JP6329418B2 - Positive displacement pump - Google Patents

Description

  The present invention relates to a positive displacement pump.

As background art of this technical field, there is JP-A-2004-316537 (Patent Document 1). In this publication, “a closed container having an oil reservoir for storing lubricating oil at the bottom, a compression mechanism part and an electric motor part housed in the closed container, and the compression mechanism part and the electric motor part up and down. A rotating shaft to be connected; a main bearing and a sub bearing that support the rotating shaft on both upper and lower sides of the electric motor unit; a sub bearing support member that supports the sub bearing; and the rotating shaft that is attached to the sub bearing support member and An oil pump driven by
The rotating shaft has an oil supply path for supplying lubricating oil supplied from the oil supply pump to the auxiliary bearing,
The auxiliary bearing support member and the oil supply pump form an internal space that communicates with the auxiliary bearing around the rotating shaft, and have a passage that communicates the internal space and the oil reservoir. (Refer to claim 1).

JP 2004-316537 A

  In Patent Document 1, an oil supply pump is provided at the lower part of the compressor in order to ensure the amount of oil supplied to the auxiliary bearing and to have high reliability. However, the oil supply efficiency and reliability of the oil pump are not particularly considered. It was. In general, the inner rotor and outer rotor constituting the fuel pump and the pump cover are designed with a gap in consideration of the dimensional tolerance of each part. When this gap is large, oil leakage occurs, and the oil supply efficiency decreases.

  On the other hand, depending on the operating conditions, the rotating shaft is swung around (inclined), and the inner rotor and outer rotor constituting the mechanism portion of the oil pump are inclined, so that the gap between the inner rotor and outer rotor and the pump cover is reduced. If this gap is made too small for improving the oil supply efficiency, the inner rotor and the outer rotor and the pump cover come into contact with each other, leading to a decrease in reliability due to wear of the pump cover.

  Accordingly, the present invention provides a scroll compressor having an oil supply pump that eliminates the gap between the inner rotor and outer rotor and the pump cover, improves the oil supply efficiency, and reduces the amount of wear during contact and improves the reliability. The purpose is to do.

In order to solve the above problems, for example, the configuration described in the claims is adopted.
The present application includes a plurality of means for solving the above-described problems. If an example is given, “an inner rotor driven by a motor via a rotating shaft,
An outer rotor that meshes with the inner rotor and rotates with the rotation of the inner rotor;
A pump case for rotatably supporting the inner rotor and outer rotor;
A pump cover for keeping the suction chamber and the discharge chamber separated by the inner rotor, the outer rotor, and the pump case; and
Consisting of
In the positive displacement pump in which the inner rotor is driven by the electric motor to transfer and supply the fluid from the suction chamber to the discharge chamber,
The pump cover is movable in the axial direction of the rotation shaft, and an elastic body that supports the pump cover;
It has a cover presser that supports the elastic body ”.

  ADVANTAGE OF THE INVENTION According to this invention, the clearance gap between an inner rotor and an outer rotor, and a pump cover is eliminated, and a positive displacement pump with high oil supply efficiency can be provided by reducing leakage. Depending on the operating conditions, both rotors may tilt and contact the pump cover as the rotating shaft tilts. At that time, the pump cover is pushed up, and wear can be avoided. Can be improved.

The longitudinal cross-sectional view of the scroll compressor of a present Example. The figure which shows the structure of the oil pump of this application. The figure which shows the structure of a present Example at the time of using a wave washer. The figure which shows the structure of the oil supply pump which does not use the structure of this application. The figure which shows the structure of a present Example at the time of providing a guide part in a housing and a cover holding | maintenance stop. The figure which shows the structure of a present Example at the time of integrating a housing and a cover presser. The figure of the wave washer used in a present Example.

  Hereinafter, examples will be described with reference to the drawings.

