JP5441982B2 - Rotary compressor - Google Patents

Description

  The present invention relates to a rotary compressor for compressing refrigerant gas used in a refrigeration cycle of a refrigerating and air-conditioning apparatus such as an air conditioner or a refrigerator.

  A two-cylinder rotary compressor that compresses low-pressure refrigerant gas into high-pressure refrigerant gas in each of the two compression chambers, or compresses low-pressure refrigerant gas into medium-pressure refrigerant gas in the low-stage compression chamber, In a two-stage rotary compressor that compresses medium-pressure refrigerant gas into high-pressure refrigerant gas in the compression chamber, the crankshaft includes two eccentric portions disposed in the cylinder, and between these eccentric portions. An intermediate shaft is provided. Conventionally, a two-cylinder rotary compressor and a two-stage rotary compressor that improve the rigidity of the intermediate shaft have been proposed. As a conventional two-cylinder rotary compressor that improves the rigidity of the intermediate shaft as described above, for example, the outer peripheral surface of the intermediate shaft extends along the anti-eccentric outer peripheral surface of the two eccentric portions. The shape of the intermediate shaft in the cross section perpendicular to the axial direction, which is formed on the axial center side of the surface, is a rugby ball shape (a shape that is convex in the direction perpendicular to the eccentric direction of the eccentric portion). It has been proposed (see, for example, Patent Document 1).

International Publication No. 2009/028633 (FIG. 2A, FIG. 2B)

  In the two-cylinder rotary compressor and the two-stage rotary compressor, a partition plate is provided between the compression chambers in order to partition the two compression chambers formed corresponding to the eccentric portions. For this reason, the partition plate is formed with a cylindrical through hole in which an intermediate shaft is disposed. Therefore, in the two-cylinder rotary compressor described in Patent Document 1, since the intermediate shaft is formed in a substantially rugby ball cross section, the inner diameter of the through hole of the partition plate in which the intermediate shaft is disposed (hereinafter simply referred to as a partition). (Also referred to as the inner diameter of the plate) needs to be larger than the maximum length (the length between the pointed ends) of the substantially rugby ball-shaped cross section of the intermediate shaft. However, when the inner diameter of the partition plate is increased, the seal length of the piston that is fitted to the eccentric portion of the crankshaft and seals the low pressure side space of the compression chamber and the high pressure space on the inner diameter side becomes insufficient. For this reason, in the two-cylinder rotary compressor described in Patent Document 1, the refrigerant gas having a high pressure on the inner peripheral side of the piston leaks to the low pressure space side in the compression chamber, and the weight flow rate of the refrigerant gas sucked into the compression chamber decreases. However, there are problems such as a decrease in refrigeration capacity and a decrease in compression efficiency. Here, in order to solve such a problem, a configuration in which the intermediate shaft is formed in a thin cylindrical shape is also conceivable. However, if the intermediate shaft is formed into a thin cylindrical shape, the rigidity of the crankshaft will be reduced, so the crankshaft will bend due to the load from the refrigerant gas being compressed, and in the bearing that supports the crankshaft rotatably. There is a problem in that oil film generation is hindered and bearings are damaged due to insufficient lubrication.

  By the way, when a partition plate is comprised with an integral component, it is necessary to let a crankshaft pass from the one edge part side through the through-hole of a partition plate, and to arrange a partition plate in the position of an intermediate shaft. That is, when the partition plate is configured as an integral part, it is necessary to pass one of the eccentric portions through the through hole of the partition plate, and the inner diameter of the partition plate needs to be larger than the outer diameter of the eccentric portion. . For this reason, when the partition plate is configured as an integral part, when the eccentric amount of the eccentric portion is increased, the inner diameter of the partition plate is also increased, and the seal length of the piston is insufficient. For this reason, the eccentric amount of the eccentric portion cannot be increased. Therefore, a rotary compressor in which the partition plate is assembled by dividing the partition plate so as to sandwich the intermediate shaft and the inner diameter of the partition plate is smaller than the eccentric portion has been proposed. In this way, by dividing the partition plate, it is possible to eliminate the insufficient seal length of the piston and to increase the eccentric amount of the eccentric portion. For this reason, the volume of a compression chamber can be expanded and the improvement of the refrigerating capacity of a compressor can be aimed at. When the compression chamber volume is not changed, the cylinder inner diameter (the inner diameter of the eccentric hole and the through hole of the cylinder in which the piston is disposed) and the piston outer diameter are equivalent to the flatness of the axial height of the compression chamber. Therefore, it is possible to secure a long seal portion, which is a location near the cylinder inner diameter and the piston, and to improve the compression efficiency.

  However, when the intermediate shaft is formed in a cross-sectional rugby ball shape as in Patent Document 1, even if the partition plate is divided, the inner diameter of the partition plate is set to the maximum length of the substantially rugby ball-shaped cross section of the intermediate shaft (the tip portion). The length between) cannot be smaller. For this reason, when the intermediate shaft is formed in a cross-sectional rugby ball shape as in Patent Document 1, even if the partition plate is divided and formed, the piston seal length is insufficient and the refrigerant gas becomes a high pressure on the inner peripheral side of the piston. However, the problem of leakage to the low pressure space side in the compression chamber cannot be solved.

  The present invention has been made to solve the above-described problems, and provides a rotary compressor that can achieve high output and high efficiency while ensuring the reliability (rigidity) of the crankshaft. For the purpose.

