Patent Publication Number: US-6669456-B2

Title: Scroll compressor having reversion preventing device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to scroll compressor, and more particularly, to a scroll compressor, and more particularly, to a scroll compressor having a reversion preventing device that is capable of preventing a driving unit of a compressor from rotating in the opposite direction of a rotational direction to compress a fluid. 
     2. Description of the Background Art 
     In general, various types of compressors can be adopted according to a compression method, and a scroll compressor is mostly used for an air-conditioning device that requires a small and light compressor. 
     FIG. 1 is a sectional view of a scroll compressor in accordance with a conventional art. 
     As shown in FIG. 1, the conventional scroll compressor includes: a casing  106  having a suction pipe  102  for sucking a fluid and a discharge pipe  104  for discharging a compressed fluid that are connected and having a closed certain space; a driving unit  108  disposed at a lower side of the casing  106  and generating a driving force; and a compressing unit  110  disposed at an upper side of the casing  106 , connected to the driving unit  108  and the rotational shaft  112  to compress the fluid sucked into the suction pipe  102  according to the rotation of the rotational shaft  112  and discharge it to the discharge pipe  104 . 
     A main frame  113  is installed at an upper side of the casing  106  to rotatably support the upper side of the rotational shaft  112  and support the compressing unit  110 , and a lower frame  114  is installed at a lower side of the casing  106  to rotatably supporting the lower side of the rotational shaft  112 . 
     A separating panel  120  is installed at one side of the casing  106 , sectioning the inside of the casing  106  into a lower pressure side and a high pressure side. 
     The driving unit  108  includes a stator  122  fixed in the circumferential direction of the casing  106  and a rotor  124  disposed at the inner circumferential face of the stator  122  and fixed at the rotational shaft  112 , so that when power is applied to the stator  122 , the rotor  124  is rotated according to the interaction between the stator  122  and the rotor  124 , to thereby rotate the rotational shaft  112 . 
     The compressing unit  110  includes a fixed scroll  127  having a fixed vane  126  in an involute shape and being fixed at the separating panel  120 ; and an orbiting scroll  132  having an orbiting vane  130  in an involute shape corresponding to the fixed vane  126  to have a certain compression space between itself and the fixed vane  126 , being orbitably supported by the support frame  114 , and orbiting when the rotational shaft  112  is rotated. 
     A discharging passage  136  is formed at the central portion of the fixed scroll  128  to discharge the fluid compressed according to the interaction between the fixed vane  126  and the orbiting vane  130 , and a check valve  138  is installed at an upper side of the discharging passage  136  to prevent reversion of the discharged fluid. 
     In the above-described conventional scroll compressor, when power is applied to the stator  122 , the rotor  124  is rotated according to the interaction between the stator  122  and the rotor  124 , and the rotational shaft  112  fixed at the rotor  124  is rotated in a normal direction. 
     Then, the orbiting scroll  132  is moved in an orbiting manner according to the rotation of the rotational shaft  112 , to compress the fluid sucked through the suction pipe  102  owing to the interacton with the fixed scroll  127  and discharge outwardly the compressed fluid through the discharge pipe  104 . 
     At this time, the fluid discharged to the high pressure side through the discharging passage  136  is prevented from reversing by the check valve  138  installed at the discharging passage  136 . 
     The upper side and lower side of the rotational shaft  112  are rotatably supported by the main frame  114  and the lower frame  114 , respectively, and rotated in the normal direction according to the driving of the driving unit  108 . 
     However, the conventional scroll compressor has the following problem. 
     That is, in case of employing a single phase motor as the driving unit generating the rotational force, if a load generated during the operation of the compressor becomes greater than a motor torque, the rotational force of the motor is reduced, and moreover, the motor is reversely rotated, causing an abnormal vibration of the compressor and an abnormal noise, resulting in that a reliability of the compressor is degraded. 
     In addition, in case of employing a three phase motor as the driving unit generating the rotational force, if a connection of the motor is made erroneously, the motor is rotated in a reverse direction, causing an abnormal vibration and a noise, also resulting in that a reliability of the compressor is degraded. 
