and the oil discharged through the oil discharge outlet  10   a  is sucked into the oil pocket P of the compressor unit  10  through the oil path  151  formed between the oil discharge cover  150  and the compressor unit  10 . 
     On the contrary, as shown in FIG. 8B, when the oil supply pipe  110  moves to a direction ‘B’, the mass  120  moves opposite to the direction ‘B’ due to the inertial force, so that the portion of the oil supply pipe  110  at the oil discharge side has a lower pressure than the portion thereof at the oil suction side. Thus, the oil valve  160  moves to the oil discharge outlet  10   a  thereby closing the oil discharge outlet  10   a , and the oil which flows to the oil suction side from the inner part of the oil supply pipe  10  by the movement of the mass  120  is partially discharged to the bottom of the hermetic vessel C through the oil suction inlet  142  of the suction cover  140  and prevented from being sucked into the oil supply pipe  110 , the above process being repeatedly performed. 
     That is, since the oil valve  160  is disposed at the outer side of the oil supply pipe  110  at the oil discharge outlet side, not the inside of the oil supply pipe  110 , the oil valve  160  is not restricted by its size, thereby enabling the fabrication and assembly of the oil supply apparatus for the linear compressor. Further, since the oil valve  160  does not contact with the compression coil springs  131 ,  132  in the assembly process, the assembly thereof becomes easier and the reliability thereof can be secured. In addition, although it is not separately illustrated, the objects of the present invention can be achieved by applying a general embodiment using the inertial force of the oil, excluding the mass and the compression coil springs in the first embodiment of the present invention. 
     Now, with the accompanying drawings, an oil supply apparatus for a linear compressor according to a second embodiment of the present invention will be described in detail. 
     Since the oil supply apparatus for the linear compressor according to the second embodiment of the present invention is similar to that according to the first embodiment, the oil supply apparatus according to the first embodiment of the present invention will be described in various aspects different from the first embodiment. As shown in FIGS. 9 through 10B, instead of using the suction cover  140  employed in the first embodiment, an end of an oil supply pipe  210  is closed. Further, an oil suction inlet  242  is formed at a predetermined portion of a bottom of the oil supply pipe  210  at an oil discharge side into which a mass  220  is slid. In addition, to increase the circulation volume of the oil by reducing the dead volume of the space formed between the oil supply pipe and the mass, an outer circumferential surface of the mass  220  is tightly slid into an inner circumferential surface of the oil supply pipe  210 , so that the oil is not discharged from the space formed between the outer circumferential surface of the mass  220  and the inner circumferential surface of the oil supply pipe  210 . Here, the mass  220  which inertially moves in the oil supply pipe  210  opens the oil suction inlet  242  when sucking the oil and closes the oil suction inlet  242  when discharging the oil. 
     While, in the second embodiment of the present invention, the oil valve  260  located between a discharge cover  250  and an oil discharge outlet  10   a  of the oil supply pipe  210  blocks the oil discharge outlet  10   a  of the oil supply pipe  210  when the oil is sucked, and moves in the direction being distant from the oil discharge outlet  10   a.    
     Now, the operation of the oil supply apparatus for the linear compressor according to the second embodiment of the present invention will be described with the accompanying drawings. 
     In the oil supply apparatus according to the second embodiment of the present invention, there will be explained, in particular, a process of which the oil supply pipe  210  sucks the oil in the hermetic vessel C while vibrating by the vibration of the compressor unit  10 , thereby supplying the oil to a slide portion formed between the cylinder  12  and the piston  13 , without describing the basic description thereof. 
     First, as shown in FIG. 10A, when the oil supply pipe  210  moves in a direction ‘A’, the mass  220  moves opposite to the direction ‘A’ due to the inertial force, so that a portion of the oil supply pipe  210  at the discharge cover side has a relatively lower pressure. Accordingly, the oil valve  260  moves towards the oil supply pipe  210 , thereby closing the oil discharge outlet  10   a  and due to the movement of the mass  220  the oil suction inlet  242  is opened, so that the oil placed in the bottom of the hermetic vessel C is sucked into the oil supply pipe  210 . 