Rotary compressor according to the present invention, between a motor having a stator and a rotor, the main shaft fixed to the rotor, countershaft provided on the shaft Direction of the main shaft, and the main shaft the the auxiliary shaft A main shaft side eccentric portion and a sub shaft side eccentric portion provided on the main shaft side, and an intermediate shaft provided between the main shaft side eccentric portion and the sub shaft side eccentric portion, and driven by the electric motor. A crankshaft, a first piston fitted to the main shaft side eccentric portion, a second piston fitted to the sub shaft side eccentric portion, and a cylindrical through hole are formed. A first cylinder in which the main shaft side eccentric part and the first piston are arranged to form a compression chamber, and a cylindrical through hole, and the sub shaft side eccentric part and A second cylinder in which the second piston is disposed to form a compression chamber; and a cylinder in which the intermediate shaft is disposed. Through hole of are formed, Bei example and a partition plate that partitions the compression chamber and the compression chamber of the first cylinder and the second cylinder,
The intermediate shaft, the same position and the outer peripheral surface of the counter-eccentric side of the main shaft side eccentric part, or the first surface has been made form the axial center side than the outer peripheral surface (A1), the auxiliary shaft side same position as the outer peripheral surface of the counter-eccentric side of the eccentric portion, or the second surface (A2) was made form the axial center side than the outer peripheral surface has a axial section perpendicular to said The first surface (A1) is formed in a convex shape in a direction perpendicular to the eccentric direction of the main shaft side eccentric portion and the auxiliary shaft side eccentric portion, and the convex tip portion is in a cross section perpendicular to the axial direction. ) And the third surface (B) formed by at least one of a curved surface and a flat surface, which is arranged on the axial center side from the intersection C where the virtual extension lines of the second surface (A2) intersect. It is what has been.

In rotary compressor according to the present invention, the intermediate shaft, the same position and the outer peripheral surface of the counter-eccentric side of the main shaft side eccentric part, or the first surface has been made form the axial center side than the outer peripheral surface ( includes a A1), the same position and the outer peripheral surface of the counter-eccentric side of the auxiliary shaft side eccentric part, or the second surface has been made form the axial center side than the outer peripheral surface (A2), a shaft A cross section perpendicular to the direction is formed in a convex shape in a direction perpendicular to the eccentric direction of the main shaft side eccentric portion and the sub shaft side eccentric portion. Further, the convex tip portion is disposed on the axial center side from the intersection C where the virtual extension lines of the first surface (A1) and the second surface (A2) in the cross section perpendicular to the axial direction intersect, and the curved surface and The third surface (B) is formed by at least one of the flat surfaces. For this reason, the rotary compressor according to the present invention can reduce the inner diameter of the partition plate while improving the strength of the intermediate shaft, so that the reliability of the crankshaft can be ensured and the output can be increased or increased. Efficiency can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Embodiment 1 of this invention, and a longitudinal cross-sectional view of the 2-cylinder rotary compressor 100. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Embodiment 1 of this invention, Sectional drawing of the intermediate shaft 4e of the crankshaft 4 ((a) is a top view which excluded a part of crankshaft 4, (b) is AA of (a). Sectional drawing and (c) are BB sectional views of (a). FIG. 5 is a diagram illustrating the first embodiment of the present invention, and is a diagram illustrating a state in which a first cylinder 8 and a main bearing 6 are fixed by bolt fastening. 1 is a diagram showing Embodiment 1 of the present invention, in which a crankshaft 4 is inserted into a main bearing 6, and a first piston 11a is passed through a countershaft 4b, a countershaft side eccentric portion 4d, and an intermediate shaft 4e so that the main shaft side deviation is reduced. The figure which shows the state assembled | attached to the core part 4c. The figure which shows Embodiment 1 of this invention, and is a figure which shows the state which temporarily attached the partition plate 10 to the intermediate shaft 4e. The figure which shows Embodiment 1 of this invention, and is a figure which shows the state which assembled | attached the partition plate 10 to the intermediate shaft 4e. In the figure showing Embodiment 1 of the present invention, the second piston 11b is inserted into the countershaft side eccentric portion 4d, the second cylinder 9 and the subbearing 7 are fixed, and the subshaft 4b of the crankshaft 4 is fixed. The figure which shows the state inserted in. In the figure which shows Embodiment 1 of this invention, the 2nd cylinder 9 is fixed to the 1st cylinder 8 on both sides of the partition plate 10 from the outer side of the subbearing 7, and the 1st cylinder 8 is mounted in parallel. The figure which shows the state fixed to the 2nd cylinder 9 on both sides of the partition plate 10 from the outer side of the main bearing 6. FIG. FIG. 5 is a diagram showing the first embodiment of the present invention, and shows a procedure for assembling the first piston 11a to the crankshaft 4 when relief shapes 11a-1 are provided at both axial ends of the inner diameter of the first piston 11a. Figure. FIG. 10 shows the first embodiment of the present invention, and is a comparison of FIG. 9 and FIG. 11 (FIG. 10 (a) is a comparative example, and FIG. 10 (b) is the present embodiment). It is a figure which shows a comparative example, and is a figure which shows the assembly | attachment procedure to the crankshaft 4 of the 1st piston 11a. It is a figure which shows the comparative example, and the figure which shows the crankshaft 4 which provided the level | step-difference part in the intermediate shaft 4e ((a) is a top view which excluded a part of crankshaft 4, (b) is AA of (a). Sectional drawing and (c) are BB sectional views of (a). It is a figure which shows a comparative example, and is a figure which shows the procedure in which the 1st piston 11a is assembled | attached to the crankshaft 4 of FIG.

Embodiment 1 FIG.
1 and 2 are views showing Embodiment 1 of the present invention. FIG. 1 is a longitudinal sectional view of a two-cylinder rotary compressor 100. FIG. 2 is a sectional view of an intermediate shaft 4e of a crankshaft 4. FIG. 3B is a cross-sectional view taken along the line AA of FIG. 5A, FIG. 3C is a cross-sectional view taken along the line BB of FIG. 3A, and FIG. FIG. 4 is a diagram showing a state in which the main bearing 6 is fixed with bolts. FIG. 4 shows that the crankshaft 4 is inserted into the main bearing 6, and the first piston 11a is the subshaft 4b, the subshaft side eccentric portion 4d, and the intermediate shaft. 4e is a view showing a state of being assembled to the main shaft side eccentric portion 4c, FIG. 5 is a view showing a state where the partition plate 10 is temporarily assembled to the intermediate shaft 4e, and FIG. 6 is a state of attaching the partition plate 10 to the intermediate shaft 4e. FIG. 7 is a diagram showing the crankcase in which the second piston 11b is inserted into the countershaft side eccentric portion 4d and the second cylinder 9 and the subbearing 7 are fixed. FIG. 8 shows a state in which the second cylinder 9 is inserted into the sub-shaft 4b of FIG. 4, and the second cylinder 9 is fixed to the first cylinder 8 from the outside of the sub-bearing 7 with the partition plate 10 interposed therebetween, and the first FIG. 9 is a view showing a state in which the cylinder 8 is fixed to the second cylinder 9 from the outside of the main bearing 6 with the partition plate 10 interposed therebetween, and FIG. 9 is a relief shape 11a− at both axial ends of the inner diameter of the first piston 11a. FIG. 10 is a diagram showing a procedure for assembling the first piston 11a to the crankshaft 4 when 1 is provided, FIG. 10 is a diagram comparing FIG. 9 and FIG. 11 (FIG. 10 (a) is a comparative example, FIG. b) is this embodiment).
Hereinafter, the two-cylinder rotary compressor 100 according to the first embodiment will be described with reference to FIGS. 1 to 10.

