CN106499634A - electric compressor - Google Patents

Abstract

The invention provides an electric compressor with high performance and reliability. The main bearing (42) has: a dividing groove (81) that divides the inner peripheral sliding surface (42t) in the upper and lower directions in the axial direction (G) of the main bearing (42); an upper inclined groove (82a) inclined with respect to the axial direction (G) on the upper side of the dividing groove (81) of the inner peripheral sliding surface (42 t); and a lower inclined groove (82b) inclined with respect to the axial direction (G) below the dividing groove (81) of the inner peripheral sliding surface (42t), wherein the upper inclined groove (82a) and the lower inclined groove (82b) are formed so as to at least partially overlap when viewed from the axial direction (G).

Description

electric compressor

technical field

The present invention relates to electric compressors.

Background technique

Electric compressors are mostly used in refrigeration and air-conditioning equipment such as refrigerators and air conditioners because of their compactness and simple structure. In such an electric compressor, it is necessary to supply oil to bearings that rotatably support the crankshaft. Patent Document 1 describes an electric compressor that supplies oil to the entire area of the main bearing by providing an inclined groove (spiral groove) that continues from the inner lower end toward the upper end of the bearing (main bearing) that supports the crankshaft.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2010-255448

Contents of the invention

The problem to be solved by the invention

However, in the electric compressor described in Patent Document 1, since it is necessary to form a continuous inclined groove, the inclination angle of the inclined groove becomes large, and the viscous pump effect decreases. The metal contact between the crankshaft and the bearings may reduce the performance and reliability.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an electric compressor having high performance and reliability.

Solution to the problem

The present invention is characterized in that it includes: an electric motor; a compression mechanism part having a crankshaft rotationally driven by the electric motor and a bearing supporting the crankshaft, and lubricating the sliding surfaces of the crankshaft and the bearing with lubricating oil; and an accommodating part. , which accommodates the above-mentioned electric motor and the above-mentioned compression mechanism part, the above-mentioned bearing and/or the above-mentioned crankshaft has: at least one dividing groove, which divides the above-mentioned sliding surface up and down in the axial direction of the above-mentioned bearing; The division grooves are positioned above and below the axial direction and are inclined with respect to the axial direction, and each of the inclined grooves is formed so as to at least partially overlap each other when viewed from above in the axial direction.

The effect of the invention

According to the present invention, it is possible to provide an electric compressor with high performance and high reliability.

Description of drawings

FIG. 1 is a longitudinal sectional view showing the overall structure of an electric compressor according to a first embodiment.

Fig. 2 is a plan view showing a main bearing of the electric compressor.

Fig. 3 is a sectional view taken along line A-A of Fig. 1 .

4 is an explanatory view of the operation of the compression mechanism, where (a) is 0 degrees, (b) is 90 degrees, (c) is 180 degrees, and (d) is 270 degrees.

Fig. 5 shows the main bearing of the first embodiment, (a) is a sectional view taken along line B-B in Fig. 2 , and (b) is a developed view of the inner peripheral surface.

6 shows the main bearing of Comparative Example 1, (a) is a longitudinal sectional view, and (b) is a developed view of the inner peripheral surface.

7 shows the main bearing of Comparative Example 2, (a) is a longitudinal sectional view, and (b) is a developed view of the inner peripheral surface.

8 shows the main bearing of Comparative Example 3, (a) is a longitudinal sectional view, and (b) is a developed view of the inner peripheral surface.

Fig. 9 shows a main bearing according to a second embodiment, where (a) is a longitudinal sectional view, and (b) is a developed view of the inner peripheral surface.

Fig. 10 shows a main bearing according to a third embodiment, where (a) is a longitudinal sectional view, and (b) is a developed view of the inner peripheral surface.

Fig. 11 shows a main bearing according to a fourth embodiment, where (a) is a longitudinal sectional view, and (b) is a developed view of the inner peripheral surface.

Fig. 12 shows a main bearing according to a fifth embodiment, wherein (a) is a longitudinal sectional view, and (b) is a developed view of an inner peripheral surface.

Explanation of symbols

1—electric compressor, 2—airtight container (storage part), 3—electric motor, 4—compression mechanism, 5—pressure accumulator, 5a—suction tube, 21—cylinder, 22—cover, 23—bottom, 23a—oil storage tank, 31—stator, 32—rotor, 41—crankshaft, 41a—eccentric part, 41b—hollow part, 42, 42A, 42B, 42C, 42D—main bearing (bearing), 42a—end plate, 42b— Cylindrical part, 42e—engraving part, 42f—discharge port, 42t—inner peripheral sliding surface (sliding surface), 43—cylinder, 43a—cylinder chamber, 44—secondary bearing, 45—roller, 46—blade, 47—disk Spring, 48—oil plate, 54—discharge pipe, 71—discharge valve, 72—stopper, 73—cup muffler, 81, 81c, 81d, 81e, 81f—division groove, 82a, 82c, 82e—on Side inclined groove (inclined groove), 82b, 82d, 82f—lower inclined groove (inclined groove), 82g, 82h, 82i—inclined groove, G—axial direction, Q1—suction chamber, Q2—compression chamber, R1—rotation Direction, R2—the direction of oil flow.

detailed description

Hereinafter, modes for implementing the present invention (hereinafter referred to as "embodiments") will be described in detail with reference to appropriate drawings. In addition, each drawing is only shown schematically so that the invention can be fully understood. Therefore, the present invention is not limited to the embodiments shown below. In addition, in each figure, the same code|symbol is attached|subjected to the common structural element, and the same structural element, and overlapping description is abbreviate|omitted. In addition, in the following, a rotary compressor will be described as an example of a hermetic electric compressor, but it is not limited to a rotary compressor, and can be applied to electric compressors such as a scroll compressor and a reciprocating compressor.

