JP2017008740A - Electric compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently suck refrigerator oil accumulated at a bottom of an accommodation portion of an electric motor in a suction chamber to a compression mechanism.SOLUTION: A compression mechanism 3 and a motor part 4 which are different in radii of trunks are made coincide with each other in heights of their bottoms, and accommodated in a motor chamber 8, and the heights of the bottoms in the motor chamber 8 are made coincide with each other between an accommodation portion of the compression mechanism 3 and an accommodation portion of the motor part 4, thus eliminating the formation of steps. Then, a rotor shaft 18 is integrally arranged at a rotor 17 of the compression mechanism 3, and a drive shaft 21 of the motor part 4 and the rotor shaft 18 which do not coincide with each other in their heights at rotation centers are connected to each other by a reduction gear row 20 as a power transmission mechanism. By this constitution, refrigerator oil O which is accumulated in the motor chamber 8, and blown up by a flow of a refrigerant in the motor chamber 8 is made to easily arrive at a suction port 49 of the compression mechanism 3 by avoiding that the steps caused by a difference of the radii of trunks between the compression mechanism 3 and the motor part 4 are formed at the bottom of the motor chamber 8 of a rear case 7 in which the compression mechanism 3 and the motor part 4 are accommodated.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a compressor for a refrigeration cycle that compresses a refrigerant, and more particularly to an electric compressor using an electric motor as a power source.

  The compressor used in the refrigeration cycle sucks low-temperature and low-pressure refrigerant and discharges the refrigerant that has been compressed to high temperature and pressure. Among compressors, there is an electric compressor having an electric motor as a power source of a refrigerant compression mechanism. In the electric compressor, an electric motor is disposed on the suction chamber side of the compression mechanism, and the electric motor to be heated is cooled with a suction refrigerant.

  By the way, the refrigerant sucked into the electric compressor from the refrigeration cycle includes mist refrigerating machine oil. This refrigerating machine oil is mainly supplied to each part of the electric compressor for lubrication.

  Further, when the compression mechanism is a vane rotary type, the refrigerating machine oil is also provided in the back pressure space of the vane as a pressure source for assisting the vane to protrude from the rotor rotating in the cylinder chamber to the inner peripheral surface side of the cylinder chamber. Is supplied.

  In this type of electric compressor, the compression mechanism is required to perform refrigerant compression according to the refrigeration load of the refrigeration cycle. Therefore, the electric motor is required to have an ability to generate a torque corresponding to the electric motor. Under such circumstances, the diameter of the electric motor is generally larger than the diameter of the compression mechanism (for example, Patent Document 1).

JP 2014-109250 A

  By the way, the mist refrigerating machine oil contained in the refrigerant sucked into the suction chamber of the electric compressor is separated from the refrigerant by colliding with the surface of the electric motor or the electric motor side of the compression mechanism. The separated refrigerating machine oil flows along the surface of the collided object and flows into the bottom of the suction chamber. At this time, if there is a difference in inner diameter corresponding to the difference in body diameter between the compression mechanism and the electric motor in the suction chamber, the refrigerating machine oil that has flowed into the bottom of the suction chamber enters the lower part of the electric motor housing than the housing part of the compression mechanism. Accumulate.

  In this way, unless the liquid level of the refrigerating machine oil collected in the electric motor housing portion of the suction chamber reaches the refrigerant suction port of the compression mechanism, it is not sucked into the compression mechanism, so the refrigerating machine oil is not easily fed into the discharge chamber side. Refrigerating machine oil for lubrication becomes insufficient. In order to prevent this, the refrigeration oil must be sealed in a larger amount than necessary.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric compressor capable of efficiently sucking refrigerating machine oil accumulated at the bottom of a housing portion of an electric motor in a suction chamber into a compression mechanism. It is in.

