Patent Application
20110123366
The present invention relates in general to a compressor, and more particularly, to a compressor which eliminates sliding contacts between a cylinder and a roller to minimize the mixing of lubricating oil into refrigerant, and is structured to be able to evenly distributing lubricating oil over sliding contact portions of a compressor actuator by pumping the oil from the inside on an axis of rotation.
In addition, the present invention relates to a compressor having a structure to accommodate a refrigerant passage separately from an oil feed passage such that the mixing of oil into refrigerant is minimized and the operational reliability is enhanced.
In general, a compressor is a mechanical apparatus that receives power from a power generation apparatus such as an electric motor, a turbine or the like and compresses air, refrigerant or various operation gases to raise a pressure. The compressor has been widely used in electric home appliances such as a refrigerator and an air conditioner, or in the whole industry.
The compressors are roughly classified into a reciprocating compressor wherein a compression chamber to/from which an operation gas is sucked and discharged is defined between a piston and a cylinder and refrigerant is compressed as the piston linearly reciprocates inside the cylinder, a rotary compressor which compresses an operation gas in a compression chamber defined between an eccentrically-rotated roller and a cylinder, and a scroll compressor wherein a compression chamber to/from which an operation gas is sucked and discharged is defined between an orbiting scroll and a fixed scroll and refrigerant is compressed as the orbiting scroll rotates along the fixed scroll.
Although the reciprocating compressor is excellent in mechanical efficiency, its reciprocating motion causes serious vibrations and noise problems. Because of this problem, the rotary compressor has been developed as it has a compact size and demonstrates excellent vibration properties.
The rotary compressor is configured in a manner that a motor and a compression mechanism part are mounted on a drive shaft in a hermetic container, a roller fitted around an eccentric portion of the drive shaft is positioned inside a cylinder that has a cylinder shape compression chamber therein, and at least one vane is extended between the roller and the compression chamber to divide the compression chamber into a suction region and a compression region, with the roller being eccentrically positioned in the compression chamber. In general, vanes are supported by springs in a recess of the cylinder to pressurize surface of the roller, and the vane(s) as noted above divide(s) the compression chamber into a suction region and a compression region. In general, vanes are supported by springs in a recess of the cylinder to pressurize surface of the roller, and the vane(s), as noted above, divide(s) the compression chamber into a suction region and a compression region. The suction region expands gradually with the rotation of the drive shaft to suck refrigerant or a working fluid into it, while the compression region shrinks gradually at the same time to compress refrigerant or a working fluid in it.
In such a conventional rotary compressor, the eccentric portion of the drive shaft continuously makes a sliding contact, during its rotation, with an interior surface of a stationary cylinder where the roller is secured and with the tip of the vane where the roller is also secured. A high relative velocity is created between constituent elements making a sliding contact with each other, and this generates frictional loss, eventually leading to degradation of compressor efficiency. Also, there is still a possibility of a refrigerant leak at the contact surface between the vane and the roller, thereby causing degradation of mechanical reliability.
Unlike the conventional rotary compressors subject to stationary cylinders, U.S. Pat. No. 7,344,367 discloses a rotary compressor having a compression chamber positioned between a rotor and a roller rotatably mounted on a stationary shaft. In this patent, the stationary shaft extends longitudinally inwardly within a housing and a motor includes a stator and a rotor, with the rotor being rotatably mounted on the stationary shaft within the housing the roller being rotatably mounted on an eccentric portion that is integrally formed with the stationary shaft. Further, a vane is interposed between the rotor and the roller to let the roller rotate along with the rotation of the roller, such that a working fluid can be compressed within the compression chamber. However, even in this patent, the stationary shaft still makes a sliding contact with an interior surface of the roller so a high relative velocity is created between them and the patent still shares the problems found in the conventional rotary compressor.
Meanwhile, WO2008/004983 discloses another type of rotary compressors, comprising: a cylinder, a rotor mounted in the cylinder to rotate eccentrically with respect to the cylinder, and a vane positioned within a slot which is arranged at the rotor, the vane sliding against the rotor, wherein the vane is connected to the cylinder to transfer a force to the cylinder rotating along with the rotation of the rotor, and wherein a working fluid is compressed within a compression chamber defined between the cylinder and the rotor. However, these rotary compressors require a separate electric motor for driving the rotor because the rotor rotates by a drive force transferred through the drive shaft. That is, when it comes to the rotary compressor in accordance with the disclosure, a separate electric motor is stacked up in the height direction about the compression mechanism part consisting of the rotor, the cylinder and the vane, so the total height of the compressor inevitably increases, thereby making difficult to achieve compact design.