(first embodiment)

FIG. 1 is a longitudinal sectional view showing the overall structure of an electric compressor according to a first embodiment. In addition, FIG. 1 simply shows only the part necessary for explaining the electric compressor 1 of 1st Embodiment.

As shown in FIG. 1 , an electric compressor 1 according to the first embodiment includes an airtight container 2 (accommodating portion), an electric motor 3 , and a compression mechanism portion 4 .

The airtight container 2 is composed of a cylindrical body 21 , a lid body 22 and a bottom body 23 . The cylindrical body 21 is made of a steel plate, and is a cylindrical casing with upper and lower openings. The lid body 22 has a disk shape and is fitted so as to close the upper opening of the cylinder body 21 . The bottom body 23 has a disk shape and is fitted so as to close the lower opening of the cylindrical body 21 . The lid body 22 and the bottom body 23 are welded to the cylindrical body 21 to form a structure for sealing the inside of the airtight container 2 .

An oil storage tank 23 a for storing refrigerating machine oil (lubricating oil, hereinafter referred to as oil) is provided on the upper surface (inner surface) of the bottom body 23 constituting the bottom of the airtight container 2 . The refrigerating machine oil is supplied to the compression mechanism unit 4 to lubricate the sliding surface of the compression mechanism unit 4 and to seal gaps in the compression mechanism unit 4 .

The motor 3 is a driving source for driving the compression mechanism 4 and includes a stator 31 fixed to the inner wall of the airtight container 2 by shrink fitting or the like, and a rotor 32 fitted on the upper part of the crankshaft 41 of the compression mechanism 4 .

The compression mechanism unit 4 is configured to compress the working fluid (refrigerant gas) according to the rotational motion of the rotor 32 of the electric motor 3, and supply the compressed working fluid to the refrigerating cycle of the refrigerating and air-conditioning apparatus. In addition, the compression mechanism unit 4 is configured by including a crankshaft 41 , a main bearing 42 , a cylinder 43 , a sub bearing 44 , a roller 45 , vanes 46 , and a coil spring 47 .

The crankshaft 41 is a member that drives the vane 46 inside the cylinder 43 and has an eccentric portion 41 a on the lower end side. The crankshaft 41 is rotatably supported inside the airtight container 2 by fitting the upper side of the eccentric portion 41 a into the main bearing 42 and fitting the lower side of the eccentric portion 41 a into the sub-bearing 44 .

Further, in the crankshaft 41, a hollow portion 41b is formed along the axial direction G of the crankshaft 41 (main bearing 42, sub-bearing 44) from the lower end surface. The hollow portion 41b is formed to extend to the height position of the lower end of the main bearing 42 . In addition, an oil plate 48 is fitted into the hollow portion 41b. The oil plate 48 has a shape obtained by twisting a thin plate in the rotation direction of the crankshaft 41 . The oil plate 48 rotates with the crankshaft 41, and the oil in the oil storage tank 23a at the bottom 53 of the airtight container 2 is sucked (suctioned up) by the centrifugal pump effect, thereby supplying oil to the main bearing 42, the auxiliary bearing 44 and the eccentric part 41a. .

The crankshaft 41 is formed with holes (not shown) communicating with the inner diameter sides of the main bearing 42, the auxiliary bearing 44, and the roller 45, and the oil pumped up by the oil plate 48 is supplied to the inner diameter lower end of the main bearing 42, the auxiliary bearing 42 through each hole. The inner diameter upper end of the bearing 44 and the inner diameter side of the roller 45 .

The main bearing 42 includes a substantially disk-shaped end plate 42a and a cylindrical portion 42b extending upward from the radial center of the end plate 42a, and supports the crankshaft 41 through the cylindrical portion 42b. The outer peripheral wall surface of the end plate 42 a is fixed to the inner peripheral wall surface of the cylindrical body 21 of the airtight container 2 by welding or the like.

In addition, a discharge port 42f (see FIG. 2 ) is formed on the end plate 42a of the main bearing 42, and a discharge valve 71 that selectively opens or closes the discharge port 42f and a device that determines the opening degree of the discharge valve 71 (controls excessive opening) are provided. Stopper 72.

The cylinder 43 has a cylindrical through hole penetrating in the axial direction G at the center in the radial direction. A cylinder chamber (through hole) 43 a is formed by the through hole, the main bearing 42 and the sub bearing 44 . In addition, the cylinder 43 is fastened to the main bearing 42 by a plurality of bolts B (see FIG. 3 ). The upper end surface of the cylinder 43 is blocked by the main bearing 42 .