  The configuration of the two-cylinder rotary compressor 100 will be described with reference to FIG. The two-cylinder rotary compressor 100 houses an electric motor 2 composed of a stator 2 a and a rotor 2 b and a compression mechanism unit 3 driven by the electric motor 2 in a sealed container 1 in a high-pressure atmosphere.

  The rotational force of the electric motor 2 is transmitted to the compression mechanism unit 3 via the crankshaft 4.

  The crankshaft 4 has a predetermined phase difference (for example, 180) between the main shaft 4a fixed to the rotor 2b of the electric motor 2, the sub shaft 4b provided on the opposite side of the main shaft 4a, and the main shaft 4a and the sub shaft 4b. And the intermediate shaft 4e provided between the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d. Have

  The main bearing 6 is fitted to the main shaft 4a of the crankshaft 4 with a clearance for sliding, and rotatably supports the main shaft 4a.

  The auxiliary bearing 7 is fitted to the auxiliary shaft 4b of the crankshaft 4 with a clearance for sliding, and rotatably supports the auxiliary shaft 4b.

  The compression mechanism unit 3 includes a first cylinder 8 on the main shaft 4a side and a second cylinder 9 on the sub shaft 4b side.

  The first cylinder 8 has a cylindrical through hole, and a first piston 11 a that is rotatably fitted to the main shaft side eccentric portion 4 c of the crankshaft 4 is provided in the through hole. Further, a first vane (not shown) that reciprocates according to the rotation of the main shaft side eccentric portion 4c is provided.

  A first piston 11 a that is rotatably fitted to the main shaft side eccentric portion 4 c of the crankshaft 4, and both axial end surfaces of the through hole of the first cylinder 8 that houses the first vane are partitioned from the main bearing 6. A compression chamber is formed by closing with the plate 10.

  The first cylinder 8 is fixed to the inner periphery of the sealed container 1.

  The second cylinder 9 also has a cylindrical through-hole, and a second piston 11 b that is rotatably fitted to the countershaft side eccentric portion 4 d of the crankshaft 4 is provided in the through-hole. Further, a second vane (not shown) that reciprocates according to the rotation of the countershaft side eccentric portion 4d is provided.

  A second piston 11b that is rotatably fitted to the sub-shaft side eccentric portion 4d of the crankshaft 4 and both axial end surfaces of the through hole of the second cylinder 9 that houses the second vane are connected to the sub-bearing 7 A compression chamber is formed by closing with the partition plate 10.

  The compression mechanism unit 3 is bolted to the first cylinder 8 and the main bearing 6, and is bolted to the second cylinder 9 and the auxiliary bearing 7, and then the partition plate 10 is sandwiched between them, The bolts are fastened and fixed in the axial direction from the outside of the bearing 6 to the second cylinder 9 and from the outside of the auxiliary bearing 7 to the first cylinder 8.

  The bolt 12 illustrated in FIG. 1 is a part of a bolt that is fastened and fixed in the axial direction from the outside of the main bearing 6 to the second cylinder 9.

  Further, the bolt 13 illustrated in FIG. 1 is a part of a bolt that fastens the second cylinder 9 and the auxiliary bearing 7.

  An accumulator 40 is provided adjacent to the sealed container 1. The suction connection pipe 21 and the suction connection pipe 22 connect the first cylinder 8 and the second cylinder 9 to the accumulator 40, respectively.

  The refrigerant gas compressed in the first cylinder 8 and the second cylinder 9 is discharged into the sealed container 1 and sent out from the discharge pipe 23 to the refrigeration cycle of the refrigeration air conditioner.

  Electric power is supplied to the electric motor 2 from the glass terminal 24 via the lead wire 25.

  Although not shown, lubricating oil (refrigeration machine oil) that lubricates each sliding portion of the compression mechanism unit 3 is stored at the bottom of the sealed container 1.

  The supply of the lubricating oil to each sliding portion of the compression mechanism unit 3 is performed by raising the lubricating oil stored in the bottom of the sealed container 1 along the inner diameter 4f of the crankshaft 4 by the centrifugal force generated by the rotation of the crankshaft 4. It is carried out from an oil supply hole 20 provided in the shaft 4. In the example of FIG. 1, the oil supply holes 20 are formed at four locations. From the respective oil supply holes 20, the main shaft 4 a and the main bearing 6, the main shaft side eccentric portion 4 c and the first piston 11 a, the sub shaft side eccentric portion 4 d and the second piston 11 b, the sub shaft 4 b and the sub bearing 7 are provided. Lubricating oil is supplied to the sliding portion.

  The crankshaft 4 uses a material having a Young's modulus of 150 GPa or more so as to suppress bending due to a compressed gas load during operation. Furthermore, in order to suppress vibration during operation, the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d have substantially the same shape (same diameter, same length in the same axial direction) and substantially the same amount of eccentricity. The balance of centrifugal force is maintained.

  Here, in Embodiment 1, the partition plate 10 is formed as an integral part. For this reason, the anti-eccentric side outer peripheral surface of the main shaft side eccentric portion 4c is formed to be closer to the shaft center side than the outer peripheral surface of the main shaft 4a for the following reason. Then, the outer diameter of the auxiliary shaft 4b is formed to be thinner than the outer diameter of the main shaft 4a, and the counter eccentric side outer peripheral surface of the auxiliary shaft side eccentric portion 4d is on the side opposite to the axial center than the outer peripheral surface of the auxiliary shaft 4b. It is formed as follows.

