JP3617221B2 - Rotary compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary compressor used in an air conditioner for air conditioning or a refrigerator.
[0002]
[Prior art]
FIG. 6 is a cross-sectional view showing the internal structure of the compression unit 11 disposed in a conventional rotary compressor. 7 is a cross-sectional view taken along line VII-VII in FIG.
[0003]
As shown in FIG. 6, the cylinder 8 includes a cylindrical cylinder chamber 13 a, a suction port 24 that opens into the cylinder chamber 13 a, a discharge port 27, and a blade rear space 20. A cylindrical rotary piston 12a having a blade 21a extending in the radial direction is disposed in the cylinder chamber 13a. A crankshaft 6 having an eccentric portion 14a is fitted on the inner periphery of the rotary piston 12a. Between the blade back space 20 and the cylinder chamber 13a, a pair of semi-circular swing bushes 23 that support the blade 21a so as to swing and advance and retract are provided. A valve 28 is provided at the tip of the discharge port 27.
[0004]
Next, a cross-sectional structure taken along line VII-VII in FIG. 6 will be described with reference to FIG. As shown in FIG. 7, the rotary piston 12b having the same structure as that of the rotary piston 12a is arranged at an interval in the axial direction, and the rotary piston 13b is arranged in the cylinder chamber 13b having the same shape as the cylinder chamber 13a. . The rotary piston 12b has a plate-like blade 21b. A crankshaft 6 having an eccentric portion 14b is fitted to the inner periphery of the rotary piston 12b. A middle plate 9 is disposed between the rotary piston 12a and the rotary piston 12b, and a front head 7 and a rear head 10 are provided so as to sandwich the rotary pistons 12a and 12b from above and below. The blade rear space 20 is defined by the front head 7, the rear head 10, and the cylinder 8, and is a sealed space as shown in FIG.
[0005]
[Problems to be solved by the invention]
As described above, since the blade back space 20 is a sealed space, the blade back space 20 has an intermediate pressure between the high pressure compression chamber 26 and the low pressure suction chamber 25 shown in FIG. This is because the gas refrigerant leaks from the compression chamber 26 into the blade back space 20 through the interface between the blade 21 a and the swing bush 23.
[0006]
On the other hand, in the lubrication between the blade 21a and the pair of swing bushes 23, the lubricating oil supplied into the cylinder chamber 13a is different from the pressure difference between the compression chamber 26 and the blade back space 20 and the blade back space 20. This is performed by supplying the pressure between the blade 25a and the pair of swing bushes 23 by the differential pressure between the suction chamber 25 and the suction chamber 25, respectively. At this time, since the inside of the compression chamber 26 is at a high pressure, the blade 21a is pressed against the swinging bush 23 located on the suction chamber 25 side. Therefore, the lubricating oil cannot be sufficiently supplied to the interface between the blade 21a located on the suction chamber 25 side and the swinging bush 23 only by the differential pressure between the blade back space 20 and the suction chamber 25, which is an intermediate pressure. There was a problem. In order to avoid this problem, the gap provided between the front head 7 or the rear head 10 and the rotary piston 12a is widened by increasing the step provided on the surface of the rotary piston 12a, and the amount of oil supplied into the cylinder chamber 13a is secured. However, there is a new problem that the leakage of the gas refrigerant increases by widening the gap.
[0007]
The present invention has been made to solve the above-described problems. An object of the present invention is to provide a rotary compressor capable of effectively suppressing leakage of gas refrigerant and efficiently supplying lubricating oil between a blade and a swing bush.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a rotary compressor having a casing in which the interior is maintained at a high pressure, a cylinder chamber disposed in the casing and containing a rotary piston having blades, and a side remote from the rotary piston. A cylinder including a blade rear space provided in the vicinity of an end of the blade, and a front head and a rear head provided to close the cylinder chamber and sandwich the cylinder. There is an oil reservoir in which the rear head is immersed in the casing, and one end of the blade rear space is closed by the front head, while the blade rear space is always in communication with the oil reservoir only from the rear head side.