The sub bearing 44 includes an end plate 44 a closing the lower end surface of the cylinder 43 and a cylindrical portion 44 b extending downward from the radial center of the end plate 44 a and supporting the lower end of the crankshaft 41 . The length of the axial direction G of the cylindrical part 44b is formed shorter than the cylindrical part 42b. In addition, the sub-bearing 44 is fastened to the cylinder 43 by bolts (not shown).

The roller 45 is formed in a cylindrical shape, and is arranged in the cylinder chamber 43a. In addition, the eccentric portion 41 a of the crankshaft 41 is fitted on the inner diameter side of the roller 45 , and the roller 45 is configured to be rotatable on the outer peripheral side of the eccentric portion 41 a.

The blade 46 is arranged to abut against the outer peripheral surface of the roller 45 . In addition, the vane 46 has a plate shape and is configured to reciprocate in the radial direction inside the cylinder 43 .

The coil spring 47 is disposed in a horizontal hole 43b extending radially in the cylinder 43 . The coil spring 47 urges the blade 46 toward the roller 45 by contacting the blade 46 at one end and fitting the other end into the horizontal hole 43 b.

In addition, an accumulator 5 and a suction pipe 5 a for guiding a working fluid from the refrigeration cycle to the compression mechanism unit 4 through the accumulator 5 are provided outside the airtight container 2 . The accumulator 5 is a container storing refrigerant gas functioning as a working fluid in a pressurized state. The suction pipe 5a is connected to an end portion of a suction port 43c (see FIG. 3 ) communicating with the cylinder chamber 43a.

Fig. 2 is a plan view showing a main bearing of the electric compressor. In addition, FIG. 2 is a state in which the discharge valve 71 (see FIG. 1 ) and the stopper 72 (see FIG. 1 ) are removed from the main bearing 42 , and is a state in which the main bearing 42 is viewed from above.

As shown in FIG. 2 , on the end plate 42 a of the main bearing 42 , around the cylindrical portion 42 b , bolt insertion holes for bolt fastening are formed at multiple places so as to penetrate in the axial direction G (see FIG. 1 ). hole 42c. In addition, the number of objects of the bolt insertion hole 42c is not limited to four, and can be changed suitably.

Moreover, the long hole 42d which penetrates in the axial direction G (refer FIG. 1) is formed in several places in the outer peripheral side of the end plate 42a. These long holes 42d are flow paths for returning the oil (refrigerator oil) discharged from the compression mechanism unit 4 into the airtight container 2 to the oil storage tank 23a.

In addition, on the end plate 42a, a concave engraved portion 42e to which the discharge valve 71 (see FIG. 1 ) is attached is formed in the vicinity of the cylindrical portion 42b. The engraved part 42e has a substantially long hole shape in plan view, and a discharge port 42f for discharging refrigerant gas (working fluid) is formed on the bottom surface of one end, and a discharge valve 71 is fixed (riveted) in a hanging state on the bottom surface of the other end. (see FIG. 1 ) of the fixing portion (caking portion) 42g.

Fig. 3 is a sectional view taken along line A-A of Fig. 1 . FIG. 3 is a cross-sectional view of FIG. 1 when the boundary portion between the main bearing 42 and the cylinder 43 is cut.

As shown in FIG. 3 , the shape of the cylinder 43 in plan view includes a circular portion 43m forming the cylinder chamber 43a and an extension portion 43n extending from a part of the circular portion 43m toward the suction pipe 5a.

In addition, the cylinder 43 is formed with a slit 43d extending in the radial direction across the circular portion 43m and the protruding portion 43n, and the vane 46 is inserted therethrough.

The vane 46 is fitted in the slit 43d of the air cylinder 43, and moves forward and backward while contacting the outer periphery of the roller 45 which rotates with the eccentric movement of the eccentric part 41a.

The cylinder chamber 43a is formed with a suction chamber Q1 for sucking the working fluid and a compression chamber Q2 for compressing the working fluid. The compression chamber Q2 is formed by the following members: an inner wall surface 43s of the cylinder chamber 43a, an outer wall surface 45s of the roller 45, a side surface (right side in the figure) 46s of the vane 46, and an inner wall surface 42s ( 1) and the inner wall surface 44s (see FIG. 1) of the sub-bearing 44 (end plate 44a).

In the compression mechanism unit 4, the crankshaft 41 is configured to be rotated in the direction of the arrow R1 by the motor 3 (see FIG. 1 ), so that the suction chamber Q1 and the compression chamber Q2 are controlled by the eccentric rotation of the eccentric portion 41a and the reciprocating motion of the blade 46. The volume is changed, and the operating fluid is pressurized by the volume change. When the gas pressure Pd1 inside the airtight container 2 (see FIG. 1 ) and the gas pressure Pd2 inside the compression chamber Q2 are in the relationship of Pd2≥Pd1, the discharge valve 71 (see FIG. 1 ) opens the discharge port 42f (see FIG. 2 ). . Accordingly, the discharge valve 71 discharges the high-pressure gas (working fluid) inside the compression chamber Q2 into the airtight container 2 . In addition, at other times, the discharge valve 71 closes the discharge port 42f. Thus, the discharge valve 71 prevents the high-pressure gas (working fluid) inside the airtight container 2 from flowing back into the compression chamber Q2.

