JP3702686B2 - Rotary compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary compressor, and more particularly to a structure of a compression element that compresses a refrigerant.
[0002]
[Prior art]
FIG. 8 shows an example of a conventional rotary compressor. As shown in FIG. 8, the rotary compressor 1 includes a casing 2, and a motor 3, a crankshaft (rotary shaft) 4, and a compression element 5 are incorporated in the casing 2.
[0003]
The crankshaft 4 is press-fitted into the rotor of the motor 3 and drives the compression element 5. The compression element 5 includes a front head 13, a cylinder 14, a rear head 17, a rotary piston 15 and an eccentric part 16. A cylinder chamber 14a is provided inside the cylinder 14, and the refrigerant is compressed in the cylinder chamber 14a.
[0004]
Here, the internal structure of the cylinder chamber 14a will be described with reference to FIG. As shown in FIG. 9, the rotary piston 15 and the eccentric portion 16 are housed in the cylinder chamber 14 a, and the rotary piston 15 is fitted on the eccentric portion 16. The rotary piston 15 has a blade 11, and the blade 11 is held by a bush 12 so as to be able to advance and retreat. The cylinder 14 is provided with a blade rear space 18 that receives the tip of the blade 11 and a suction port 6 that guides the refrigerant to the cylinder chamber 14a.
[0005]
As shown in FIG. 9, the cylinder chamber 14 a is partitioned into a suction chamber 9 and a compression chamber 10 by the blade 11 and the rotary piston 15. The refrigerant after passing through the suction port 6 is fed into the suction chamber 9, and the refrigerant is compressed in the compression chamber 10.
[0006]
Referring to FIG. 8 again, the casing 2 is provided with a suction pipe 7 for sending the refrigerant into the cylinder chamber 14a and a discharge pipe 8 for discharging the compressed refrigerant to the outside.
[0007]
In the rotary compressor 1 having the above-described configuration, the refrigerant is fed into the suction chamber 9 through the suction pipe 7 and the suction port 6, and the refrigerant is compressed by the rotary piston 15 in the compression chamber 10. The compressed refrigerant is discharged into the casing 2, rises in the casing 2, and is then discharged from the discharge pipe 8 to the outside of the compressor.
[0008]
[Problems to be solved by the invention]
As described above, the refrigerant is compressed in the cylinder chamber 14a. However, as shown in FIG. 9, a contact point gap (hereinafter referred to as "CP gap") is formed between the wall surface of the cylinder chamber 14a and the outer periphery of the rotary piston 15. There is a minute gap called 19).
The presence of the CP gap 19 causes a gas leak from the compression chamber 10 to the suction chamber 9 at the time of compression, which causes a problem of reducing the efficiency of the compressor. In particular, in recent years, energy saving has been promoted throughout the year by driving an inverter, and importance has been placed on improving efficiency in low-speed operation that is susceptible to gas leakage.
[0009]
The present invention has been made to solve the above-described problems. An object of the present invention is to improve the efficiency of the compressor by reducing gas leakage from the compression chamber 10 to the suction chamber 9.
[0010]
[Means for Solving the Problems]
The rotary compressor according to claim 1 includes a rotating shaft (4), a rotating piston (15), and an eccentric ring (20). The rotating shaft (4) has an eccentric part (16) housed in a cylinder chamber (14a) into which the refrigerant is fed, and is arranged so as to sandwich the cylinder chamber (14a) and a rear head. (14). The rotating piston (15) is fitted on the eccentric portion (16), and is rotated by the eccentric portion (16) to compress the refrigerant in the cylinder chamber (14a). The eccentric ring (20) is interposed between the eccentric portion (16) and the rotary piston (15), and presses the rotary piston (15) radially outward to form the wall surface of the cylinder chamber (14a) and the rotary piston. The CP gap with the outer peripheral surface of (15) is reduced, and the center (24) of the circumscribed circle is deviated toward the axis (23) side of the rotating shaft (4) with respect to the center (25) of the inscribed circle. Core .