The present embodiment relates to a positive displacement pump applied to a refrigerant compressor used in a refrigeration cycle such as refrigeration or air conditioning, or a gas compressor that compresses air or other gas. In the following, a scroll compressor will be described as an example of an applied product. First, the basic structure of the scroll compressor will be described.
FIG. 1 is a longitudinal sectional view of the scroll compressor of this embodiment. As shown in the figure, the fixed scroll (fixed scroll member) 7 includes a disk-shaped fixed-side flat plate portion 7a (base plate) and a first wrap erected in a spiral shape on the fixed-side flat plate portion 7a. 7b, and a support portion 7d that is located on the outer peripheral side of the fixed-side flat plate portion 7a, has a mirror plate surface that is continuous with the tip surface of the first wrap 7b, and surrounds the first wrap 7b.

  The surface of the fixed-side flat plate portion 7a on which the first wrap 7b is erected is called a tooth bottom 7c because it is between the first wrap 7b. The surface of the support portion 7 d that contacts the orbiting flat plate portion 8 a (end plate) of the orbiting scroll (orbiting scroll member) 8 is an end plate surface 7 e of the fixed scroll 7. The support portion 7d of the fixed scroll 7 is fixed to the frame 17 by bolts or the like, and the frame 17 integrated with the fixed scroll 7 is fixed to the sealed container 9 by fixing means such as welding.

  The orbiting scroll 8 is disposed so as to face the fixed scroll 7, and the first wrap 7 b of the fixed scroll 7 and the second wrap 8 b of the orbiting scroll 8 are engaged with each other, and are provided in the frame 17 so as to be orbitable. The orbiting scroll 8 includes a disc-shaped orbiting side flat plate portion 8a, a second wrap 8b that stands upright from a tooth bottom 8c that is the surface of the orbiting side flat plate portion 8a, and an orbiting side flat plate portion 8a. And a boss portion 8d provided at the center of the back surface of the head. Further, the surface of the outer peripheral portion of the orbiting flat plate portion 8 a that contacts the fixed scroll 7 is the end plate surface 8 e of the orbiting scroll 8. While the second wrap 8b and the first wrap 7b are engaged with each other, the volume of the compression chamber 13 is reduced by turning with respect to the fixed scroll 7, and the refrigerant in the compression chamber 13 is compressed.

  The hermetic container 9 has a structure in which a scroll portion including the fixed scroll 7 and the orbiting scroll 8, an electric motor portion 16 (16a: rotor, 16b: stator), lubricating oil 53, and the like are housed. The rotary shaft 10 fixed integrally with the rotor 16 a of the electric motor unit 16 is rotatably supported by the frame 17 via the main bearing 5 and is coaxial with the central axis of the fixed scroll 7.

  A crank portion 10 a is provided at the tip of the rotating shaft 10, and the crank portion 10 a is inserted into a turning bearing 11 provided on a boss portion 8 d of the orbiting scroll 8. It is configured to be able to turn. The center axis of the orbiting scroll 8 is decentered by a predetermined distance with respect to the center axis of the fixed scroll 7. The second wrap 8b of the orbiting scroll 8 is overlapped with the first wrap 7b of the fixed scroll 7 while being shifted by a predetermined angle in the circumferential direction. Reference numeral 12 denotes an Oldham ring for causing the orbiting scroll 8 to relatively rotate with respect to the fixed scroll 7 while restraining it from rotating.

  When the rotating shaft 10 is rotationally driven by the electric motor unit 16, the rotating shaft 10 is transmitted from the crank portion 10 a of the rotating shaft 10 to the orbiting scroll 8 via the orbiting bearing 11, and the orbiting scroll 8 has a predetermined distance around the center axis of the fixed scroll 7. It turns with a turning radius.