The cup muffler 73 is configured in a disk shape covering the discharge valve 71 and the stopper 72 and functions as a muffler. In addition, a discharge hole (not shown) for discharging the operating fluid discharged from the discharge port 42f into the airtight container 2 is provided in the cup muffler 73 . The refrigerant gas discharged from the cup-shaped muffler 73 into the airtight container 2 passes through the gaps and air holes (not shown) of the motor 3, and is discharged from the discharge pipe 54 (refer to FIG. Outside of container 2 (refrigerated cycle).

4 is an explanatory view of the operation of the compression mechanism, where (a) is 0 degrees, (b) is 90 degrees, (c) is 180 degrees, and (d) is 270 degrees.

In FIG. 4( a ), the state where the vane 46 retreats to the innermost portion of the slot 43 d of the air cylinder 43 is defined as 0 degrees. In this case, the entire cylinder chamber 43a is a suction space, and the force of the compression load that the crankshaft 41 presses the main bearing 42 does not operate.

As shown in FIG. 4( b ), when the eccentric portion 41 a is rotated 90 degrees in the counterclockwise direction from the state shown in FIG. 4( a ), a part of the vane 46 is pushed out from the slot 43 d of the cylinder 43 to the cylinder chamber. The state in 43a is divided into a suction chamber and a compression chamber by vanes 46 . The compression load direction S1 in this case is a direction perpendicular to the straight line connecting the contact point P1 between the blade 46 and the roller 45 and the contact point P2 between the roller 45 and the air cylinder 43 . In addition, the direction 180 degrees opposite to the compressive load direction S1 is the anti-compressive load direction S2.

As shown in Figure 4(c), when the eccentric portion 41a is rotated 180 degrees in the counterclockwise direction from the state described in Figure 4(a), the blade 46 is pushed out from the slot 43d of the cylinder 43 to the maximum The state in the chamber 43a. The compressive load direction S3 in this case is a direction perpendicular to the straight line connecting the contact point P3 of the blade 46 and the roller 45 and the contact point P4 of the roller 45 and the air cylinder 43 . In addition, the direction 180 degrees opposite to the compressive load direction S3 is the anti-compressive load direction S4.

As shown in FIG. 4( d), when the eccentric portion 41a is rotated 270 degrees in the counterclockwise direction from the state shown in FIG. The state within the way is pushed into. The compression load direction S5 in this case is a direction perpendicular to the straight line connecting the contact point P5 of the blade 46 and the roller 45 and the contact point P6 of the roller 45 and the air cylinder 43 . In addition, the direction 180 degrees opposite to the compressive load direction S5 is the anti-compressive load direction S6.

In the fluid lubrication system, the contact between the crankshaft 41 and the main bearing 42 is prevented by the oil film pressure, and the portion where the groove (inclined groove) is formed is a portion where the gap between the crankshaft 41 and the main bearing 42 increases, so the oil film pressure is easy to escape. Therefore, if inclined grooves are provided in the range of -90 degrees to 90 degrees relative to the compressive load directions S1, S3, and S5 (grooves exist at places receiving compressive loads), the crankshaft 41 and the main bearing 42 become easy to contact . Therefore, in this embodiment, by providing inclined grooves on the anti-compression load surfaces formed outside the range of -90 degrees to 90 degrees in the relative direction of the compression load directions S1, S3, and S5, it is possible to prevent the crankshaft 41 from colliding with the main bearings. The contact of 42 can improve the performance and reliability of the electric compressor 1 .

Fig. 5 shows the main bearing of the first embodiment, (a) is a sectional view taken along line B-B of Fig. 2 , and (b) is a developed view. In addition, the angle shown on the horizontal axis of FIG. 5(b) corresponds to the angles (0 degrees, 90 degrees, 180 degrees, 270 degrees) shown in FIG. degrees (the entire range of the anti-compression load surface is approximately 135 degrees). In addition, about 45 degrees (135 degrees), it changes with a model and an operation state, and it is not limited to this embodiment.

As shown in FIG. 5(a), the main bearing 42 has a divided groove 81, an upper inclined groove (inclined groove) 82a, and a lower inclined groove (inclined groove) 82b. The inner peripheral sliding surface 42t (sliding surface) is divided up and down, the upper inclined groove (inclined groove) 82a is located on the upper side of the divided groove 81 and is inclined with respect to the axial direction G, and the lower inclined groove (inclined groove) 82b is located in the divided groove 81 The lower side of and inclined relative to the axis G.

The division groove 81 is located in the middle of the cylindrical portion 42b of the main bearing 42 in the height direction (axial direction G), and is formed on the entire circumference in the circumferential direction. In addition, if the dividing groove 81 is formed with the oil passage which connects the upper side inclined groove 82a and the lower side inclined groove 82b, it does not need to be formed in the whole circumference.

The upper inclined groove 82a is an oil passage for communicating the upper end 81a of the division groove 81 with the upper end 42h of the main bearing 42 (cylindrical portion 42b ), and is inclined with respect to the axial direction G. As shown in FIG.

The lower inclined groove 82b is an oil passage for communicating the lower end 81b of the division groove 81 with the lower end 42i of the main bearing 42 (cylindrical portion 42b ), and is inclined with respect to the axial direction G. As shown in FIG.