  As described above, the countershaft side eccentric portion 4d has the same shape and the same amount of eccentricity as the main shaft side eccentric portion 4c. For this reason, when the outer diameter of the sub-shaft 4b is the same as the outer diameter of the main shaft 4a, the anti-eccentric outer peripheral surface of the main shaft-side eccentric portion 4c is formed so as to be closer to the axial center than the outer peripheral surface of the main shaft 4a. The counter eccentric side outer peripheral surface of the sub shaft side eccentric portion 4d is also closer to the shaft center side than the outer peripheral surface of the sub shaft 4b. Then, when it is going to attach the 1st piston 11a and the 2nd piston 11b from the subshaft 4b side as mentioned later, the subshaft side eccentric part 4d is inserted in the 1st piston 11a and the 2nd piston 11b. Can not do. That is, the first piston 11a and the second piston 11b cannot be attached to the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d. Therefore, in the first embodiment, the anti-eccentric side outer peripheral surface of the sub-shaft side eccentric portion 4d is formed closer to the counter-axis center side than the outer peripheral surface of the sub-shaft 4b, and the first piston 11a and the second piston 11b. It is possible to install. Further, the main shaft 4a that does not affect the attachment of the first piston 11a and the second piston 11b has an outer diameter larger than that of the auxiliary shaft 4b in order to ensure the strength of the crankshaft 4.

  Further, in the first embodiment, the shape shown in FIG. 2 is used in order to increase the eccentric amount of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d while ensuring the strength of the intermediate shaft 4e. FIG. 2A shows the crankshaft 4 so that the main shaft 4a is on the lower side of the paper and the auxiliary shaft 4b is on the upper side of the paper.

  As shown in FIG. 2, the intermediate shaft 4e corresponds to the A1 surface corresponding to the first surface of the present invention, the A2 surface corresponding to the second surface of the present invention, and the third surface of the present invention. It is formed by the B surface. Then, in a cross section perpendicular to the axis of the crankshaft 4 (more specifically, the intermediate shaft 4e), a convex shape is formed in a direction perpendicular to the eccentric direction of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d. ing.

  Specifically, the A1 surface is formed closer to the shaft center side than the outer peripheral surface on the anti-eccentric side of the main shaft side eccentric portion 4c, and has a shape along the outer peripheral surface on the anti eccentric side of the main shaft side eccentric portion 4c. ing. Similarly, the A2 surface is formed closer to the shaft center side than the outer peripheral surface on the anti-eccentric side of the sub-shaft side eccentric portion 4d, and is shaped along the outer peripheral surface on the anti-eccentric side of the sub-shaft side eccentric portion 4d. It has become. By configuring the intermediate shaft 4e with the A1 surface and the A2 surface in this way, the intermediate shaft 4e has a main shaft side eccentric portion 4c and a sub shaft in a cross section perpendicular to the axis of the crank shaft 4 (more specifically, the intermediate shaft 4e). It becomes a convex shape in a direction perpendicular to the eccentric direction of the shaft-side eccentric portion 4d. For this reason, the cross-sectional area of the intermediate shaft 4e is increased, and the strength of the intermediate shaft 4e can be improved.

  Here, the intermediate shaft 4e is disposed inside a through hole formed in the partition plate 10, as shown in FIG. For this reason, it is necessary to form the inner diameter 10a of the through hole of the partition plate 10 to be larger than the maximum length in a cross section perpendicular to the axial direction of the intermediate shaft 4e. At this time, in the intermediate shaft described in Patent Document 1 described above, the ends of the main shaft side eccentric portion and the sub shaft side eccentric portion in the direction perpendicular to the eccentric direction are the virtual extension line of the A1 surface and the A2 surface. The position of the intersection C with the virtual extension line (see FIG. 2). For this reason, the inner diameter 10a of the partition plate 10 has become large. Therefore, when trying to increase the eccentric amount of the eccentric portion (corresponding to the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d of the first embodiment), the seal length of the piston (for example, FIG. c), which corresponds to the distance between the first piston 11a and the inner diameter 10a of the partition plate 10) is insufficient, and the refrigerant gas having a high pressure on the inner peripheral side of the piston enters the low-pressure space side in the compression chamber. The weight flow rate of the refrigerant gas leaked and sucked into the compression chamber decreased, leading to a decrease in refrigeration capacity and a decrease in compression efficiency.

  On the other hand, in the intermediate shaft 4e according to the first embodiment, the end portions in the direction perpendicular to the eccentric direction of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d are configured as B surfaces. The B surface is formed closer to the axial center than the position of the intersection C between the virtual extension line of the A1 surface and the virtual extension line of the A2 surface. For this reason, the inner diameter 10a of the partition plate 10 can be reduced. Therefore, even if the eccentric amount of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d is increased, the seal length of the piston (that is, the inner diameter of the first piston 11a and the partition plate 10 shown in FIG. 2C). 10a and the distance between the second piston 11b and the inner diameter 10a of the partition plate 10 shown in FIG. 2B) can be sufficiently secured. Therefore, by forming the intermediate shaft 4e as in the first embodiment, the refrigerant gas having a high pressure on the inner peripheral side of the piston leaks to the low-pressure space side in the compression chamber and is sucked into the compression chamber. It is possible to prevent the flow rate from decreasing.

  Therefore, the crankshaft 4 configured as in the first embodiment can increase the eccentric amount of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d, and expand the excluded volume of the compression chamber. Thus, the output of the two-cylinder rotary compressor 100 can be increased.

  In other words, the volume of the compression chamber can be reduced to obtain the same output, and the two-cylinder rotary compressor 100 can be reduced in size and weight.

  In other words, when the volume of the compression chamber is not changed, the axial height of the compression chamber is flattened, that is, the thickness of the first cylinder 8 and the second cylinder 9 is thinned. The cylinder inner diameters of the first cylinder 8 and the second cylinder 9 and the outer diameters of the first piston 11a and the second piston 11b can be increased. For this reason, the cylinder inner diameters of the first cylinder 8 and the second cylinder 9 and the seal portion between the first piston 11a and the second piston 11b can be secured long, and the compression efficiency can be improved.