     On the contrary, as shown in FIG. 10B, when the oil supply pipe  210  moves to a direction ‘B’, the mass  220  moves opposite to the direction ‘B’ due to the inertial force, so that a portion of the oil supply pipe  210  at the oil discharge side has a relatively lower pressure. Thus, the oil placed in the oil supply pipe  210  moves the oil valve  20  in the direction being distant from the oil discharge outlet  10   a , thereby opening the oil discharge outlet  10   a , so that the oil is discharged to the oil path  251  and an outer circumferential surface of the mass  220  covers the oil suction inlet  242  due to which the mass  220  moves towards the oil discharge outlet  10   a.    
     That is, in the second embodiment of the present invention, the oil supply pipe  210  is formed in a cylindrical shape and the oil suction inlet  242  and the oil discharge outlet  10   a  are provided together at the same side of the oil supply pipe  210  on the basis of the mass  220 , and particularly the oil suction inlet  242  is formed at a slide surface so as to be open and closed by the mass  220  which slides in the oil supply pipe  210 .  231  and  232  are compression coil springs which are connected to both ends of the mass  220 . 
     FIG. 11 illustrates a modified example of the oil supply apparatus for the linear compressor according to the second embodiment of the present invention. As shown therein, a mass  220 ′ is not placed in a single oil supply pipe, but a plurality of oil supply pipes  210 ′ each of which is formed in a ring shape are disposed in parallel so that the mass  220 ′ is flexibly slid to an inner circumferential surface of each of the oil supply pipe  210 ′. Here, an oil suction inlet  242 ′ is formed in a bottom of one of the oil supply pipes  210 ′ which is disposed at the oil discharge side. Further, elastic members are provided at both ends of the mass  220 ′ inserted into the oil supply pipes  210 ′ —one is a compression coil spring  232 ′ provided at an end of the oil discharge outlet  10   a  and the other is a plate spring  271  protruded form the oil supply pipe  210 ′. The operation of the oil supply apparatus according to the modification of the second embodiment of the present invention is the same as the that of the second embodiment of the present invention. 
     In the oil supply apparatus for the linear compressor according to the second embodiment of the present invention, since the single valve  260  is only employed and disposed out of the oil supply pipe  210 ,  210 ′, the overall assembly becomes easier and the dead volume of the space formed between the mass  220 ,  220 ′ and the oil supply pipe  210 ,  210 ′ is reduced, thereby increasing the circulation volume of the oil. 
     In other words, the oil valve is disposed out of a portion of the oil supply means on the oil discharge side and the oil suction inlet is formed at the slide surface of the oil supply means, particularly, on the same side as the oil discharge outlet in the basis of the mass, so that the oil suction inlet is naturally open and closed, being covered or uncovered by the mass, in the sliding of the mass, thereby increasing the circulation volume of the oil. 
     Next, an oil supply apparatus for a linear compressor according to a third embodiment of the present invention will be described with reference to the accompanying drawings. 
     In the oil supply apparatus for the linear compressor according to the third embodiment of the present invention, in an oil supply tube  310  of a hollow cylindrical type which is an oil supply means disposed at an outer side of the compressor unit  10 , an end thereof is connected with a discharge cover  350  under the condition of which a lower semicircle of the end thereof is open. 
     That is, as shown in FIGS. 12 through 14B, the oil supply tube  310  is connected with the compressor unit  10  by which an upper semicircle portion of the end of the oil supply tube  310  at the oil discharge side is compressively inserted into the discharge cover  350 . In addition, an end of the oil supply tube  310  is closed, instead of using the suction cover  140  employed in the first embodiment of the present invention. 
     Further, an oil valve  360  formed in a disk type is disposed at a connecting area of the oil supply tube  310  and the discharge cover  350  in order to selectively communicate the oil supply tube  310  with the discharge cover  350  in accordance with the moving direction of the oil supply tube  310 , the oil valve  360 , as shown in FIG. 13, being disposed from a top to a bottom of the inside of the oil supply tube  310  and a center of which being fixed by a bottom of the discharge cover  350 . 