Moreover, rotary compressors require lubrication to reduce frictional force and frictional heat between members that make a sliding contact while rotating. In a conventional compressor, the roller and the cylinder are typical members making a sliding contact so an interior of the compression chamber had to be lubricated, and this made it unavoidable the mixing of refrigerant and lubricating oil. On account of this, an accumulator had to be installed additionally to separate the refrigerant from the lubricating oil, which required extra large compressors and became the leading cause of manufacturing cost.
Besides, in case the electromotive mechanism and the compression mechanism are connected with a drive shaft and laminated in the height direction, an oil pump and an oil feed passage had to be provided additionally. Also, with the approach of pumping up the lubricating oil stored at the bottom of the interior of the housing and then scattering the oil upward to feed it to the compression mechanism, the lubricating oil could not be distributed evenly over the sliding contact portions.
The present invention is conceived to solve the aforementioned problems in the prior art. An object of the present invention is to provide a compressor
which eliminates sliding contacts between a cylinder and a roller thereby minimizing the mixing of lubricating oil into refrigerant, and is structured a structure to be able to evenly distributing lubricating oil over sliding contact portions.
Another object of the present invention is to provide a compressor having a structure of high oil recovery and enhanced operational reliability by minimizing the mixing of oil into refrigerant.
An aspect of the present invention provides a compressor, comprising: a hermetic container storing oil at a lower portion; a stator mounted within the hermetic container; a cylinder type rotor rotating within the stator by a rotating electromagnetic field from the stator, with the rotor defining a compression chamber inside; a roller rotating within the compression chamber of the cylinder type rotor by a rotational force transferred from the rotor, with the roller compressing refrigerant during rotation; an axis of rotation integrally formed with the roller and extending in an axial direction; a vane dividing the compression chamber into a suction region where refrigerant is sucked in and a compression region where the refrigerant is compressed/discharged from, with the vane transferring the rotational force from the cylinder type rotor to the roller; and oil feed passages provided to the axis of rotation and the roller, with the oil feed passage feeding oil that is pumped along the motion of the axis of rotation to an area where two or more members are slid onto within the compression chamber.
The compressor of in accordance with the first embodiment of the present invention further comprises: first and second covers joined to the cylinder type rotor in the axial direction, with the covers defining the compression chamber therebetween and receiving the axis of rotation therethrough; and first and second bearings joined to the first and second covers for rotatably supporting the axis of rotation, the roller, and the first and second covers onto the hermetic container.
In the compressor of in accordance with the first embodiment of the present invention, the oil feed passage comprises an oil feeder formed within the axis of rotation that is protruded from one side of the roller in the axis direction, and a first oil feed hole radially passing through one portion of the axis of rotation that is contiguous with the roller to be in communication with the oil feeder.
In the compressor of in accordance with the first embodiment of the present invention, the oil feed passage further comprises first oil storage cavities formed in the axis of rotation having the first oil feed hole and in one axial side of the roller, with the roller being connected to the axis of rotation, so as to temporarily collect oil supplied through the first oil feed hole.
In the compressor of in accordance with the first embodiment of the present invention, the first oil storage cavities are formed to lubricate a bearing in contact with an outer circumferential surface of the axis of rotation and with one axial side of the second rotating member.
In the compressor of in accordance with the first embodiment of the present invention, the oil feed passage further comprises a second oil feed hole axially passing through the second rotating member to be in communication with the first oil storage cavities, and second oil storage cavities formed in the other axial side of the second rotating member having the second oil feed hole and in the axis of rotation connected thereto so as to temporarily collect oil supplied through the second feed hole.
In the compressor of in accordance with the first embodiment of the present invention, the second oil storage cavities are formed to lubricate a bearing in contact with the axis of rotation and the other axial side of the roller.
In the compressor of in accordance with the first embodiment of the present invention, the oil feed passage further comprises oil feed cavities provided to the roller and the vane so as to communicate with at least one of the first and second oil storage cavities.
In the compressor of in accordance with the first embodiment of the present invention, the oil feed passage is mounted with an oil feed member for pumping oil up to an oil feeder, with the oil feed member being twisted in a spiral shape.
In the compressor of in accordance with the first embodiment of the present invention, the oil feeder feeds oil through the oil feed passage by a capillary phenomenon.
In the compressor of in accordance with the first embodiment of the present invention, the oil feeder has a groove in an inner circumferential thereof, and an oil feed member is press fitted therein except for the groove.
In the compressor of in accordance with the first embodiment of the present invention, the oil feed member having a groove in an outer circumferential surface is press fitted into the oil feeder.
