Abstract:
Systems and techniques are disclosed to sense a temperature and a flow rate of oil in a compressor. A compressor includes: a casing; a frame on the casing; a fixed scroll on the frame; an orbiting scroll supported by the frame and defining a compression chamber while engaging the fixed scroll; and a crank shaft. The crank shaft transfers, to the orbiting scroll, a rotational force of a motor. The casing includes: a main housing including a refrigerant discharge passage and an oil passing passage; and a sub-housing including a refrigerant discharge port and an oil channel, which includes an oil reservoir, that each face the main housing. A sensor module attached to a sensor receptor in the sub-housing includes: a sensor housing covering the sensor receptor; and an oil sensor and a temperature sensor located on the sensor housing that each protrude towards the oil reservoir.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of an earlier filing date and right of priority to Korean Patent Application Number 10-2014-0149212, filed on Oct. 30, 2014, the entire contents of which are incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present application relates to a compressor and a method of autonomously inspecting oil. 
       BACKGROUND 
       [0003]    In general, a compressor is a mechanical device that compresses gas and generates increased pressure. 
         [0004]    A compressor is typically installed in consumer electronics such as refrigerators, air conditioners, or vehicles and functions to compress a refrigerant. A compressor may be connected with a condenser and an evaporator to compress a refrigerant evaporated by the evaporator and supply the compressed refrigerant to the condenser. 
         [0005]    There are various types of compressors such as reciprocating compressors, scroll compressors, and screw compressors. In the case of a scroll compressor, a pair of compression members, or scrolls, with three-dimensional involute curves may compress the refrigerant while gradually decreasing a volume in a space therebetween. Such scroll compressors may have low-noise and low-vibration properties, and as a result, may be suitable for use in consumer electronics or vehicles that in which low-noise and low-vibration operation are desirable. 
         [0006]    Oil may be accommodated at a lower side of the compressor, and an oil channel may be formed in the compressor that guides the oil to a compression unit. The oil flows to the compression unit through the oil channel, thereby reducing abrasion in the compression unit, and increasing the operational lifespan of the compressor. 
       SUMMARY 
       [0007]    Systems and techniques are disclosed that provide a compressor configured to sense a temperature and a flow rate of oil in the compressor. 
         [0008]    In one aspect, a compressor includes: a casing; a frame fixed on the casing; a fixed scroll fixed on the frame; an orbiting scroll supported by the frame and defining a compression chamber while engaging with the fixed scroll; and a crank shaft. The crank shaft is coupled to the orbiting scroll and is configured to transfer, to the orbiting scroll, a rotational force of a motor. The casing includes: a main housing including a refrigerant discharge passage and an oil passing passage; and a sub-housing including a refrigerant discharge port and an oil channel that each face the main housing, the oil channel including an oil reservoir. The compressor also includes a sensor module attached to a sensor receptor in the sub-housing, the sensor module including: a sensor housing covering the sensor receptor; and an oil sensor and a temperature sensor that are each located on the sensor housing and that each protrude towards the oil reservoir. 
         [0009]    In some implementations, the compressor further includes: a partition wall located in at least one of the main housing or the sub-housing, the partition wall partitioning a space between the main housing and the sub-housing into a refrigerant discharge chamber at an upper side of the partition wall and an oil storage space at a lower side of the partition wall; and a communicating portion located at the partition wall and configured to allow the refrigerant discharge chamber and the oil storage space to be in communication with each other. 
         [0010]    In some implementations, the oil passing passage faces the oil storage space, and the refrigerant discharge port and the refrigerant discharge passage face the refrigerant discharge chamber. 
         [0011]    In some implementations, the sub-housing includes: a central portion that houses the oil reservoir, the central portion being recessed and protruding towards the main housing, and a partition wall extending from the central portion and separating a refrigerant discharge chamber at an upper side of the partition wall and an oil storage space at a lower side of the partition wall. 
         [0012]    In some implementations, the main housing includes: a central portion facing the oil reservoir and including a through passage through which a rotary shaft of the motor penetrates, a partition wall extending from the central portion and separating a refrigerant discharge chamber at an upper side of the partition wall and an oil storage space at a lower side of the partition wall, and a communicating portion located at the partition wall and configured to allow the refrigerant discharge chamber and the oil storage space to be in communication with each other. 
         [0013]    In some implementations, the motor includes: a motor shaft including an inner channel into which the oil in the oil reservoir flows; and an oil pump located on the motor shaft, wherein the sensor module faces the inner channel. 
         [0014]    In some implementations, the oil channel includes a vertical channel that is elongated at a lower side of the oil reservoir in a vertical direction and that is configured to guide the oil to the oil reservoir. 
         [0015]    In some implementations, the compressor further includes a fixing ring located on the sensor housing and configured to fix the sensor housing to the sub-housing. 