[0011]
By providing the eccentric ring (20) in this way, the rotary piston (15) can be moved radially outward. Thereby, the rotating piston (15) can be brought close to the wall surface of the cylinder chamber (14a), and the CP gap can be reduced. As a result, gas leakage from the compression chamber to the suction chamber in the cylinder chamber (14a) can be suppressed.
[0012]
In the rotary compressor according to claim 2, the eccentric ring (20) is provided so as to be movable in the circumferential direction of the eccentric part (16), and the thickness of the eccentric part (16) in the radial direction is relatively long. It has a large first part (20a) and a second part (20b) having a relatively small thickness.
[0013]
By moving the eccentric ring (20) along the circumferential direction of the eccentric portion (16), the first portion (20a) having a relatively large thickness also extends along the circumferential direction of the eccentric portion (16). Moving. By moving the first portion (20a) in a direction approaching the wall surface of the cylinder chamber (14a), the rotary piston (15) can be moved radially outward to approach the wall surface of the cylinder chamber (14a). it can. Thereby, the CP gap can be reduced.
[0015]
When employing the eccentric ring, in the the rotary piston (15) between the eccentric portion (16) only interposed eccentric ring, it is possible to rotate the eccentric ring by eccentric portion (16). This is because the center of the outer periphery (25) of the eccentric ring and the center of the inner periphery (the center of the outer periphery of the eccentric portion (16)) (24) are deviated, and the point of action of the gas force received from the refrigerant and the eccentric portion (16 This is because the point of action of the driving force due to () shifts as shown in FIG. By rotating the eccentric ring, the relatively thick first portion (20a) of the eccentric ring can be moved toward the wall surface of the cylinder chamber (14a). Thereby, the rotating piston (15) can be brought close to the wall surface of the cylinder chamber (14a), and the CP gap can be reduced. During low-speed operation of the compressor, it is preferable that the rotary piston (15) and the wall surface of the cylinder chamber (14a) are brought into contact with each other with the CP gap being zero. Since power loss due to the contact is small and does not cause a problem during low-speed operation, gas leakage can be suppressed by the contact. When the pressing force of the rotating piston (15) against the cylinder wall surface becomes excessive, the eccentric ring automatically reverses and the pressing force of the rotating piston (15) can be reduced. On the other hand, during high-speed operation of the compressor, unlike in low-speed operation, loss increases due to contact between the rotating piston (15) and the wall surface of the cylinder chamber (14a). However, during high-speed operation, a viscous force generated by oil shearing on the outer periphery of the eccentric ring becomes large, and rotation of the eccentric ring can be prevented or reversed. Thereby, it is possible to avoid contact between the rotary piston (15) and the wall surface of the cylinder chamber (14a) during high-speed operation with little influence of gas leak, and it is possible to suppress the occurrence of loss due to the contact.
[0016]
In the rotary compressor according to the third aspect , the movable range regulating mechanism (29) for regulating the movable range of the eccentric ring (20) is provided.
[0017]
The movable range of the eccentric ring (20) can be regulated by the movable range regulating mechanism (29).
[0018]
In the rotary compressor according to claim 4 , the movable range restricting mechanism (29) is engaged with the groove portion (21) provided in the eccentric ring (20) or the eccentric portion (16) and the wall surface of the groove portion (21). And an engaging portion (22) for restricting the movement of the eccentric ring (20).
[0019]
By providing the groove portion (21) and the engaging portion (22) as described above, the eccentric ring (20) can be moved only within a range defined by the pair of side walls of the groove portion (21). it can.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing an internal structure of a cylinder chamber 14a of a rotary compressor according to one embodiment of the present invention.
[0021]
An important feature of the present invention is that a pressing member 20 is provided between the rotary piston 15 and the eccentric portion 16 and presses the rotary piston 15 outward in the radial direction to reduce the CP gap 19. . By providing this pressing member, when the rotary piston 15 is rotated to compress the refrigerant, the CP gap 19 can be reduced by moving the rotary piston 15 radially outward. Thereby, the gas leak from the compression chamber 10 to the suction chamber 9 in the cylinder chamber 14a can be suppressed. In particular, the efficiency of the compressor can be improved by reducing the CP gap 19 during low-speed operation of the rotary compressor.