[0009]
In the rotary compressor according to claim 2, the blade back space is communicated with the oil reservoir by providing a through hole in the rear head located immediately below the blade back space.
[0010]
In the rotary compressor according to claim 3, the outer peripheral edge of the rear head located immediately below the blade back space is disposed closer to the cylinder chamber than the outer end of the blade back space farthest from the cylinder chamber. The back space communicates with the oil sump.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the present invention will be described below with reference to FIGS.
[0012]
(Embodiment 1)
FIG. 1 is a cross-sectional view showing a rotary compressor 1 according to Embodiment 1 of the present invention. Referring to FIG. 1, a motor 5 serving as an electric element and a compression unit 11 serving as a compression element are disposed in a casing 2 that is hermetically sealed and maintained at a high pressure. The motor 5 has a stator 3 and a rotor 4. The stator 3 includes a cylindrical stator core 3a made of a material that is attached to the inner wall of the casing 2 and that allows easy passage of magnetic flux lines, and coils 3b that are disposed at both upper and lower ends of the stator core 3a. The rotor 4 is made of a permanent magnet, and is provided in the central space of the stator 3 with an air gap 17 interposed.
[0013]
A crankshaft 6 is press-fitted into the rotor 4, and the motor 5 and the compression unit 11 are connected via the crankshaft 6. In this case, the compression unit 11 has two cylinders 8a and 8b. The two cylinders 8a and 8b have cylinder chambers 13a and 13b, respectively. Further, a middle plate 9 is disposed between the two cylinders 8a and 8b, and the front head 7 and the rear head 10 are respectively closed so as to close the cylinder chambers 13a and 13b and sandwich the two cylinders 8a and 8b from above and below. Provided.
[0014]
A rotating piston 12a attached to the outer periphery of the crankshaft 6 is disposed in the cylinder chamber 13a via an eccentric portion 14a, and is attached to the outer periphery of the crankshaft 6 via an eccentric portion 14b in the cylinder chamber 13b. A rotating piston 12b is arranged. The cylinders 8a and 8b are connected to suction pipes 15a and 15b for feeding gas refrigerant into the cylinder chambers 13a and 13b, respectively.
[0015]
Further, a discharge muffler 16 a for suppressing noise when discharging the compressed gas refrigerant into the casing 2 is attached to the upper end surface of the front head 7. A discharge muffler 16 b is attached to the lower end surface of the rear head 10. The casing 2 is provided with a discharge pipe 18 for discharging a gas refrigerant compressed to a high pressure to the outside. An oil reservoir 30 in which the rear head 10 and the like are immersed is provided at the bottom of the casing 2.
[0016]
Next, the characteristic part of the rotary compressor 1 in this Embodiment 1 is demonstrated using FIG. 2 and FIG. FIG. 2 is a bottom view of the rotary compressor 1 viewed in accordance with the arrow A in FIG. In FIG. 1, a through-hole 19 to be described later is not shown for convenience of illustration.
[0017]
Referring to FIG. 2, rotary piston 12b arranged in cylinder chamber 13b has blade 21b protruding from the outer periphery thereof. A blade back space 20 is provided in the vicinity of the end of the blade 21b on the side away from the rotary piston 12b. The blade 21b is sandwiched between a pair of swinging bushes 23 disposed between the blade back space 20 and the cylinder chamber 13b so as to freely advance and retract. Further, the swing bush 23 is fitted into the cylinder 8b so as to be swingable with the blade 21b sandwiched therebetween. The rear head 10 is provided with a through hole 19 that communicates with the blade back space 20.
[0018]
FIG. 3 shows a cross-sectional structure taken along line III-III in FIG. As shown in FIG. 3, the blade rear space 20 is located behind the blade 21b of the rotary piston 12b disposed in the cylinder chamber 13b from behind the blade 21a of the rotary piston 12a disposed in the cylinder chamber 13a. A through hole 19 is provided in the rear head 10 so that the blade back space 20 and the internal space of the casing 2 communicate with each other. As shown in FIG. 1, the rear head 10 is normally disposed in the oil reservoir 30, so that oil is supplied from the oil reservoir 30 into the blade back space 20 according to the arrow shown in FIG. 3.