As shown in FIG. 5( b ), the upper inclined groove 82 a and the lower inclined groove 82 b are formed to have the same length and parallel to each other. In addition, the upper side inclined groove 82 a and the lower side inclined groove 82 b are formed so as to overlap each other when viewed in plan from the axial direction G. That is, one end of the upper inclined groove 82 a is at a position of 270 degrees of the main bearing 42 in plan view, and the other end is at a position of 45 degrees of the main bearing 42 in plan view. Similarly, the lower inclined groove 82b has a position of 270 degrees at one end and a position of 45 degrees at the other end. Therefore, both the upper inclined groove 82a and the lower inclined groove 82b are located within the range of the above-mentioned anti-compression load surface.

The upper inclined groove 82a is inclined so as to form an inlet on the upstream side and an outlet on the downstream side with respect to the rotation direction R1 of the crankshaft 41 (see FIG. 3 ) (with respect to the oil flow direction R2). The lower inclined groove 82b is inclined so as to form an outlet on the downstream side and an inlet on the upstream side with respect to the rotational direction R1 of the crankshaft 41 (see FIG. 3 ) (with respect to the oil flow direction R2). In addition, the inlet of the upper side inclined groove 82a is located on the upstream side with respect to the rotation direction R1 (oil flow direction R2) than the outlet of the lower side inclined groove 82b. Therefore, the oil flowing out of the lower inclined groove 82b flows in the direction indicated by the thin solid arrow, circulates in the division groove 81 for a long time (225 degrees), and then flows to the upper inclined groove 82a, so that the main bearing 42 can be effectively cooled.

Here, the viscous pump effect of the inclined grooves (upper inclined groove 82a, lower inclined groove 82b) will be described.

For the oil supply quantity brought about by the viscous pump effect of the inclined groove, if the oil supply quantity Q[mm ³ /min], the shaft radius R[mm], the shaft speed N[min ^-1 ], the cross-sectional area A of the inclined groove [mm ² ] and the horizontal angle (hereinafter referred to as inclination angle) θ [degree] of the inclined groove with respect to the rotation direction can be expressed by the following formula (1).

Q＝AπRNcosθ···(1)

Here, the cross-sectional area A [mm ² ] and the inclined angle θ [degree] of the inclined groove can be adjusted when setting the inclined groove, but changing the cross-sectional area A [mm ² ] of the inclined groove requires changing the shape of the tool, so It is difficult to set an optimum inclined groove for electric compressors of various specifications. On the other hand, the change of the inclination angle θ [degree] can be handled by changing the angle during machining as the same tool, so in consideration of production efficiency, it is desirable to adjust the amount of oil supplied by the inclination angle θ [degree]. conduct.

However, in order to suppress the bending of the crankshaft 41 due to the centrifugal force of the rotor 32, the main bearing 42 is lengthened in the axial direction G with respect to the sub bearing 44, and the sliding loss tends to increase. Therefore, by providing the division groove 81 on the inner peripheral sliding surface 42t of the main bearing 42, the area of the inner peripheral sliding surface 42t of the main bearing 42 can be reduced to the minimum area that can ensure the reliability of the bearing against the compressive load, and the sliding loss can be realized. decrease.

In addition, the oil (refrigerator oil) supplied to the lower end of the main bearing 42 is sucked into the division groove 81 by the viscous pump effect of the lower inclined groove 82b. By providing the division groove 81 on the inner peripheral sliding surface 42t of the main bearing 42 , the sucked oil passes through the division groove 81 and the oil circulates through the division groove 81 to cool the main bearing 42 . The cooled oil is again attracted to the upper end of the main bearing 42 by the viscous pumping effect of the upper inclined groove 82 a, and finally discharged into the airtight container 2 .

However, even in the structure in which the dividing groove 81 is formed in the main bearing 42, the following problems arise. This point will be described with reference to the comparative examples shown in FIGS. 6 to 8 . Fig. 6 shows the main bearing of Comparative Example 1, (a) is a longitudinal sectional view, (b) is a developed view of the inner peripheral surface, Fig. 7 shows the main bearing of Comparative Example 2, (a) is a longitudinal sectional view, (b) is an internal As for the developed view of the peripheral surface, FIG. 8 shows the main bearing of Comparative Example 3, (a) is a longitudinal sectional view, and (b) is a developed view of the inner peripheral surface. In addition, in FIGS. 6 to 8 , only the main bearings 100 , 110 , and 120 are illustrated, and the other configurations are the same as those of the first embodiment.

Main bearing 100 shown in FIG. In addition, as shown in FIG. 6( b ), the upper inclined groove 101 a and the lower inclined groove 101 b are formed so as to overlap in plan view in the axial direction G. As shown in FIG. In other words, the upper inclined groove 101a and the lower inclined groove 101b are located on the same straight line (on the same spiral).

In the main bearing 100 of Comparative Example 1, the oil discharged from the lower inclined groove 101 b to the dividing groove 81 may flow into the upper inclined groove 101 a without circulating in the dividing groove 81 . Therefore, the circulation of the oil in the split groove 81 is impaired, impairing the cooling effect of the main bearing 42 . In addition, if the upper inclined groove 101a and the lower inclined groove 101b are formed so as to be included in the range of the anti-compression load surface, the upper inclined groove 101a and the lower inclined groove 101b are based on a plane (circumferential direction) perpendicular to the axial direction G. The inclination angle θ10 becomes larger, thereby reducing the viscous pump effect and reducing the fuel supply.