  By the orbiting motion of the orbiting scroll 8, the compression chamber 13 formed between the first wrap 7b and the second wrap 8b continuously moves to the center, and the volume of the compression chamber 13 is continuously reduced according to the movement. Thereby, the fluid (for example, refrigerant gas circulating through the refrigeration cycle) sucked from the suction port 14 is sequentially compressed in each compression chamber 13, and the compressed fluid is discharged from the discharge port 15 to the discharge space 54 above the sealed container. Discharged. The discharged fluid enters the electric motor chamber 52 in the sealed container 9 from the discharge space 54 and is supplied from the discharge pipe 6 to the outside of the compressor, for example, to the refrigeration cycle.

  Lubricating oil 53 is stored in the bottom of the airtight container 9, and a positive displacement oil pump 21 is provided at the lower end of the rotating shaft 10. The oil supply pump 21 is also rotated together with the rotation of the rotary shaft 10, and the lubricating oil 53 is drawn from the lubricating oil suction port 25 provided in the pump case 22 and discharged from the discharge port 28 of the oil supply pump 21. The discharged lubricating oil 53 is supplied to the upper part through the oil passage 3 provided in the rotating shaft 10. Part of the lubricating oil 53 lubricates the auxiliary bearing 23 through the lateral hole 24 provided in the rotating shaft 10 and returns to the bottom of the sealed container. Most of the other lubricating oil 53 passes through the oil passage 3 and reaches the upper portion of the crank portion 10a of the rotary shaft 10, and lubricates the slewing bearing 11 through the oil groove 57 provided in the crank portion 10a. And after lubricating the main bearing 5 provided in the lower part of the slewing bearing 11, it returns to an airtight container bottom part through the oil drain hole 26a and the oil drain pipe 26b.

  Hereinafter, details of the positive displacement pump of this embodiment will be described. First, the problem of the positive displacement pump when the present invention is not applied will be described with reference to FIG. In FIG. 4, the oil supply pump 21 includes an inner rotor 92 that is driven by the electric motor 16 via the rotary shaft 10, an outer rotor 93 that meshes with the inner rotor 92 and rotates as the inner rotor 92 rotates, and rotatably supports the inner rotor 92 and the outer rotor 93. A pump case 22 is provided. The suction chamber 95 and the discharge chamber 96 of the oil pump 21 are formed by an inner rotor 92, an outer rotor 93, a pump case 22, and a pump cover 94.

  The oil supply pump 21 is fixed by a housing 97 fixed to the lower frame 58 and a coupler 91. Then, when the inner rotor 92 is driven by the motor unit 16, the lubricating oil 53 is transferred from the suction chamber 95 to the discharge chamber 96, and the main bearing 5, the slewing bearing 11, and the like via the oil passage 3 communicating with the center of the rotating shaft. Supplied to sliding parts such as the auxiliary bearing 23.

  Here, in FIG. 4, the inner rotor 92 and the outer rotor 93 and the pump cover 94 are designed with a gap 98 in consideration of the dimensional tolerance of each part. Oil leakage is caused by the gap 98, resulting in a decrease in oil supply efficiency. However, if this gap is made too small for improving the lubrication efficiency, the inner rotor 92 and the outer rotor 93 may be inclined and contact the pump cover 94 as the rotary shaft 10 is inclined depending on the operating conditions. The reliability of the cover 94 is reduced due to wear. Therefore, in the following, the structure of the oil supply pump 21 in which the clearances between the inner rotor 92 and the outer rotor 93 and the pump cover 94 are eliminated to improve the oil supply efficiency, and the wear during contact is reduced and the reliability is improved will be described. To do.

  FIG. 2 is a view showing the structure of the positive displacement pump of this embodiment. The components having the same functions as those shown in FIG. 4 are denoted by the same reference numerals and have already been described, and thus detailed description thereof will be omitted. The oil supply pump 21 of this embodiment supports the elastic body 101 that supports the pump cover 94 and the elastic body 101 and is fixed to the pump case 22 in order to keep the gap between the pump cover 94 and the inner rotor 92 and the outer rotor 93 at a constant interval. It is characterized by having a cover presser 102. In FIG. 4, the pump cover 94 is fixed to the pump case 22 by means such as caulking, but the pump case 22 of this embodiment only supports the pump cover 94 so that it can freely move up and down. Thus, the pump cover 94 is not completely fixed.