  The shape of the intermediate shaft 4e is not limited to the shape described above, and may be as follows, for example. For example, the A1 surface and the A2 surface of the intermediate shaft 4e may be formed at the same position as the anti-eccentric outer peripheral surface of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d. As will be described later, the first piston 11a is fitted into the main shaft side eccentric portion 4c after passing through the sub shaft side eccentric portion 4d and the intermediate shaft 4e. At this time, if the A1 surface and the A2 surface of the intermediate shaft 4e do not protrude from the outer peripheral surface on the opposite eccentric side of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d, the first piston 11a is eccentric on the main shaft side. It can be fitted to the part 4c. For example, a part or front part of the B surface may be a flat surface. If the B surface is formed closer to the axial center side than the position of the intersection C between the virtual extension line of the A1 surface and the virtual extension line of the A2 surface, the inner diameter 10a of the partition plate 10 can be formed small. An effect can be obtained.

Next, the assembly procedure of the compression mechanism unit 3 will be described with reference to FIGS.
(1) As shown in FIG. 3, first, the first cylinder 8 and the main bearing 6 are fastened and fixed with bolts 14. A plurality of bolts 14 are used.
(2) As shown in FIG. 4, the main shaft 4a of the crankshaft 4 is inserted into the main bearing 6 from the first cylinder 8 side. Next, the first piston 11a is passed through the sub shaft 4b, the sub shaft side eccentric portion 4d, and the intermediate shaft 4e in this order, and is assembled to the main shaft side eccentric portion 4c.
(3) As shown in FIG. 5, the partition plate 10 is assembled to the intermediate shaft 4e by passing through the sub shaft 4b and the sub shaft side eccentric portion 4d. In this state, as indicated by the arrow, the partition plate 10 is merely passed through in the axial direction, so the center of the partition plate 10 and the center of the first cylinder 8 do not coincide.
(4) As shown in FIG. 6, the partition plate 10 is moved in the direction perpendicular to the axis, and is set so that the center is aligned with the first cylinder 8. This is because the bolt through holes 10b provided in the partition plate 10, the bolt through holes 8a of the first cylinder 8, and the bolt through holes 6a of the main bearing 6 are aligned so that the bolts described later can be passed therethrough.
(5) As shown in FIG. 7, the second piston 11b is inserted into the sub-shaft side eccentric portion 4d after passing through the sub-shaft 4b.
(6) Further, the second cylinder 9 and the auxiliary bearing 7 are fixed with bolts 13 (plural pieces). It is inserted into the countershaft 4b of the crankshaft 4.
(7) As shown in FIG. 8, the second cylinder 9 is fixed to the first cylinder 8 with bolts 15 (plural) with the partition plate 10 sandwiched from the outside of the auxiliary bearing 7. At the same time, the first cylinder 8 is fixed to the second cylinder 9 with bolts 12 (plural) with the partition plate 10 sandwiched from the outside of the main bearing 6.

  Here, the conventional two-cylinder rotary compressor described in Patent Document 1 described above also has the following problems when the compression mechanism is assembled as shown in FIGS. That is, as described above, the conventional two-cylinder rotary compressor described in Patent Document 1 needs to increase the inner diameter of the partition plate, so that the piston seal length is insufficient and the refrigeration capacity decreases. And the compression efficiency deteriorated. In order to prevent this, it seems that the inner diameter of the partition plate should be made small so that the inner diameter of the partition plate is as close as possible to the outer peripheral portion of the intermediate shaft. However, when the inner diameter of the partition plate is reduced in this way, when the inner diameter central axis of the partition plate and the center axis of the cylinder are set together (corresponding to the process of FIG. 6 of the first embodiment), the compression mechanism section The inner diameter of the partition plate and the intermediate shaft may interfere with each other due to processing errors of the component parts, and the central axes may not be aligned. For this reason, in the process corresponding to FIG. 8 of the first embodiment, the bolts (corresponding to the bolts 12 and 15) inserted into the bolt through holes of the partition plate cannot pass through the partition plate, and it is necessary to reassemble the compression mechanism. As a result, the assembly work efficiency is lowered.

  On the other hand, in the two-cylinder rotary compressor 100 according to the first embodiment, the seal length of the piston (that is, the distance between the first piston 11a shown in FIG. 2C and the inner diameter 10a of the partition plate 10). 2 and the distance between the second piston 11b and the inner diameter 10a of the partition plate 10 shown in FIG. 2B), the inner diameter 10a of the partition plate 10 and the outer peripheral surface of the intermediate shaft 4e A sufficient space can be formed between the two. For this reason, since the inner diameter 10a of the partition plate 10 and the intermediate shaft 4e do not interfere in the step shown in FIG. 6, the bolts 12 and 15 are securely passed through the bolt through holes 10b of the partition plate 10 in the step shown in FIG. be able to. For this reason, it is not necessary to reassemble the compression mechanism section 3, and the assembly work efficiency of the compression mechanism section 3 can be improved.

  In addition to the crankshaft disclosed in Patent Document 1, a crankshaft that has improved the strength of the intermediate shaft has been proposed. Even in such a conventional crankshaft, the problem solved by the two-cylinder rotary compressor 100 according to the first embodiment cannot be solved. The comparative example shown in FIGS. This will be described based on an example of a conventional crankshaft aiming for the above.

  As shown in the comparative examples of FIGS. 12 and 13, conventionally, in order to suppress the bending of the crankshaft 4 due to the compression load, the intermediate shaft 4 e is connected to the first intermediate shaft 4 e-1 on the main shaft side eccentric portion 4 c side, Some are divided into the second intermediate shaft 4e-2 on the subshaft side eccentric portion 4d side.

  As shown in FIG. 12A, the first intermediate shaft 4e-1 and the second intermediate shaft 4e-2 are formed so as to be shifted in the radial direction. The first intermediate shaft 4e-1 is eccentric (projects) in the eccentric direction of the main shaft side eccentric portion 4c. The second intermediate shaft 4e-2 is eccentric (protruded) in the eccentric direction of the sub-shaft side eccentric portion 4d.