         [0016]    In another aspect, a compressor includes: a casing; a frame fixed on the casing; a fixed scroll fixed on the frame; an orbiting scroll supported by the frame and defining a compression chamber while engaging with the fixed scroll; a crank shaft coupled to the orbiting scroll and configured to transfer, to the orbiting scroll, a rotational force of a motor; an oil reservoir and an oil injection channel located in the frame, the oil injection channel configured to guide the oil in the oil reservoir to the compression chamber; and a sensor module. The sensor module is attached to a sensor receptor in the frame, and includes: a sensor housing covering the sensor receptor; and an oil sensor and a temperature sensor that are each located on the sensor housing and that each protrude towards the oil reservoir. 
         [0017]    In some implementations, the frame includes: an inner frame including the oil reservoir and the oil injection channel; and an oil cover coupled to the inner frame and covering the oil reservoir, wherein the sensor receptor is located in the inner frame. 
         [0018]    In another aspect, a compressor includes: a compression chamber; a casing surrounding the compression chamber and configured to accommodate oil at a lower side of the casing; an oil recovery channel configured to guide, to the compression chamber, the oil that is accommodated at the lower side of the casing, the oil recovery channel including at least one oil reservoir; and a sensor module. The sensor module is attached to a sensor receptor in the at least one the oil reservoir, and includes: a sensor housing covering the sensor receptor; and an oil sensor and a temperature sensor that are each disposed on the sensor housing and that each protrude towards the at least one oil reservoir. 
         [0019]    In another aspect, a method of autonomously inspecting oil in a compressor is disclosed. The method includes: sensing oil by an oil sensor of a sensor module that is located in an oil reservoir in the compressor; sensing a temperature by a temperature sensor of the sensor module; and determining an amount of the oil sensed by the oil sensor. The method further includes determining that: the amount of the oil sensed by the oil sensor is less than a predetermined value, the temperature sensed by the temperature sensor is within a predetermined range, and a time duration, during which the oil sensed by the oil sensor is less than a predetermined value, is greater than or equal to a predetermined time duration. The method further includes transmitting, to an outside of the compressor, an indication of an abnormal state of the oil based on the determination that the amount of the oil sensed by the oil sensor is less than the predetermined value, the temperature sensed by the temperature sensor is within the predetermined range, and the time duration, during which the oil sensed by the oil sensor is less than a predetermined value, is greater than or equal to the predetermined time duration. 
         [0020]    In some implementations, the method further includes: determining that the amount of the oil sensed by the oil sensor is less than the predetermined value, and the temperature sensed by the temperature sensor is outside of the predetermined range; and transmitting, to the outside of the compressor, an indication of the abnormal state of the oil based on the determination that the amount of the oil sensed by the oil sensor is less than the predetermined value, and the temperature sensed by the temperature sensor is outside of the predetermined range. 
         [0021]    In some implementations, the method further includes: determining that the amount of the oil sensed by the oil sensor is greater than or equal to the predetermined value; and operating the compressor in a normal operation mode based on the determination that the amount of the oil sensed by the oil sensor is greater than or equal to the predetermined value. 
         [0022]    In some implementations, the method further includes: determining a temperature outside of the compressor; and changing the predetermined range for the temperature sensor based on the determined temperature outside of the compressor. 
         [0023]    The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. The description and specific examples below are given by way of illustration only, and various changes and modifications will be apparent. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1  is a diagram illustrating a perspective view of an example of a compressor; 
           [0025]      FIG. 2  is a diagram illustrating a cross-sectional view of the interior of an example of a compressor; 
           [0026]      FIG. 3  is a diagram illustrating a side view of an example of a main housing of a compressor that faces a sub-housing of the compressor; 
           [0027]      FIG. 4  is a diagram illustrating a side view of an example of a sub-housing of a compressor that faces a main housing of the compressor; 
           [0028]      FIG. 5  is a diagram illustrating a detailed perspective view of an example of a sensor module of a compressor that is separated from a sub-housing of the compressor; 
           [0029]      FIG. 6  is a diagram illustrating a partially cut-away cross-sectional view of an example of a sensor module of a compressor that is mounted to a sub-housing of the compressor; 
           [0030]      FIG. 7  is a diagram illustrating a cross-sectional view of an interior of an example of a compressor; and 
           [0031]      FIG. 8  is a flowchart illustrating an example of a method of autonomously inspecting oil in a compressor. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    Systems and techniques are disclosed to sense a temperature and a flow rate of oil in a compressor. Such techniques and systems may help mitigate abrasion and improve reliability of a compressor. 
         [0033]    If a compressor is operated in a scenario in which an insufficient amount of oil is available in the oil channel of the compressor, then this may cause problems such as abrasion or damage in the compressor. 
