KR20140043287A - Rotary compressor - Google Patents

Abstract

[Problem to be solved] Provided is a rotary compressor which can make a capacity by which the rotary compressor is pushed larger while preventing a property between a high pressure side space and a low pressure side space in a cylinder chamber from deteriorating. [Solution] A rotary compressor (100) includes a piston (20) attached to an eccentric portion (4c) of a crank shaft (4) to be slid, a cylinder (7) having a cylindrical cylinder chamber and in which the eccentric portion (4c) and the piston (20) are disposed in the cylinder chamber, and a compression mechanism having a vein (9) dividing the cylinder chamber into a low pressure space and a high pressure space. The piston (20) includes an inner piston (21) provided on an outer peripheral surface of the eccentric portion (4c) to be slid freely and an outer piston (22) provided on an outer surface of the inner piston (21), and the inner piston (21) is divided into a plurality of arc-shaped members (21a) cut to have a cross-section along the center axis of the eccentric portion (4c).

Description

[0001] ROTARY COMPRESSOR [0002]

This invention relates to the rotary compressor which compresses refrigerant gas used for the refrigeration cycle of refrigeration air conditioning apparatuses, such as an air conditioner and a refrigerator.

Conventionally, a piston sliding freely attached to an eccentric portion of a crankshaft, a cylindrical cylinder chamber is formed, a cylinder in which the piston is disposed, and a vane that divides the cylinder chamber into a low pressure space and a high pressure space. One rotary compressor (rotary compressor) has been proposed. In such a rotary compressor, a space partitioned into a cylinder chamber inner circumferential surface, a piston outer circumferential surface and a vane becomes a compression chamber, and the piston eccentrically rotates in the cylinder chamber, thereby compressing the refrigerant sucked into the cylinder chamber. Such a conventional rotary compressor has also been proposed in which a piston is divided into a plurality of members.

For example, the conventional rotary compressor configured by dividing the piston into a plurality of members is designed to prevent abrasion of the piston outer circumferential surface caused by the sliding of the vane and the piston outer circumferential surface. It consists of a double of the roller 16a and the inner 2nd roller 16b, and provides the hole 24 in which the inner surface and outer surface of the said 2nd roller 16b communicate. "(Refer patent document 1) ) Is proposed.

Patent Document 1: Japanese Patent Laid-Open No. 5-256282 (Summary, FIGS. 1 and 2)

In the rotary compressor described in Patent Literature 1, an inner circumferential side piston (described in Patent Literature 1 as the second roller 16b) freely attached to the eccentric portion is molded into a cylindrical integral body. The inner circumferential side piston is attached to the eccentric part after passing the main or sub-axis of the crankshaft adjacent to the eccentric part through the inner circumferential side piston. For this reason, it is necessary for the rotary compressor of patent document 1 to have the structure which the outer peripheral surface (outer peripheral surface on the opposite side to the eccentric direction in an eccentric part) from the eccentric part protruded more than the outer peripheral surface of a main axis or a minor axis. Alternatively, it is necessary to form the outer circumferential surface on the side of the eccentric side of the eccentric portion and the outer circumferential surface of the main shaft or the minor shaft in the same plane shape.

That is, as shown in Fig. 7A, the radius of the eccentric portion 4c is Re, and the amount of eccentricity of the eccentric portion 4c (the central axis and the eccentric portion 4c of the major axis 4a and the subordinate axis 4b) is reduced. When the distance from the central axis is set to e, the distance from the central axis of the main axis 4a and the subordinate axis 4b to the outer circumferential surface on the half eccentric side of the eccentric portion 4c becomes Re-e. For this reason, in the rotary compressor of patent document 1, when attaching the inner peripheral piston 50 to the eccentric part 4c from the main shaft 4a side, if the radius of the main shaft 4a is set to Rm, Re-e It is necessary to form the crankshaft 4 so as to be ≥ Rm. Further, in the rotary compressor described in Patent Document 1, when the inner circumferential side piston 50 is attached to the eccentric portion 4c from the side of the sub-axis 4b, when the radius of the sub-axis 4b is Ra, Re-e≥ It is necessary to form the crankshaft 4 so as to be Ra.