     While, a mass  320  is inserted in the oil supply tube  310 , the mass  320  sucking/discharging the oil to/from the oil supply tube  310  by the pressure difference due to the inertial force produced by the oil supply tube  310  which reciprocates by the vibration of the compressor unit  10 , and first and second compression coil springs  331 ,  332  are respectively connected with both ends of the mass  320 . Further, an end of the second coil spring  332  which is placed at the open end of the oil supply tube is fixed at the center portion of the oil valve  360 . Here, it is noted that the inside of the oil supply tube  310  becomes narrower, as being distanced from the oil discharge side, by which the inner portion of the oil supply tube  310  is formed being stepped at least twice. That is, a discharge cover and oil valve receiving unit  314  is formed at the end of the oil supply tube  310  at the discharge cover side, and a suction/discharge unit  311  is formed in a space which is formed being stepped towards the opposite side of the discharge cover  350  from the discharge cover and oil valve receiving unit  314 , to receive the second compression coil spring  332  and an end portion of the mass  320 . Further, the mass  320  and a mass sliding portion  312 , into which the first compression coil spring  331  is inserted, are provided in the space which is formed being stepped from the suction/discharge unit  311  towards the oil suction side. While, an oil valve latching protrusion  313  is upwardly protruded from an end of the bottom of the oil supply tube  310  which is placed directly under the discharge cover and oil valve receiving unit  314 . 
     As described above, the center of one side of the oil valve  360  is fixed to the bottom of the discharge cover  350 , and the center of the side thereof is connected with the second compressing spring  332  supporting the mass  320 . Thus, the upper part of the oil valve  360  selectively opens/closes the oil discharge side of the oil supply tube  310  and the lower part thereof selectively opens/closes the oil suction side of the oil supply tube  310 . 
     Now, an operation of the oil supply apparatus for the linear compressor according to the third embodiment of the present invention will be described with the accompanying drawings. 
     In the oil supply apparatus according to the third embodiment of the present invention, there will be explained, in particular, a process of which the oil supply tube  310  sucks the oil in the hermetic vessel C while vibrating by the vibration of the compressor unit  10 , thereby supplying the oil to a slide portion between the cylinder  12  and the piston  13 . 
     That is, as shown in FIG. 14A, when the oil supply tube  310  moves in a direction ‘A’, the mass  320  moves opposite to the direction ‘A’ by the inertial force, so that the space of the suction/discharge unit  311  is relatively larger than the space of the sliding portion  312  of the mass  320  and accordingly the suction/discharge unit  311  has a lower pressure. Accordingly, the upper and lower portions of the oil valve  360  which are not fixed by the second compression coil spring  332  have a tendency to move towards the suction/discharge unit  311 . Here, the upper portion of the oil valve  360  does not move by being latched by an end portion  314   a  of the discharge cover and oil valve receiving unit  314 , so that the oil discharge side is not open, while the lower portion thereof moves towards the suction/discharge unit  311  centering around the center of the lower portion thereof, thereby opening the oil suction side, so that the oil is flowed into the oil supply tube  310  from the bottom of the hermetic vessel C. 
     On the contrary, as shown in FIG. 14B, when the oil supply tube  310  moves in a direction ‘B’, the mass  320  moves opposite to the direction ‘B’ by the inertial force, thereby thrusting the oil out of the suction/discharge unit  311 , which moves the upper portion of the oil valve  360  towards the discharge cover  350  centering around the center of the upper portion thereof, so that the oil discharge side is opened and thus the oil is flowed into the oil pocket P of the compressor unit  10  through the oil path  351 . Here, the lower portion of the oil valve  360  does not move by being latched by the oil valve latching protrusion  313 , so that the oil suction side is not opened. That is, in the oil supply apparatus for the linear compressor according to the third embodiment of the present invention, while disposing the valve which controls the suction and discharge of the oil in the oil supply means, the suction and discharge of the oil is securely processed, thereby improving the efficiency of the device. 
     As described above, the oil supply apparatus for the linear compressor according to the present invention enables the fabrication and assembly of the valve which controls the oil suction and discharge, and during the opening/closing of the valve, any part thereof does not interfere with other constituent elements, thereby improving the reliability of the compressor. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the oil supply apparatus for the linear compressor of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.