         [0034]    Techniques and systems disclosed herein may offer an advantage that oil in the oil reservoir of the compressor may be more accurately sensed even if the compressor is tilted or rattles. 
         [0035]    Such techniques and systems may also enable more accurate monitoring of an oil supply in the compressor by sensing an amount of oil and a temperature in the oil channel by using a single sensor module, thereby increasing reliability of the compressor. 
         [0036]      FIG. 1  is a perspective view of a compressor,  FIG. 2  is a cross-sectional view illustrating the interior of a compressor,  FIG. 3  is a side view illustrating a side of a main housing of a compressor that faces a sub-housing of the compressor,  FIG. 4  is a side view illustrating a side of a sub-housing of a compressor that faces a main housing of the compressor,  FIG. 5  is an exploded perspective view illustrating a state in which a sensor module of a compressor is separated from a sub-housing of the compressor, and  FIG. 6  is a partially cut-away cross-sectional view of a sensor module of a compressor that is mounted to a sub-housing of the compressor. 
         [0037]    The compressor includes a compression unit  2  which has a compression chamber C that compresses a refrigerant, and a motor  4  which is connected to the compression unit  2 . As an example, the compressor may be installed in a vehicle, and may be a compressor for a vehicle. In general, however, the compressor may be used for any suitable purpose in other types of systems. 
         [0038]    The compressor may include a casing  6  that defines an external appearance of the compressor. Oil may be accommodated in the casing  6 . The oil may be accommodated at a lower side in the casing  6 . The compressor may be configured as a horizontal compressor that lies on its side in a horizontal direction. The casing  6  may be elongated in the horizontal direction. 
         [0039]    The casing  6  may be configured as an assembly of a plurality of members. The casing  6  may include a main housing  10 , and a sub-housing  14 . The casing  6  may further include a cover  16  which is coupled to the main housing  10 . 
         [0040]    The main housing  10  may have a space S in which the compression unit  2  and the motor  4  are accommodated. A refrigerant discharge hole  8  and an oil passing hole  9  may be formed in the main housing  10 . Oil may be accommodated in the space S of the main housing  10 , and oil may be accommodated at a lower side in the main housing  10 . Oil in the main housing  10  may move between the main housing  10  and the sub-housing  14  through the oil passing hole  9 . The refrigerant compressed by the compression unit  2  may pass through the space S of the main housing  10 , and the refrigerant may pass through the refrigerant discharge hole  8 , and then may move between the main housing  10  and the sub-housing  14 . 
         [0041]    The sub-housing  14  may be installed to face the main housing  10 . A refrigerant discharge port  11  and an oil channel  12  may be formed in the sub-housing  14 . The sub-housing  14  may have an oil reservoir  12 B formed in the oil channel  12 . A sensor hole  13  in which a sensor module  20  to be described below is installed may be formed in the sub-housing  14 . The sensor hole  13  may be formed to penetrate the sub-housing  14 . The sensor module  20  may be mounted in the sensor hole  13 , and may sense oil and temperature in the oil reservoir  12 B. The refrigerant between the main housing  10  and the sub-housing  14  may be discharged to the outside of the compressor through the refrigerant discharge port  11 . The oil between the main housing  10  and the sub-housing  14  may flow into the oil reservoir  12 B while being guided to the oil channel  12 , and the oil in the oil reservoir  12 B may flow by the motor  4 . 
         [0042]    The cover  16  may be coupled to the main housing  10 . The cover  16  may be coupled to the main housing  10  so as to be positioned at the opposite position to the sub-housing  14 . The cover  16  may be configured as a single member, or may be configured as an assembly of a plurality of members. The cover  16  may be installed on the main housing  10  so as to surround a fixed scroll  22 . A refrigerant intake port  17  may be formed in the cover  16 . 
         [0043]    The compressor may include an inverter  18  that controls the motor  4 . The inverter  18  of the compressor may be mounted to the cover  16 . The casing  6  may further include an inverter housing  19  that is coupled to the cover  16  and protects the inverter  18 . A space, which accommodates the inverter  18 , may be formed between the inverter housing  19  and the cover  16 . The inverter  18  may be mounted to at least one of the cover  16  and the inverter housing  19 . 
         [0044]    The compressor may include the sensor module  20  installed on the sub-housing  14 . The sensor module  20  may sense an amount of oil and a temperature in the oil reservoir  12 B formed in the sub-housing  14 . 
         [0045]    The compressor may be configured as a scroll compressor in which the compression unit  2  has a pair of scrolls. The compression unit  2  may include the fixed scroll  22 , and an orbiting scroll  24 , and the compression chamber C may be formed between the fixed scroll  22  and the orbiting scroll  24 . 
         [0046]    The fixed scroll  22  may be installed to be positioned in the casing  6 . A discharge hole  26  through which the refrigerant compressed in the compression chamber C is discharged to the outside of the compression unit  2  may be formed in the fixed scroll  22 . The fixed scroll  22  may be installed on a frame  64  to be described below. 