This is because, as shown in Fig. 7 (b), if the outer circumferential surface on the half eccentric side of the eccentric portion 4c has a configuration that is less than the outer circumferential surface of the main shaft 4a or the minor shaft 4b (that is, the inner circumferential side piston ( When 50 is attached to the eccentric portion 4c from the main shaft 4a side, Re-e <Rm, and the inner circumferential side piston 50 is attached to the eccentric portion 4c from the side of the minor shaft 4b. Is set to Re-e <Ra), when the inner circumferential side piston 50 is to be attached to the eccentric portion 4c, the eccentric portion 4c and the inner circumferential side piston 50 interfere with each other, and the inner circumferential side piston ( This is because 50) cannot be attached to the eccentric portion 4c.

On the other hand, when it is going to enlarge the volume pushed out for the capacity expansion (high output) of a rotary compressor, it is necessary to enlarge the eccentric amount (the eccentric amount from the main axis and the minor axis of a crankshaft) of a piston, suppressing the expansion of the outer diameter of a piston. That is, when trying to enlarge the volume pushed out for the capability expansion of a rotary compressor, it is necessary to enlarge the eccentric amount (eccentric amount from the main axis and the minor axis of a crankshaft) of an eccentric part, suppressing the expansion of the outer diameter of an eccentric part. Therefore, if the eccentric amount of the eccentric portion is increased while suppressing the enlargement of the outer diameter of the eccentric portion, the outer circumferential surface on the half eccentric side of the eccentric portion 4c is less than the outer circumferential surface of the main shaft 4a or the minor axis 4b (that is, Re -e <Rm or Re-e <Ra state).

However, as explained in Fig. 7, the rotary compressor described in Patent Document 1 sets the relation between the outer circumferential surface of the eccentric side of the eccentric portion and the outer circumferential surface of the main shaft or the minor shaft to be Re-e? Rm or Re-e? Ra. Otherwise, the piston cannot be attached to the eccentric. For this reason, the rotary compressor of patent document 1 suppresses the expansion of the outer diameter of an eccentric part, even if the outer peripheral surface of the eccentric side of the eccentric part 4c is more than the outer peripheral surface of the main shaft 4a or the sub-axis 4b. There is a problem that the amount of eccentricity of the eccentric portion cannot be increased, so that the capacity of the rotary compressor is limited.

Here, as a method of increasing the pushing volume of the rotary compressor, it is also conceivable to keep the eccentricity of the eccentric portion and the piston as it is and to increase the height of the piston and the cylinder. However, between the outer circumferential surface on the eccentric side of the piston (the outer circumferential surface on the eccentric direction side of the eccentric portion) and the cylinder chamber inner circumferential surface is a seal portion that divides the cylinder chamber into a low pressure space and a high pressure space. For this reason, when the height of a piston and a cylinder is made high, the length of the said seal part will increase. Therefore, when attempting to expand the capacity of the rotary compressor by increasing the height of the piston and the cylinder, the refrigerant gas on the high pressure space side leaks to the low pressure space side and the weight flow rate of the refrigerant gas sucked into the compression chamber (in the cylinder chamber) ( There is a problem that the weight decreases, leading to a significant deterioration of the efficiency of the rotary compressor.

This invention is made | formed in order to solve the problem as mentioned above, The rotation which can make the pushing-out volume of a rotary compressor large can be made, preventing the deterioration between the high pressure side space and the low pressure side space in a cylinder chamber deteriorating. It is an object to provide a compressor.

The rotary compressor according to the present invention has a motor having a stator and a rotor, a main shaft fixed to the rotor, a sub shaft provided on the side opposite to the axial direction of the main shaft, and an eccentric portion formed between the main shaft and the sub shaft. And a crank shaft driven by the electric motor, a piston slidably attached to the eccentric portion, a cylindrical cylinder chamber, wherein the eccentric portion and the piston are disposed in the cylinder chamber, and the cylinder chamber. A rotary compressor comprising a compression mechanism portion having a vane that divides the pressure into a low pressure space and a high pressure space, and a sealed container for accommodating the electric motor, the crankshaft, and the compression mechanism portion, wherein the piston is provided to slide freely on an outer circumferential surface of the eccentric portion. An inner circumferential side piston and an outer circumferential side piston provided on an outer circumferential surface of the inner circumferential side piston; And a plurality of arc-shaped members.

