Pursuant to 35 U.S.C. §119(a), this application claims the benefit of earlier filing date and right of priority to Korean Application No. 10-2013-0063591, filed on Jun. 3, 2013, the contents of which is incorporated by reference herein in its entirety.
1. Field
This relates to a scroll compressor.
2. Background
A scroll compressor may include a fixed scroll fixed in an inner space of a container, and an orbiting scroll engaged with the fixed scroll and performing an orbiting movement forming a pair of compression chambers that continuously move between a fixed wrap of the fixed scroll and an orbiting wrap of the orbiting scroll. Scroll compressors may smoothly performs suctioning, compressing, and discharging operations on refrigerant to obtain stable torque, while achieving a relatively high compression ratio compared to other types of compressor, may be used for compressing refrigerant in, for example, air-conditioning devices, and the like. Scroll compressors may include a fixed radius type scroll compressor in which the orbiting scroll rotates in the same track all the time, regardless of changes in compression conditions, and a variable radius type scroll compressor in which the orbiting scroll may retreat in a radial direction based on compression conditions.
The embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein:
Description will now be given in detail of the exemplary embodiments, with reference to the accompanying drawings. For the sake of brief description with reference to the drawings, the same or equivalent components will be provided with the same reference numbers, and description thereof will not be repeated.
The main frame 3 is coupled to an inner circumferential surface of the container 1. A bearing hole 31 is formed at the center of the main frame 3, penetrating the main frame 3. A pocket recess 32 is formed at an upper end of the bearing hole 31 to allow a boss portion 53 of the orbiting scroll 5 to be inserted such that the boss portion is orbitable.
A fixed wrap 42 is formed on a lower surface of a disk plate 41 of the fixed scroll 4, a suction opening 43 is formed in one side of the disk plate 41 of the fixed scroll 4, and a discharge opening 44 is formed in the center of the fixed scroll 4.
An orbiting wrap 52 is formed on an upper surface of a disk plate 51 of the orbiting scroll 5 and engaged with the fixed wrap 42 of the fixed scroll 4 to form the compression chamber P. The boss portion 53 is formed on a lower surface of the disk plate 51 of the orbiting scroll 5 and coupled to the crank shaft 23. A bush bearing 54 is inserted into an inner circumferential surface of the boss portion 53 such that the bush bearing 54 is coupled with a pin 23d of the crank shaft 23.
The crank shaft 23 includes a shaft 23a press-fit to a rotor 22 of the driving motor 2, a main bearing portion 23b and a sub-bearing portion 23c respectively provided at upper and lower ends of the shaft 23a and supported by the main frame 3 and a sub-frame 7, with the pin 23d eccentrically formed at an upper end portion of the main bearing portion 23b shaft 23a and coupled to the bush bearing 54 inserted in the boss portion 53 of the orbiting scroll 5. An eccentric mass 8 is coupled to the main bearing portion 23b or the shaft 23a to cancel out an eccentric load generated while the orbiting scroll 5 performs an orbiting motion.
A suction pipe and a discharge pipe 12 extend through an outer wall of the container 1.
In the scroll compressor shown in
In this case, behavior of the orbiting scroll 5 may be unstable due to centrifugal force produced as a result of the orbiting movement, gas force produced as the refrigerant is compressed, and gas repulsive force in a direction opposite the centrifugal force applied thereto, but the orbiting scroll 5 supported by the main frame 3 may be appropriately adjusted to continue to make an orbiting movement.
However, in the scroll compressor shown in
Also, since the crank shaft 23 is subjected to a large eccentric load, a weight of the eccentric mass 8 installed in the crank shaft 23 is increased, thus increasing cost, deformation of the crank shaft 23 is increased, thus degrading compression efficiency due to friction loss, centrifugal force of the eccentric mass 8 is increased, thus increasing acting force at a welding point, increasing noise of the compressor and degrading reliability.