  As shown in FIG. 12C, which is a BB cross-section of FIG. 12A, the distance between the first intermediate shaft 4e-1 and the inner diameter 10a of the partition plate 10 is particularly set to the first intermediate shaft 4e-. 1 is narrow on the outer peripheral surface on the eccentric side.

  Further, as shown in FIG. 12B, which is a cross section taken along the line AA of FIG. 12A, the distance between the second intermediate shaft 4e-2 and the inner diameter 10a of the partition plate 10 is particularly set to the second intermediate shaft. It is narrow on the outer peripheral surface on the eccentric side of 4e-2.

  The comparative example shown in FIG. 12 requires the steps shown in FIGS. 13A to 13D in order to set the partition plate 10 to the intermediate shaft 4e. That is, when the partition plate 10 is set on the intermediate shaft 4e, the partition plate 10 is inclined at the boundary between the second intermediate shaft 4e-2 and the first intermediate shaft 4e-1 so as to move toward the main shaft side eccentric portion 4c. It was necessary to move and correct the inclination of the partition plate 10 again.

  Further, the first intermediate shaft 4e-1 and the second intermediate shaft 4e-2 protrude in the eccentric direction, and the distance from the inner diameter 10a of the partition plate 10 is narrow. Therefore, the outer peripheral portion on the eccentric side of the first intermediate shaft 4e-1 and the second intermediate shaft 4e-2 and the inner diameter 10a of the partition plate 10 are easy to contact, and the partition plate 10 is centered on the first cylinder 8. When setting the axes together, there was an adverse effect that it was difficult to align the central axes. When a workpiece whose center axis is not aligned flows out to the subsequent process, the bolts 12 and 15 shown in FIG. 8 cannot pass through the partition plate 10 and need to be reassembled, which lowers the assembly work efficiency.

  On the other hand, in the crankshaft 4 according to the first embodiment, unlike the comparative examples shown in FIGS. 12 and 13, the intermediate shaft 4e protrudes from the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d. And no boundaries. The intermediate shaft 4e is in a region where the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d overlap.

  Thereby, as shown in FIGS. 5 and 6, when the partition plate 10 is inserted into the intermediate shaft 4e, the partition plate 10 can be moved smoothly.

  Further, as described above with reference to FIG. 2, the interval between the intermediate shaft 4e and the inner diameter 10a of the partition plate 10 can be widened, and there is no contact. When the partition plate 10 is set with the first cylinder 8 aligned with the central axis, there is no obstacle and assembly work efficiency is improved.

Further, the comparative example shown in FIGS. 12 and 13 has the following problems as compared with the crankshaft 4 according to the first embodiment.
In the two-cylinder rotary compressor 100, the rotational torque of the electric motor 2 is transmitted to the crankshaft 4 that is shrink-fitted and fixed to the rotor 2b, and is fitted to the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d. The first piston 11a and the second piston 11b to be joined together are the air chambers of the first cylinder 8 and the second cylinder 9, the first piston 11a and the second piston 11b, and the first vane and the second piston 11b. The refrigerant is compressed by rotating eccentrically in each compression chamber constituted by two vanes.

  The oil supply to each sliding part of the compression mechanism part 3 raises the lubricating oil stored in the bottom part of the airtight container 1 along the inner diameter 4f of the crankshaft 4 by the centrifugal force generated by the rotation of the crankshaft 4, It is performed from the provided oil supply hole 20.

  Here, the lubricating oil discharged from the oil supply hole 20 is supplied to each sliding portion of the compression mechanism portion 3, and is also surrounded by the intermediate shaft 4e and the inner diameter 10a of the partition plate 10 (see FIG. 1). Accumulate. It is known that the intermediate shaft 4e rotates at a high speed in the high-pressure space 30 and the lubricating oil is stirred, resulting in a loss of driving force of the crankshaft 4. However, as in the comparative examples (FIGS. 12 and 13) In addition, the first intermediate shaft 4e-1 of the intermediate shaft 4e is eccentric (projected) in the eccentric direction of the main shaft side eccentric portion 4c, and the second intermediate shaft 4e-2 is of the sub shaft side eccentric portion 4d. In the case of eccentricity (protrusion) in the eccentric direction, the rotation radius of the intermediate shaft 4e is increased, and the agitation loss is increased.

  As shown in FIG. 2, the crankshaft 4 according to the first embodiment has a small rotation radius of the intermediate shaft 4e and a wide space between the partition plate 10 and the inner diameter 10a. Can be reduced. If only the reduction of stirring loss is pursued, the intermediate shaft 4e may naturally have a circular shape with the same diameter or less as the sub shaft 4b. However, considering the suppression of the bending of the crankshaft 4, the assembly workability is not hindered. Thus, the shape of the first embodiment in which the cross-sectional area of the intermediate shaft 4e is maximized is optimal.

  Incidentally, the two-cylinder rotary compressor 100 according to the first embodiment is also devised to shorten the axial length of the compression mechanism section 3. At this time, when the axial lengths of the first piston 11a and the second piston 11b are not changed, that is, when the axial height of the compression chamber is not changed, the first piston 11a can pass through the intermediate shaft 4e. There is concern about disappearing. In order to eliminate this concern, the following method of shortening the axial length of at least one of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d, or the axial length of the intermediate shaft 4e can be reduced. The following method of shortening can be considered.

  Although not shown, the method of shortening the axial length of at least one of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d is the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d. In this method, the axial length of at least one of the pistons is made shorter than the lengths of the pistons (the first piston 11a and the second piston 11b) attached to the eccentric part. In this case, the eccentric portion that shortens the axial length shortens the axial length by scraping the intermediate shaft 4e side.

  If the axial length of the intermediate shaft 4e is longer than the axial length of the first piston 11a, the first piston 11a can be assembled to the main shaft side eccentric portion 4c.

  That is, the main shaft side eccentric portion 4c and the sub shaft side eccentric portion are such that the axial length of the intermediate shaft 4e is substantially the minimum dimension that allows the first piston 11a to be assembled to the main shaft side eccentric portion 4c. The axial length of at least one of 4d is made shorter than the lengths of the pistons (first piston 11a and second piston 11b) attached to the eccentric portion. Thereby, the axial direction length of the compression mechanism part 3 can be shortened, without changing the axial direction length of the 1st piston 11a and the 2nd piston 11b.