In the rotary compressor according to the present invention, the piston is composed of an inner circumferential side piston provided freely on the outer circumferential surface of the eccentric portion, and an outer circumferential side piston provided on the outer circumferential surface of the inner circumferential side piston. The inner circumferential side piston is composed of a plurality of arc-shaped members. Therefore, the rotary compressor according to the present invention can provide each arc-shaped member, that is, the inner circumferential side piston, so as to sandwich the eccentric portion with a plurality of arc-shaped members (from the direction perpendicular to the central axis of the eccentric portion). For this reason, even if the outer peripheral surface of the eccentric side of an eccentric part becomes a crankshaft in the structure which was inclined more than the outer peripheral surface of a main shaft or a minor shaft, an inner peripheral piston can be attached to an eccentric part. Accordingly, the rotary compressor according to the present invention can increase the pushing volume without increasing the height of the piston and the cylinder.

That is, the rotary compressor according to the present invention can increase the volume to be pushed out without causing a significant deterioration in efficiency caused by leakage of refrigerant in the seal portion between the piston and the inner circumferential surface of the cylinder chamber. In other words, the rotary compressor according to the present invention can make the height of the piston and the cylinder lower than those of the conventional rotary compressor when the volume to be pushed out is not changed, and in the seal portion between the piston and the inner circumferential surface of the cylinder chamber, Leakage of refrigerant can be suppressed than before.

Accordingly, the present invention can provide a rotary compressor capable of higher output and higher efficiency than before.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal cross-sectional view which shows the rotary compressor which concerns on embodiment of this invention.
2 is a cross-sectional view showing a compression mechanism portion of a rotary compressor according to an embodiment of the present invention.
FIG. 3 is an explanatory diagram for explaining the inner circumferential side piston of the rotary compressor according to the embodiment of the present invention, wherein (a) is a longitudinal sectional view showing the crankshaft and the inner circumferential side piston, and (b) shows the inner circumferential side piston. Floor plan.
4 is a view for explaining a piston attachment method to an eccentric portion in a rotary compressor according to an embodiment of the present invention, and is a perspective view showing a state before assembling the inner circumferential side piston on an eccentric portion of a crankshaft.
It is a figure for demonstrating the piston attachment method to the eccentric part in the rotary compressor which concerns on embodiment of this invention. After an inner peripheral piston is attached to the eccentric part of a crankshaft, it is an outer peripheral side to the inner peripheral piston. The perspective view which shows the state before attaching a piston.
FIG. 6 is a view for explaining a method of attaching a piston to an eccentric part in a rotary compressor according to an embodiment of the present invention. After the inner circumferential side piston is attached to the eccentric part of the crankshaft, the outer circumference is further applied to the inner circumferential side piston. The figure which shows the state which attached the side piston.
7 is a detailed view showing the vicinity of an eccentric portion of a conventional rotary compressor.

Embodiments.

1 is a longitudinal sectional view showing a rotary compressor according to an embodiment of the present invention. 2 is a cross sectional view showing a compression mechanism part of the rotary compressor. 3 is explanatory drawing for demonstrating the inner peripheral piston of this rotary compressor, (a) is a longitudinal cross-sectional view which shows a crankshaft and an inner peripheral piston, (b) is a top view which shows an inner peripheral piston. Hereinafter, the structure of the rotary compressor which concerns on this embodiment is demonstrated using these FIGS.

The rotary compressor 100 accommodates the electric motor 2 which consists of the stator 2a and the rotor 2b, and the compression mechanism part 3 driven by the electric motor 2 in the airtight container 1. The rotational force of the electric motor 2 is transmitted to the compression mechanism section 3 through the crankshaft 4. In the sealed container 1, lubricating oil (freezer oil) for lubricating the compression mechanism part 3 is stored.

The crankshaft 4 includes a main shaft 4a fixed to the rotor 2b of the electric motor 2, a subshaft 4b provided on the opposite side of the main shaft 4a, a main shaft 4a and a subshaft 4b, It has an eccentric part 4c formed in between.