A compressor in accordance with the second embodiment of the present invention further comprises a shaft cover and a main cover joined to the cylinder type roller and the roller in the axial direction for defining a compression chamber therebetween, with the shaft cover covering the axis of rotation, with the main cover receiving the axis of rotation; a mechanical seal axially joined to the shaft cover and rotatably supporting the shaft cover onto the hermetic container; and a bearing axially joined to the main cover and rotatably supporting the main cover, the axis of rotation and the roller onto the hermetic container.
In the compressor of in accordance with the second embodiment of the present invention, the oil feed passage comprises an oil feeder formed within the axis of rotation in the axis direction, and a first oil feed hole radially passing through one portion of the axis of rotation that is contiguous with the roller to be in communication with the oil feeder.
In the compressor of in accordance with the second embodiment of the present invention, the oil feed passage further comprises first oil storage cavities formed in the axis of rotation having the first oil feed hole and in one axial side of the roller, with the roller being connected to the axis of rotation, so as to temporarily collect oil supplied through the first oil feed hole.
In the compressor of in accordance with the second embodiment of the present invention, the first oil storage cavities are formed to lubricate a bearing in contact with an outer circumferential surface of the axis of rotation and with one axial side of the second rotating member.
In the compressor of in accordance with the second embodiment of the present invention, the oil feed passage further comprises a second oil feed hole axially passing through the second rotating member to be in communication with the first oil storage cavities, and second oil storage cavities formed in the other axial side of the roller having the second oil feed hole so as to temporarily collect oil supplied through the second feed hole.
In the compressor of in accordance with the second embodiment of the present invention, the second oil storage cavities are formed to lubricate a bearing in contact with the axis of rotation and with the other axial side of the roller.
In the compressor of in accordance with the second embodiment of the present invention, the shaft cover has cavities for storing oil which are formed on an opposite side of the second oil storage cavities.
In the compressor of in accordance with the second embodiment of the present invention, the oil feed passage further comprises oil feed cavities provided to the roller and the vane so as to communicate with at least one of the first and second oil storage cavities.
In the compressor of in accordance with the second embodiment of the present invention, the oil feed passage is mounted with an oil feed member for pumping oil up to an oil feeder, with the oil feed member being twisted in a spiral shape.
In the compressor of in accordance with the second embodiment of the present invention, the oil feeder feeds oil through the oil feed passage by a capillary phenomenon.
In the compressor of in accordance with the second embodiment of the present invention, the oil feeder has a groove in an inner circumferential thereof, and an oil feed member is press fitted therein except for the groove.
In the compressor of in accordance with the second embodiment of the present invention, the oil feed member having a groove in an outer circumferential surface is press fitted into the oil feeder.
The compressor of the present invention comprises a refrigerant suction passage for sucking refrigerant into the compression chamber through the axis of rotation and the roller, with the refrigerant suction passage formed separately from an oil feed passage.
The compressor having the above configuration in accordance with the present invention arranges the refrigerant passage separately from the oil passage, so it can prevent the mixing of refrigerant and oil and further reduce a much refrigerant and oil leak, thereby guaranteeing an enhanced operational reliability. Moreover, since the roller and the cylinder rotate together with the cover, a sliding contact is noticeably reduced so there is no need to extend the oil feed passage into the interior of the cylinder. In result, nearly none of the oil is mixed with the refrigerant, and the operational reliability as well as the endurance of drive members can be maximized.
The operational reliability of the compressor is also enhanced by providing a compressor with an efficient lubrication structure to evenly distribute lubricating oil over contact portions.
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
As shown in
The hermetic container 110, as shown in
The first rotating member 130, as shown in
The first cover 133 and the second cover 134 are coupled to the rotor 131 and/or the cylinder 132 in the axial direction, and the compression chamber P (see
The second rotating member 140, as shown in
To explain the mount structure of the vane 143 with reference to
At this time, the rotation of the cylinder shape rotors 131 and 132 is transferred to the vane 143 formed at the second rotating member 143 so as to rotate the rotating member, and the bushes 144 inserted into the vane mount slot 132h oscillate, thereby enabling the cylinder shape rotors 131 and 132 and the second rotating member 140 to rotate together. While the cylinder 132 and the roller 142 rotate, the vane 143 makes a relatively linear reciprocating motion with respect to the vane mount slot 132h of the cylinder 132.