Also, since the bearing hole 31 of the main frame 3 supporting the crank shaft 23 and the pocket recess 32 in which the boss portion 53 of the orbiting scroll 5 is inserted are spaced apart by a predetermined gap, a length of the main bearing portion 23b of the crank shaft 23 is increased and the crank shaft 23 is subjected to a large eccentric load 8, increasing a size of the main frame 3, which may increase a length of the compressor in an axial direction, an increase in material costs, and a limitation in a lamination height of the motor.
As shown in
The main frame 130 may be coupled to an inner circumferential surface of the container 110, and a bearing hole 131 may be formed in the center of the main frame 130, penetrating main frame 130. The bearing hole 131 may have a uniform diameter from an upper end of the bearing hole 131 to a lower end thereof.
The fixed scroll 140 may include a fixed wrap 142 that protrudes from a lower surface of a disk plate 141 to form the compression chamber P together with an orbiting wrap 152 of the orbiting scroll 150, and a suction opening 143 may be formed in the disk plate 141 of the fixed scroll 140 and communicate with the compression chamber P together with the orbiting wrap 152.
A discharge opening 144 may be formed at the center of the disk plate 141 of the fixed scroll 140 to allow the compression chamber P and an inner space of the container 110 to communicate with each other, and a check valve (not shown) may be installed in an end portion of the discharge opening 144 to open the discharge opening 144 when the compressor is normally operated and close the discharge opening 144 when the compressor is stopped to prevent a discharged refrigerant to flow backward to the compression chamber P.
In the orbiting scroll 150, the orbiting wrap 152 may protrude from an upper surface of a disk plate 151 and be engaged with the fixed wrap 142 of the fixed scroll 140 to form the pair of compression chambers P, and a boss portion 153 may be formed on a lower surface of the disk plate 151 of the orbiting scroll 150 and inserted into a boss coupling recess 123d of the crank shaft 123 to receive rotary power.
The boss portion 153 may be formed at a geometric center of the orbiting scroll 150. The boss portion 153 may be formed as a solid bar shape or may be formed as a hollow cylindrical shape in order to reduce the weight of the orbiting scroll 150.
The crank shaft 123 may include a shaft 123a press-fit to a rotor 122 of the driving motor 120, a main bearing portion 123b and a sub-bearing portion 123c respectively provided at upper and lower ends of the shaft 123a and supported by the main frame 130 and a sub-frame 170. The boss coupling recess 123d may be eccentrically formed at the upper end portion of the main bearing portion 123b, allowing the boss portion 153 of the orbiting scroll 150 to be insertedly coupled thereto.
An eccentric mass 180 may be coupled to the main bearing portion 123b or the shaft 123a to cancel out or balance an eccentric load generated while the orbiting scroll 10 makes an orbiting movement.
As illustrated in
For example, when an outer diameter of the main bearing portion 123b is D, an outer diameter of the boss portion 153 of the orbiting scroll 150 is d, and eccentricity of the boss coupling recess 123d is rs, the minimum gap (a) may be a=(D−d)/2−rs.
Here, if the diameter of the main bearing portion 123b is small, the minimum gap (a) may be excessively thin, degrading reliability of the main bearing portion 123b. Conversely, when the diameter of the main bearing portion 123b is large, the minimum gap (a) may be sufficiently secured, increasing reliability of the main bearing portion 123b, but a bearing area may increase, increasing friction loss. Thus, a minimum gap for securing reliability of the main bearing portion 123b and minimizing friction loss may be appropriately maintained. To this end, the minimum gap (a) may be within a range of d/20<a<d/4.
A bush bearing 200 may be installed between the boss portion 153 of the orbiting scroll 150 and the boss coupling recess 123d of the crank shaft 123.