[0022]
Hereinafter, a specific configuration of the present embodiment will be described. With reference to FIG. 1, an eccentric ring 20, which is an example of a pressing member, is interposed between the rotary piston 15 and the eccentric portion 16. The eccentric ring 20 is movable along the outer periphery of the eccentric portion 16, and the eccentric ring 20 rotates along the outer periphery of the eccentric portion 16 to move the rotary piston 15 toward the wall surface side of the cylinder chamber 14 a. It can be pressed and moved.
[0023]
A movable range regulating mechanism 29 that regulates the movable range of the eccentric ring 20 is provided. Thereby, the movable range of the eccentric ring 20 can be regulated.
[0024]
In FIG. 1, the same components as those in the conventional example are denoted by the same reference numerals, and redundant description is omitted. The overall configuration of the rotary compressor is also the same as that of the conventional example shown in FIG.
[0025]
Next, the eccentric ring 20 and the movable range regulating mechanism 29 will be described in more detail.
[0026]
First, the eccentric ring 20 will be described. As shown in FIG. 2, the eccentric ring 20 includes first and second portions 20 a and 20 b having different thicknesses in the radial direction of the eccentric portion 16. The first portion 20a having a relatively large thickness and the second portion 20b having a relatively small thickness (the minimum thickness in the case shown in FIG. 2) are sequentially arranged in the rotation direction 26 of the eccentric portion 16. That is, the center of the outer periphery of the eccentric ring 20 (corresponding to the inner periphery or the center of the outer periphery of the rotary piston 15) 24 is set to the crankshaft (rotary shaft) with respect to the inner periphery center of the eccentric ring 20 (the outer periphery center of the eccentric portion 16) This is because it is shifted to the axis 23 side of 4).
[0027]
The eccentric ring 20 rotates in the same direction by rotating the eccentric portion 16 in the rotation direction 26.
[0028]
The reason will be described below with reference to FIG. When the refrigerant is compressed, the outer periphery of the rotary piston 15 receives a gas force from the refrigerant, and this gas force also acts on the outer periphery of the eccentric ring 20. On the other hand, the driving force when the eccentric portion 16 drives the rotary piston 15 acts on the inner periphery of the eccentric ring 20. As shown in FIG. 3, the resultant force of the gas force from the refrigerant acts on the outer peripheral center 24 of the rotary piston 15, and the resultant force of the driving force from the eccentric portion 16 acts on the outer peripheral center 25 of the eccentric portion 16. Since the operating points of the gas force and the driving force are thus different, the eccentric ring 20 rotates in the direction indicated by the arrow in FIG. 3, that is, in the same direction as the eccentric portion 16.
[0029]
When the eccentric ring 20 rotates in the above direction, the relatively thick first portion 20a moves to the portion where the CP gap 19 is formed, and presses the rotary piston 15 radially outward. The outer periphery of the rotary piston 15 is moved in a direction approaching the side wall of the cylinder chamber 14a. Thereby, the CP gap 19 is reduced, and gas leakage from the compression chamber 10 to the suction chamber 9 can be suppressed.
[0030]
During low-speed operation of the rotary compressor, since the power loss does not matter even if the outer periphery of the rotary piston 15 is brought into contact with the side wall of the cylinder chamber 14a, the outer periphery of the rotary piston 15 is brought into contact with the side wall of the cylinder chamber 14a. Thus, it is preferable to set the CP gap 19 to zero.
[0031]
When the cylinder wall surface and the rotary piston 15 are brought into contact with each other in this way, there is a concern that the pressing force of the rotary piston 15 becomes excessive. However, as shown in FIG. Since the thickness gradually decreases toward the second portion 20b, even if the pressing force is excessive, the eccentric ring 20 is automatically reversely rotated to avoid excessive pressing force. it can.