Therefore, when the rotor 131 receives a rotational force derived from the rotating electromagnetic field of the stator 120 (see
To see how the suction, compression and discharge cycle of the compression mechanism part works,
As shown in
The first bearing 150 is constructed to adopt a journal bearing for rotatably supporting the outer peripheral surface of the axis of rotation 141 and the inner peripheral surface of the first cover 133, and a trust bearing for rotatably supporting the upper surface of the first cover 133. The first bearing 150 includes a suction guide passage 151 communicated with a suction passage 141a of the axis of rotation 141. The suction guide passage 151 is opened in communication with the interior of the hermetic container 110 to let the refrigerant having been sucked in through the suction tube 114 enter the hermetic container 110. Moreover, the first bearing 150 includes a discharge guide passage 152 which is opened in communication with the discharge port 133a of the first cover 133, with the discharge port 133a taking the form of a ring or an annular ring to accommodate a revolving orbit of the discharge port 133a of the first cover 133 so as to discharge the refrigerant coming out through the discharge port 133a of the first cover 133 via the discharge tube 115 even if the discharge port 133a of the first cover 133 is revolving. Of course, the discharge guide passage 152 includes a discharge tube mount hole 153 through which it can be connected directly to the discharge tube 115 for a direct discharge of the refrigerant outside.
The second bearing 160 is constructed to adopt a journal bearing for rotatably supporting the outer peripheral surface of the axis of rotation 141 and the inner peripheral surface of the second cover 134, and a trust bearing for rotatably supporting the lower surface of the roller 142 and the lower surface of the second cover 134. The second bearing 160 is composed of a planar shape support 161 that is bolt-fastened to the lower shell 113, and a shaft 162 disposed at the center of the support 161, with the shaft having an upwardly protruded hollow 162a. At this time, the center of the hollow 162a of the second bearing 160 is formed at a position eccentric from the center of the shaft 162 of the second bearing 160, with the center of the shaft 162 of the second bearing 160 being collinear with the rotation centerline of the first rotating member 130, the center of the hollow 162a of the second bearing 160 being collinear with the axis of rotation 141 of the second rotating member 140. That is to say, although the center line of the axis of rotation 141 of the second rotating member 140 can be formed eccentric with respect to the rotation center line of the first rotating member 130, it can also be formed concentrically along the longitudinal center line of the roller 142. More details are now provided below.
To enable the first and second rotating members 130 and 140 to compress refrigerant while rotating the second rotating member 140 is positioned eccentric with respect to the first rotating member 130. One example of relative positioning of the first and second rotating members 130 and 140 is illustrated in
As for the preferred embodiment of the present invention illustrated in
To see an example of how the compressor according to the first embodiment of the present invention is assembled by referring to
After a rotation assembly assembled with the first and second rotating members 130 and 140 are put together as described above, the second bearing 160 is bolt-fastened to the lower shell 113, and the rotation assembly is then assembled to the second bearing 160, with the inner circumferential surface of the shaft 134a of the second cover 134 circumscribing the outer circumferential surface of the shaft 162, with the outer circumferential surface of the axis of rotation 141 being inscribed in the hollow 162a of the second bearing 160. Next, the stator 120 is press fitted into the body 111, and the body 111 is joined to the upper shell 112, with the stator 120 being positioned to maintain an air-gap with the outer circumferential surface of the rotation assembly. After that, the first bearing 150 is joined or assembled to the upper shell 112 in a way that the discharge tube 115 of the upper shell 112 is press fitted into the discharge mount hole 153 (see
Therefore, with all of the rotation assembly assembled with the first and second rotating members 130 and 140, the body 111 mounted with the stator 120, the upper shell 112 mounted with the first bearing 150, and the lower shell 113 mounted with the second bearing 160 being joined in the axial direction, the first and second bearings 150 and 160 rotatably support the rotation assembly onto the hermetic container 110 in the axial direction.
To see how the first embodiment of the compressor of the present invention operates by referring to
During the rotation of the first and second rotating members 130 and 140, oil is supplied to sliding contact portions between the bearings 150 and 160 and the first and second rotating members 130 and 140, or to sliding contact portions between the first rotating member 130 and the second rotating member 140, so as to lubricate between the members. To this end, the axis of rotation 141 is dipped into the oil that is stored at the lower area of the hermetic container 110, and any kind of oil feed passage for oil supply is provided to the second rotating member 140. In more detail, when the axis of rotation 141 starts rotating in the oil stored at the lower area of the hermetic container 110, the oil pumps up or ascends along the helical member 145 or groove disposed within an oil feeder 141b of the axis of the rotation 141 and escapes through an oil feed hole 141c of the axis of the rotation 141, not only to gather up at an oil storage cavity 141d between the axis of rotation 141 and the second bearing 160 but also to lubricate between the axis of rotation 141, the roller 142, the second bearing 160, and the second cover 134. The oil having been gathered up at the oil storage cavity 141 d between the axis of rotation 141 and the second bearing 160 pumps up or ascends through the oil feed hole 142b of the roller 142, not only to gather up at oil storage cavities 141e and 142c between the axis of rotation 141, the roller 142 and the first bearing 150, but also to lubricate between the axis of rotation 141, the roller 142, the first bearing 150, and the first cover 133.