         [0047]    The orbiting scroll  24  may engage with the fixed scroll  22  and form the compression chamber C. The orbiting scroll  24  may be supported by the frame  64 . The orbiting scroll  24  may be connected to a motor shaft  46  of the motor  4 , which will be described below, through a crank shaft  28 . The crank shaft  28  may be coupled to the orbiting scroll  24 , and may transfer rotational force of the motor  4  to the orbiting scroll  24 . When the motor  4  is operated, the orbiting scroll  24  may move relative to the fixed scroll  22  while being rotated eccentrically to the motor shaft  46 . When the orbiting scroll  24  is rotated, the compression chamber C in the form of a crescent may be formed between the fixed scroll  22  and the orbiting scroll  24 , and refrigerant vapor may be compressed (e.g., continuously) through a change in volume caused by the relative motion between the fixed scroll  22  and the orbiting scroll  24 . 
         [0048]    At least one orbiting scroll oil channel  30 , through which the oil in an inner channel  48 , which is formed in the motor shaft  46  and will be described below, is sucked and guided to the compression chamber C, may be formed in the orbiting scroll  24 . The oil flowing into the inner channel  48  of the motor shaft  46  may flow between the fixed scroll  22  and the orbiting scroll  24  through the orbiting scroll oil channel  30 , thereby minimizing abrasion between the fixed scroll  22  and the orbiting scroll  24 . 
         [0049]    The motor  4  may include an outer stator  42 , and an inner rotor  44 . Further, the motor  4  may further include the motor shaft  46 . The motor shaft  46  may be installed on the inner rotor  44 , and rotated together with the inner rotor  44  when the inner rotor  44  is rotated. The motor shaft  46  may have the inner channel  48  into which the oil in the oil channel  12  formed in the sub-housing  14  flows. One end of the inner channel  48  may face the oil reservoir  12 B formed in the sub-housing  14 . The motor  4  may include an oil pump  50  installed on the motor shaft  46 . 
         [0050]    The outer stator  42  may be installed in the casing  6 . The outer stator  42  may be installed on an inner wall of the main housing  10 . The outer stator  42  may be formed in a hollow shape. 
         [0051]    The inner rotor  44  may be positioned inside the outer stator  42 , and rotated by an interaction with the outer stator  42 . The inner rotor  44  may be formed in a hollow shape. 
         [0052]    The motor shaft  46  may be disposed to penetrate the inner rotor  44 , and rotated together with the inner rotor  44  when the inner rotor  44  is rotated. One end  46 A of the motor shaft  46  may face the sub-housing  14  of the casing  6 , and the other end  46 B thereof may be directed toward the compression unit  2 . 
         [0053]    The inner channel  48  may be elongated in a longitudinal direction of the motor shaft  46 . One end of the inner channel  48  may face a part of the oil reservoir  12 B, and the oil in the oil reservoir  12 B may flow into the inner channel  48  through the one end of the inner channel  48 , may pass through the inner channel  48 , and then may be guided to the compression unit  2 . The inner channel  48  may include a first channel which is elongated in the longitudinal direction of the motor shaft  46  from the one end  46 A of the motor shaft  46 , and a second channel which is formed in a circumferential direction of the motor shaft  46  from the first channel. 
         [0054]    The oil pump  50  may be configured as a trochoid pump that is a kind of rotary pump, and the inner rotor with a trochoid curve may be installed on an outer circumference of the motor shaft  46 . When the motor shaft  46  is rotated, the oil pump  50  may pump the oil in the oil channel  12 , particularly, in the oil reservoir  12 B to be described below, to the inner channel  48  of the motor shaft  46 . 
         [0055]    The compressor may include the frame  64  fixedly installed on the casing  6 . The frame  64  may support the compression unit  2 . 
         [0056]    An outer circumference of the frame  64  may be fixed to an inner circumference of the main housing  10 , such that the frame  64  may be disposed in the main housing  10 . 
         [0057]    A part of the frame  64  may be positioned between the main housing  10  and the cover  16 , and the part, which is positioned between the main housing  10  and the cover  16 , may be exposed to the outside of the compressor. 
         [0058]    The frame  64  may be coupled to the fixed scroll  22 , and may form, together with the fixed scroll  22 , an orbiting scroll accommodating space in which the orbiting scroll  24  is accommodated. 