  As shown in FIG. 9, another method for shortening the axial length of the compression mechanism section 3 is to shorten the axial length of the intermediate shaft 4e from the axial length of the first piston 11a, In order to allow the piston 11a to be assembled to the main shaft side eccentric portion 4c, a relief shape 11a-1 is provided on both axial end surfaces of the inner diameter of the first piston 11a. The relief shape 11a-1 is formed with an inclination, a step or the like.

The procedure for assembling the first piston 11a to the main shaft side eccentric portion 4c will be described with reference to FIG.
(1) As shown in FIG. 9A, the first piston 11a is passed through the sub shaft 4b and the sub shaft side eccentric portion 4d, and one end of the first piston 11a in the axial direction is displaced from the main shaft side. It is made to contact | abut to the core part 4c.
(2) Next, as shown in FIG. 9B, the first piston 11a is tilted (counterclockwise in FIG. 9B).
(3) Then, as shown in FIG. 9C, the main shaft side eccentric portion 4c is moved in an inclined state while being inclined. The first piston 11a is moved while being inclined until the inner diameter of the first piston 11a abuts on the outer circumferential surface of the main shaft side eccentric portion 4c in the anti-eccentric direction.
(4) Finally, the first piston 11a is inserted into the main shaft side eccentric portion 4c.

  Before explaining the effect of providing the relief shape 11a-1 on both axial end surfaces of the inner diameter of the first piston 11a, the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d are shown in FIG. A comparative example in which at least one axial length or the axial length of the intermediate shaft 4e is not shortened will be described.

The assembly procedure of the comparative example shown in FIG. 11 is as follows.
(1) As shown in FIG. 11 (a), the first piston 11a is passed through the countershaft 4b and the countershaft side eccentric portion 4d so that one end of the first piston 11a in the axial direction is offset from the main shaft side. It is made to contact | abut to the core part 4c.
(2) As shown in FIG. 11B, the first piston 11a is moved to the main shaft side eccentric portion 4c side in the intermediate shaft 4e.
(3) As shown in FIG. 11C, the first piston 11a is inserted into the main shaft side eccentric portion 4c.

  FIG. 10 is a diagram comparing the present embodiment in which the relief shape 11a-1 is provided on both end surfaces in the axial direction of the inner diameter of the first piston 11a shown in FIG. 9 and the comparative example shown in FIG. FIG. 10 (a) is a view corresponding to FIG. 11 (c), and FIG. 10 (b) is a view corresponding to FIG. 9 (d).

  The crankshaft 4 provided with the relief shape 11a-1 on both axial end surfaces of the inner diameter of the first piston 11a shown in FIG. 9 has an axial length of the intermediate shaft 4e that is the axis of the intermediate shaft 4e of the comparative example. The dimension d is shorter than the length in the direction. Therefore, the axial length of the compression mechanism unit 3 can be shortened by the dimension d.

  The axial length of at least one of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d is determined from the lengths of the pistons (the first piston 11a and the second piston 11b) attached to the eccentric portion. In order to shorten the axial length of the intermediate shaft 4e to be shorter than the axial length of the first piston 11a so that the first piston 11a can be assembled to the main shaft side eccentric portion 4c. According to the method of providing the relief shape 11a-1 on both axial end surfaces of the inner diameter of one piston 11a, there is an advantage that the compression mechanism can be designed compactly as described above.

  Furthermore, the distance between the main shaft side eccentric portion 4c or the sub shaft side eccentric portion 4d of the crankshaft 4 which is the operating point of the compressed gas load and the main bearing 6 or the sub bearing 7 serving as a support point can be reduced. The bending of the crankshaft 4 can be suppressed even under a gas load. When the bending of the crankshaft 4 is increased, the inclination of the crankshaft 4 with respect to the main bearing 6 or the sub-bearing 7 is increased, and one-sided contact occurs. However, by suppressing the bending of the crankshaft 4, it is possible to suppress the contact with each other and improve the reliability of the main bearing 6 or the sub-bearing 7.

  It should be noted that the axial length of at least one of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d is set to the piston (first piston 11a and second piston 11b) attached to the eccentric portion. To shorten the axial length of the intermediate shaft 4e from the axial length of the first piston 11a and to make the first piston 11a assembled to the main shaft side eccentric portion 4c. A method of providing the relief shape 11a-1 on both axial end surfaces of the inner diameter of the first piston 11a may be combined. Thereby, the assembly | attachment to the main axis | shaft side eccentric part 4c of the 1st piston 11a can be performed still more easily.

  As described above, in the two-cylinder rotary compressor 100 configured as in the first embodiment, the intermediate shaft 4e is perpendicular to the axis of the crankshaft 4 (more specifically, the intermediate shaft 4e) by the A1 surface and the A2 surface. In the cross section, the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d are convex in a direction perpendicular to the eccentric direction. Further, the B surface serving as the convex end is formed on the axial center side from the position of the intersection C between the virtual extension line of the A1 surface and the virtual extension line of the A2 surface. For this reason, the two-cylinder rotary compressor 100 according to the first embodiment can reduce the inner diameter of the partition plate while improving the strength of the intermediate shaft, while ensuring the reliability of the crankshaft 4. In addition, higher output and higher efficiency can be achieved.

  In the first embodiment, the partition plate 10 that is an integral part has been described as an example. However, the partition plate 10 that is divided into a plurality of sections through the inner diameter 10a may be used. In this case, the partition plate 10 can be assembled so as to sandwich the intermediate shaft 4e, and the inner diameter a of the partition plate 10 is formed smaller than the outer diameters of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d. Can do. For this reason, compared with the case where the partition plate 10 of an integral part is used, the eccentric amount of the main shaft side eccentric part 4c and the sub shaft side eccentric part 4d can be made still larger. For this reason, the volume of a compression chamber can be expanded further and the refrigerating capacity of a compressor can be improved further. In other words, the volume of the compression chamber can be reduced to obtain the same output, and the two-cylinder rotary compressor 100 can be further reduced in size and weight. Further, when the volume of the compression chamber is not changed, the cylinder inner diameters of the first cylinder 8 and the second cylinder 9 and the seal portion between the first piston 11a and the second piston 11b can be secured longer, and the compression Efficiency can be further improved.