In order to achieve the above object, the electric compressor of the present invention is
A compression mechanism for compressing the refrigerant by rotation of the rotating body;
An electric motor that rotates the rotating body with a different radius from the compression mechanism,
A housing for accommodating the compression mechanism and the electric motor in the suction chamber by shifting the rotation center of each other so that the difference in height between the bottoms is smaller than the difference in radius between the trunks;
Is provided.

  According to the present invention, the refrigerating machine oil accumulated at the bottom of the housing portion of the electric motor in the suction chamber can be efficiently sucked into the compression mechanism.

It is a front sectional view of a general electric compressor. It is explanatory drawing which shows typically the structure of the principal part of the electric compressor which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front sectional view showing an electric compressor having a general configuration to which the present invention is applied.

  An electric compressor 1 shown in FIG. 1 controls a substantially cylindrical housing 2, a compression mechanism 3 that compresses a refrigerant, a motor unit 4 (corresponding to an electric motor in claims), and a motor unit 4. The inverter unit 5 is provided.

  The substantially cylindrical housing 2 includes a rear case 7 that accommodates the compression mechanism 3 and the motor unit 4 therein, a front case 9 that is disposed so as to cover the opening end of the rear case 7, and the rear case 7 and the other side. And an inverter case 11 connected to the front case 9.

  The compression mechanism 3 accommodated in the rear case 7 formed in a bottomed cylindrical shape includes a cylinder block 13 having an elliptical shape on the inner periphery, and a side block arranged so as to sandwich both ends of the cylinder block 13. 15 constitutes the housing 12. In addition, the compression mechanism 3 includes a rotor 17 (corresponding to a rotating body in claims) that is rotatably accommodated on the inner periphery of the cylinder block 13, and a vane 19 that is accommodated in a vane groove formed in the rotor 17. Have.

  The compression mechanism 3 is press-fitted and fixed to the rear case 7, whereby a discharge chamber 43 for discharging refrigerant is formed on the bottom surface side of the rear case 7. In the discharge chamber 43, a gas-liquid separator 47 that separates gaseous refrigerant from oil or the like that is liquid contained in the discharged refrigerant is disposed.

  Further, by sandwiching both ends of the cylinder block 13 by the rear side block 15 a and the front side block 15 b of the side block 15, a cylinder chamber 35 is formed on the inner periphery of the cylinder block 13. As the rotor 17 rotates, the vane 19 pops out from the vane groove formed in the rotor 17, the tip of the vane 19 comes into contact with the inner wall of the cylinder block 13, and the rotor 17 rotates to compress the refrigerant. Yes. The compressed refrigerant is discharged into the discharge chamber 43 described above.

  The motor unit 4 serving as a drive source for rotating the rotor 17 includes a stator 23 that is evenly disposed along the inner periphery of the rear case 7, a drive shaft 21 that is disposed on the inner side of the stator 23, and a drive And a motor rotor portion 25 that press-fits and fixes the shaft 21. The drive shaft 21 is formed integrally with the rotor 17 of the compression mechanism 3.

  The stator 23 is formed by winding a coil 37 around a tooth portion (not shown). A current flows through the coil 37 to generate a magnetic field, and the motor rotor portion 25 disposed inside the stator 23. Is rotating.

  Further, a motor neutral point 45 that draws out the coils 37 wound around a plurality of teeth and concentrates them in one place for connection is formed on the upper side in the vehicle vertical direction X when the vehicle is mounted. The motor neutral point 45 is connected to the inverter unit 5 through a hermetic terminal 30 described later.

  The inverter unit 5 that controls the motor unit 4 is formed on the rear case 7 and the other end side of the front case 9, and is disposed in an inverter chamber 26 that is sealed by the inverter case 11.

  The inverter unit 5 includes an electronic component 27 and a substrate 29, and the electronic component 27 includes a switching element 39 that generates heat (such as an intelligent power module) and a tall component that has a larger protruding height than the switching element 39. 41 (common mode coil, normal mode coil, inverter input capacitor, transformer, internal power supply capacitor, etc.).