         [0059]    An oil reservoir  66 A, which is separated from the space S in the casing  6 , and an oil injection channel  66 B, which guides the oil in the oil reservoir  66 A to the compression chamber C, may be formed in the frame  64 . The oil reservoir  66 A of the frame  64  may store the oil at a different location from the oil reservoir  12 B of the sub-housing  14 . An oil reservoir injection channel  66 C, which guides the oil flowing out from the inner channel  48  of the motor shaft  46  to the oil reservoir  66 A, may be formed in the frame  64 . In a case in which the orbiting scroll oil channel  30  is formed in the orbiting scroll  22 , an orbiting scroll injection channel  66 D, which may guide the oil flowing out from the inner channel  48  of the motor shaft  46  to the orbiting scroll oil channel  30 , may be further formed in the frame  64 . Here, the oil reservoir  66 A may be a space which accommodates the oil flowing out from the inner channel  48  of the motor shaft  46 . The frame  64  may receive the oil flowing out from the inner channel  48  of the motor shaft  46 , and guide the oil to the compression unit  2  through the oil injection channel  66 B. 
         [0060]    The frame  64  may include an inner frame  68  having the oil reservoir  66 A and the oil injection channel  66 B. The inner frame  68  may be fastened to the fixed scroll  22  to fix the fixed scroll  22 , and may support the orbiting scroll  24 . The frame  64  may include an oil cover  70  which is coupled to the inner frame  68  and covers the oil reservoir  66 A. 
         [0061]    Hereinafter, the main housing  10  and the sub-housing  14  will be described in detail below. 
         [0062]    The main housing  10  may include a hollow tubular body  72 , and a plate body  74 . 
         [0063]    The hollow tubular body  72  may have the space S which accommodates the outer stator  42  and the inner rotor  44 . 
         [0064]    The plate body  74  may face the frame  64 . The plate body  74  may be a sub-housing opposing plate that faces the sub-housing  14 . 
         [0065]    A motor shaft bearing  75 , which rotatably supports the motor shaft  46 , may be installed on the plate body  74 , and a rotary shaft through hole  76 A, which the motor shaft  46  rotatably penetrates, may be formed. 
         [0066]    The sub-housing  14  may be installed to face the plate body  74  of the main housing  10 . 
         [0067]    A refrigerant discharge chamber R, through which the refrigerant passing through the refrigerant discharge hole  8  passes to flow to the refrigerant discharge port  11 , may be formed between the main housing  10  and the sub-housing  14 . 
         [0068]    The refrigerant compressed by the compression unit  2  may pass through the interior of the main housing  10  and the refrigerant discharge hole  8 , may flow into the refrigerant discharge chamber R, and may flow from the refrigerant discharge chamber R to the refrigerant discharge port  11 , and then may be discharged to the outside of the compressor. The refrigerant discharge chamber R may have lower pressure than the space S in the main housing  10 . 
         [0069]    Oil storage spaces O 1  and O 2 , which may accommodate the oil passing through the oil passing hole  9 , may be formed between the main housing  10  and the sub-housing  14 . 
         [0070]    When the motor shaft  46  is rotated, the oil in the oil storage spaces O 1  and O 2  may be pumped by the oil pump  50  and raised along the oil channel  12 , and the oil may be pumped from the oil channel  12 , particularly, the oil reservoir  12 B to the inner channel  48  of the motor shaft  46 . 
         [0071]    The refrigerant discharge hole  8  may be formed to face the refrigerant discharge chamber R. 
         [0072]    The refrigerant discharge hole  8  may be formed to penetrate an upper portion of the plate body  74  of the main housing  10 . 
         [0073]    The oil passing hole  9  may be formed to face the oil storage spaces O 1  and O 2 . The oil passing hole  9  may be formed to penetrate a lower portion of the plate body  74  of the main housing  10 . 
         [0074]    The refrigerant discharge port  11  may be formed to face the refrigerant discharge chamber R. The refrigerant discharge port  11  may be formed in an upper portion of the sub-housing  14 . 
         [0075]    A partition wall, which partitions a space between the main housing  10  and the sub-housing  14  into the refrigerant discharge chamber R at the upper side and the oil storage spaces O 1  and O 2  at the lower side, may be formed on at least one of the main housing  10  and the sub-housing  14 . Communicating portions  77   a  and  78   a , which allow the refrigerant discharge chamber R and the oil storage spaces O 1  and O 2  to be in communication with each other, may be formed at a part of the partition wall. The communicating portions  77   a  and  78   a  may be portions for forming low pressure in the oil storage space, which allow the refrigerant discharge chamber R and the oil storage spaces O 1  and O 2  to be in communication with each other in order to allow the oil storage spaces O 1  and O 2  to have lower pressure than the space S. 
         [0076]    In the compressor, among pressure P 1  in the space S, pressure P 2  in the oil storage spaces O 1  and O 2 , and pressure P 3  in the refrigerant discharge chamber R, the pressure P 1  in the space S may be highest, the pressure P 3  in the refrigerant discharge chamber R may be lowest, and the pressure P 2  in the oil storage spaces O 1  and O 2  may be pressure between the pressure P 1  in the space S and the pressure P 3  in the refrigerant discharge chamber R. As illustrated in  FIGS. 2 to 4 , because the pressure P 2  in the oil storage spaces O 1  and O 2  is lower than the pressure P 1  of the space S, an oil level H 2  in the oil storage spaces O 1  and O 2  may be higher than an oil level H 1  in the space S, and there may be a height difference H 2 -H 1  between the oil level H 2  in the oil storage spaces O 1  and O 2  and the oil level H 1  in the space S. 