The bush bearing 200 may be formed on an inner circumferential surface of the boss coupling recess 123d. Alternatively, as illustrated in
Thus, in a case in which the bush bearing 200 is installed on the boss coupling recess 123d, one point of the bush bearing 200 may be abraded in a concentrated manner, degrading reliability. Thus, instead, the bush bearing 200 may be installed on the outer circumferential surface of the boss portion 153 so as to be prevented damage.
As illustrated in
In a scroll compressor in accordance with the embodiment shown in
Then, refrigerant provided from the outside of the container 110 through a suction pipe 111 is introduced through the suction opening 143 of the fixed scroll 140, compressed as it moves toward a final compression chamber by the orbiting scroll 150, and is discharged to an inner space of the container 110 through the discharge opening 144 of the fixed scroll 140 from the final compression chamber. These sequential processes are repeatedly performed.
Here, as illustrated in
Also, since the eccentric load exerted on the crank shaft 123 is reduced, a weight and material cost of the eccentric mass 180 installed in the crank shaft 123 may be reduced and deformation of the crank shaft 123 may be reduced, enhancing compression efficiency. In addition, acting force on the welding points C and D between the container 110 and the main frame 130 may be reduced due to centrifugal force of the eccentric mass 180, reducing compressor noise and enhancing reliability.
Also, the main frame 130 does not need a pocket recess, reducing a length L and a diameter D1 of the main frame 130, thus reducing material costs, and reducing a length L2 of the compressor in an axial direction, thus increasing a lamination height of the motor.
In addition, since the bush bearing 200 is formed on the boss portion 153 of the orbiting scroll 150, the entire outer circumferential surface of the bush bearing 200 may be in contact with one point of the inner circumferential surface of the boss coupling recess 123d, whereby one point of the bush bearing 200 may be prevented from being in concentrated contact, and thus, damage to the bush bearing 200 may be prevented.
Another example of a bush bearing for a scroll compressor, according to embodiments as broadly described herein, will be described as follows.
In the embodiment described above, the bush bearing is formed by coating a self-lubricating material on the outer circumferential surface of the boss portion. In contrast, in the embodiment shown in
A basic configuration and operational effects of this arrangement are similar to those of the previous embodiment described above. However, in this embodiment, a thickness of the bearing portion may be greater than that of the previous embodiment. However, since stiffness of the bearing portion is increased, reliability thereof may be enhanced.
In a scroll compressor as embodied and broadly described herein, as illustrated in
In this embodiment, a basic configuration and operational effects are similar to those of the previous embodiment described above. However, in this embodiment, since the bush bearing 200 is formed of an engineering plastic material having an ether ketone linkage such as PEEK having self-lubricating properties, a thickness of the bush bearing 200 is not significantly increased and a predetermined extra thickness may be secured, relative to the case of forming the bush bearing 200 through coating, whereby damage to the bush bearing 200 due to abrasion may be alleviated.
A scroll compressor is provided in which a height difference between a point of support at which a crank shaft is supported by a main frame and a point of application at which the crank shaft acts on an orbiting scroll is eliminated or reduced to reduce an eccentric load applied to the crank shaft to thus reduce friction loss of a bearing to improve compression efficiency, and acting force at a welding point is reduced to reduce noise of the compressor and enhance reliability.
A scroll compressor is provided in which an eccentric load applied to a crank shaft is reduced to reduce a weight of an eccentric mass installed in the crank shaft and material cost, deformation of the crank shaft is reduced to enhance compression efficiency, and acting force at a welding point due to centrifugal force of the eccentric mass is also reduced to reduce compressor noise and enhance reliability.
A scroll compressor is provided in which a length and size of a main frame are reduced to reduce material cost and a length of the compressor in an axial direction is reduced to increase a lamination height of a motor.