  The electronic component 27 disposed in the inverter chamber 26 includes a switching element 39 having a low projecting height in the direction of the drive shaft 21 among the electronic components 27 disposed below the inverter chamber 26 in the vehicle vertical direction X. In addition, the tall component 41 having a protruding height in the direction of the drive shaft 21 is arranged above the inverter chamber 26 in the vehicle vertical direction X.

  A front case 9 is disposed between the rear case 7 and the inverter case 11. By arranging the front case 9 so as to cover the opening end of the rear case 7, a motor chamber 8 (corresponding to the suction chamber in the claims) is formed. The motor chamber 8 accommodates the compression mechanism 3 and the motor unit 4 described above, and oil is sealed in order to maintain lubrication in the motor chamber 8. A refrigerant suction port (not shown) is provided on the outer periphery of the motor chamber 8 to inject the refrigerant into the motor chamber 8.

  The interior of the front case 9 is partitioned into a motor chamber 8 and an inverter chamber 26 by a partition wall 28. A hermetic terminal 30 that electrically connects the motor unit 4 and the inverter unit 5 described above is provided through the partition wall 28. The hermetic terminal 30 is disposed above the front case 9 in the vehicle vertical direction X.

  In the electric compressor 1 configured as described above, when the motor unit 4 is driven, the drive shaft 21 rotates, and the rotor 17 formed integrally with the drive shaft 21 rotates. When the rotor 17 is rotated, the vane 19 accommodated in the vane groove in the rotor 17 jumps out of the vane groove by a centrifugal force or the like and comes into sliding contact with the inner wall of the cylinder block 13.

  As a result, the refrigerant sucked into the compression chamber between the two adjacent vanes 19 from the suction port (not shown) is sealed, and the amount of protrusion of the vane 19 from the rotor 17 decreases with the rotation of the rotor 17. By reducing the volume of the compression chamber, the refrigerant in the compression chamber is compressed. The compressed refrigerant is discharged into a discharge chamber 43 from a discharge hole (not shown), discharged from a discharge port (not shown) to a refrigeration cycle via a gas-liquid separator 47, and after passing through the refrigeration cycle, into the motor chamber 8. Inhaled.

  The refrigerant sucked into the motor chamber 8 is mixed with the refrigerating machine oil O separated from the refrigerant by the gas-liquid separator 47 and supplied to each part as a lubrication or pressure source in the form of a mist. When the refrigerant collides with the motor unit 4 for cooling, the mist of the refrigerating machine oil O in the refrigerant adheres to the surface of the motor unit 4, and the adhering mist of the refrigerating machine oil O aggregates into droplets, and the motor It falls along the surface of the part 4 and accumulates at the bottom of the motor chamber 8 of the housing 2.

  In addition, while the motor unit 4 is stopped and the refrigerant compression operation by the electric compressor 1 is stopped, the refrigerant in the discharge chamber 43 is caused by the pressure difference between the discharge chamber 43 and the motor chamber 8 (suction chamber). When the refrigerant flows back to 8, the refrigerating machine oil O stored in the discharge chamber 43 flows into the motor chamber 8 together with the refrigerant that flows back, and accumulates at the bottom of the motor chamber 8 of the housing 2.

  Here, in order to supply a sufficient torque from the motor unit 4 to the refrigerant compression according to the refrigeration load of the refrigeration cycle to the compression mechanism 3, the radius of the barrel of the motor unit 4 is set to be equal to that of the barrel of the compression mechanism 3. When the radius is larger than the radius, a step is generated between the accommodating portion of the compression mechanism 3 and the accommodating portion of the motor unit 4 in the motor chamber 8.