         [0077]    The main housing  10 , particularly, the plate body  74  may include a central portion  76  which the rotary shaft  46  of the motor  4  penetrates and which has a through hole  76 A that faces the oil reservoir  12 B of the sub-housing  14 . 
         [0078]    Partition walls  77  and  78 , which separate the refrigerant discharge chamber R at the upper side and the oil storage spaces O 1  and O 2  at the lower side, may be formed in the main housing  10 , particularly, the plate body  74 . The partition walls  77  and  78  of the main housing  10  may extend from the central portion  76 , and separate the refrigerant discharge chamber R at the upper side and the oil storage spaces O 1  and O 2  at the lower side. The partition walls  77  and  78  of the main housing  10  may be formed to protrude toward the sub-housing  14 . The partition walls  77  and  78  of the main housing  10  may be upper partition walls positioned at the upper side of the main housing  10 , and may be provided as a pair. The communicating portions  77   a  and  78   a , which allow the refrigerant discharge chamber R and the oil storage spaces O 1  and O 2  to be in communication with each other, may be formed in a part of each of the partition walls  77  and  78  of the main housing  10 . The communicating portions  77   a  and  78   a  may be configured as a stepped portion that is recessed in the partition walls  77  and  78  in a direction opposite to the sub-housing  14 . 
         [0079]    A lower partition wall  79 , which partitions a space at the lower side of the partition walls  77  and  78  into the two oil storage spaces O 1  and O 2 , may be formed in the main housing  10 , particularly, the plate body  74  so as to protrude toward the sub-housing  14 . The lower partition wall  79  may be a partition wall positioned at the lower side of the main housing  10 , and a single partition wall may be elongated in an up and down direction. 
         [0080]    The sub-housing  14  may include a central portion  86  in which the oil reservoir  12 B is formed to be recessed and which protrudes toward the main housing  10 . The sensor hole  13  may be formed to penetrate the oil reservoir  12 B. 
         [0081]    The sub-housing  14  may include partition walls  87  and  88  that separate the refrigerant discharge chamber R at the upper side and the oil storage spaces O 1  and O 2  at the lower side. The partition walls  87  and  88  of the sub-housing  14  may extend from the central portion  86  of the sub-housing  14 , and separate the refrigerant discharge chamber R at the upper side and the oil storage spaces O 1  and O 2  at the lower side. The partition walls  87  and  88  of the sub-housing  14  may be formed to protrude toward the main housing  10 . The partition walls  87  and  88  of the sub-housing  14  may be upper partition walls positioned at the upper side of the sub-housing  14 , and may be provided as a pair. 
         [0082]    A lower partition wall  89 , which partitions a space at the lower side of the partition walls  87  and  88  into the two oil storage spaces O 1  and O 2 , may be formed in the sub-housing  14  so as to protrude toward the main housing  10 . The lower partition wall  89  may be a partition wall positioned at the lower side of the sub-housing  14 , and a single partition wall may be elongated in the up and down direction. 
         [0083]    The oil channel  12  may include a vertical channel  12 A that is elongated in the up and down direction at the lower side of the oil reservoir  12 B and guides the oil to the oil reservoir  12 B. The oil channel  12  may include the vertical channel  12 A at the lower side, and the oil reservoir  12 B at the upper side, and the oil may be raised to the oil reservoir  12 B along the vertical channel  12 A, and then may flow from the oil reservoir  12 B to the inner channel  48  of the motor shaft  46 . 
         [0084]    The vertical channel  12 A may be elongated in the lower partition wall  89  of the sub-housing  14  in the up and down direction, and the oil in the oil storage spaces O 1  and O 2  may be raised to the oil reservoir  12 B of the sub-housing  14  along a portion between the lower partition wall  79  of the plate body  74  and the lower partition wall  89  of the sub-housing  14 . 
         [0085]    The compressor may include an oil recovery channel P which guides the oil accommodated at the lower side in the casing  6  to the compression chamber C and has at least one of the oil reservoirs  12 B and  66 A, and the sensor module  20  which is installed in the oil reservoirs  12 B and  66 A, the oil reservoirs  12 B and  66 A may have the sensor hole  13 , and the sensor module  20  may be mounted in the sensor hole  13 . 