In addition, in this embodiment, the shape of the crankshaft 4 is formed as follows. That is, in this embodiment, in order to enlarge the pushing-out volume of the rotary compressor 100, the amount of eccentricity of the eccentric part 4c (main axis | shaft 4a and the subshaft () is suppressed, while the expansion of the outer diameter of the eccentric part 4c is suppressed. Eccentricity from 4b) is increased. For this reason, as for the crankshaft 4, the outer peripheral surface (outer peripheral surface on the opposite side to the eccentric direction in the eccentric part 4c) of the eccentric part 4c loses more than the outer peripheral part of the main axis 4a and the subshaft 4b. It is in an aftershock shape. In other words, the radius of the eccentric portion 4c is Re, and the eccentricity of the eccentric portion 4c (the distance between the central axis of the main shaft 4a and the minor axis 4b and the central axis of the eccentric portion 4c) is e. In this case, the distance from the central axis of the main axis 4a and the subordinate axis 4b to the outer circumferential surface on the half-eccentric side of the eccentric portion 4c becomes Re-e. For this reason, when the radius of the main shaft 4a is set to Rm and the radius of the minor shaft 4b is set to Ra, the crankshaft 4 of the rotary compressor 100 is set to Re-e <Rm, and Re-e <Ra.

The crankshaft 4 comprised in this way is rotatably supported by the main shaft support 5 and the subordinate bearing 6. In detail, the spindle support 5 is provided in the upper part of the compression mechanism part 3, and supports the spindle 4a of the crankshaft 4 rotatably. In addition, the subordinate bearing 6 is provided below the compression mechanism part 3, and supports the minor axis 4b of the crankshaft 4 freely to rotate.

The compression mechanism part 3 is provided with the cylinder 7, the piston 20, the vane 9, etc.

The cylinder 7 is fixed to the inner peripheral part of the airtight container 1, and has the cylindrical cylinder chamber in the center part. And the cylinder 20 which slides and fits freely to the eccentric part 4c of the crankshaft 4 is provided in this cylinder chamber. In addition, both axial end surfaces of the cylinder chamber of the cylinder 7 are occluded by the main shaft support 5 and the secondary shaft support 6. Moreover, the cylinder 7 is provided with the vane 9 which reciprocates according to the rotation of the eccentric part 4c. That is, the space partitioned by the outer peripheral surface of the piston 20, the inner peripheral surface of the cylinder chamber, and the vanes 9 turns into a compression chamber. In addition, the vane 9 divides the inside of the compression chamber (in the cylinder chamber) into a high pressure side space and a low pressure side.

Here, in this embodiment, the piston 20 is comprised like FIG. 2 and FIG.

That is, the piston 20 is an inner circumferential side piston 21 that is freely provided on the outer circumferential surface of the eccentric portion 4c and an outer circumferential side piston 22 that is freely provided on the outer circumferential surface of the inner circumferential side piston 21, for example. Consists of. In addition, the inner circumferential side piston 21 is composed of a plurality of arc-shaped members 21a divided into cross sections along the central axis of the eccentric portion 4c. In addition, in this embodiment, the inner peripheral side piston 21 is comprised by the two arc-shaped members 21a.

As for the rotary compressor 100 comprised in this way, when the rotor 2b rotates, the crankshaft 4 inserted in the rotor 2b rotates. As a result, the piston 20 slidably attached to the eccentric portion 4c of the crankshaft 4 is eccentrically rotated in the cylinder chamber of the cylinder 7. With the eccentric rotation of the piston 20, the volume of the high pressure side space of the cylinder 7 gradually decreases, and the refrigerant gas in the high pressure side space is compressed. The compressed refrigerant gas is discharged into the sealed container 1 and then discharged from the discharge tube 11 to the outside. Moreover, the accumulator 12 is provided adjacent to the airtight container 1, and this accumulator 12 communicates with the cylinder chamber of the cylinder 7 through the suction connection pipe 10. As shown in FIG. That is, refrigerant gas is sent to the cylinder chamber of the cylinder 7 using the accumulator 12 and the suction connection pipe 10.

Then, the method of attaching the piston 20 to the eccentric part 4c of the crankshaft 4 is demonstrated using FIG.