The main bearing 110 shown in FIG. 7( a ) includes an upper inclined groove 110 a provided on the upper side of the divided groove 81 and a lower inclined groove 110 b provided on the lower side of the divided groove 81 . In addition, as shown in FIG. 7( b ), the upper inclined groove 110 a and the lower inclined groove 110 b are formed so as not to overlap each other when viewed in plan view in the axial direction G. As shown in FIG. In other words, the upper inclined groove 110a and the lower inclined groove 110b are located on the same straight line (on the same spiral).

In the main bearing 110 of Comparative Example 2, the oil discharged from the lower inclined groove 110b to the dividing groove 81 may flow into the upper inclined groove 110a without circulating in the dividing groove 81 . Therefore, the cooling effect of the bearing 110 by the dividing groove 81 is impaired. In addition, if the inclination angle θ1 of the lower inclined groove 110b is set to be smaller than the inclination angle θ10 of FIG. Possibility of metal contact.

The main bearing 120 shown in FIG. 8(a) is formed to be longer than the main bearing 100 shown in FIG. 6(a) and the main bearing 110 shown in FIG. 7(a) in the axial direction G, and has a The upper inclined groove 120 a on the upper side of the dividing groove 81 and the lower inclined groove 120 b provided on the lower side of the dividing groove 81 . In addition, as shown in FIG. 8( b ), the upper inclined groove 120 a and the lower inclined groove 120 b are formed so as not to overlap each other when viewed in plan view in the axial direction G. As shown in FIG. In other words, the upper inclined groove 120a and the lower inclined groove 120b are located on the same straight line (on the same spiral).

In the main bearing 120 of Comparative Example 3, the refrigerating machine oil discharged from the lower inclined groove 120 b into the divided groove 81 may flow into the upper inclined groove 120 a without circulating in the divided groove 81 . Therefore, the cooling effect of the main bearing 120 by the dividing groove 81 is impaired. In addition, if the inclination angle θ10 of the lower inclined groove 120b is set to be the same as the inclination angle θ10 of FIG. Possibility of making metal contact.

Therefore, the electric compressor 1 of the first embodiment is provided with the division groove 81 that divides the inner peripheral sliding surface 42t of the main bearing 42 up and down in the axial direction G, and the upper side inclined with respect to the axial direction G on the upper side of the division groove 81 is inclined. The groove 82 a and the lower inclined groove 82 b inclined with respect to the axial direction G are formed on the lower side of the dividing groove 81 . Further, the upper inclined groove 82a and the lower inclined groove 82b are configured to at least partially overlap (in the first embodiment, completely overlap) when viewed from above in the axial direction G of the main bearing 42 . Accordingly, compared with the case where the upper inclined grooves 100a, 110a, 120a and the lower inclined grooves 100b, 110b, 120b are located on the same spiral (on the same straight line) as shown in Comparative Examples 1, 2, and 3, the In the present embodiment, the upper inclined groove 82a and the lower inclined groove 82b can be arranged in the anti-compression load surface, so the inclination angle θ1 can be reduced, and the pressure caused by the upper inclined groove 82a and the lower inclined groove 82b can be suppressed. The reduction of the oil film pressure increases the amount of oil supplied to the main bearing 42 .

In addition, the oil supplied to the inner diameter lower end of the main bearing 42 flows in the main bearing 42 at a rotational speed corresponding to the circumferential speed of the outer circumference of the crankshaft 41 due to the rotational motion of the crankshaft 41 and the viscosity of the oil. After flowing, the oil reaching the lower inclined groove 82b flows in the lower inclined groove 82b and the upper inclined groove 82a at a speed corresponding to the inclination of the lower inclined groove 82b, thereby supplying the entire area of the main bearing 42. Oil. In addition, as described above, oil can be supplied to the lower end of the upper inclined groove 82a from any position on the inner circumference of the main bearing 42 for 360 degrees by storing oil in the divided groove 81 provided in the main bearing 42 . Furthermore, as shown in FIG. 5( b ), the lower end 82a1 of the upper inclined groove 82a is provided on the upstream side in the rotation direction R1 (flow direction of oil) of the crankshaft 41 than the upper end 82b1 of the lower inclined groove 82b, thereby The rotation direction R1 of the crankshaft 41 from the upper end 82b1 of the lower inclined groove 82b to the split groove 81 ensures a long flow path in the split groove 81 and improves the cooling effect of the main bearing 42 .

According to the electric compressor 1 of the first embodiment configured in this way, the divided groove 81, the upper inclined groove 82a, and the lower inclined groove 82b are provided, and when viewed from the axial direction G, the upper inclined groove 82a and the lower inclined groove are inclined. The slots 82b overlap. Therefore, the oil supply property and lubricity to the main bearing 42 can be improved, and the performance and reliability can be improved. In addition, in this embodiment, although the main bearing 42 is mentioned as a bearing and demonstrated, the sub-bearing 44 is similarly provided with the inclined groove, and oil flows in the inclined groove from the upper end toward the lower end of the sub-bearing 44, and can Carry out oil supply. In addition, in the case of the sub-bearing 44, according to the structure of the electric compressor 1, the entire sub-bearing 44 is always immersed in the oil storage tank 23a at the bottom of the airtight container 2, so active oil supply by the inclined tank is unnecessary. Therefore, it is also possible to provide the oil groove in a straight line parallel to the axial direction G instead of an inclined groove.