         [0086]    Here, the oil recovery channel P may be a channel which guides oil supply from the lower side in the main housing  10  to the compression chamber C. The oil recovery channel P may be a channel that includes the oil passing hole  9  of the main housing  10 , the oil channel  12  having the oil reservoir  12 B, the inner channel  48  of the motor shaft  46 , and the oil reservoir injection channel  66 C, the oil reservoir  66 A, and the oil injection channel  66 B of the frame  64 . 
         [0087]    The sensor module  20  includes a sensor housing  160  which covers the sensor hole  13 , an oil sensor  162  which is installed on the sensor housing  160  so as to protrude toward the oil reservoir  12 B, and a temperature sensor  164  which is installed on the sensor housing  160  so as to protrude toward the oil reservoir  12 B. 
         [0088]    Two oil sensors  162  may be two cylindrical condensers that are installed to overlap each other, in which one oil sensor  162  may sense quality of the oil, and the other oil sensor  162  may sense an amount of oil. One of the two oil sensors  162  may be installed at a higher position than the other one, and the oil sensor  162 , which is positioned at a relatively higher position, may measure an amount of oil. 
         [0089]    The sensor module  20  may sense oil and a temperature at a position adjacent to the inner channel  48  of the motor shaft  46  so as to sense whether the oil is smoothly supplied to the inner channel  48  of the motor shaft  46  when the compressor is operated. The sensor module  20  may be installed to face the inner channel  48  of the motor shaft  46 . The sensor module  20  may be disposed in the oil reservoir  12 B, and may sense an amount of oil and a temperature in the oil reservoir  12 B. The sensor module  20  may be installed at a position where the oil level is higher than the space S, e.g., in the oil reservoir  12 B, and may more accurately sense an amount of oil and a temperature even though the compressor is tilted or rattles. 
         [0090]    The sensor housing  160  may be positioned in the oil reservoir  12 B, and installed to face the inner channel  48  of the motor shaft  46 . The oil sensor  162  and the temperature sensor  164  may be installed to be positioned in the oil reservoir  12 B, the oil sensor  162  may sense an amount of oil in the oil reservoir  12 B, and the temperature sensor  164  may sense the temperature in the oil reservoir  12 B. 
         [0091]    The compressor may further include a fixing ring  168  which is installed on the sensor housing  160  and fixes the sensor housing  160  to the sub-housing  14 . The sensor module  20  may be installed by being inserted into the sensor hole  13  from the outside of the sub-housing  14 , and the fixing ring  168  may inhibit the sensor module  20  from being arbitrarily detached from the sub-housing  14 . 
         [0092]    The sensor module  20  may be connected to an engine control unit (ECU) for a vehicle through a signal line, and may output the sensed result to the ECU for a vehicle. The ECU for a vehicle may communicate with an HVAC (heating, ventilation, and air conditioning) controller for a vehicle, and may output signals for controlling the compressor to the HVAC controller for a vehicle. The ECU for a vehicle may communicate with a display or a buzzer that is installed in the vehicle, and may output a signal for informing of an abnormal state of the oil in the compressor using the display and the buzzer when the oil in the compressor is abnormal. 
         [0093]      FIG. 7  is a cross-sectional view illustrating the interior of a compressor. 
         [0094]    In the example shown in  FIG. 7 , an oil reservoir  66 A, which is separated from the space S in the casing  6 , and an oil injection channel  66 B, which guides the oil in the oil reservoir  66 A to the compression chamber C, may be formed in a frame  64 ′, and a sensor hole  64 A in which a sensor module  20 ′ is installed may be formed in the frame  64 ′. 
         [0095]    A part of the frame  64 ′ may be installed to be exposed to the outside of the casing  6 . A part  64 ″ of the frame  64 ′ may be positioned between the main housing  10  and the cover  16 , and the sensor module  20 ′ may be mounted to the part  64 ″ of the frame  64 ′, which is positioned between the main housing  10  and the cover  16 . The sensor hole  64 A may be formed to penetrate a portion  64 ″ of the frame  64 ′ which is positioned between the main housing  10  and the cover  16 , and the sensor module  20 ′ may be installed to penetrate the frame  64 ′. 
         [0096]    The sensor module  20 ′ may include a sensor housing  160 ′ which covers the sensor hole  64 A formed in the frame  64 ′, an oil sensor  162  which is installed on the sensor housing  160 ′ so as to protrude toward the oil reservoir  66 A, and a temperature sensor  164 . 
         [0097]    The frame  64 ′ may include an inner frame  68 ′ which has the oil reservoir  66 A and the oil injection channel  66 B, and an oil cover  70  which is coupled to the inner frame  68 ′ and covers the oil reservoir  66 A. The sensor hole  64 A may be formed in the inner frame  68 ′. The sensor housing  162 ′ may be installed on the frame  64 ′ so as to cover the sensor hole  64 A. 
         [0098]      FIG. 8  is a flowchart illustrating a method of autonomously inspecting oil in the compressor. 