  Further, when the partition plate 10 formed in a divided manner is used, it is not necessary to pass the auxiliary shaft 4b through the inner diameter 10a of the partition plate 10 when the compression mechanism portion 3 is assembled. For this reason, the outer diameter of the sub-shaft 4b is formed to be larger than that of the main shaft 4a so that the anti-eccentric side outer peripheral surface of the sub-shaft side eccentric portion 4d is closer to the shaft center side than the outer peripheral surface of the sub shaft 4b The strength of the crankshaft 4 may be further improved. At this time, the B surface of the intermediate shaft 4e may be formed closer to the shaft center side than the outer peripheral surface of the sub shaft 4b, and the inner diameter 10a of the partition plate 10 is also formed closer to the shaft center side than the outer peripheral surface of the sub shaft 4b. May be. The eccentric amount of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d can be further increased.

  In the first embodiment, when the compression mechanism unit 3 is assembled, the first piston 11a, the second piston 11b, the partition plate 10 and the like are attached from the auxiliary shaft 4b side, but these are attached from the main shaft 4a side. May be. When the partition plate 10 of an integral part is used, the first piston 11a, the second piston 11a, the second piston 11a, and the second piston 11a are formed by forming the anti-eccentric side outer peripheral surface of the main shaft-side eccentric portion 4c on the side opposite to the central axis. The piston 11b and the partition plate 10 can be attached. At this time, it is of course possible to increase the strength of the crankshaft 4 by increasing the outer diameter of the countershaft 4b that does not affect the attachment of the first piston 11a, the second piston 11b, the partition plate 10, and the like.

  In the first embodiment, the description has been given by taking the two-cylinder rotary compressor in which the pressure of the suction refrigerant and the pressure of the discharge refrigerant in each compression chamber are the same as an example. It is of course possible to implement the present invention in a two-stage rotary compressor that compresses the refrigerant gas into a high-pressure refrigerant gas and compresses the medium-pressure refrigerant gas into the high-pressure refrigerant gas in the high-stage compression chamber.

  DESCRIPTION OF SYMBOLS 1 Airtight container, 2 Electric motor, 2a Stator, 2b Rotor, 3 Compression mechanism part, 4 Crankshaft, 4a Main shaft, 4b Secondary shaft, 4c Main shaft side eccentric part, 4d Subshaft side eccentric part, 4e Intermediate shaft, 4e-1 first intermediate shaft, 4e-2 second intermediate shaft, 4f inner diameter, 6 main bearing, 6a bolt through hole, 7 auxiliary bearing, 8 first cylinder, 8a bolt through hole, 9 second cylinder 10 partition plate, 10a inner diameter, 10b bolt through hole, 11a first piston, 11a-1 relief shape, 11b second piston, 12 bolt, 13 bolt, 14 bolt, 20 oil supply hole, 21 suction connection pipe, 22 Suction connection pipe, 23 discharge pipe, 24 glass terminal, 25 lead wire, 30 high-pressure space, 40 accumulator, 100 2-cylinder rotary compressor.

Claims (5)

An electric motor having a stator and a rotor;
Spindle fixed to the rotor, axial direction countershaft provided direction of the main shaft, the main shaft side eccentric part and the countershaft side eccentric portion provided between said main shaft auxiliary shaft, as well as the A crankshaft having an intermediate shaft provided between a main shaft side eccentric portion and the sub shaft side eccentric portion, and driven by the electric motor;
A first piston fitted into the main shaft side eccentric portion;
A second piston fitted to the countershaft side eccentric portion;
A first cylinder in which a cylindrical through hole is formed, the main shaft side eccentric portion and the first piston are arranged in the through hole, and a compression chamber is formed;
A second cylinder in which a cylindrical through-hole is formed, and the sub-shaft side eccentric portion and the second piston are arranged in the through-hole to form a compression chamber;
A cylindrical through hole in which the intermediate shaft is disposed is formed, and a partition plate that partitions the compression chamber of the first cylinder and the compression chamber of the second cylinder;
Bei to give a,
The intermediate shaft, the same position and the outer peripheral surface of the counter-eccentric side of the main shaft side eccentric part, or the first surface has been made form the axial center side than the outer peripheral surface (A1), the auxiliary shaft side same position as the outer peripheral surface of the counter-eccentric side of the eccentric portion, or the second surface (A2) was made form the axial center side than the outer peripheral surface has a axial section perpendicular to said Formed in a direction perpendicular to the eccentric direction of the main shaft side eccentric portion and the sub shaft side eccentric portion,
The convex tip is disposed on the axial center side from the intersection C where the virtual extension lines of the first surface (A1) and the second surface (A2) in a cross section perpendicular to the axial direction intersect. And a third surface (B) constituted by at least one of the flat surfaces.   The rotary compressor according to claim 1, wherein the partition plate is divided into a plurality of sections by a cross section passing through a through hole formed in the partition plate. Before SL first piston and the second piston, which is fitted from the counter shaft side,
The outer peripheral surface of the auxiliary shaft of the counter-eccentric side of the auxiliary shaft side eccentric part than said outer circumferential surface of the counter-eccentric side of the auxiliary shaft side eccentric part is formed at the axial center side,
The rotary compressor according to claim 1, wherein an outer diameter of the sub shaft is formed to be thinner than an outer diameter of the main shaft. Before SL first piston and the second piston, which is fitted from the spindle side,
The outer peripheral surface of the main shaft of the counter-eccentric side of the spindle side eccentric portion is formed in the axial center side than the outer peripheral surface of the counter-eccentric side of the main shaft side eccentric part,
The rotary compressor according to claim 1, wherein an outer diameter of the main shaft is formed thinner than an outer diameter of the sub shaft.   The rotary compressor according to any one of claims 1 to 4, wherein the crankshaft is made of a material having a Young's modulus of 150 GPa or more.

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