     SUMMARY OF THE INVENTION 
     Therefore, an object of the present invention is to provide a scroll compressor having a reversion preventing device in which when a driving unit of a compressor is rotated in a normal direction, the rotation is allowed, while when the driving unit is rotated in a reverse direction, its rotation is stopped, thereby preventing occurrence of an abnormal vibration and noise of the driving unit and improving a reliability of the compressor. 
     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 a scroll compressor having a reversion preventing device including: a driving unit inserted in a closed casing and generating a driving force; a compressing unit for compressing and discharging a fluid when the driving unit is driven; a rotational shaft rotatably supported by a main frame and a sub-frame that are fixed at the casing and transmitting the rotational force generated from the driving unit to the compressing unit; and a reversion preventing device installed at one side of the rotational shaft and stopping the rotation of the rotational shaft when the driving unit is rotated in a direction opposite to the direction in which the driving unit compresses the fluid. 
     The reversion preventing device of the scroll compressor of the present invention includes: an eccentric part formed eccentrically as long as a certain distance from the center of the rotational shaft at one side of the rotational shaft; an eccentric ring rotatably inserted in a certain range into the eccentric part, and formed such that the center of an inner diameter is eccentric as long as a certain distance from the center of an outer diameter; a supporting part formed to be corresponded to the center of the rotational shaft at an outer side of the rotational shaft, so as to limit a rotational range of the eccentric ring; and a stopper protruded upwardly from the lower frame and interfering the eccentric ring when the rotational shaft is rotated in a reverse direction. 
     In the scroll compressor having a reversion preventing device of the present invention, the eccentric part of the reversion preventing device is formed as a disk type having a radius larger than the radius of the rotational shaft at the outer circumferential surface of the rotational shaft, and the center of the eccentric part is eccentric as long as a certain distance from the center of the rotational shaft. 
     In the scroll compressor having a reversion preventing device of the present invention, the supporting part of the reversion preventing device is formed as a disk type extended in a right angle direction of the rotational shaft from the lower surface of the eccentric part, and a hinge pin is protruded upwardly from the upper side of the opposite side of the portion that is eccentric of the eccentric part. 
     In the scroll compressor having a reversion preventing device of the present invention, the supporting part of the reversion preventing device has a radius larger than that of the eccentric part, and the center of the supporting part is corresponded to the center of the rotational shaft. 
     In the scroll compressor having a reversion preventing device of the present invention, the eccentric ring of the reversion preventing device is formed as a disk type with a certain thickness, and a slot in a circular arc shape is formed as long as a certain distance from the center of the portion that is eccentric of the eccentric ring. 
     In the scroll compressor having a reversion preventing device of the present invention, the slot of the reversion preventing device is formed having a range of about 45° from the center of the outer diameter of the eccentric ring. 
     In the scroll compressor having a reversion preventing device of the present invention, the stopper of the reversion preventing device has a certain curvature radius protruded upwardly of the upper frame and is maintained to have a certain interval from the outer diameter of the eccentric ring. 
     In the scroll compressor having a reversion preventing device of the present invention, the center of the rotational shaft of the reversion preventing device, the center of the eccentric part and the center of the hinge pin come in a straight line. 
     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     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 is a sectional view showing a scroll compressor in accordance with a conventional art; 
     FIG. 2 is a sectional view showing a scroll compressor having a reversion preventing device in accordance with the present invention; 
     FIG. 3 is an exploded perspective view showing the reversion preventing device of the scroll compressor in accordance with the present invention; 
     FIG. 4 is a sectional view taken along line I—I of FIG. 3 in accordance with the present invention; 
     FIG. 5 is an upper side view of an eccentric ring of the reversion preventing device in accordance with the present invention; 
     FIG. 6 is an upper side view showing an operation state of the reversion preventing device when a rotational shaft of the scroll compressor is rotated in a normal direction; and 
     FIG. 7 is an upper side view showing an operation state of the reversion preventing device when a rotational shaft of the scroll compressor is rotated in a reverse direction. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
     There may include a plurality of embodiments of a scroll compressor having a reversion preventing device in accordance with the present invention, of which the most preferred one will now be described. 
     FIG. 2 is a sectional view showing a scroll compressor having a reversion preventing device in accordance with the present invention. 