It is a figure for demonstrating the piston attachment method to the eccentric part in the rotary compressor which concerns on embodiment of this invention, It is a perspective view which shows the state before assembling an inner peripheral side piston in the eccentric part of a crankshaft. Fig. 5 is a view for explaining the piston attachment method to the eccentric portion in the rotary compressor, and after the inner circumference side piston is attached to the eccentric portion of the crankshaft, the state before the outer circumference side piston is attached to the inner circumference side piston. It is a perspective view which shows. 6 is a figure for explaining the piston attachment method to the eccentric part in this rotary compressor. After the inner circumference side piston is attached to the eccentric part of the crankshaft, the outer circumference side piston is attached to the inner circumference side piston. It is a figure which shows one state. More specifically, Fig. 6A is a longitudinal cross-sectional view showing a state in which the outer circumferential side piston is assembled to the inner circumferential side piston. Fig. 6B is a perspective view showing a state in which the outer circumferential side piston is assembled to the inner circumferential side piston. 6 (c) is a plan view showing a state in which the outer circumferential side piston is assembled to the inner circumferential side piston. In addition, illustration of the crankshaft is abbreviate | omitted in FIG.6 (c).

When attaching the piston 20 to the eccentric part 4c of the crankshaft 4, first, as shown in FIG. 4, the inner peripheral piston 21 is attached to the eccentric part 4c. Specifically, the two arc-shaped members 21a (that is, the inner circumference) are mounted on the eccentric portions 4c so as to sandwich the eccentric portions 4c into the two arc-shaped members 21a constituting the inner circumferential side piston 21. Attach the side piston (21). In other words, two arc-shaped members 21a constituting the inner circumferential side piston 21 are attached to the eccentric portion 4c in a direction perpendicular to the central axis of the eccentric portion 4c.

As described above, the inner circumferential side piston of the conventional rotary compressor is formed in one piece. Therefore, in the conventional rotary compressor, in order to attach the inner circumferential side piston to the eccentric portion of the crankshaft, the outer circumferential surface on the half eccentric side of the eccentric portion needs to be configured to protrude more than the outer circumferential surface of the main shaft or the minor shaft. Alternatively, it is necessary to form the outer circumferential surface on the side of the eccentric side of the eccentric portion and the outer circumferential surface of the main shaft or the minor shaft in the same plane shape. In other words, in the conventional rotary compressor, the outer circumferential surface of the crankshaft 4 (half eccentricity side of the eccentric part 4c) of the shape similar to this embodiment has more than the outer peripheral part of the main shaft 4a and the subshaft 4b. Crank shaft), the inner circumferential side piston could not be attached. However, by constituting the inner circumferential side piston 21 with two arc-shaped members 21a as in the present embodiment, the outer circumferential surface on the half eccentric side of the eccentric portion 4c is formed of the main shaft 4a and the subshaft 4b. The inner circumferential side piston 21 can also be attached to the crankshaft 4 of the shape which was recessed rather than the outer peripheral part.

After attaching the inner circumferential side piston 21 to the eccentric portion 4c of the crankshaft 4 as shown in FIG. 4, and as shown in FIGS. 5 and 6, the outer circumferential side to the outer circumferential surface of the inner circumferential side piston 21. Attach the piston (22). In detail, the main shaft 4a or the subshaft 4b is made to pass through the outer peripheral side piston 22 formed from the substantially cylindrical integral body. Thereafter, the outer circumferential side piston 22 is attached to the outer circumferential surface of the inner circumferential side piston 21.

In addition, in this embodiment, as shown in FIG. 3, when setting it as the radius Rp of the inner peripheral piston 21, Rp-e becomes a value larger than the radius Rm of the main shaft 4a. . For this reason, in the state where the inner circumferential side piston 21 is attached to the eccentric part 4c, the outer circumferential surface of the half eccentric side of the inner circumferential side piston 21 protrudes more than the outer circumferential surface of the main shaft 4a. For this reason, the outer peripheral side piston 22 can be attached to the eccentric part 4c from the main shaft 4a side. In addition, in this embodiment, as shown in FIG. 3, when setting it as the radius Rp of the inner peripheral piston 21, Rp-e becomes a value larger than the radius Ra of the sub-axis 4b. . Therefore, in the state where the inner circumferential side piston 21 is attached to the eccentric portion 4c, the outer circumferential surface of the half eccentric side of the inner circumferential side piston 21 protrudes from the outer circumferential surface of the subshaft 4b. For this reason, the outer peripheral side piston 22 can also be attached to the eccentric part 4c from the sub-axis 4b side.