To see in more detail how oil is fed through the inside of the axis of rotation 141 by referring to
As for a preferred embodiment, the oil fee member 145a may take the form of a helical shape to function as a centrifugal pump for example. The helical oil feed member can be prepared by twisting a roughly rectangular board in a spiral form. In such case, the board may be twisted to the left or right to help the oil climb up along the face of the board according to the rotational direction of the axis of rotation 141. Besides the helical shape, the oil feed member may also take the form of a pillar shape with a helical groove formed in its outer circumferential surface, or a propeller shape. The helical oil feed member 145a rotates together with the axis of rotation 141 within the oil feeder 141b to pump up oil by the rotational force.
Moreover, there is provided an oil feed passage communicating with peripheral area and the roller 142 to evenly distribute the oil having been pumped up along the axis of rotation 141. As such, the oil feeder 141b has one end blocked to prevent the mixing of oil into the refrigerant in an area close to the roller 142 in the axial direction, and an oil feed hole 141c is drilled, passing through the axis of rotation 141 located contiguous with the roller 142. The oil flowing out through the oil feed hole 141c is fed between the outer circumferential surface of the axis of rotation 141 and the second bearing 160, and between the roller 142 and the second cover 134, thereby forming a film of a uniform thickness for lubrication. The second cover 134 has a collection cavity to collect the oil having been used for lubricating between the roller 142 and the contact surface to the bottom of the hermetic container 110.
In addition, an oil storage cavity 141d is formed between the axis of rotation 141 and the second bearing 160 to serve as a temporal reservoir of the oil flowing out from the oil feed hole 141c. Meanwhile, the roller 142 has an oil feed hole 142b that is drilled in the axial direction to be in communication with the oil storage cavity 141d. Thus, the rotational friction of the axis of rotation 141 is lubricated through oil in the oil storage cavity 141e that is formed between the outer circumferential surface of the axis of rotation 141 and the first bearing 150 at the upper portion of the roller, and the oil is temporarily collected in the oil storage cavity 142c between the roller 142 and the first bearing 150 and used later for lubricating the friction between the roller 142 and the first bearing 150 or the first cover 133.
The refrigerant flow will now be explained in details based on
When the first and second rotating members 130 and 140 rotate by the medium of the vane 143, refrigerant is sucked in, compressed and discharged. In more detail, the roller 142 and the cylinder 132 repeatedly contact, separate, and retouch, thereby varying the volume of the suction region and the discharge region divided by the vane 143 within the compression chamber P so as to suck in, compress, and discharge refrigerant. That is to say, as the volume of the suction region gradually expands, refrigerant is sucked into the suction region of the compression chamber P through the suction tube 114 of the hermetic container 110, the interior of the hermetic container 110, the suction guide passage 151 of the first bearing 150, the suction passage 141a of the axis of rotation 141 and the suction passage 142a of the roller 142. Concurrently, as the volume of the discharge region gradually shrinks along the motions of the roller 142 and the cylinder 132, refrigerant is compressed, and when a discharge valve (not shown) is open at a pressure above the preset level the compressed refrigerant is then discharged in the direction of the first cover 133 through the discharge incline portion 136 (see
Refrigerant having passed through the suction guide passage 151 is sucked in axially through the suction passage 141a (see
In reference to
As shown in
The stator 220 is composed of a core 221, and a coil 222 primarily wound around the core 221. Since the stator 220 has the same construction with the compressor stator in accordance with the first embodiment of the present invention, it will not be explained here.