[0019]
Thereby, the blade back space 20 can be filled with high-pressure oil, and the lubricating oil can be supplied directly and efficiently between the swing bush 23 and the blades 21a and 21b. As a result, the lubricity between the blades 21a and 21b and the swing bush 23 can be improved.
[0020]
In addition, since oil can be efficiently supplied between the blades 21a and 21b and the swing bush 23 as described above, it is possible to reduce the level difference provided on the surfaces of the rotary pistons 12a and 12b to ensure oil supply. It becomes. Thereby, it is possible to reduce leakage of the gas refrigerant.
[0021]
Furthermore, by filling the blade back space 20 with high-pressure oil, the behavior of the swing bush 23 can be stabilized, and the generation of sound due to the unstable behavior of the swing bush 23 is also effective. Can be suppressed.
[0022]
Further, as shown in FIG. 3, by providing the through-hole 19 only on the rear head 10 side and closing the front head 7 side, it is possible to effectively disturb the oil level and increase the oil rising due to the reciprocating motion of the blades 21a and 21b. Can be suppressed.
[0023]
Further, since the blade back space 20 can be maintained as a high-pressure oil reservoir until the oil level in the casing 2 moves below the bottom surface 10b of the rear head 10, the positions of the cylinders 8a and 8b can be increased or introduced into the casing 2. It is also possible to reduce the amount of oil produced.
[0024]
(Embodiment 2)
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a sectional view showing a rotary compressor 1 according to Embodiment 2 of the present invention. FIG. 5 is a bottom view of the rotary compressor 1 viewed in accordance with an arrow A in FIG.
[0025]
Referring to FIG. 4, the second embodiment shows a case where the idea of the present invention is applied to a one-cylinder rotary compressor 1. Specifically, the compression unit 11 includes one cylinder 8 that surrounds one cylinder chamber 13, and a front head 7 and a rear head 10 that are provided so as to sandwich the cylinder 8 from above and below. A rotating piston 12 attached to the crankshaft 6 via an eccentric portion 14 is disposed in the cylinder chamber 13. A gas refrigerant is fed into the cylinder chamber 13 from the suction pipe 15, and a discharge muffler 16 is attached to the upper end surface of the front head 7. Other configurations are the same as those in the first embodiment shown in FIG.
[0026]
In the second embodiment, an important feature is that the outer peripheral edge 10a of the rear head 10 is subjected to processing unique to the present invention. This feature will be described with reference to FIG. As shown in FIG. 5, the outer periphery of the rear head 10 is rounded so that the outer peripheral edge 10 a of the rear head 10 is positioned directly below the blade rear space 20. By performing such processing, it becomes possible to supply oil from the oil reservoir 30 into the blade back space 20 and fill the blade back space 20 with high-pressure oil as in the case of the first embodiment. It becomes possible to do. Thereby, the same effect as in the case of the first embodiment can be obtained.
[0027]
The outer peripheral edge 10a of the rear head 10 only needs to be disposed closer to the cylinder chamber 13 than the outer end 20a of the blade back space 20 farthest from the cylinder chamber 13, and is not limited to the case shown in FIG. Further, as shown in FIG. 5, it is not always necessary to round the entire circumference of the rear head 10, and the machining may be performed only on the outer peripheral edge 10 a of the rear head 10 located immediately below the blade rear space 20. . Furthermore, the idea disclosed in the second embodiment can be applied to a two-cylinder rotary compressor. The idea in the first embodiment can also be applied to a one-cylinder rotary compressor.