As described above, the rotary compressor 100 configured as in the present embodiment can obtain the following effects.

That is, as mentioned above, the inner peripheral piston of the conventional rotary compressor is formed in one piece. Therefore, in the conventional rotary compressor, in order to attach the inner circumferential side piston to the eccentric portion of the crankshaft, the outer circumferential surface on the half eccentric side of the eccentric portion needs to be configured to protrude more than the outer circumferential surface of the main shaft or the minor shaft. Alternatively, it is necessary to form the outer circumferential surface on the side of the eccentric side of the eccentric portion and the outer circumferential surface of the main shaft or the minor shaft in the same plane shape. For this reason, the conventional rotary compressor is a limitation of the expansion of the volume pushed out by the said structure. However, the rotary compressor according to the present embodiment does not have such a restriction, and the crankshaft 4 having a shape in which the outer circumferential surface on the half eccentric side of the eccentric portion 4c is recessed than the outer circumferential portions of the main shaft 4a and the subshaft 4b. ) Can also be attached to the inner circumferential side piston 21. Therefore, in the rotary compressor according to the present embodiment, the volume to be pushed out can be enlarged (that is, high output is possible) without being limited to the above limitations.

Here, as a method of increasing the pushing volume of the rotary compressor, it is also conceivable to keep the eccentricity of the eccentric portion and the piston as it is and to increase the height of the piston and the cylinder. However, between the outer circumferential surface on the eccentric side of the piston (the outer circumferential surface on the eccentric direction side of the eccentric portion) and the cylinder chamber inner circumferential surface is a seal portion that divides the cylinder chamber into a low pressure space and a high pressure space. For this reason, when the height of a piston and a cylinder is made high, the length of the said seal part will increase. Therefore, when attempting to expand the capacity of the rotary compressor by increasing the height of the piston and the cylinder, the refrigerant gas on the high pressure space side leaks to the low pressure space side, and the weight flow rate of the refrigerant gas sucked into the compression chamber (in the cylinder chamber) It will fall and it will cause the deterioration of the remarkable efficiency of a rotary compressor. However, the rotary compressor 100 according to the present embodiment can enlarge the pushing volume without increasing the height of the piston 20 and the cylinder 7 as described above. That is, the rotary compressor 100 according to the present embodiment has a volume of pushing out without causing a significant deterioration in efficiency caused by leakage of refrigerant in the seal portion between the piston 20 and the inner circumferential surface of the cylinder chamber. Can be increased.

In other words, in order to improve the efficiency of the rotary compressor without changing the pushing volume, the heights of the piston 20 and the cylinder 7 are lowered, and in the seal portion formed between them, from the high pressure space side to the low pressure space side It is important to reduce the amount of refrigerant gas leaked into the air. At this time, in order to lower the height of the piston and the cylinder without changing the pushing volume, it is necessary to increase the eccentricity of the eccentric portion of the crankshaft. However, in the conventional rotary compressor, the amount of eccentricity of the eccentric portion cannot be large because of the above limitations. For this reason, the conventional rotary compressor had little efficiency improvement range. On the other hand, since the rotary compressor 100 which concerns on this embodiment is not bound by the above restrictions, the eccentricity of the eccentric part 4c can be made larger than before. For this reason, the rotary compressor 100 which concerns on this embodiment can fully improve efficiency compared with the former.

In addition, in order to improve the efficiency of the rotary compressor without changing the pushing volume, it is also important to reduce the radius of the eccentric portion (in other words, the diameter) in order to reduce the sliding speed between the outer circumferential surface of the eccentric portion and the inner circumferential surface of the piston. However, the conventional rotary compressor cannot reduce the radius of an eccentric part very much when it tries to expand the eccentric amount of an eccentric part because of the above restrictions. This is because if the radius of the eccentric portion is made smaller, the outer circumferential surface on the side of the eccentric side of the eccentric portion will be cut out than the outer circumferential surface of the main shaft or the minor axis. For this reason, the conventional rotary compressor has little efficiency improvement range by making the radius of an eccentric part small. On the other hand, since the rotary compressor 100 which concerns on this embodiment is not bound by the above-mentioned restrictions, when the eccentric amount of the eccentric part 4c is made equal to the conventional one, the radius of the eccentric part 4c is changed. It can be made smaller than before. For this reason, the rotary compressor 100 which concerns on this embodiment can further improve efficiency.