The first rotating member 230, as shown in
The shaft cover 233 and the main cover 234 are coupled to the rotor 231 or the cylinder 232 in the axial direction, and the compression chamber P is defined between the cylinder 232 and the shaft cover 233 and the main cover 234. The shaft cover 233 is composed of a planar shape cover portion 233A for covering the upper surface of the roller 242, and a downwardly projecting hollow shaft 233B at the center. The cover portion 233A of the shaft cover 233 includes a suction port 233a for sucking in refrigerant therethrough, a discharge port 233b for discharging a compressed refrigerant therethrough from the compression chamber P, and a discharge valve (not shown) mounted thereon. The shaft 233B of the shaft cover 233 includes discharge guide passages 233c and 233d for guiding refrigerant to the outside of the hermetic container 210, with the refrigerant having been discharged through the discharge port 233b of the shaft cover 233. Also, the shaft 233B is designed to be inserted into the mechanical seal 270 by forming part of its outer circumferential surface at the tip. Similar to the shaft cover 233, the main cover 234 is composed of a planar shape cover portion 234a for covering the lower surface of the roller 242, and a downwardly projecting hollow shaft portion 234b at the center. Although the shaft portion 234b may be optionally omitted, its role in receiving a load acting thereon increases a contact area with the bearing 260 and give more stable support to the main cover 234. Since the shaft cover 233 and the main cover 234 are bolt-fastened to the rotor 231 or the cylinder 232 in the axial direction, the rotor 231, the cylinder 232, and the shaft cover and the main cover 233 and 234 rotate together as one unit. Moreover, the muffler 250, which includes a suction chamber 251 communicated with the suction port 233a of the shaft cover and a discharge chamber 252 communicated with the discharge port 233b and the discharge guide passages 233c and 233d of the shaft cover 233, with the suction chamber 251 being defined separately from the discharge chamber 252, is also joined in the axial direction of the shaft cover 233. Of course, the suction chamber 251 of the muffler 250 may be omitted, but it is better for the muffler 250 to have the suction chamber with the suction port 251a to be able to suck the refrigerant within the hermetic container 210 into the suction port 233a of the shaft cover 233.
The second rotating member 240 is composed of an axis of rotation 241, a roller 242, and a vane 243. The axis of rotation 241 is protrusively formed towards one side, i.e., lower surface, in the roller 242 axis direction. Because the axis of rotation 241 is protruded only from the lower surface, its protruded length is longer than that in the case where the axis of rotation is protruded from both the upper and lower surfaces so it can support the motion of the second rotating member more stably. Also, even if the axis of rotation 241 and the roller 242 may have been manufactured separately, they must join together to be able to rotate as one unit. The axis of rotation 241 takes the form of a hollow shaft passing through the inside of the roller 242, with the hollow being composed of an oil feeder 241a for pumping oil. Here, the oil feeder 241a of the axis of rotation 241 is provided with a helical member to assist oil ascending by a rotational force, or a groove to assist oil ascending by a capillary phenomenon. The axis of rotation 241 and the roller 242 each have all kinds of oil feed holes 241b and oil storage grooves 242b and oil storage cavities 242a and 242c for supplying oil from the oil feeder 241a into between two or more members subject to sliding interactions.
The vane mount structure and a running cycle of the cylinder 232 and the roller 242 are the same as those in the first embodiment.
The first and second rotating members 230 and 240 described earlier are rotatably supported on the inside of the hermetic container 210 by the bearing 260 and the mechanical seal 270 that are coupled in the axial direction. The bearing 260 is bolt-fastened to the lower shell 213, and the mechanical seal 270 is secured to the inside of the hermetic container 210 by welding or the like in communication with the discharge tube 215 of the hermetic container 210.
The mechanical seal 270 is a device for preventing a fluid leak because of the contact between a rapidly spinning shaft and a fixed element/rotatory element in general, and is disposed between the discharge tube 215 of the stationary hermetic container 210 and the rotating shaft 233B of the shaft cover 233. Here, the mechanical seal 270 rotatably supports the shaft cover within the hermetic container 210 and communicates the shaft 233B of the shaft cover 233 with the discharge tube 215 of the hermetic container 210, while preventing a refrigerant leak between them.
The bearing 260 is constructed to adopt a journal bearing for rotatably supporting the outer peripheral surface of the axis of rotation 241 and the inner peripheral surface of the main cover 234, and a trust bearing for rotatably supporting the lower surface of the roller 242 and the lower surface of the main cover 234. The bearing 260 is composed of a planar shape support 261 that is bolt-fastened to the lower shell 213, and a shaft 262 disposed at the center of the support 261, with the shaft having an upwardly protruded hollow 262a (see
To enable the first and second rotating members 230 and 240 to compress refrigerant while rotating the second rotating member 240 is positioned eccentric with respect to the first rotating member 230. One example of relative positioning of the first and second rotating members 230 and 240 is illustrated in
To see an example of how the compressor according to one embodiment of the present invention is assembled by referring to
After a rotation assembly assembled with the first and second rotating members 230 and 240 are put together as described above, the bearing 260 is bolt-fastened to the lower shell 213, and the rotation assembly is then assembled to the bearing 260, with the inner circumferential surface of the shaft 234a of the main cover 234 circumscribing the outer circumferential surface of the shaft 262 of the bearing 260, with the outer circumferential surface of the axis of rotation 241 being inscribed in the hollow 262a of the bearing 260. Next, the stator 220 is press fitted into the body 211, and the body 211 is joined to the upper shell 212, with the stator 220 being positioned to maintain an air-gap with the outer circumferential surface of the rotation assembly. After that, the mechanical seal 270 is assembled within the upper shell 212 in a way that it is communicated with the discharge tube 215, and the upper shell 212 having the mechanical seal 270 being secured thereon is joined to the body 211, with the mechanical seal 270 being inserted into a stepped portion on the outer circumferential surface of the shaft 233B of the shaft cover 233. Of course, the mechanical seal 270 is assembled to enable the communication between the shaft 233B of the shaft cover 233 and the discharge tube 215 of the upper shell 212.