  When such a level difference occurs, as described above, the refrigerating machine oil O collected at the bottom of the motor chamber 8 is exclusively accumulated in the accommodating portion of the motor unit 4 having a large trunk radius. Then, even if the suction port 49 of the compression mechanism 3 is disposed at the lowermost part, if the liquid level of the refrigerating machine oil O accumulated in the housing portion of the motor unit 4 does not reach the suction port 49, the refrigerating machine oil is supplied to the compression mechanism 3. O cannot be sucked into the discharge chamber 43 side.

  Therefore, in the present invention, the structure described below is adopted as the structure of the path for sucking the refrigerant into the motor chamber 8 of the front case 9.

  FIG. 2 is an explanatory diagram schematically showing a configuration in the motor chamber 8 of the front case 9 used in the electric compressor 10 according to the embodiment of the present invention.

  In the electric compressor 10 of the present embodiment shown in FIG. 2, the compression mechanism 3 and the motor unit 4 having different body radii are accommodated in the motor chamber 8 with the heights of the bottoms being matched, thereby compressing. The height of the bottom of the motor chamber 8 is matched between the housing portion of the mechanism 3 and the housing portion of the motor unit 4 to eliminate the step.

  Therefore, in the electric compressor 10 of the present embodiment, the height of the rotation center of the rotor 17 of the compression mechanism 3 and the rotation center of the motor rotor portion 25 of the motor unit 4 do not coincide with each other, and the general electric compressor 1 shown in FIG. Thus, the drive shaft 21 of the motor unit 4 cannot be formed integrally with the rotor 17 of the compression mechanism 3.

  Therefore, the rotor shaft 18 is provided integrally with the rotor 17 of the compression mechanism 3, and the drive shaft 21 and the rotor shaft 18 of the motor unit 4 whose rotational centers do not coincide with each other are used as a reduction gear train 20 as a power transmission mechanism. To connect with.

  In the present embodiment, the reduction gear train 20 is configured by the gear 61 attached to the rotor shaft 18 and the gear 63 attached to the drive shaft 21 and meshing with the gear 61 of the rotor shaft 18. The reduction gear train 20 reduces the rotation of the drive shaft 21 and transmits it to the rotor shaft 18.

  Further, the power transmission mechanism that connects the rotor shaft 18 of the compression mechanism 3 and the drive shaft 21 of the motor unit 4 may be configured by something other than the reduction gear train 20 (for example, a constant speed gear train, a speed increasing gear). Column, belt pulley mechanism, chain sprocket mechanism, etc.). However, by connecting the rotor shaft 18 and the drive shaft 21 with the reduction gear train 20 as in the present embodiment, the rotor 17 of the compression mechanism 3 can be rotated even if the torque generated in the motor unit 4 is small. .

  Furthermore, in this embodiment, the front end of the drive shaft 21 press-fitted into the motor rotor portion 25 is supported by the bearing portion 16 formed on the front side block 15 b of the casing 12 of the compression mechanism 3. As a result, it is possible to prevent the front end of the drive shaft 21 from becoming a free end and the meshing of the gear 63 of the drive shaft 21 and the gear 61 of the rotor shaft 18 from becoming insufficient.

  Incidentally, the rotor shaft 18 and the drive shaft 21 are arranged with the heights of their rotation centers shifted so that the height of the bottom of the compression mechanism 3 having a different body radius matches the height of the bottom of the motor unit 4. In doing so, both the rotation centers may be arranged not only in the height direction (vertical direction X) but also in other directions (except for the axial direction of the rotor shaft 18 and the drive shaft 21). Good.

  In the electric compressor 1 of the present embodiment configured as described above, the compression mechanism 3 and the motor unit 4 having different trunk radii are arranged in the rear case 7 of the housing 2 so that the heights of the bottoms thereof coincide with each other. The rotor shaft 18 of the compression mechanism 3 and the drive shaft 21 of the motor unit 4 are connected by a reduction gear train 20 so that power can be transmitted.