In addition, in this embodiment, although the example which divided the inner peripheral piston 21 into two arc-shaped member 21a was demonstrated, the inner peripheral piston 21 was divided into three or more arc-shaped member 21a, Of course good too. By increasing the number of arc-shaped members 21a constituting the inner circumferential side piston 21, the size of the material used when manufacturing the inner circumferential side piston 21 can be reduced, so that the yield of the material is improved. Moreover, the loading efficiency in the transportation of a raw material is also improved. That is, by increasing the number of the arc-shaped members 21a constituting the inner circumferential side piston 21, it is possible to provide an effect that the rotary compressor 100 can be provided at low cost and with high efficiency.

In addition, in this embodiment, although the rotary compressor 100 which has one compression mechanism part 3 was demonstrated, you may comprise the rotary compressor 100 as a multi-cylinder rotary compressor which has several compression mechanism parts 3. As shown in FIG. . In this case, a plurality of eccentric portions 4c are formed between the main shaft 4a and the subordinate shaft 4b, and these eccentric portions 4c are connected to the intermediate shaft. Moreover, the some cylinder 7 is provided corresponding to each eccentric part 4c, and the cross section of the cylinder chamber opened between each cylinder 7 is closed by the partition plate provided between the cylinders 7, and is. do. In addition, when constituting the rotary compressor 100 as a multi-cylinder rotary compressor, it is preferable that the eccentric portions 4c are arranged symmetrically with respect to the central axes of the main shaft 4a and the subordinate shaft 4b. For example, when the rotary compressor 100 is configured as a two-cylinder rotary compressor, it is preferable to form two eccentric portions 4c with a phase difference of 180 ° with respect to the central axis of the main shaft 4a and the subordinate shaft 4b. Do. Thus, by forming each eccentric part 4c, the vibration etc. which generate | occur | produce due to the rotation of the crankshaft 4 can be suppressed.

In addition, in this embodiment, "the clearance between the outer peripheral surface of the eccentric part 4c and the inner peripheral surface of the inner peripheral piston 21", and "the clearance between the outer peripheral surface of the inner peripheral piston 21 and the inner peripheral surface of the outer peripheral piston 22" Although the relationship with the clearance is not specifically mentioned, both clearances may be, for example, approximately the same dimension (also referred to below as "approximately the same", that is, substantially the same as "the same." "Identical" shown in this embodiment does not represent exactly the same thing). For example, dimensions of "a clearance between the outer peripheral surface of the eccentric part 4c and the inner peripheral surface of the inner peripheral piston 21", and "the clearance between the outer peripheral surface of the inner peripheral piston 21 and the inner peripheral surface of the outer peripheral piston 22" Is too different, "the frictional force between the outer peripheral surface of the eccentric part 4c and the inner peripheral surface of the inner peripheral piston 21" and "the outer peripheral surface of the inner peripheral piston 21 and the inner peripheral surface of the outer peripheral piston 22" Friction force ”increases. Therefore, the rotational speeds of the inner circumferential side piston 21 and the outer circumferential side piston 22 are significantly different, so that the sliding speed of the inner circumferential surface of the inner circumferential side piston 21 and the inner circumferential surface of the outer circumferential side piston 22 becomes faster, It is concerned that causing abnormal wear. However, "the clearance between the outer peripheral surface of the eccentric part 4c and the inner peripheral surface of the inner peripheral piston 21" and the "clearance between the outer peripheral surface of the inner peripheral piston 21 and the inner peripheral surface of the outer peripheral piston 22" have the same dimensions. By doing so, the sliding speed of the inner circumferential surface of the inner circumferential side piston 21 and the inner circumferential surface of the outer circumferential side piston 22 can be properly maintained, and abnormal wear at this portion can be prevented.