  According to the configuration of the present embodiment, the oil supply efficiency can be improved by eliminating the gap 98 generated by the configuration of FIG. 4 and reducing oil leakage. Further, when the inner rotor 92 and the outer rotor 93 are inclined due to the swiveling (inclination) of the rotating shaft 10 and come into contact with the pump cover 94, a force is generated in a direction to push up the pump cover 94, and the elastic body 101 contracts upward, and the pump The cover 94 follows the inclination of the inner rotor 92 and the outer rotor 93. Thereby, compared with the case where the pump cover 94 is fixed, the surface pressure applied locally to the pump cover 94 is reduced and wear is suppressed.

  Therefore, according to the present embodiment, it is possible to provide a scroll compressor having the oil supply pump 21 with reduced oil leakage and wear of the inner rotor 92 and the outer rotor 93 and the pump cover 94.

  Here, when the rotating shaft 10 swings, the rotating shaft 10 can be inclined in all directions over the entire circumference of a plane perpendicular to the shaft. In contrast to the inclination, the inner rotor 92 and the outer rotor 93 that meshes with the inner rotor 92 are inclined following the rotating shaft 10, and therefore the inner rotor 92 and the outer rotor 93 may be inclined in all directions as with the rotating shaft 10. For example, if two spring members at the counter electrode centered on the rotary shaft 10 are used for the pump cover 94 as the elastic body 101, an elastic force acts on the inclination with respect to the direction between the two spring members. For the inclination in the other direction, the elastic force is weaker than that in the direction between the spring members. Then, the followability to the inclination of the inner rotor 92 and the outer rotor 93 is weakened and the gap 98 is increased, so that oil leakage from the high pressure discharge chamber 96 to the low pressure suction chamber 95 increases, and the oil supply efficiency of the oil supply pump 21 is increased. Decreases.

  Therefore, it is desirable that the elastic body 101 described above has a structure that supports the pump cover 94 over the entire circumference. For example, in the configuration as shown in FIG. 3, an annular wave washer as shown in FIG. 7 is used. The wave washer is made of spring steel, and is curved alternately upward and downward in the thickness direction.

  Since the elastic body 101 has a structure that supports the pump cover 94 over the entire circumference, it exerts an elastic force so as to suppress inclination in all directions. Therefore, according to the above configuration, the increase in the gap 98 is suppressed by exerting an elastic force against the inclination in all directions, and the leakage of oil from the high pressure discharge chamber 96 to the low pressure suction chamber 95 is reduced. The oil supply efficiency of the oil supply pump 21 can be improved. If it is a wave washer, since the elastic body 101 can be comprised by a single component, productivity can be improved.

  Instead of the above-described wave washer, the elastic body 101 may be composed of three or more elastic members, for example, spring members. Alternatively, the elastic body 101 may be constituted by one spring member having a diameter larger than that of the rotating shaft 10.

  The pump cover 94 is rotatably supported by the cover presser 102. However, when the pump cover 94 rotates in the configuration of this embodiment, friction occurs between the elastic body 101 and the cover presser 102, and the pump cover 94 94, the elastic body 101 and the cover presser 102 are worn.

  Therefore, it is desirable that the pump cover 94 is supported so as to be freely movable in the vertical direction and restricted in rotation. For example, as shown in FIG. 5, the pump cover 100 is provided with a rotation stopper 104, and the pump case 22 is provided with a guide 105 serving as a rotation stopper. That is, the pump cover 100 is provided with one or a plurality of protrusions (rotation stoppers 104) that serve as rotation stoppers, and one or more guides the rotation stopper 104 in the vertical direction at a position facing the rotation stopper 104 on the pump case 22. By having a plurality of guide portions, the pump cover 100 can freely move in the vertical direction while being restrained in the rotational direction with respect to the pump case 22. Therefore, according to the above configuration, wear between the pump cover 100, the elastic body 101, and the cover presser 102 can be suppressed.