In addition, in the first embodiment, the upper inclined groove 82 a and the lower inclined groove 82 b are provided on the anti-compression load surface with respect to the compression load of the compression mechanism part 4 (see FIG. 5( b )). Thereby, metal-to-metal contact between the crankshaft 41 and the main bearing 42 can be prevented, and a reduction in sliding loss can be achieved.

(second embodiment)

Fig. 9 shows a main bearing according to a second embodiment, where (a) is a longitudinal sectional view, and (b) is a developed view of the inner peripheral surface. In addition, the same code|symbol is attached|subjected to the same structure as 1st Embodiment, and overlapping description is abbreviate|omitted (it is also the same for the following embodiment). In addition, only the main bearing 42A is shown in FIG. 9, and other structures are the same as those of the first embodiment (the same applies to the following embodiments).

As shown in FIG. 9( a ), the main bearing 42A includes a split groove 81 c divided up and down in the axial direction G, an upper inclined groove 82 a provided above the split groove 81 c , and an inclined groove 82 a provided on the lower side of the split groove 81 c. The lower inclined groove 82b. In addition, when the main bearing 42A is cut by a plane perpendicular to the axial direction G, the cross-sectional area A1 of the dividing groove 81 (see FIG. (a)) and the cross-sectional area A3 (refer to FIG. 9(a)) of the lower inclined groove 82b are large. The cross-sectional area A1 refers to the cross-sectional area of the annular gap formed between the main bearing 42 and the crankshaft 41 . The cross-sectional areas A2 and A3 refer to the cross-sectional areas of the concave gap formed between the main bearing 42 and the crankshaft 41 . In addition, as shown in FIG. 9( b ), the upper inclined groove 82 a and the lower inclined groove 82 b are formed so as to overlap each other when viewed from the axial direction G, as in the first embodiment.

According to the second embodiment constituted in this way, the oil that reaches the divided groove 81c from the lower inclined groove 82b is stored in the divided groove 81 once, so the oil passing through the divided groove 81c can be cooled more effectively, and the oil flow to the main bearing 42A can be improved. Oil supply and lubricity can improve performance and reliability.

(third embodiment)

Fig. 10 shows a main bearing according to a third embodiment, where (a) is a longitudinal sectional view, and (b) is a developed view of the inner peripheral surface.

As shown in FIG. 10( a ), the main bearing 42B is configured such that the groove depths of the upper inclined groove 82 c and the lower inclined groove 82 d are deeper than the groove depth of the dividing groove 81 , and a part and the lower side of the upper inclined groove 82 c are inclined. Parts of the grooves 82d are respectively located in the division grooves 81 (the upper side inclined groove 82c and the lower side slope groove 82d enter the middle of the division groove 81).

That is, as shown in FIG. 10( b ), the lower end 82c1 of the upper inclined groove 82c extends to a position overlapping with the upper part of the dividing groove 81, and the upper end 82d1 of the lower inclined groove 82d extends to the lower side of the dividing groove 81. partially overlapping positions. Further, by forming the upper inclined groove 82c and the lower inclined groove 82d deeper than the dividing groove 81 , the upper inclined groove 82c and the lower inclined groove 82d can be formed in the dividing groove 81 .

According to the third embodiment constituted in this way, since the opening (outlet) of the flow path when the oil flows out from the lower inclined groove 82d to the division groove 81 can be ensured to be wide, the oil can easily flow out to the division groove 81. Since the opening (inlet) of the flow path when oil flows into the upper inclined groove 82c from the dividing groove 81 is wide, the oil easily flows into the upper inclined groove 82c. Thereby, oil flows easily, cooling can be performed more effectively, the oil supply property and lubricity to the main bearing 42 can be improved, and performance and reliability can be improved.

(fourth embodiment)

Fig. 11 shows a main bearing according to a fourth embodiment, where (a) is a longitudinal sectional view, and (b) is a developed view of the inner peripheral surface.

As shown in FIG. 11( a ), the main bearing 42C is configured such that the surface roughness of the upper inclined groove 82e, the lower inclined groove 82f, and the dividing groove 81d is higher than the surface roughness of the inner peripheral sliding surface 42t (surface on which no groove is formed). big. In addition, in Fig. 11(a), (b), dots are added to indicate that the surface roughness is greater.

As shown in FIG. 11( b ), the inclination angles of the upper inclined groove 82e and the lower inclined groove 82f are the same as those of the first embodiment, and the upper inclined groove 82e and the lower inclined groove 82f are formed so that All overlap when looking down.

According to the fourth embodiment constituted in this way, the surface area of the divided groove 81d, the upper inclined groove 82e, and the lower inclined groove 82f is larger than that of the case where the surface is not roughened. The oil supply and lubricity of the main bearing 42 can improve performance and reliability.

(fifth embodiment)

Fig. 12 shows a main bearing according to a fifth embodiment, wherein (a) is a longitudinal sectional view, and (b) is a developed view of an inner peripheral surface.