         [0099]    A method of autonomously inspecting oil in the compressor may include sensing oil by the oil sensor  162  of the sensor module  20  installed in the oil reservoirs  12 B or  66 A formed in the compressor, and sensing a temperature by the temperature sensor  164  of the sensor module  20  (S 1 ). 
         [0100]    When the compressor is operated, the sensor module  20  may sense an amount of oil and an oil temperature in the oil reservoir  12 B or  66 A, and may output the sensed result to the ECU for a vehicle, and the ECU for a vehicle determines an abnormal state of the oil in the compressor based on the amount of oil and the oil temperature sensed by the sensor module  20 . 
         [0101]    The method of autonomously inspecting oil in the compressor may include informing the outside about an abnormal state of the oil when an amount of the oil sensed by the oil sensor  162  is less than a predetermined value, the temperature sensed by the temperature sensor  164  is within a predetermined range, and a time for which the oil is insufficient is a predetermined time or longer (S 2 , S 3 , S 4 , and S 5 ). 
         [0102]    Here, the predetermined value may be a reference for determining that the amount of oil is insufficient, and the ECU for a vehicle compares the amount of oil sensed by the oil sensor  162  with the predetermined value, and may determine that the oil in the oil reservoir  12 B or  66 A is currently insufficient when the amount of oil is less than the predetermined value. 
         [0103]    The predetermined range may be a reference for determining whether a temperature in the oil reservoir  12 B or  66 A is excessive. The predetermined range may be changed by the outside temperature. The predetermined range may be set to be high when the outside temperature is high. The predetermined range may be set to be low when the outside temperature is low. 
         [0104]    Further, the time for which the oil is insufficient may be a counted time for which the compressor is operated in a state in which the oil is insufficient in the compressor. The time for which the oil is insufficient may be counted from a point of time at which the insufficiency of the oil is sensed, and may be the time that is counted from a point of time at which a state in which the amount of oil is less than the predetermined value is sensed. 
         [0105]    Further, the predetermined time may be a reference time that is set to determine whether to inform the outside about an abnormal state of the compressor. 
         [0106]    In a case in which an amount of oil is less than the predetermined value and insufficient, or a time duration during which the temperature in the oil reservoir  12 B or  66 A is within a proper range is less than a predetermined time duration, the ECU for a vehicle may not inform the outside about an abnormal state of the oil. However, if the amount of oil is less than a predetermined value and insufficient, and a time duration during which a temperature in the oil reservoir  12 B or  66 A is within the proper range is greater than a predetermined time duration, the ECU for a vehicle may inform the outside about the insufficiency of the oil. 
         [0107]    The ECU for a vehicle may output a control signal to a notification device such as a display or a buzzer, and the display or the buzzer may warn the outside about an abnormal state of the oil. 
         [0108]    In some implementations, the method of autonomously inspecting oil in the compressor may include informing the outside about an abnormal state of the oil when an amount of the oil sensed by the oil sensor  162  is less than a predetermined value, and the temperature sensed by the temperature sensor  164  is outside of a predetermined range (S 2 , S 3 , and S 6 ). 
         [0109]    In a case in which the amount of oil is less than a predetermined value and insufficient, and the temperature in the oil channel  12  may deviate from a proper temperature range, the compressor may be damaged when the compressor is operated (e.g., continuously), and as a result, the ECU for a vehicle may output control signals by using a notification device such as a display or a buzzer, and may warn the outside about an abnormal state of the oil through a display or a buzzer, regardless of the operating time of the compressor or the time for which the oil is insufficient. 
         [0110]    The method of autonomously inspecting oil in the compressor may include operating the compressor (S 2  and S 7 ) according to a normal operation mode when an amount of oil sensed by the oil sensor  162  is equal to or greater than a predetermined value. 
         [0111]    As an example, a normal operation mode may be a scenario of driving a vehicle in which the compressor is operated according to signals from an HVAC control unit for the vehicle, and the compressor may be operated or stopped depending on loads in the interior of the vehicle. In a state in which the amount of oil sensed by the oil sensor  162  is equal to or greater than a predetermined value, the compressor may be operated when the interior of the vehicle is in a thermo-on condition, and the compressor may be stopped when the interior of the vehicle is in a thermo-off condition. 
         [0112]    Implementations are not limited to configurations in which the compressor is a compressor for a vehicle or installed in a vehicle, as implementations should be understood to be applicable to other technical fields to which the present disclosure pertains. 
         [0113]    Although the operations of the disclosed techniques may be described herein as being performed in a certain order and/or in certain combinations, in some implementations, individual operations may be rearranged in a different order, combined with other operations described herein, and/or eliminated, and desired results still may be achieved. Similarly, components in the disclosed systems may be combined in a different manner and/or replaced or supplemented by other components and desired results still may be achieved.