  For this reason, in the bottom part of the motor chamber 8 of the rear case 7 in which the compression mechanism 3 and the motor part 4 are accommodated, a step due to a difference in radius between the compression mechanism 3 and the motor part 4 is not formed. The refrigerating machine oil O accumulated in the motor chamber 8 and spouted by the flow of the refrigerant in the motor chamber 8 can easily reach the suction port 49 of the compression mechanism 3. As a result, the refrigerating machine oil O in the motor chamber 8 is efficiently sucked into the compression mechanism 3, and the refrigerating machine oil O is fed into the discharge chamber 43 side together with the compressed refrigerant, and the refrigerating machine oil O for lubrication is supplied in the discharge chamber 43. It is possible to prevent the shortage.

  In this embodiment, the compression mechanism 3 and the motor unit 4 having different trunk radii are accommodated in the rear case 7 of the housing 2 so that the heights of the bottoms thereof coincide with each other. The heights of do not necessarily have to match. That is, the difference in height between the bottom of the compression mechanism 3 and the bottom of the motor unit 4 is smaller than the difference between the radius of the body of the compression mechanism 3 and the radius of the body of the motor 4. Even if the compression mechanism 3 and the motor unit 4 are accommodated in the rear case 7 of the housing 2 by shifting the rotation center, the refrigerating machine oil O in the motor chamber 8 can be efficiently sucked into the compression mechanism 3.

  Further, in the present embodiment, the case where the present invention is applied to the electric compressor 1 having the vane rotary type compression mechanism 3 that rotates the rotor 17 in the cylinder chamber 35 has been described as an example. However, the present invention has a rotary compression mechanism that sucks and compresses gas by rotating a rotating body, such as a scroll compressor that rotates a movable scroll with respect to a fixed scroll to compress gas. This is widely applicable when the compressor is rotated by a motor.

  INDUSTRIAL APPLICATION This invention can be utilized in the electric compressor which rotates the rotary body of the compression mechanism which compresses a refrigerant | coolant with an electric motor.

DESCRIPTION OF SYMBOLS 1,10 Electric compressor 2 Housing 3 Compression mechanism 4 Motor part (electric motor)
5 Inverter section (drive circuit)
7 Rear case 8 Motor room (suction room)
9 Front case 11 Inverter case 12 Housing 13 Cylinder block 15 Side block 15a Rear side block 15b Front side block 16 Bearing portion 17 Rotor (rotating body)
18 Rotor shaft (rotary shaft)
19 Vane 20 Reduction gear train (power transmission mechanism)
21 Drive shaft (output shaft)
DESCRIPTION OF SYMBOLS 23 Stator 25 Motor rotor part 26 Inverter chamber 27 Electronic component 28 Partition wall 29 Board | substrate 30 Hermetic terminal 35 Cylinder chamber 37 Coil 39 Switching element 41 Tall parts 43 Discharge chamber 45 Motor neutral point 47 Gas-liquid separator 49 Inlet 53 Inhaler Refrigerant passage 55 Suction port 57 Refrigerant outlet 59 Liquid level O Refrigerating machine oil X Vehicle vertical direction

Claims (3)

A compression mechanism (3) for compressing the refrigerant by rotation of the rotating body (17);
An electric motor (4) for rotating the rotating body (17), which has a barrel radius different from that of the compression mechanism (3);
The compression mechanism (3) and the electric motor (4) are arranged so that the rotation chambers are shifted from each other so that the difference in height between the bottoms becomes smaller than the difference in radius between the trunks. 8) a housing (2) for housing
An electric compressor (10) comprising:   The output shaft (21) of the electric motor (4) is supported by the bearing portion (16) of the housing (12) of the compression mechanism (3), and the rotation shaft (18) of the rotating body (17) and the output The electric compressor (10) according to claim 1, wherein the shaft (21) is connected by a power transmission mechanism (20).   The electric compressor (10) according to claim 2, wherein the power transmission mechanism (20) comprises a reduction gear train.

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