     The scroll compressor of the present invention includes: a casing  2  having a closed space; a driving unit  4  inserted in the casing  2  and generating a driving force; a compressing unit  6  connected to the driving unit  4  by a rotational shaft  8  so as to compress a fluid and discharge it outwardly when the driving unit  4  is driven; and a reversion preventing device installed at one side of the rotational shaft  8  and preventing reversion of the driving unit  4 . 
     A suction pipe  10  for sucking a fluid and a discharge pipe  12  for discharging the compressed fluid are respectively connected at one side of the casing  2 . Inside the casing  2 , a main frame  14  for rotatably supporting the upper side of the rotational shaft  8  and supporting the compressing unit  6 , and a lower frame  16  for rotatably supporting the lower side of the rotational shaft  8  are installed. 
     A separating plane  20  is installed at an upper side of the casing  2 , sectioning the inside of the casing  2  into a high pressure side and a lower pressure side. 
     The driving unit  4  includes a stator  22  fixed at an inner circumferential face of the casing  2  and a rotor  24  disposed at the inner circumferential face of the stator  22  and fixed at the rotational shaft  8 , so that when power is applied to the stator  22 , the rotor  24  is rotated according to an interaction between the stator  22  and the rotor  24 , thereby rotating the rotational shaft  8 . 
     The compressing unit  6  includes a fixed scroll  28  having a fixed vane  26  in an involute shape and fixed at the separating plane  20 , and an orbiting scroll  32  having an orbiting vane  30  in an involute shape corresponding to the fixed vane  26  so as to have a certain compression space between itself and the fixed vane  26 , being supported by the main frame  14  so as to be able to orbit and making an orbiting movement when the rotational shaft  8  is rotated. 
     A discharge hole  34  is formed at the center of the fixed scroll  28  to discharge the fluid compressed according to the interaction between the fixed vane  26  and the orbiting vane  30  toward the high pressure side. 
     A check valve  40  is installed at an upper side of the fixed scroll  28  to open and close the discharge hole  34  to prevent reversion of the fluid discharged toward the high pressure side. 
     The upper portion and the lower portion of the rotational shaft  8  are rotatably supported by the main frame  14  and the lower frame  16 , a central portion of which is fixed at the rotor  24  and the upper end portion thereof is eccentrically connected to the orbiting scroll  32  so as to transmit the rotational force of the driving unit  4  to the compressing unit  6 . At a certain lower portion thereof, a reversion preventing device is installed to prevent reversion of the driving unit  4 . 
     As shown in FIG. 3, the reversion preventing device includes: an eccentric part  50  formed at a lower portion of the rotational shaft  8  so as to be eccentric as long as a certain distance from the center of the rotational shaft  8 ; an eccentric ring  54  rotatably inserted to the outer circumferential face of the eccentric part  50 , and the center of the inner diameter being eccentric as long as a certain width from the center of an outer diameter; a supporting part  52  supporting the eccentric ring  54  and limiting a rotation range of the eccentric ring  54 ; and a stopper  56  vertically protruded from the lower frame  16  and stopping a reversion of the rotational shaft  8  by being interfered with the eccentric ring  54  when the driving unit  4  is rotated reversely. 
     As shown in FIG. 4, the eccentric part  50  is formed as a disk type having a radius R 2  greater than the radius R 1  of the rotational shaft at the outer circumferential face of the rotational shaft  8 , and the center of the eccentric part  50  is eccentric as long as a certain distance L 1  from the center of the rotational shaft  8 . 
     As shown in FIG. 4, the supporting part  52  is formed as a disk type extended at a right angle direction of the rotational shaft  8  from the lower surface of the eccentric part  50  and has a radius R 3  greater than the radius R 2  of the eccentric part  50 . The center of the supporting part  52  corresponds to the center of the rotational shaft  8 . 
     A hinge pin  58  is protruded in a vertical direction at the side opposite to the portion that is eccentric of the eccentric part  50 . 
     The center of the rotational shaft, the center of the eccentric part and the center of the hinge pen come in the straight line (P). 
     As shown in FIG. 5, the eccentric ring  54  is formed as a disk type with a certain thickness having a structure that the center of an inner diameter and the center of an outer diameter are eccentric as much as the eccentric amount L 2 . 