As shown in FIG. 12( a ), the main bearing 42D has split grooves 81e, 81f (at least one split groove) divided up and down in the axial direction G, and inclined grooves 82g positioned up and down in the axial direction G with respect to the split grooves 81e, 81f. , 82h, 82i. In addition, the inclined grooves 82g, 82h, and 82i are formed inclined with respect to the axial direction G. As shown in FIG.

As shown in FIG. 12(b), the upper end 82g1 of the inclined groove 82g communicates with the upper end of the main bearing 42D, and the lower end 82g2 communicates with the dividing groove 81e. The upper end 82h1 of the inclined groove 82h communicates with the dividing groove 81e, and the lower end 82h2 communicates with the dividing groove 81f. The upper end 82i1 of the inclined groove 82i communicates with the upper end of the main bearing 42D, and the lower end 82g2 communicates with the dividing groove 81e.

Moreover, as shown in FIG.12(b), 82g of inclined grooves, 82h of inclined grooves, and 82i of inclined grooves are formed so that all may overlap with each other when viewed from the axial direction G planarly.

In the fifth embodiment thus constituted, the inner peripheral sliding surface 42t of the main bearing 42D is provided with division grooves 81e and 81f divided vertically in the axial direction G and vertical grooves inclined with respect to the axial direction G in the upper and lower directions of the division grooves 81e and 81f. The inclined grooves 82g, 82h, and 82i, and the inclined grooves 82g, 82h, and 82i are all configured to overlap when viewed from the axial direction G of the main bearing 42 . Accordingly, compared with the case where the upper inclined grooves 100a, 110a, 120a and the lower inclined grooves 100b, 110b, 120b are located on the same spiral (on the same straight line) (see FIGS. In this way, the inclination angle θ2 of the inclined grooves 82g, 82h, 82i is reduced. Therefore, the amount of oil supplied to the main bearing 42 can be further increased, and since the dividing grooves 81e and 81f are provided, the main bearing 42 can be effectively cooled. Therefore, in the main bearing 42 , the performance and reliability of the electric compressor can be improved by effectively cooling the oil and improving the oil supply and lubricity.

In addition, in the fifth embodiment, since the inclined grooves 82g, 82h, and 82i are arranged in the anti-compression load surface, the reduction of the oil film pressure of the inclined grooves 82g, 82h, and 82i can be suppressed, and the performance and performance of the electric compressor can be improved. reliability.

In addition, in the fifth embodiment, although two dividing grooves 81e, 81f and three inclined grooves 82g, 82h, 82i are provided and described, it is also possible to provide three or more dividing grooves and four or more inclined grooves. .

In addition, this invention is not limited to above-mentioned embodiment, Various modification examples are included. For example, the above-mentioned embodiments have been described in detail for the convenience of describing the present invention, and are not limited to having all the described configurations. In addition, a part of the structure of a certain embodiment can be replaced with the structure of another embodiment, and the structure of another embodiment can also be added to the structure of a certain embodiment. In addition, addition, deletion, and replacement of other configurations can be performed on a part of the configurations of each embodiment.

For example, in the above-mentioned embodiment, the hermetic vertical rotary compressor was exemplified, and the oil groove between the main bearing 42 and the crankshaft 41 (upper inclined grooves 82a, 82c, 82e, The case of the lower inclined grooves 82b, 82d, 82f, inclined grooves 82g, 82h, 82i, and dividing grooves 81, 81c, 81d, 81e, 81f). But, the present invention is not limited thereto, also can be other structure, for example, non-hermetic type rotary compressor, scroll compressor, reciprocating compressor etc. are provided with main bearing 42 and crankshaft 41 on the crankshaft 41 side. oil tank in between. Alternatively, an oil groove between the main bearing 42 and the crankshaft 41 may be provided on both the main bearing 42 side and the crankshaft 41 side.

Claims (5)

1. An electric compressor, characterized in that, possesses: motor; A compression mechanism unit having a crankshaft rotationally driven by the electric motor and a bearing supporting the crankshaft, wherein sliding surfaces of the crankshaft and the bearing are lubricated with lubricating oil; and a housing unit housing the motor and the compression mechanism unit, Said bearing and/or said crankshaft has: at least one dividing groove dividing the sliding surface up and down in the axial direction of the bearing; and an inclined groove that is positioned above and below the axial direction with respect to the dividing groove of the sliding surface and is inclined relative to the axial direction, The respective inclined grooves are formed so as to at least partially overlap each other when viewed from above in the axial direction. 2. The electric compressor according to claim 1, wherein: The inclined groove is provided on an anti-compression load surface against a compression load of the compression mechanism part. 3. The electric compressor according to claim 1 or 2, characterized in that, A cross-sectional area of the dividing groove on a plane perpendicular to the axial direction is larger than a cross-sectional area of the inclined groove on a plane perpendicular to the axial direction. 4. The electric compressor according to any one of claims 1 to 3, wherein: The groove depth of the inclined groove is deeper than the groove depth of the dividing groove, and a part of the inclined groove is located in the dividing groove. 5. The electric compressor according to any one of claims 1 to 4, wherein: The surface roughness of the inclined groove and/or the dividing groove is greater than that of the sliding surface.