In the rotary compressor 100 according to the present embodiment, since the inner circumferential side piston 21 is a split part and the outer circumferential side piston 22 is an integrally molded part, it is assumed that each case is formed of a different material. In such a case, it is preferable to select both materials so that the material of the inner circumferential side piston 21 and the material of the outer circumferential side piston 22 have the same linear expansion coefficient. When the rotary compressor 100 is operated, the inner circumferential side piston 21 and the outer circumferential side piston 22 thermally expand. At this time, if both linear expansion coefficients are too different, the "clearance between the inner circumferential side piston 21, the main shaft bearing 5, and the subaxial bearing 6", and "the outer circumferential side piston 22, the main shaft bearing 5, and the minor shaft The difference between the clearance between the receivers 6 becomes large. For this reason, "friction force between the inner circumferential side piston 21, the spindle support 5, and the auxiliary bearing 6," and "friction force between the outer circumferential side piston 22, the spindle support 5, and the auxiliary bearing 6" Becomes bigger. Therefore, the rotational speeds of the inner circumferential side piston 21 and the outer circumferential side piston 22 are remarkably different, and the sliding speed of the inner circumferential surface of the inner circumferential side piston 21 and the inner circumferential surface of the outer circumferential side piston 22 is increased, thereby causing an abnormality in this portion. It is concerned about causing wear. However, by selecting both materials such that the material of the inner circumferential side piston 21 and the material of the outer circumferential side piston 22 have the same linear expansion coefficient, the "inner circumferential side piston 21, the spindle support 5, and the auxiliary support 6 are selected. ) And "clearance between outer peripheral piston 22, main shaft support 5, and subordinate bearing 6" can be made the same. Therefore, the sliding speed of the inner circumferential surface of the inner circumferential side piston 21 and the inner circumferential surface of the outer circumferential side piston 22 can be properly maintained, and abnormal wear at this portion can be prevented.

1: sealed container
2: electric motor
2a: stator
2b: rotor
3: compression mechanism part
4: crankshaft
4a: spindle
4b: minor shaft
4c: eccentric
5: headrest
6: support
7: cylinder
9: vane
10: suction connector
11: discharge tube
12: accumulator
20: piston
21: inner peripheral piston
21a: arc-shaped member
22: outer peripheral piston
50: inner peripheral piston (conventional)
100: rotary compressor

Claims (7)

A motor having a stator and a rotor,
A crank shaft driven by the electric motor, having a main shaft fixed to the rotor, a sub shaft provided on an opposite side in the axial direction of the main shaft, and an eccentric portion formed between the main shaft and the sub shaft;
A piston freely attached to the eccentric portion, a cylindrical cylinder chamber, a cylinder in which the eccentric portion and the piston are disposed, and a vane partitioning the cylinder chamber into a low pressure space and a high pressure space. Compression mechanism part to have,
A sealed container for storing the electric motor, the crankshaft and the compression mechanism
As a rotary compressor,
The piston is composed of an inner circumferential side piston freely provided on an outer circumferential surface of the eccentric portion, and an outer circumferential side piston provided on an outer circumferential surface of the inner circumferential side piston,
The said inner circumference side piston is comprised by the some arc-shaped member, The rotary compressor characterized by the above-mentioned. The method of claim 1,
The said inner circumference side piston is comprised by the three or more said arc-shaped members, The rotary compressor characterized by the above-mentioned. The method of claim 1,
When the radius of the main shaft is Rm, the radius of the eccentric portion is Re, the radius of the inner circumferential piston is Rp, and the eccentricity of the eccentric portion is e,
Re-e <Rm <Rp-e
A rotary compressor having a phosphorus relationship. The method of claim 1,
When the radius of the minor axis is Ra, the radius of the eccentric part is Re, the radius of the inner circumferential side piston is Rp, and the eccentricity of the eccentric part is e,
Re-e <Ra <Rp-e
A rotary compressor having a phosphorus relationship. 5. The method according to any one of claims 1 to 4,
A plurality of said eccentric part of the said crankshaft, and the said compression mechanism part are provided, The rotary compressor characterized by the above-mentioned. The method of claim 1,
A clearance formed between the outer circumferential surface of the eccentric portion and the inner circumferential surface of the inner circumferential side piston and the clearance formed between the outer circumferential surface of the inner circumferential side piston and the outer circumferential side piston are the same. The method of claim 1,
The linear expansion coefficient of the said outer peripheral piston and the linear expansion coefficient of the said inner peripheral piston were made the same, The rotary compressor characterized by the above-mentioned.

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