[0032]
During high-speed operation, it is preferable that the outer periphery of the rotary piston 15 and the side wall of the cylinder chamber 14a do not contact each other. This is because during high-speed operation, power loss due to contact between the rotary piston 15 and the cylinder 14 is so large that it cannot be ignored. However, by adopting the eccentric ring 20, the contact can be avoided during high-speed operation. The reason will be described below.
[0033]
An oil film exists around the eccentric ring 20, and a viscous force generated by oil shearing acts on the surface of the eccentric ring 20. This viscous force increases as the eccentric portion 16 rotates at high speed, and tries to rotate the eccentric ring 20 in the reverse direction. When the viscous force exceeds the rotational driving force of the eccentric ring 20, the eccentric ring 20 rotates in the reverse direction. Thereby, the contact between the rotary piston 15 and the cylinder 14 can be avoided. Therefore, the CP gap 19 exists during high-speed operation, but the influence of gas leakage is less during high-speed operation than during low-speed operation, so even if the CP gap 19 exists, it does not matter much.
[0034]
Next, the movable range regulating mechanism 29 will be described. As shown in FIG. 1, in the present embodiment, the movable range regulating mechanism 29 includes a groove portion 21 and a limit pin 22. The groove portion 21 is formed on the outer periphery of the eccentric portion 16, and the limit pin 22 is attached to the inner periphery of the eccentric ring 20.
[0035]
When the limit pin 22 engages with the pair of side walls of the groove portion 21, the rotation angle of the eccentric ring 20 can be limited. Specifically, the eccentric ring 20 rotates clockwise or counterclockwise within a range indicated by an arrow 27 in FIG.
[0036]
By regulating the movable range of the eccentric ring 20 in this way, the CP gap can be controlled to an appropriate value, and the pressing force of the rotary piston 15 against the cylinder 14 becomes excessive, or the eccentric ring 20 However, it is possible to prevent the rotating piston 15 from biting into the cylinder 14 by rotating more reversely (rotating in the direction opposite to the arrow 26) than necessary.
[0037]
In the embodiment shown in FIG. 2, the groove portion 21 is provided in the eccentric portion 16, but this groove portion 21 is the inner periphery or outer periphery of the eccentric ring 20, the front head 13, the rear head 17, or the inner periphery of the rotary piston 15. It may be provided in an element around the equi-eccentric ring 20. Similarly, the limit pin 22 may be provided on the eccentric portion 16 or the rotary piston 15. Furthermore, a movable range regulating mechanism other than the groove portion 21 and the limit pin 22 can be employed.
[0038]
As for the eccentric ring 20 described above, a member having a shape other than the ring shape may be employed as long as the member can apply a pressing force to the rotary piston 15 from the inside of the rotary piston 15.
[0039]
Next, operation | movement of the eccentric ring 20 in this Embodiment is demonstrated using FIGS.
[0040]
First, the eccentric part 16 rotates 90 degrees according to the arrow 26 from the state immediately after compression shown in FIG. 4 to be in the state shown in FIG. In this process, the suction of the refrigerant into the suction chamber 9 is started. However, at this stage, the eccentric ring 20 has not yet rotated.
[0041]
Next, the eccentric portion 16 is further rotated by 90 degrees from the state shown in FIG. This state is shown in FIG. Even at this stage, the eccentric ring 20 has not yet rotated. FIG. 7 shows a state where the eccentric portion 16 is further rotated 90 degrees from the state shown in FIG. In this process, the final refrigerant is compressed in the compression chamber 10, and the eccentric ring 20 rotates according to the arrow 28 at the same time. Thereby, the CP gap 19 is reduced, and gas leakage from the compression chamber 10 to the suction chamber 9 can be suppressed. At this time, the rotation angle of the eccentric ring 20 is limited by the limit pin 22 and the groove 21.
[0042]
After compressing the refrigerant in this way, the state again moves to the state shown in FIG. 4 and the above-described operation is repeated.
[0043]
Although the embodiments of the present invention have been described as above, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and includes meanings equivalent to the terms of the claims and all modifications within the scope.