  Furthermore, productivity can be improved by forming the cover presser 102 integrally with the housing 97 as shown in FIG. The housing 97 is a fixing member that supports the sub bearing 23 and is fixed to the lower frame 58.

  Further, by subjecting the pump cover 94 to a surface treatment such as manganese phosphate treatment or DLC treatment, the wear resistance against wear is improved, and a highly reliable oil supply pump can be provided.

3 oil passage 5 main bearing 6 discharge pipe 7 fixed scroll (7a: fixed flat plate portion, 7b: first lap, 7c: tooth bottom, 7d: support portion, 7e: end plate surface)
8 orbiting scroll (8a: orbiting side flat plate portion, 8b: second lap, 8c: tooth bottom, 8d: boss portion, 8e: end plate surface)
9 Sealed container 10 Rotating shaft (10a: Crank part)
DESCRIPTION OF SYMBOLS 11 Slewing bearing 12 Oldham ring 13 Compression chamber 14 Suction port 15 Discharge port 16 Electric motor part (16a: Rotor, 16b: Stator)
17 Frame 18 Back pressure chamber 20 Suction chamber 21 Oil pump 23 Sub bearing 30 Hole 52 Motor chamber 53 Lubricating oil 92 Inner rotor 93 Outer rotor 94 Pump cover 101 Elastic body 102 Cover presser

Claims (8)

An inner rotor driven by a motor via a rotating shaft;
And an outer rotor which rotates with the rotation of the inner rotor meshing with the inner rotor,
A pump casing for rotatably supporting the inner rotor and the outer rotor,
A pump cover for keeping the suction chamber and the discharge chamber separated by the inner rotor, the outer rotor, and the pump case; and
Consisting of
The rotating shaft is supported by a main bearing and a sub bearing of the electric motor,
By the inner rotor is driven by the electric motor, the fluid transported to the discharge chamber from the suction chamber, the displacement pump supplies,
An elastic member of the pump cover, and movable in the axial direction of said rotary shaft, for supporting the pump cover,
Have a, a cover pressing for supporting the elastic body,
The positive displacement pump , wherein the cover presser is formed integrally with a fixing member that supports the auxiliary bearing . The positive displacement pump according to claim 1, wherein
The positive displacement pump according to claim 1 , wherein the elastic body is configured to support the pump cover over the entire circumference. The positive displacement pump according to claim 2, wherein
A positive displacement pump using a wave washer as the elastic body. The positive displacement pump according to claim 1, wherein
The elastic body is composed of three or more resilient members,
These elastic members, by being attached to the different positions of the outer peripheral side of the pump cover, positive displacement pump, which is a structure for supporting said pump cover. In the positive displacement pump according to any one of claims 1 to 4,
A positive displacement pump characterized in that the pump cover has a detent portion. The positive displacement pump according to claim 5, wherein
The pump cover is provided with one or a plurality of protrusions that serve as rotation stoppers, and the pump case has one or more guide portions that guide the rotation stoppers in a vertical direction at positions facing the rotation stoppers. Feature positive displacement pump. In the positive displacement pump according to any one of claims 1 to 4,
A positive displacement pump characterized in that the pump cover is subjected to surface treatment such as manganese phosphate treatment or DLC treatment. A sealed container for sealing the fluid ;
A compression mechanism that is disposed in the sealed container and compresses the fluid;
An electric motor comprising a stator and a rotor arranged in the sealed container and driving the compression mechanism;
A rotation shaft that couples the compression mechanism and the electric motor and transmits a rotational force;
A bearing that supports the rotating shaft;
An oil reservoir located at the bottom of the sealed container;
An oil supply pump for supplying the bearing;
In the compressor provided with,
The compressor , wherein the oil supply pump is the positive displacement pump according to any one of claims 1 to 4.