[0028]
Although the embodiments of the present invention have been described 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 is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0029]
【The invention's effect】
In the rotary compressor according to the first aspect, the space behind the blade and the oil reservoir are communicated from the rear head side. Since the inside of the casing of the rotary compressor is maintained at a high pressure, the blade back space can be filled with high-pressure oil by communicating the blade back space and the oil reservoir in this way. Thereby, it becomes possible to supply oil directly and efficiently between a pair of swinging bushes arranged so as to sandwich the blade between the space behind the blade and the cylinder chamber and the blade. As a result, it is possible to significantly improve the lubricity between the swing bush and the blade as compared with the conventional example. Further, since the oil can be efficiently supplied between the swing bush and the blade in this way, it is possible to reduce the step provided on the surface of the rotary piston so as to ensure the oil supply into the cylinder chamber. Thereby, it is possible to effectively suppress leakage of the gas refrigerant. Furthermore, because the space behind the blade can be filled with high-pressure oil, the back and forth movement of the swinging bush due to the pressure change in the cylinder chamber can be effectively suppressed, and the generation of sound due to the behavior of such swinging bushing can be prevented. Can also be effectively suppressed. Furthermore, by making the space behind the blade communicate with the oil reservoir only from the rear head side, it is possible to effectively suppress oil level disturbance and oil rise due to the reciprocating motion of the blade. Furthermore, the cylinder position can be increased and the amount of oil introduced into the casing can be reduced.
[0030]
In the rotary compressor according to the second aspect, a through hole is provided in the rear head located directly under the blade rear space. Thereby, the space behind the blade and the oil reservoir can be communicated, and the above-described effect can be obtained.
[0031]
In the rotary compressor according to the third aspect, the outer peripheral edge of the rear head located immediately below the blade back space is arranged on the cylinder chamber side with respect to the outer end portion of the blade back space farthest from the cylinder chamber. Also in this case, the space behind the blade and the oil reservoir can be communicated, and the above-described effect can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a rotary compressor according to Embodiment 1 of the present invention.
FIG. 2 is a bottom view of the rotary compressor viewed along arrow A in FIG.
3 is a cross-sectional view taken along line III-III in FIG.
FIG. 4 is a sectional view showing a rotary compressor in a second embodiment of the invention.
FIG. 5 is a bottom view of the rotary compressor viewed along arrow A in FIG. 4;
FIG. 6 is a sectional view showing a part of a cylinder chamber of a conventional rotary compressor and its vicinity.
7 is a cross-sectional view taken along line VII-VII in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rotary compressor 2 Casing 7 Front head 8, 8a, 8b Cylinder 10 Rear head 10a Outer peripheral edge 11 Compression part 12, 12a, 12b Rotary piston 13, 13a, 13b Cylinder chamber 19 Through-hole 20 Blade back space 20a Outer end part 21, 21a, 21b Blade 30 Oil reservoir

Claims (3)

A casing (2) whose interior is maintained at a high pressure ;
A cylinder chamber (13, 13b) disposed in the casing (2) and containing a rotary piston (12b) having a blade (21b), and the blade (21b) on the side away from the rotary piston (12b) A cylinder (8b) including a blade back space (20) provided in the vicinity of an end of the blade;
A front head (7) and a rear head (10) provided to close the cylinder chamber (13, 13b) and sandwich the cylinder (8b) from above and below,
In the casing (2) is an oil sump (30) into which the rear head (10) is immersed,
One end of the blade rear space (20) is closed by the front head (7), while the blade rear space (20) is always in communication with the oil reservoir (30) only from the rear head (10) side. A rotary compressor that is characterized. The blade rear space (20) is communicated with the oil reservoir (30) by providing a through hole (19) in the rear head (10) located immediately below the blade rear space (20). Rotary compressor. The outer peripheral edge (10a) of the rear head (10) located immediately below the blade rear space (20) is more than the outer end (20a) of the blade rear space (20) farthest from the cylinder chamber (13). The rotary compressor according to claim 1, wherein the blade rear space (20) communicates with the oil reservoir (30) by being arranged on the cylinder chamber (13) side.

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