Therefore, with all of the rotation assembly assembled with the first and second rotating members 230 and 240, the body 211 mounted with the stator 220, the upper shell 212 mounted with the mechanical seal 270, and the lower shell 213 mounted with the bearing 260 being joined in the axial direction, the mechanical seal 270 and the bearing 260 rotatably support the rotation assembly onto the hermetic container 210 in the axial direction.
To see how the compressor according to the second embodiment of the present invention operates by referring to
Moreover, during the rotation of the first and second rotating members 230 and 240, oil is supplied to sliding contact portions between the bearing 260 and the first and second rotating members 230 and 240 to lubricate between the members. To this end, the axis of rotation 241 is dipped into the oil that is stored at the lower area of the hermetic container 210, and any kind of oil feed passage for oil supply is provided to the second rotating member 240. In more detail, when the axis of rotation 241 starts rotating while being dipped in the oil stored at the lower area of the hermetic container 210, the oil pumps up or ascends along the helical member 245a or grooves 245c disposed within an oil feeder 241a of the axis of the rotation 241 and flows out through an oil feed hole 24 lb of the axis of the rotation 241, not only to gather up at an oil storage cavity 241c between the axis of rotation 241 and the bearing 260, but also to lubricate between the axis of rotation 241, the roller 242, the bearing 260, and the main cover 234. Also, the oil having been gathered up at the oil storage cavity 241c between the axis of rotation 241 and the bearing 260 pumps up or ascends through the oil feed hole 242b of the roller 242, not only to gather up at oil storage cavities 233e and 242c between the axis of rotation 241, the roller 242 and the first cover 233, but also to lubricate between the axis of rotation 241, the roller 242, the shaft cover 233.
To see in more detail how oil is fed through the inside of the axis of rotation 241 by referring to
As for a preferred embodiment, the oil fee member 245a may take the form of a helical shape to function as a centrifugal pump for example. The helical oil feed member can be prepared by twisting a roughly rectangular board in a spiral form. In such case, the board may be twisted to the left or right to help the oil climb up along the face of the board according to the rotational direction of the axis of rotation 241. Optionally, the oil feed member may also take the form of a pillar shape with a helical groove formed in its outer circumferential surface, or a propeller shape. The helical oil feed member 245a rotates together with the axis of rotation 141 within the oil feeder 241b to pump up oil by the rotational force.
Moreover, there is provided an oil feed passage communicating with peripheral area and the roller 242 to evenly distribute the oil having been pumped up along the axis of rotation 241. In this embodiment, a refrigerant suction passage is separately formed above the roller 242, with the axis of rotation 241 being integrally formed with the roller 241 underneath it, and an oil passage is formed on the lower side (i.e. below the roller 242 of the axis of rotation 241). In so doing the oil feeder 241a is arranged even in the interior of the roller 242 in the axial direction, and the roller has one end blocked inside. The blocked end of the roller may be covered by the cover portion 233A of the shaft cover 233, or the upper side of the roller may optionally be blocked. In this way, the oil feed hole 241b is drilled, radially passing through the axis of rotation 241 located contiguous with the lower side of the roller 242. The oil flowing out through the oil feed hole 241c is fed between the outer circumferential surface of the axis of rotation 241 and the second bearing 260, and between the roller 242 and the second cover 234, thereby forming an oil film of a uniform thickness for lubrication. The second cover 234 has a collection cavity to collect the oil having been used for lubricating between the roller 242 and the contact surface to the bottom of the hermetic container 210.