[0044]
【The invention's effect】
According to the rotary compressor of the first to fourth aspects, the CP gap can be reduced. Thereby, gas leak can be suppressed and the efficiency of a compressor can be improved. In particular, when an eccentric ring is adopted, the rotary piston (15) is brought into contact with the wall surface of the cylinder chamber (14a) during low-speed operation of the compressor to suppress gas leakage, and the rotary piston (15 is used during high-speed operation of the compressor. ) And the wall surface of the cylinder chamber (14a) can be prevented to reduce power loss. Further, when the movable range restricting mechanism (29) is provided, the eccentric ring (20) can be prevented from rotating more than necessary, the CP gap can be maintained within an appropriate range, and the rotation to the cylinder wall surface can be performed. Preventing the occurrence of problems such as excessive pressing force of the piston (15), the eccentric ring (20) reverses more than necessary, and the rotating piston (15) bites into the wall surface of the cylinder chamber (14a). Can do.
[Brief description of the drawings]
FIG. 1 is a diagram showing an internal structure of a cylinder chamber of a rotary compressor in one embodiment of the present invention.
FIG. 2 is an enlarged view of a cylinder chamber in FIG.
FIG. 3 is a diagram showing a relationship between forces acting on an eccentric ring.
FIG. 4 is a diagram showing a state immediately after the refrigerant is compressed.
FIG. 5 is a diagram showing a state after the eccentric portion is rotated 90 degrees from the state shown in FIG. 4;
6 is a view showing a state where the eccentric portion is further rotated 90 degrees from the state shown in FIG.
7 is a view showing a state where the eccentric portion is further rotated by 90 degrees from the state shown in FIG. 6;
FIG. 8 is a cross-sectional view showing an example of a conventional rotary compressor.
FIG. 9 is a diagram showing an internal structure of a conventional cylinder chamber.
[Explanation of symbols]
1 Rotary compressor 2 Casing 3 Motor 4 Crankshaft (Rotating shaft)
5 Compression Element 6 Suction Port 7 Suction Pipe 8 Discharge Pipe 9 Suction Chamber 10 Compression Chamber 11 Blade 12 Bush 13 Front Head 14 Cylinder 14a Cylinder Chamber 15 Rotating Piston 16 Eccentric Portion 17 Rear Head 18 Blade Rear Space 19 CP Clearance 20 Eccentric Ring 20a 1st part 20b 2nd part 21 Groove part 22 Limit pin 23 Center axis 24 of a crankshaft The outer periphery (inner periphery) center of a rotating piston (the outer periphery center of an eccentric ring)
25 Center of the eccentric part (center of the inner periphery of the eccentric ring)
26 Rotating direction of eccentric part 27 Movable angle of eccentric ring 28 Rotating direction of eccentric ring 29 Movable range regulating mechanism

Claims (4)

It has an eccentric part (16) housed in a cylinder chamber (14a) into which refrigerant is fed, and is held by a front head (13) and a rear head (14) arranged so as to sandwich the cylinder chamber (14a). Rotating shaft (4),
A rotating piston (15) fitted around the eccentric part (16), and rotated by the eccentric part (16) to compress the refrigerant in the cylinder chamber (14a);
It is interposed between the eccentric part (16) and the rotary piston (15), and presses the rotary piston (15) radially outward to provide a wall surface of the cylinder chamber (14a) and the rotary piston (15). The center of the circumscribed circle (24) is decentered toward the axis (23) side of the rotating shaft (4) with respect to the center (25) of the inscribed circle. A ring (20);
A rotary compressor with   The eccentric ring (20) is provided to be movable in the circumferential direction of the eccentric portion (16), and the first portion (20a) having a relatively large thickness in the radial direction of the eccentric portion (16). And the second portion (20b) having a relatively small thickness.   The rotary compressor according to claim 2, further comprising a movable range regulating mechanism (29) for regulating a movable range of the eccentric ring (20). The movable range regulating mechanism (29) includes a groove (21) provided in the eccentric ring (20) or the eccentric part (16),
The rotary compressor according to claim 3 , further comprising an engaging portion (22) that engages with the wall surface of the groove portion (21) and restricts the movement of the eccentric ring (20).

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