A scroll compressor, as embodied and broadly described herein, may include a container; a frame coupled to the container and having a bearing hole formed therein; a fixed scroll coupled to the frame and having a fixed wrap formed therein; an orbiting scroll supported by the frame and including an orbiting wrap engaged with the fixed wrap to form continuously moving compression chambers and a boss portion protruded toward the bearing hole to receive rotary power from a driving motor; and a crank shaft, to which the boss portion of the orbiting scroll is coupled, configured to transfer rotary power from the driving motor to the orbiting scroll, wherein a boss coupling recess is formed in the crank shaft such that the boss portion of the orbiting scroll is inserted into the boss coupling recess, and a bush bearing is provided on an outer circumferential surface of the boss portion and forms a bearing surface with an inner circumferential surface of the boss coupling recess.
The boss coupling recess may be formed to be eccentric with respect to a central axis.
Based on a diameter (d) of the boss portion of the orbiting scroll, a minimum gap (a) from an outer circumferential surface of the bush bearing to an inner circumferential surface of the boss coupling recess may be within a range of /20<a<d/4.
The bush bearing may be coated to be formed on the boss portion.
The bush bearing may be formed of a self-lubricative material.
The bush bearing may be press-fit to be coupled to the boss portion.
The bush bearing may be formed as a single member having self-lubricativeness.
The bush bearing may have an annular cross-sectional shape.
The bush bearing may include a fixed bush having an annular cross-sectional shape and a lubricating bush formed on an outer circumferential surface of the fixed bush, wherein the fixed bush may be formed of a material having high stiffness relative to that of the lubricating bush.
The lubricating bush may be formed of a plastic material having self-lubricativeness.
At least a portion of the bush bearing may be formed of a plastic material having an ether ketone linkage.
A bearing portion may be formed in the crank shaft and inserted into the bearing hole of the frame so as to be supported in a radial direction, and the boss coupling recess may be formed in the bearing portion.
A scroll compressor, as embodied and broadly described herein, may include a fixed scroll having a fixed wrap formed therein; an orbiting scroll having an orbiting wrap engaged with the fixed wrap to form continuously moving compression chambers and including a boss portion to receive rotary power from a driving motor; and a crank shaft having a boss coupling recess to which the boss portion of the orbiting scroll is coupled, the boss coupling recess eccentrically formed with respect to a central axis, wherein a bush bearing is coupled to an outer circumferential surface of the boss portion and the bush bearing has an annular cross-sectional shape.
Based on a diameter (d) of the boss portion of the orbiting scroll, a minimum gap (a) from an outer circumferential surface of the bush bearing to an inner circumferential surface of the boss coupling recess may be within a range of d/20<a<d/4.
The bush bearing may be formed as a single member having self-lubricativeness.
The bush bearing may include a fixed bush having an annular cross-sectional shape and a lubricating bush formed on an outer circumferential surface of the fixed bush, wherein the fixed bush may be formed of a material having high stiffness relative to that of the lubricating bush.
The lubricating bush may be formed of a plastic material having self-lubricativeness.
At least a portion of the bush bearing may be formed of a plastic material having an ether ketone linkage.
In a scroll compressor as embodied and broadly described herein, since the boss portion of the orbiting scroll is inserted into and coupled to the boss coupling recess of the crank shaft, an eccentric load exerted on the crank shaft is reduced to reduce friction loss of the bearing portion, enhancing compression efficiency and reliability and reducing noise. Also, a weight and material cost of the eccentric mass may be reduced and deformation of the crank shaft is reduced, enhancing compression efficiency.
Also, since the main frame does not need a pocket recess, a length L and a diameter of the main frame may be reduced to reduce material costs and reduce a length of the compressor in an axial direction to increase a lamination height of the motor.
In addition, since the bush bearing is coated to be formed on the boss portion of the orbiting scroll, the outer circumferential surface of the bush bearing may be in contact with the entirety of the inner circumferential surface of the boss coupling recess, whereby the bush bearing may be prevented from being concentratively brought into contact with one point of the inner circumferential surface of the boss coupling recess, and thus, damage to the bush bearing may be prevented.
Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
Number | Date | Country | Kind |
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10-2013-0063591 | Jun 2013 | KR | national |