     The eccentric ring  54  is rotatably inserted into the eccentric part  50  and supported by the supporting part  52  so as not to be released. 
     The outer diameter R 4  of the eccentric ring  54  is greater than the radius R 3  of the supporting part  52 , and a slot  60  in an arc shape is formed at one side of the eccentric ring  54 , into which the hinge pin  58  is inserted. 
     The slot  60  is formed such that its one end portion is positioned at a portion that is the longest at the center of the inner diameter of the eccentric ring  54 , and the slot  60  is formed at about 45° in the circumferential direction. 
     The center of the inner diameter of the eccentric ring, the center of the outer diameter of the eccentric ring and one end portion of the slot of the eccentric ring are positioned in a straight line (Q). 
     When the eccentric ring  54  is insertedly assembled in the eccentric part  50 , the center of the outer diameter of the eccentric ring  54  and the center of the rotational shaft  8  are corresponded. 
     In this manner, as for the reversion preventing device, when the rotational shaft  8  is rotated in the normal direction, the direction in which itself compresses the fluid, the reversion preventing device corresponds with the center of the rotational shaft  8 , not affecting the rotation of the rotational shaft  8 . 
     The stopper  56  is formed to have a certain curvature radius maintaining a certain interval with the outer circumferential face of the eccentric ring  54  when the center of the outer diameter of the eccentric ring  54  is positioned to correspond with the center of the rotational shaft  8 . 
     Thus, when the rotational shaft  8  is rotated in the normal direction, the stopper  56  maintains a certain space from the eccentric ring  54 , not affecting the rotation of the rotational shaft  8 . If, however, the rotational shaft  8  is rotated in the reverse direction, the center of the rotational shaft  8  and the center of the outer diameter of the eccentric ring  54  become different to each other. Then, the outer side of the eccentric ring  54  and the inner side of the rotational shaft  8  are interfered with each other, and thus, the reverse rotation of the rotational shaft  8  is suspended. 
     The operation of the reversion preventing device of the scroll compressor of the present invention constructed as described will now be explained. 
     FIGS. 6 and 7 show operational states of the reversion preventing device of the scroll compressor in accordance with the present invention. 
     First, when the driving unit  4  is rotated in the normal direction (S), that is, the direction in which the driving unit compresses a fluid, as shown in FIG. 6, the eccentric part  50  and the supporting part  52  are rotated together, and accordingly, the hinge pin  58  formed at the supporting part  52  is moved along the slot  60  and positioned at one portion of the slot  60 . 
     Then, the center of the outer diameter of the eccentric ring  54  and the center of the rotational shaft  8  correspond and a certain interval is maintained between the eccentric ring  54  and the stopper  56 . 
     At this time, since the mutual combination of the eccentric part  50 , the supporting part  52  and the eccentric ring  54  makes a concentric circle with the rotational shaft  8 , so that no influence is made to the rotation of the rotational shaft  8 . 
     Meanwhile, if the driving unit  4  is rotated in the reverse direction, the opposite direction in which the driving unit  4  sucks the fluid, as shown in FIG. 7, the rotational shaft  8  is rotated in the reverse direction, and accordingly, the eccentric part  50  and the supporting part  52  are rotated in the reverse direction like the rotational shaft  8 . 
     At this time, the hinge pin  58  formed at the supporting part  52  is moved along the slot  60  and positioned at the other end portion of the slot  60 . 
     Then, the center of the outer diameter of the eccentric ring  54  goes beyond the center of the rotational shaft  8 , and at this time, the outer face of the eccentric ring  54 , the farthest from the center of the rotational shaft  8  is interfered by the stopper  56 , stopping the reverse rotation of the rotational shaft  8 . 
     As so far described, the scroll compressor having a reversion preventing device of the present invention has the following advantage. 
     That is, since the reversion preventing device is installed at the rotational shaft in order to stop the rotation of the rotational shaft if the rotational shaft is rotated in the reverse direction, blocking the driving unit from being rotated in the reverse direction. Thus, an abnormal vibration and a noise occurrence of the driving unit can be prevented, and thus, a reliability of the compressor can be improved. 
     As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims.