Compressor Cooling

Abstract

A compressor comprises a suction port configured to receive a refrigerant and means for compressing the refrigerant. The means for compressing forms at least one compression chamber, a discharge port configured for discharging the compressed refrigerant from the compressor, and a motor. The means for compressing comprises at least one opening for extracting a portion of the refrigerant from the at least one compression chamber and supplying the extracted portion of the refrigerant to the motor. A method comprises receiving a refrigerant at a suction port of the compressor, compressing the refrigerant in at least one compression chamber formed by a means for compressing of the compressor, discharging the refrigerant from the compressor at a discharge port of the compressor, and extracting a portion of the refrigerant from the at least one compression chamber and supplying the extracted portion of the refrigerant to a motor of the compressor.

Claims

1. A compressor for compressing a refrigerant comprising: a suction port configured to receive the refrigerant at the compressor; a means for compressing the refrigerant, wherein the means for compressing forms at least one compression chamber; a discharge port configured for discharging the compressed refrigerant from the compressor; and a motor; wherein the means for compressing comprises at least one opening for extracting a portion of the refrigerant from the at least one compression chamber and supplying the extracted portion of the refrigerant to the motor.

2. The compressor of claim 1, wherein the means for compressing is a scroll set, which is configured for compressing the refrigerant.

3. The compressor of claim 2, wherein the scroll set comprises two scroll plates and wherein at least one scroll plate performs a motion relatively to the other scroll plate.

4. The compressor of claim 3, wherein each scroll plate comprises a spiral wrap and wherein the two scroll plates are arranged such that the spiral wraps are interleaved and form at least one compression chamber.

5. The compressor of claim 4, wherein the spiral wraps of the scroll plates are symmetric to one another.

6. The compressor of claim 4, wherein the spiral wraps of the scroll plates are asymmetric to one another.

7. The compressor of claim 3, wherein one of the two scroll plates comprises the at least one opening for extracting the portion of the refrigerant.

8. The compressor of claim 3, wherein means for compressing comprises at least two openings and wherein each scroll plate comprises at least one opening for extracting the portion of the refrigerant.

9. The compressor of claim 1, further comprising a low pressure side and a high pressure side, wherein the discharge port is arranged at the high pressure side of the compressor and the suction port and the motor are arranged at the low pressure side, and wherein a transition area between the low pressure side and the high pressure side is formed by the means for compressing.

10. The compressor of claim 9, further comprising at least one tube, wherein the tube is in fluid communication with the opening and ends in the low pressure side below the motor, thereby being configured for piping the extracted portion of the refrigerant from the at least one compression chamber to the low pressure side and for distributing the extracted portion of the refrigerant in a proximity to the motor.

11. The compressor of claim 10, further comprising a lubricant reservoir, and wherein the tube is further configured for supplying at least a portion of the extracted portion of the refrigerant to a proximity of the lubricant reservoir.

12. The compressor of claim 1, wherein 5 to 50 percent of the amount of refrigerant, which is received by the means for compressing, is extracted via the opening.

13. A method for compressing a refrigerant, the method being performed by a compressor, comprising: receiving a refrigerant at a suction port of the compressor; compressing the refrigerant in at least one compression chamber, which is formed by a means for compressing of the compressor; discharging the refrigerant from the compressor at a discharge port of the compressor; and extracting a portion of the refrigerant from the at least one compression chamber formed by the means for compressing and supplying the extracted portion of the refrigerant to a motor of the compressor.

14. The method of claim 13, wherein the portion of the refrigerant is extracted from the at least one compression chamber formed by the means for compressing before the refrigerant is compressed.

15. The method of claim 13, wherein the compressor further comprises a lubricant reservoir and wherein the method further comprises supplying at least a portion of the extracted portion of the refrigerant to the lubricant reservoir.

Description

DRAWINGS

[0043] In the following description, various embodiments of the invention are described with reference to the following drawings, in which:

[0044] FIG. 1 shows a cross-sectional view of an embodiment of a compressor according to the invention.

[0045] FIGS. 2a and 2b show cross-sectional views of exemplary scroll plates of a compressor according to the invention.

[0046] FIG. 3 shows a cross-sectional view of interleaved scroll plates, which form a scroll set and multiple compression chambers.

[0047] FIGS. 4a-4d show cross-sectional views of the interleaved scroll plates of FIG. 3, wherein the FIGS. 4a-4d show the transformation of an exemplary compression chamber through different time instances.

[0048] FIG. 5 shows a cross-sectional view of another embodiment of a compressor according to the invention.

DETAILED DESCRIPTION

[0049] The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced.

[0050] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs.

[0051] FIG. 1 shows a cross-sectional view of an embodiment of a compressor 1 according to the invention. The compressor 1 comprises a suction port 7 for receiving a refrigerant and a discharge port 8 for discharging the refrigerant from the compressor 1.

[0052] The compressor design, which is depicted in FIG. 1, comprises a high pressure side and a low pressure side. The low pressure side comprises the suction port 7 and receives the refrigerant at a low temperature and a low pressure. The high pressure side comprises the discharge port 8 and receives the compressed refrigerant from the low pressure side and discharges said portion of the compressed refrigerant from the compressor 1. The low pressure side and the high pressure side are connected to each other via a means for compressing.

[0053] The compressor design, which is depicted in FIG. 1, is a scroll compressor. In this design, the means for compressing is formed by a scroll set 2a, 2b. The scroll set 2a, 2b comprises a first scroll plate 2a, which is a stationary scroll plate in this example, and a second scroll plate 2b, which is an orbiting scroll plate in this example. In the particular example depicted in FIG. 1, the stationary scroll plate 2a and the orbiting scroll plate 2b each comprise a spiral wrap and a base plate. Further, the stationary scroll plate 2a and the orbiting scroll plate 2b are arranged in such a way that the sides of the scroll plates 2a, 2b, which comprise the spiral wraps, face each other. Further, the spiral wraps are interleaved. By interleaving the spiral wraps, the scroll plates 2a, 2b form one or more compression chambers, which are configured for compressing the refrigerant.

[0054] The orbiting scroll plate 2b is configured to change the volumes of the compression chambers by a motion relative to the stationary scroll plate 2a. In this regard, the orbiting scroll plate 2b, the stationary scroll plate 2a and their relative arrangement are configured to compress the refrigerant.

[0055] The motion of the orbiting scroll plate 2b is actuated by the motor 3 of the compressor 1. The motor 3 is located in the low pressure side of the compressor 1 and is connected to the orbiting scroll plate 2b by ease of a crank shaft 4 and a coupling. Further, the compressor 1 comprises a lubricant reservoir 5, which is used for lubricating the crankshaft 4, the coupling, the motor 3, and the scroll set 2a, 2b. The lubricant reservoir is also located at the low pressure side.

[0056] By adding an opening 10 to either the stationary scroll plate 2a or the orbiting scroll plate 2b, a portion of the refrigerant is extracted from one of the compression chambers via the opening 10. In this case, the motion of the orbiting scroll plate 2b may pump a portion of the refrigerant through the opening 10 to the motor 3.

[0057] The opening 10 is in fluid communication with a tube 9 and the extracted portion of the refrigerant may be piped to the motor via the tube 9. As depicted in FIG. 1, the tube 9 ends below the motor 3 and the extracted portion of the refrigerant will diffuse in the low pressure side of the compressor 1. Thereby, the extracted portion of the refrigerant will reach the motor 3 and the lubricant reservoir 5 and will cool these components.

[0058] During the cooling of the components in the low pressure side of the compressor 1, the extracted portion of the refrigerant will accept heat from said components. Thereby, the extracted portion of the refrigerant will heat up and will come back to the scroll set 2a, 2b. Once the extracted portion of the refrigerant reaches the scroll set 2a, 2b, the extracted portion of the refrigerant may be received from the means for compressing, for example caused by a suction caused by the motion of the orbiting scroll plate 2b.

[0059] With respect to the compressor 1 depicted in FIG. 1, the person skilled in the art will appreciate that the refrigerant, when it is received by the compressor 1 at its suction port 7, will not evenly cool the components in the low pressure side of the compressor 1. Because the refrigerant has a low temperature and the motor 3 has a high temperature during operation, the refrigerant may be in more contact with the upper part of the motor 3, and in less contact with the lower part of the motor 3. This raises a need for cooling the motor 3 more evenly, which is addressed by the motor cooling according to the invention.

[0060] FIGS. 2a, 2b show cross-sectional views of exemplary scroll plates 2a, 2b of a compressor 1 according to an embodiment of the invention.

[0061] The scroll plate 2a depicted in FIG. 2a is an example of a stationary scroll plate. The stationary scroll plate 2a comprises a base plate 11 and a spiral wrap 13, which is used to form a series of compression chambers upon interleaving with a corresponding spiral wrap of another scroll plate. At the center of the spiral wrap 13, the scroll plate 2a comprises an outlet 12. This outlet 12 may either correspond to the outlet of the means for compressing or may be in fluid connection with the outlet of the means for compressing.

[0062] The scroll plate 2b depicted in FIG. 2b is an example of an orbiting scroll plate. The orbiting scroll plate 2b comprises a base plate 11 and a spiral wrap 14, which is used to form a series of compression chambers upon interleaving with a corresponding spiral wrap of another scroll plate, for example spiral wrap 13 of the stationary scroll plate 2a. Further, the orbiting scroll plate 2b comprises an opening 10, which is arranged at the base plate 11. The opening 10 is arranged at the base plate 11 in such a way that the opening 10 will be in fluid communication with at least one of the compression chambers for at least a portion of time, when the orbiting scroll plate 2b is interleaved with a corresponding stationary scroll plate 2a. An example of a preferred location of the opening 10 on the base plate 11 is depicted in FIG. 3.

[0063] FIG. 3 shows a cross-sectional view of interleaved scroll plates, which form a scroll set and multiple compression chambers. The example depicted in FIG. 3 shows a stationary scroll plate 2a as depicted in FIG. 2a on top of an orbiting scroll plate 2b as depicted in FIG. 2b. The interleaved spiral wraps 13, 14 engage each other at different locations and form compression chambers 15 in the spaces between the spiral wraps 13, 14. The location and the volume of the compression chambers 15 changes upon motion of the orbiting scroll plate 2b, when the outermost compression chamber 15 will be transformed into an inner compression chamber.

[0064] In the time instance depicted in FIG. 3, the compression chamber 15 is formed at a radially outer location of the spiral wraps 13, 14. Further, compression chamber 15 is closed because the radially outermost end of the spiral wrap 14 of the orbiting scroll plate 2b engages the spiral wrap 14 of the stationary scroll plate 2a. At this time instance, the opening 10 engages the edge of the compression chamber 15, such that the opening 10 and the compression chamber 15 are in direct fluid communication. Upon further motion of the orbiting scroll plate 2b, the compression chamber 15 will be moved along the course dictated by the involute curve of the spiral wraps 13, 14. Thereby, the volume of the compression chamber 15 will be reduced and the refrigerant inside the compression chamber 15 will be compressed. Additionally, as long as the opening 10 is in direct fluid communication with the compression chamber 15, the refrigerant will only slightly be compressed, because a portion of the refrigerant will be pumped through the opening 10 in order to avoid an increase in pressure caused by a reduction in the volume of the compression chamber 15. Thereby, a portion of the refrigerant will be extracted from the compression chamber 15.

[0065] FIGS. 4a to 4d show cross-sectional views of the interleaved scroll plates of FIG. 3, wherein the FIGS. 4a to 4d show the transformation of an exemplary compression chamber through different time instances.

[0066] FIG. 4a shows a first time instance t=0. This time instance corresponds to the time instance depicted in FIG. 3. Compression chamber 15 as depicted in FIG. 3 is highlighted as black space in FIG. 4a.

[0067] FIG. 4b shows the situation at the time instance t=T, which means after the orbiting scroll 2b performs one complete cycle of its periodic motion with the cycle duration T. Compression chamber 15, which was initially located at a radially outer location of the spiral wraps 13, 14, has now been transformed to an inner compression chamber with a reduced volume. After a further motion cycle of the orbiting scroll plate 2b, the FIG. 4c shows the situation at the time instance t=2T. The compression chamber is again moved further along the course dictated by the spiral wraps 13, 14 and is transformed into a compression chamber the volume of which is even further reduced. After a third motion cycle, the compression chamber has been even more compressed and reached the center of the spiral wraps 13, 14, which is also the location of the outlet of the scroll set, from where the refrigerant will be provided to the discharge port 8. This time instance is shown in FIG. 4d at the time t=3T.

[0068] FIG. 5 shows a cross-sectional view of another embodiment of a compressor according to the invention.

[0069] The embodiment example depicted in FIG. 5 differs from the embodiment example depicted in FIG. 1 in that the opening 10 for extracting the portion of the refrigerant is located in the stationary scroll plate 2a instead of the orbiting scroll plate 2b as depicted in FIG. 1. The person skilled in the art will appreciate that this difference may not change the operation of the cooling but only has an effect on the course of the tube 9, which is used for supplying the extracted portion of the refrigerant to the motor 3 and/or the lubricant reservoir 5. Furthermore, although not shown in the drawings, it would also be possible that the stationary scroll plate 2a and the orbiting scroll plate 2b each comprise at least one opening 10. In such a case, the operation of the cooling itself is not different to the examples shown, but the amount of extracted refrigerant and the number of tubes 9 may increase.

[0070] In the embodiment example depicted in FIG. 5, the tube 9 is located at least partially outside of the casing 6 of the compressor 1. Thereby, the tube 9 may pass the orbiting scroll plate 2b without encountering the orbiting scroll plate 2b. This allows to save space inside the casing 6 because the entire cross-section of the casing 6 is available for the motion of the orbiting scroll plate 2b. However, it may also be possible that the tube 9 is located entirely within the casing 6 of the compressor 1 when the opening 10 is in the stationary scroll plate 2a. In this case, the tube 9 would pass the orbiting scroll plate 2b within the casing 6 and reduce the space, which is available for the motion of the orbiting scroll plate 2b.

[0071] Furthermore, the embodiment example depicted in FIG. 5 differs from the embodiment example depicted in FIG. 1 in that the outlet of the tube 9 in the low pressure side of the compressor 1 is oriented horizontally. The person skilled in the art will appreciate that this is merely a design aspect and does not substantially affect the operation of the motor cooling. This is because the motion of the orbiting scroll 2b pumps the extracted portion of the refrigerant through the tube 9, such that the extracted portion of the refrigerant will be ejected from the tube 9 in the low pressure side at a pressure, which may be slightly higher than the pressure of the low pressure side.

[0072] What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the described embodiments are intended to embrace all such alterations, modifications and variations that fall within the scope of the appended claims.