In addition, an oil storage cavity 241c is formed between the axis of rotation 241 and the second bearing 260 to serve as a temporal reservoir of the oil flowing out from the oil feed hole 241b. Meanwhile, the roller 242 has an oil feed hole 242b that is drilled in the axial direction to be in communication with the oil storage cavity 241c, so the oil is temporarily collected at the oil storage cavities 233e and 242c formed between the shaft cover 233 and the roller 233 and then used for lubrication of friction between the roller 242 and the shaft cover 233. In detail, the oil which is supplied directly from the oil feeder 241a and the oil which is supplied through the oil feed hole 242b are temporarily stored at the oil storage cavity 233e formed in the roller 242 and the oil storage cavity 242c formed in the shaft cover 233 contacting the roller 242, and then form an oil film between the roller 242 and the shaft cover 233 to lubricate the friction between them.
Optionally, it is possible to extend the oil feeder 242a of the compressor of the second embodiment of the present invention up to the height of a contact portion between the roller 242 and the shaft cover 233 and feed oil directly to the oil storage cavities 233e and 242c. In this case, the oil feed hole 242b may not necessarily drilled in the roller 242.
According to this embodiment of the invention, because the roller 242, the cylinder 232, the shaft cover 233 and the main cover 234 rotate together, a frictional loss becomes small. In more detail, unlike the conventional techniques, the sliding contact between the cylinder 232 and the roller 242 is noticeably reduced by rotating the roller 242, the cylinder 232, the shaft cover 233 and the main cover 234 together with the rotor 231. Furthermore, the friction between the roller 242 and the shaft cover/cover 233/234 is relatively smaller than that of the conventional compressors. This is primarily because the roller 242 of the present invention compressor makes a translational motion at the contact surface with the shaft cover 233/cover 234, unlike the conventional roller making both rotational and translational motions between the covers. Thus, there is no need to extend the oil feed passage of the present invention compressor into the interior of the cylinder 232, and this assures that the oil will hardly mix with the refrigerant. If so, a separate installation of an accumulator can be omitted, and the compressor can be manufactured in a simple structure and with an enhanced operational reliability.
The refrigerant flow will now be explained in details based on
When the first and second rotating members 230 and 240 rotate by the medium of the vane 243, refrigerant is sucked in, compressed and discharged. In more detail, the roller 242 and the cylinder 232 repeatedly contact, separate, and retouch during the motion of the first and second rotating members 230 and 240, thereby varying the volume of the suction region and the discharge region divided by the vane 243 so as to suck in, compress, and discharge refrigerant. That is to say, as the volume of the suction region gradually expands according to the rotation of both, refrigerant is sucked into the suction region of the compression chamber P through the suction tube 214 of the hermetic container 210, the interior of the hermetic container 210, the suction port 251a and suction chamber 251 of the muffler 250, and the suction port 233a of the shaft cover 233.
With the refrigerant being sucked into the suction region, the volume of the discharge region gradually shrinks along the motions of the roller 242 and the cylinder 232, refrigerant is compressed, and when a discharge valve (not shown) is open at a pressure above the preset level the compressed refrigerant is then discharged in the direction of the shaft cover 233 through the discharge incline part 236 (see
With the compressor having the above configuration in accordance with the present invention, lubrication is done smoothly in presence of the oil feed passage at the contact surface between drive members. In addition, because the refrigerant suction passage and the refrigerant discharge passage circulate in separation from the oil circulation passage, it is possible to isolate the refrigerant passage from the oil passage. Accordingly, the possibility of the mixing of oil into refrigerant is minimized, and the compressor of high oil recovery can be provided. Besides, a much oil and refrigerant leak is reduced to thus guarantee an enhanced operational reliability.
Moreover, because the roller 142, 242, the cylinder 132, 232, and the cover 133, 134, 233, 234 according to the embodiment of the invention rotate together, a frictional loss becomes small. In more detail, unlike the conventional techniques, the sliding contact between the cylinder 132, 232 and the roller 142, 242 is noticeably reduced by rotating the roller 142, 242, the cylinder 132, 232, the cover 133, 134, 233, 234 together with the rotor 131, 231. In addition, the friction between the roller and the cover is relatively smaller than that of the conventional compressors. This is primarily because the roller of the present invention compressor makes a translational motion at the contact surface with the cover, unlike the conventional roller making both rotational and translational motions between the covers. Therefore, there is no need to extend the oil feed passage of the present invention compressor into the interior of the cylinder 132, 232, and this assures that the oil will hardly mix with the refrigerant. If so, a separate installation of an accumulator can be omitted, and the compressor can be manufactured in a simple structure and with an enhanced operational reliability.
The present invention has been described in detail with reference to the embodiments and the attached drawings. However, the scope of the present invention is not limited to the embodiments and the drawings, but defined by the appended claims.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/KR08/07015 | 11/28/2008 | WO | 00 | 1/20/2011 |
